Analysis gtstrudl

GT STRUDL

®

Integrated CAE System for Structural Engineering Analysis and Design The information found in this User Guide represents a subset of the Analysis features of GTSTRUDL. For a more detailed description of any GTSTRUDL feature, please refer to the GTSTRUDL User Reference Manuals that are installed with GTSTRUDL software in PDF format. To purchase a printed version of any GTSTRUDL user document, please contact your software distributor for details.

Analysis GT STRUDL User Guide

Revision 6, April 2009 Computer Aided Structural Engineering Center School of Civil and Environmental Engineering Georgia Institute of Technology Atlanta, Georgia 30332-0355 U.S.A. Telephone: +1-404-8942260 FAX: +1-404-8948014 E-Mail: [email protected]

GTSTRUDL User Guide: Analysis

Revision History Revision No. First Edition

1

Date Released 4/97

6/99

Description First Edition describing general structural modeling concepts, global and local reference frames, input/output, automatic mesh generation, graphical display, data base management, static frame and finite element analysis, and introduction to dynamic analysis. Complete rewrite for GTSTRUDL 9901 for use under Windows NT/95/98. In addition, the chapter on Dynamic Analysis Commands is expanded to include a description of the more frequently used commands to perform dynamic analysis, output dynamic analysis results, and combine dynamic analysis results with static analysis results.

2

2/02

Relevant updates describing new features in GTSTRUDL Versions 25 and 26, and various typographical error corrections.

3

6/03

Relevant updates describing new features in GTSTRUDL Version 27, and various typographical error corrections.

4

1/05

Relevant updates describing new features in GTSTRUDL Version 28, and various typographical error corrections.

5

12/06

Relevant updates describing new features in GTSTRUDL Version 29, and various typographical error corrections.

6

4/09

Relevant updates describing new features in GTSTRUDL Version 30, and various typographical error corrections.

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Notices This GTSTRUDL® User Guide: Analysis, Revision 6, is applicable to: ®

GTSTRUDL® Version 30 and higher numbered versions for use on PC’s under the Windows Vista/XP/2000/NT operating systems. The GTSTRUDL computer program is proprietary to, and a trade secret of, the Georgia Tech Research Corporation, Atlanta, Georgia, U.S.A.

Disclaimer The Georgia Tech Research Corporation (GTRC) and the Georgia Institute of Technology make no representation or warranty expressed or implied as to the adequacy of this documentation or the software described herein. In no event shall the Georgia Tech Research Corporation, or the Georgia Institute of Technology, their employees, their contractors, or the authors of this documentation be liable for special, direct, indirect, or consequential damages, losses, costs, charges, claims, demands, or claim for lost profits, fees, or expenses of any nature or kind.

Restricted Rights Legend Any use, duplication, or disclosure of this software by or for the United States Government shall be restricted to the terms of a license agreement in accordance with the clause at DFARS 227.7202-3 (June 2005). This material may be reproduced by or for the United States Government pursuant to the copyright license under the clause at DFARS 252.227-7013, September 1989. Copyright © 1997 to 2009 by Georgia Tech Research Corporation Atlanta, Georgia 30332-0355 U.S.A. All Rights Reserved Printed in United States of America

GTSTRUDL® is a registered service mark of the Georgia Tech Research Corporation, Atlanta, Georgia, U.S.A. ® ® ® ® Windows Vista , Windows XP , Windows 2000 , and Windows NT are registered trademarks of Microsoft Corporation in the United States and/or other countries.

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Forward The development of GTSTRUDL began in September 1975 by the School of Civil Engineering, Georgia Institute of Technology, Atlanta, Georgia U.S.A. Since then, over 390 manyears have been invested in the continuous research, development, maintenance, validation, education, and technical support activities in connection with GTSTRUDL. Today, GTSTRUDL is fully supported by the Computer Aided Structural Engineering Center ("CASE Center"), School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, Georgia U.S.A., and is licensed worldwide through the Georgia Tech Research Corporation. The CASE Center is committed to continually improving its position of leadership in the research and development of structural engineering analysis and design software, and to serving as a technological pipeline through which results of research and development flow from Georgia Tech to industry, government, and educational institutions in a form which sets the highest standards of quality, performance, and value.

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Table of Contents CHAPTER

PAGE

Revision History . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Notices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . DISCLAIMER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Restricted Rights Legend . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Forward . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Table of Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

1.

2.

3.

INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

1- 1

Commands and the Graphical User Interface . . . . . . . . . . . . . . . . . . . . . . . . . . Format of the Descriptions of Commands in This Guide . . . . . . . . . . . . . . . . . . Subset of GTSTRUDL Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

1- 1 1- 4 1- 5

CHARACTERISTICS OF THE STRUCTURAL ANALYTICAL MODEL . . . . . . .

2- 1

Joints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Member and Finite Elements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . External World . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Structure Support Boundary Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Member and Finite Element Boundary Conditions . . . . . . . . . . . . . . . . . . . . . . . Independent Loading Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Dependent Loading Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

2222222-

GLOBAL AND LOCAL COORDINATE REFERENCE FRAMES . . . . . . . . . . . .

3- 1

3.1 3.2 3.3 3.4

Global Reference Frame . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Local Member Reference Frame . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Orientation of Local Member Reference Frame (The BETA Angle) . . . Local and Planar Finite Element Reference Frames . . . . . . . . . . . . . . 3.4.1 2D Finite Element Local Reference Frame . . . . . . . . . . . . . . . . . 3.4.2 2D Finite Element Planar Reference Frame . . . . . . . . . . . . . . . . Local Joint Reference Frame . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

3- 1 3- 4 3- 8 3- 8 3- 9 3- 10 3- 13

GENERAL COMMANDS AND FILE MANAGEMENT . . . . . . . . . . . . . . . . . . . .

4- 1

4.1 4.2 4.3 4.4 4.5

4- 3 4-11 4-12 4-12 4-18

3.5 4.

ii iii iii iii iv v

"list" Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . STRUDL Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . FINISH Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . CINPUT Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . COUTPUT Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

-v-

1 1 3 6 6 9 9

4.6 4.7 4.8 4.9 4.10 4.11 4.12 4.13 4.14 4.15 4.16 4.17 4.18 4.19 4.20 4.21 4.22 4.23 4.24 4.25

5.

4-21 4-23 4-25 4-26 4-30 4-31 4-35 4-36 4-37 4-38 4-39 4-40 4-43 4-46 4-47 4-49 4-52 4-56 4-58 4-60

DATA BASE MANAGEMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

5- 1

5.1 5.2 5.3

5- 2 5- 5 5- 8 5- 8 5-11 5-12 5-14 5-17

5.4 5.5 5.6 6.

FLIST 1 and FLIST 2 Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . SCAN Error Flag Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . BYPASS Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . UNITS Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . QUERY Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . DEFINE GROUP Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . PRINT GROUP Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . DELETION of GROUPS Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . PRINT GENERATE Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . CONSISTENCY CHECK Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . OPEN USERDATA FILE Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . Files Created by GTSTRUDL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . The GTSTRUDL Batch Processor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . LARGE PROBLEM Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . RUN Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ALIGN Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . NOTES Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . PRINT COMMAND ARCHIVE Command . . . . . . . . . . . . . . . . . . . . . . . . ACTIVE SOLVER Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . DEFINE PHYSICAL MEMBER and SMOOTH PHYSICAL MEMBER Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Data Base Management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . The GTSTRUDL Data Base . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . SAVE, RESTORE, and AUTOMATIC BACKUP Commands . . . . . . . . . 5.3.1 SAVE and RESTORE Commands . . . . . . . . . . . . . . . . . . . . . . . . 5.3.2 AUTOMATIC BACKUP Commands . . . . . . . . . . . . . . . . . . . . . . . ADDITIONS, CHANGES, and DELETIONS Commands . . . . . . . . . . . . ACTIVE and INACTIVE Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . LOAD LIST Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

GEOMETRY AND TOPOLOGY COMMANDS . . . . . . . . . . . . . . . . . . . . . . . . . . 6.1 6.2 6.3 6.4 6.5 6.6 6.7 6.8 6.9 6.10 6.11 6.12 6.13 6.14 6.15 6.16

6- 1

JOINT COORDINATES Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6- 3 GENERATE n JOINTS Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-12 DELETION of JOINTS Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-31 TYPE Command for Members and Finite Elements . . . . . . . . . . . . . . . . 6-33 MEMBER and ELEMENT INCIDENCES Command . . . . . . . . . . . . . . . . 6-49 GENERATE m MEMBERS Command . . . . . . . . . . . . . . . . . . . . . . . . . . 6-60 GENERATE m ELEMENTS Command . . . . . . . . . . . . . . . . . . . . . . . . . . 6-69 DELETION of MEMBERS and ELEMENTS Command . . . . . . . . . . . . . 6-80 DEFINE OBJECT Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-82 DELETE OBJECT Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-85 PRINT OBJECT Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-86 MOVE OBJECT Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-87 COPY OBJECT Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-91 LOCATE INTERFERENCE JOINTS Command . . . . . . . . . . . . . . . . . . . 6-97 LOCATE DUPLICATE JOINTS Command . . . . . . . . . . . . . . . . . . . . . . . 6-98 LOCATE DUPLICATE MEMBERS Command . . . . . . . . . . . . . . . . . . . 6-100

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7.

8.

BOUNDARY CONDITION COMMANDS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

7- 1

7.1. 7.2. 7.3. 7.4. 7.5. 7.6.

7- 2 7- 3 7- 6 7-17 7-21 7-29

MEMBER, FINITE ELEMENT, AND MATERIAL PROPERTIES, AND MEMBER BETA ANGLE COMMANDS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.1

8.2 8.3 8.4 8.5 8.6 8.7 9.

STATUS Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . DETERMINE PLANAR JOINTS Command . . . . . . . . . . . . . . . . . . . . . JOINT RELEASES Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . CALCULATE SOIL SPRING VALUES Command . . . . . . . . . . . . . . . . MEMBER RELEASES Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . MEMBER ECCENTRICITIES Command . . . . . . . . . . . . . . . . . . . . . . . .

MEMBER PROPERTIES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.1.1 MEMBER PROPERTIES Command . . . . . . . . . . . . . . . . . . . . . 8.1.2 MEMBER DIMENSIONS Command . . . . . . . . . . . . . . . . . . . . . . ELEMENT PROPERTIES Command . . . . . . . . . . . . . . . . . . . . . . . . . . MATERIAL Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . CONSTANTS Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . BETA Angle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . BETA REFERENCE JOINT Command . . . . . . . . . . . . . . . . . . . . . . . . . . CALCULATE MEMBER ORIENTATION Command . . . . . . . . . . . . . . . .

INDEPENDENT STATIC LOADING CONDITION COMMANDS . . . . . . . . . . . . 9.1 9.2 9.3 9.4

9.5 9.6 9.7 9.8 9.9 9.10.

9.11. 9.12. 9.13. 9.14. 9.15.

8- 1 8- 2 8- 2 8-21 8-25 8-28 8-30 8-34 8-42 8-49 9- 1

Static Loading Classes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9- 2 Independent Static Loading Conditions . . . . . . . . . . . . . . . . . . . . . . . . 9- 5 LOADING Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9- 7 Computation of Member Dead Loads . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-11 9.4.1.1 SELF WEIGHT LOADING Command . . . . . . . . . . . . . . . . . . . 9-13 9.4.1.2 SELF WEIGHT LOADING RECOMPUTE Command . . . . . . . 9-18 9.4.2 DEAD LOADING Command . . . . . . . . . . . . . . . . . . . . . . . . . . 9-19 JOINT LOADS Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-25 JOINT DISPLACEMENTS Command . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-32 MEMBER LOADS Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-37 MEMBER TEMPERATURE LOAD Command . . . . . . . . . . . . . . . . . . . . 9-49 MEMBER DISTORTIONS Command . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-52 The Moving Load Generator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-55 9.10.1 MOVING LOAD GENERATOR Command . . . . . . . . . . . . . . . 9-56 9.10.2 SUPERSTRUCTURE Command . . . . . . . . . . . . . . . . . . . . . . 9-57 9.10.3 TRUCK / VEHICLE LOAD Command . . . . . . . . . . . . . . . . . . . 9-62 9.10.4 LANE LOAD Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-71 9.10.5 GENERATE LOAD Command . . . . . . . . . . . . . . . . . . . . . . . . 9-77 9.10.6 END LOAD GENERATOR Command . . . . . . . . . . . . . . . . . . 9-79 9.10.7 Moving Load Generator Examples . . . . . . . . . . . . . . . . . . . . . 9-80 ELEMENT LOADS Command for Non-Isoparametric Elements . . . . . . . 9-90 ELEMENT LOADS Command for Isoparametric Elements . . . . . . . . . . . 9-93 JOINT TEMPERATURE Command . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-102 ROTATE LOAD Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-105 AREA LOAD Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-108

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10.

COMBINATIONS OF INDEPENDENT LOAD COMPONENTS AND STATIC ANALYSIS RESULTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.1.

10.2.

11.

STATIC ANALYSIS COMMAND . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11.1 11.2 11.3

12.

13.

14.

FORM LOADING Command (Combinations of Independent Loading Condition Components) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.1.1 FORM LOAD REFORM Command . . . . . . . . . . . . . . . . . . . . 10.1.2 CONVERT LOAD COMBINATIONS TO/FROM FORM LOADS Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.1.3 FORM NOTIONAL LOAD Command . . . . . . . . . . . . . . . . . . Combinations of Static Analysis Results . . . . . . . . . . . . . . . . . . . . . . 10.2.1. LOADING COMBINATION Command . . . . . . . . . . . . . . . . 10.2.2. CREATE LOADING COMBINATION Command . . . . . . . . . 10.2.3. COMBINE Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.2.4. CREATE AUTOMATIC LOAD COMBINATIONS Command

10- 1

10- 2 10- 7 10- 9 10-12 10-15 10-17 10-23 10-29 10-33 11- 1

STIFFNESS ANALYSIS Command . . . . . . . . . . . . . . . . . . . . . . . . . . 11- 2 ACTIVE SOLVER Command and the GT64M/GTSES Solvers . . . . . . 11-11 GT64M and GTSES Stand-Alone Solvers and the ASSEMBLE FOR STATICS and COMPUTE GROSS RESULTS Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-12

ANALYSIS ERRORS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

12- 1

12.1

PERFORM NUMERICAL INSTABILITY ANALYSIS Command . . . . .

12- 2

PRINTED OUTPUT COMMANDS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

13- 1

13.1 13.2 13.3 13.4 13.5 13.6 13.7 13.8 13.9 13.10 13.11 13.12 13.13

13- 2 13- 7 13-11 13-35 13-38 13-40 13-41 13-46 13-61 13-72 13-81 13-83 13-85

PRINT Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . OUTPUT Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . LIST Joint, Member, and Finite Element Results Command . . . . . . . . LIST MAXIMUM JOINT DISPLACEMENT Command . . . . . . . . . . . . . LIST MAXIMUM REACTION (ENVELOPE) Command . . . . . . . . . . . . . Internal Member Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . SECTION Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . LIST Internal Member Results Command . . . . . . . . . . . . . . . . . . . . . . . CALCULATE AVERAGE Finite Element Results Command . . . . . . . . LIST SUM FORCES Command (Resultant Section Forces) . . . . . . . . . STEEL TAKE OFF Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . LIST CODE CHECK RESULTS Command . . . . . . . . . . . . . . . . . . . . . . CALCULATE PRESSURE Command . . . . . . . . . . . . . . . . . . . . . . . . . .

SCOPE ENVIRONMENT GRAPHICAL DISPLAY COMMANDS . . . . . . . . . . .

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14- 1

15.

LINEAR DYNAMIC ANALYSIS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

15- 1

15.1 15.2

Summary of Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15- 2 Dynamic Data Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15- 6 15.2.1 INERTIA OF JOINTS Command . . . . . . . . . . . . . . . . . . . . . . 15- 9 15.2.2 MEMBER ADDED INERTIA Command . . . . . . . . . . . . . . . . 15-22 15.2.3 DAMPING RATIO and DAMPING PERCENT Commands . . 15-23 15.2.4 STORE TIME HISTORY Command . . . . . . . . . . . . . . . . . . . 15-26 15.2.5 STORE RESPONSE SPECTRUM Command . . . . . . . . . . . 15-29 15.2.6 CREATE TIME HISTORY Command & Ramp Feature . . . . 15-34 15.2.7 CREATE RESPONSE SPECTRUM Command . . . . . . . . . . 15-40 15.2.8 DELETE TIME HISTORY and DELETE RESPONSE SPECTRUM Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-43 15.2.9 TRANSIENT LOADING with JOINT LOADS Command . . . . 15-44 15.2.10 TRANSIENT LOADING with SUPPORT ACCELERATION Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-48 15.2.11 RESPONSE SPECTRUM LOADING with SUPPORT ACCELERATION Command . . . . . . . . . . . . . . . . . . . . . . . . . 15-50 15.2.12 FORM STATIC EARTHQUAKE LOAD Command Automatic Generation of Static Equivalent Earthquake Loads ( Section 3.3.3.2.C of NEHRP Guidelines for the Seismic Rehabilitation of Buildings - FEMA Publication 273) . . . . . . . . . . . . . . . . . . 15-55 15.2.13 FORM UBC97 LOAD Command - Automatic Generation of Static Seismic Loads According to 1997 UBC . . . . . . . . . . . 15-65 15.2.14 FORM IS1893 STATIC SEISMIC LOAD Command Automatic Generation of Static Earthquake Loads According to the Indian Standard IS 1893 Seismic Code . . . . . . . . . . . 15-73

15.3

Dynamic Analysis Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-79 15.3.0 15.3.1 15.3.2 15.3.3 15.3.4 15.3.5 15.3.6 15.3.7

ACTIVE SOLVER Command . . . . . . . . . . . . . . . . . . . . . . . . 15-83 EIGEN PARAMETERS Command . . . . . . . . . . . . . . . . . . . . 15-84 DYNAMIC PARAMETERS Command . . . . . . . . . . . . . . . . . 15-90 LIST RAYLEIGH LOADING Command . . . . . . . . . . . . . . . . . 15-94 DYNAMIC ANALYSIS EIGENSOLUTION Command . . . . . . 15-96 LIST DYNAMIC PARTICIPATION FACTORS Command . . . 15-97 INACTIVE / ACTIVE MODES Command . . . . . . . . . . . . . . . 15-98 RESPONSE SPECTRUM ANALYSIS . . . . . . . . . . . . . . . . 15-100 15.3.7.1 PERFORM RESPONSE SPECTRUM ANALYSIS Command . . . . . . . . . . . . . . . . . . . . 15-101 15.3.7.2 LIST RESPONSE SPECTRUM: SPECTRAL ACCELERATIONS, and PARTICIPATION FACTORS Commands (for use in Base Shear calculations) . . . . . . . . 15-103 15.3.7.3 Base Shear Calculations . . . . . . . . . . . . . . . . . . 15-105

- ix -

15.3.7.4

15.3.8 15.3.9 15.3.10

15.4

15.5.3 15.5.4 15.5.5 15.5.6 15.5.7

B

15-120

COMPUTE RESPONSE SPECTRUM Results Command . 15-123 COMPUTE TRANSIENT Results Command . . . . . . . . . . . 15-127 CREATE PSEUDO STATIC LOADING Command . . . . . . . 15-129

PRINT DYNAMIC DATA Command . . . . . . . . . . . . . . . . . . Graphical Display of Dynamic Analysis Loading Data and Dynamic Analysis Results . . . . . . . . . . . . . . . . . . . . . . . . . . Normalization of Eigenvectors Command . . . . . . . . . . . . . . LIST DYNAMIC Eigen Results and Mass Summary Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . OUTPUT MODAL CONTRIBUTIONS Command . . . . . . . . LIST RESPONSE SPECTRUM Results Command . . . . . . LIST TRANSIENT Results Command . . . . . . . . . . . . . . . . .

15-137 15-140 15-144 15-145 15-148 15-149 15-154

Example Sequence of Dynamic Analysis Commands . . . . . . . . . . . . 15-157

APPENDICES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A

15-114 15-116 15-118

Dynamic Data and Analysis Results Output Commands . . . . . . . . . . 15-134 15.5.1 15.5.2

15.6

15-107 15-111

Dynamic Results Back Substitution Commands . . . . . . . . . . . . . . . . . 15-121 15.4.1 15.4.2 15.4.3

15.5

Designing Shear Walls Based on a Response Spectrum Earthquake Analysis . . . . . . . . . . . . . 15.3.7.5 FORM MISSING MASS LOAD Command . . . . 15.3.7.6 Extended Example: RESPONSE SPECTRUM ANALYSIS, FORM MISSING MASS LOAD, and Base Shear Computation . . . . . . . . . . . . . . . . . PERFORM TRANSIENT ANALYSIS Command . . . . . . . . . PERFORM PHYSICAL ANALYSIS Command . . . . . . . . . . PERFORM NUMBER OF MODES COMPUTATION Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Appendices-1

Subset of GTSTRUDL Commands Ordered by Functional Area, and Ordered by Processing Requirements in Each Area . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

A-1

Subset of GTSTRUDL Commands Ordered by Functional Area, and Ordered by Command in Each Area . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

B-1

INDEX OF COMMANDS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Index-1 READER COMMENT FORM

-x-

General

1.

Introduction

Introduction This GTSTRUDL User Guide: Analysis contains a condensed description of a subset of the following often used features of GTSTRUDL: 1.

Data base management,

2.

Automatic mesh generation using commands (note that the GTMenu feature of GTSTRUDL provides an interactive, menu driven interface, to create structural models),

3.

General description of frame and finite element structures,

4.

Output of general information and analysis results,

5.

Graphical display,

6.

Linear static analysis, and

7.

Dynamic analysis.

The GTSTRUDL User Guide: Analysis is one of sixteen (16) volumes which constitute the full set of user documentation for GTSTRUDL and GTTABLE as described in Section 1.3 of the GTSTRUDL User Guide: Getting Started.

Commands and the Graphical User Interface Figure 1.1 shows an overview of the use of GTSTRUDL including input, output, and interfaces to postprocessing software. The communication interface between the engineer and GTSTRUDL consists of both: 1.

A command driven Problem-Oriented-Language ("POL") of structural engineering vocabulary words and data (GTSTRUDL User Guide: Getting Started, Chapter 4), hereinafter referred to simply as "commands", and

2.

A menu driven GTMenu Graphical User Interface ("GUI") which provides simple menu picks to create the finite element model of the structure.

1-1

Introduction

General

Figure 1.1 Overview of Using GTSTRUDL

1-2

General

Introduction

Commands are used in both the interactive and batch modes of execution of GTSTRUDL, while the GUI is only used interactively, as follows: a.

b.

In the interactive mode of execution, GTSTRUDL i.

Processes commands directly typed by the engineer,

ii.

Reads commands in a previously created text file and referenced by the CINPUT command,

iii.

Processes commands created by menu picks, and

iv.

Responds directly to the GTMenu graphical user interface menu picks.

In the batch mode of execution, GTSTRUDL only reads commands that are contained in a previously created text file.

For commands contained in a previously created text file, such text file may be created by the engineer using a text editor, or by GTMenu, or by any preprocessor software such as one written by the engineer and/or a commercially available CAD system. The commands in the text file may then be read by GTSTRUDL by using the CINPUT command (Section 4.4) in either an interactive or batch mode of execution. It should be noted that the ability to process text files of commands is a particularly important feature of GTSTRUDL since such text files represent a detailed and permanent record of the description of the structural model, and since the commands in the text file may be processed in order to directly recreate the structural model. Such use of text files of commands can also significantly reduce the time required to create, analyze, and design new structural models which may be similar to an old model by simply editing and directly processing the text file of commands. The ability to use both command-oriented POL and menu-oriented GTMenu facilities are very powerful features of GTSTRUDL which permit the engineer to achieve maximum flexibility of creating structural models, in addition to realizing substantial productivity and cost savings. GTSTRUDL creates and maintains a data base of structural information during each execution. The user may modify, SAVE, and RESTORE this data base through the use of various commands. This data base contains all information supplied by the user through the use of commands and GUI menu picks. In addition, the data base contains all result information created by GTSTRUDL as a consequence of analysis and design processing.

1-3

Introduction

General

Output from GTSTRUDL is completely controlled by the user through appropriate commands and GUI menu picks. Output may be displayed on an interactive graphics screen or placed in a text file for review and subsequent printing. In addition, the user may request GTSTRUDL to translate information (such as problem description information and analysis and design results) in its data base and output such translated information to the DBX (Data Base Exchange) neutral files. The DBX files may subsequently be processed by user developed software and CAD system software.

Format of the Descriptions of Commands in This Guide The following format is used to describe each command in this Guide: 1.

Simple form of a command: The vocabulary words and syntax of the command are described. In most cases, only a simplified subset of the command is shown in this Guide. Refer to the GTSTRUDL User Reference Manual for a complete description of each command.

2.

Command elements: A very brief description of the elements of the command is provided. Such elements include command options and the meaning of the data provided with the command.

3.

Example: One or more very simple examples of how the command may be used are shown.

4.

Explanation: A general description of the purpose of the command, and a detailed description of how the command operates in the ADDITIONS mode, is given.

5.

CHANGES Mode: A detailed description of how the command operates in the CHANGES mode is given.

6.

DELETIONS Mode: A detailed description of how the command operates in the DELETIONS mode is given.

7.

Extended Examples: A more complete example of the use of the command is given.

1-4

General

Introduction

Subset of GTSTRUDL Commands Appendices A and B contain a summary of a subset of GTSTRUDL commands that may be used to perform various types of information processing. The GTSTRUDL User Reference Manual (Table 1.2) should be referred to for a complete description of all available commands. The GTSTRUDL User Guide: Getting Started, and the latest GTSTRUDL Release Guide, Volume 2 (GTMenu), should be referred to for example tutorials and explanations of the use of the GTMenu Graphical User Interface features.

1-5

Introduction

General

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1-6

General

2.

Characteristics of the Structural Analytical Model

Characteristics of the Structural Analytical Model GTSTRUDL generally treats a real-world physical structure as an analytical model consisting of an assemblage of a finite number of discrete elements (members and finite elements) interconnected at a finite number of joints. Elements are connected to joints through element boundary conditions, while joints are, in turn, connected to the external world through structure boundary conditions. This analytical model (i.e., the "Finite Element model") may be subjected to a variety of loading conditions. In order to fully appreciate the significance of the GTSTRUDL commands as they relate to the characteristics of the analytical model treated by GTSTRUDL, the following descriptions are presented.

Joints A joint in GTSTRUDL is an infinitesimally small, perfectly rigid body which can experience up to a maximum number of six displacement degrees-of-freedom (three translational and three rotational) in the general 3D structure. The actual number of relevant degrees-of-freedom of a joint is determined by the types of members and finite elements incident on the joint. For example, if only space truss members are incident on a joint, then there are only three translational displacement degrees-of-freedom for the joint. On the other hand, if a space truss member, space frame member, and plane stress finite element are incident on the same joint, then the element with the highest order of displacement degrees-of-freedom (the space frame member) determines that there are six displacement degrees-of-freedom (three translations and three rotations) for the joint. Member and finite elements are incident on joints where the connection to a joint is determined by the member and finite element boundary conditions. Joints, in turn, are attached to the external world where the type of attachment is determined by structure boundary conditions. Loads may be applied directly to the joints. Figure 2.1(a) shows a simple structure drawn in a conventional way, and Figure 2.2(b) shows the joints heavily accentuated. It is important to visualize all analytical models of structures in the way shown in Figure 2.1(b).

Members and Finite Elements The elements of a structure, which interconnect the structure's joints, fall into three general categories as follows:

2-1

Characteristics of the Structural Analytical Model

1.

General

A member is a one dimensional element whose centroidal axis is incident on only two joints, and which has one dimension (i.e., distance along the centroidal axis of the member) that is large relative to its other two dimensions (i.e., crosssection dimensions). All applied member loads, and resulting member behavior (i.e., deformations and internal member forces), are expressed as functions of one member dimension, the distance along the centroidal axis of the member. The member boundary condition connection to joints is implied by the type of member such as PLANE TRUSS (hinged to joints) or SPACE FRAME (rigidly connected to joints), and may be modified using the MEMBER RELEASES command such as a SPACE FRAME member hinged to a joint. Figure 2.2(a) shows a typical member element, and Figure 2.1 shows member elements numbered 1 to 8. There are six (6) member element types which are plane truss, plane frame, plane grid, space truss, space frame, and curved member.

2.

Two-Dimensional (2D) Element, commonly referred to as a surface finite element, is an element whose mid-plane surface is incident on three or more joints, and which has two in-plane dimensions that are large relative to its third dimension (i.e., its thickness). All 2D finite element applied loads, and resulting element behavior (i.e., stretching and bending deformations and stress resultants), are expressed as functions of two dimensions in the mid-plane surface. The 2D finite element boundary condition connection to joints is implied by the particular element used and is part of the element's theoretical formulation, and its boundary conditions cannot be further modified. Figure 2.2(b) shows two example 2D finite elements, and Figure 2.1 shows finite elements numbered 9 to 12. The basis of the theoretical formulations of the 2D finite elements available in GTSTRUDL is summarized in Volume 3 of the GTSTRUDL User Reference Manual.

3.

Three-Dimensional (3D) Element, commonly referred to as a solid finite element, is an element whose edges are defined by six or more nonplanar joints, and which has no one dimension that is large relative to the other two dimensions. All 3D finite element applied loads, and resulting element behavior (i.e., stresses), are expressed as functions of all three element dimensions. The 3D finite element boundary condition connection to joints is implied by the element's theoretical formulation, and cannot be further modified. Figure 2.2(c) shows two example 3D finite elements. The basis of the theoretical formulations of the 3D finite elements available in GTSTRUDL is summarized in Volume 3 of the GTSTRUDL User Reference Manual.

2-2

General

Characteristics of the Structural Analytical Model

There are presently six (6) finite element types: plane strain, plane stress, plate bending, plate stretching and bending, tridimensional, and axisymmetric. Among the six (6) finite element types, there are over one-hundred specific finite elements to choose from, including modern elements with isoparametric or hybrid stress formulations. Note that although the finite element formulations insure certain compatibility conditions along common finite element edges, the connectivity of the structure is, nevertheless, through the joints. Except for these finite element edge compatibility conditions, elements do not touch other elements, and element actions are transferred to other elements and the external world through the joints of the structure as shown in Figure 2.1(b).

External World The external world is an infinitely large half-space rigid body to which various structure support joints connect. The external world may influence the displacement boundary condition (e.g., a support settlement) of a support joint (applied as a loading type in GTSTRUDL) in a way specified by the engineer, while the structure, in turn, has no influence whatsoever on the external world. If a condition such as an elastic soil supporting a structure foundation is to be modeled, the soil model becomes part of the structure analytical model, and boundaries of the soil/structure analytical model are connected to joints which, in turn, are connected to the external world. In Figure 2.1(b), support joints 8, 9, 10, and 11 are connected to the external world.

2-3

Characteristics of the Structural Analytical Model

General

Figure 2.1 Structure Joints with Members 1 to 8, and 2D Finite Elements 9 to 12

2-4

General

Characteristics of the Structural Analytical Model

Figure 2.2 Typical Member and Finite Elements

2-5

Characteristics of the Structural Analytical Model

General

Structure Support Boundary Conditions A structure boundary condition refers to the connection condition between a support joint and the external world. Displacement degrees-of-freedom of a support joint, which are involved in the connection condition, are determined by the types of member and finite elements incident on the support joint. All support joint relevant degrees-of-freedom are restrained (rigidly connected to the external world), when a joint is defined as a SUPPORT joint (Section 7.3). For example, the fully supported joints in Figure 2.3(a) have only two translational degreesof-freedom restrained (and consequently only two corresponding translational force reaction components), while the fully supported joints in Figure 2.3(b) have three degrees-of-freedom restrained (two translational displacements and corresponding force reactions, and one rotational displacement and corresponding moment reaction). Note that full support restraint may be modified by using the JOINT RELEASES command as described in Section 7.3.

Member and Finite Element Boundary Conditions An element boundary condition refers to the connection condition between a member's start or end, or finite element corner node, and a structure joint. The fully connected (rigid) condition is dependent on the specific member type, or specific finite element used. For example, a space truss member is pin connected to a joint, where its three global direction translational degrees-of-freedom are rigidly connected to the joint, but where its rotational degrees-of-freedom are not defined for the truss member. For a space frame member, three translational degrees-of-freedom and three rotational degrees-of-freedom are all rigidly connected to the joint. For a plate bending finite element, one translational degree-of-freedom perpendicular to the plate, and two rotational degrees-of-freedom about the axes in the plane of the plate, are rigidly connected to the joint. Sections 7.4 and 7.5 further describes member boundary conditions. Element boundary conditions for finite elements are inherent in the finite element's formulation and may not be modified. However, member boundary conditions may be modified by using the MEMBER RELEASE command as described in Section 7.4. It is of interest to note here the potential misinterpretation of structure/element boundary conditions, and the importance of visualizing structures as shown in Figure 2.3 (C1 to C4). Consider the simple case shown in the plane frame member structure at support joint 3 in Figure 2.3(C1). This joint is shown in Figure 2.3(C1) as a pinned 6 applied to it. In order to be stable, joint, but it also has a concentrated joint moment M 6 whether or not M 6 is zero in magnitude. the joint must provide a path for the moment M,

2-6

General

Characteristics of the Structural Analytical Model

It is not clear in Figure 2.3(C1) how stability of the joint is provided. However, Figures 2.3(C2), (C3), and (C4) show three different joint and member boundary condition cases where moment applied to the joint is transferred into the start end of member 2 in (C2), the external world (reaction moment) in (C3), and the start end of member 3 in (C4). Although this is an oversimplified example, it is obviously critical for correct analysis and design which of these three boundary condition cases represents a proper model of the structure's support joint 3.

2-7

Characteristics of the Structural Analytical Model

Figure 2.3 Structure and Element Boundary Conditions

2-8

General

General

Characteristics of the Structural Analytical Model

Independent Loading Conditions All loads applied to a structure are defined by being specified in one or more independent loading conditions. These independent loading conditions may consist of one or more types of loads such as joint force and displacement loads, member force, temperature, and initial distortion loads, and finite element force and temperature loads. For example, in a typical structural analysis, gravity loads applied to members, finite elements, and joints could be included in one independent loading condition, while wind loads could be included in another independent loading condition. When GTSTRUDL performs analysis, only the independent loading conditions are included in the governing equations to be solved. Analysis results which are generated (joint displacements, support reactions, member end forces, and finite element stresses and/or stress resultants) are then stored in the problem data base and are associated with each independent loading condition name.

Dependent Loading Conditions Dependent loading conditions are loading conditions for which structural analysis results are formed as linear, absolute, or RMS (Root Mean Square) combinations of structural analysis results associated with any number of independent loading conditions and/or other dependent loading conditions. Results for dependent loadings may be generated during a STIFFNESS ANALYSIS, or following a STIFFNESS or any other type of analysis, depending on the GTSTRUDL commands used. Such results are then stored in the problem data base and associated with each dependent loading condition name. Any number of independent and dependent loading conditions may be defined in GTSTRUDL, where complete structural analysis results are stored in the problem data base under each loading condition, and which results may be selectively or completely output for review. In fact, selective results may be output for any one, or any combination of, independent and/or dependent loading conditions. Loading details are described in Chapters 9 and 10.

2-9

Characteristics of the Structural Analytical Model

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2 - 10

General

General

3.

Global and Local Coordinate Reference Frames

Global and Local Coordinate Reference Frames Coordinate reference frames are required in order to uniquely and precisely describe the geometric position of a structure in space, the direction of applied joint, member and finite element loads, the direction of computed joint displacements, the direction of computed reactions, and the direction of member and finite element forces and stresses. In addition, coordinate reference frames are required to reference other structural information such as member end eccentricities, end joint sizes, and member properties. GTSTRUDL uses right-handed, orthogonal cartesian reference frames as shown in Figure 3.1. In addition, for input of joint coordinates, right-handed cylindrical and spherical coordinate systems may also be used as described in the GTSTRUDL User Reference Manual. Five types of reference frames are used in GTSTRUDL which are the global, local member, local and planar finite element, and local joint reference frames. They are described in the following sections.

3.1

Global Reference Frame The geometry of a structure, applied joint loads, joint displacements, and support reactions are referenced to the global cartesian reference frame (Figure 3.2). Member and finite element loads and stresses, member eccentricities, and other data may be referenced to either the global or local member and finite element reference frames. The orientation of the global reference frame with respect to the structure's orientation is completely arbitrary and is implied by the engineer through the joint coordinate input. Generally, one or more global axes are selected to be parallel to one or more characteristic directions of the structure. There is one limitation, however, and that is a member defined as a plane truss, plane frame, or plane grid member must lie in a plane parallel to one of the three global planes (i.e., the XY, XZ, or YZ global plane). Also, although not required, it is recommended that the global Y-axis be oriented opposite to the force of gravity (i.e., positive up), for ease of interpretation of the BETA angle (Section 8.5).

3-1

Global and Local Coordinate Reference Frames

Figure 3.1 Coordinate Reference Frame - General

3-2

General

General

Global and Local Coordinate Reference Frames

u1, u2, u3 =

positive global joint translation displacement components

u4, u5, u6 =

positive global joint rotation displacement components

Fx, Fy, Fz =

positive global joint force components

Mx, My, Mz

=

positive global joint moment components

Figure 3.2 Global Reference Frame

3-3

Global and Local Coordinate Reference Frames

3.2

General

Local Member Reference Frame Each member has a local reference frame associated with it. Member cross-section area properties, member end joint sizes, member end and internal section forces, stresses, and distortions, and other member actions are referenced to the local member reference frame. Applied member loads, member eccentricities, and certain other member data may be referenced to either the global or local member reference frames. As is shown in Figure 3.3, the local x-axis coincides with the centroidal axis of the member, where the local x-axis (centroidal axis) is taken as a straight line which passes through the joints upon which the member is incident (unless member eccentricities are specified (Section 7.5)), and whose positive direction is arbitrarily selected by the engineer as going from the start joint to the end joint as specified by member incidence input (Sections 6.5 and 6.6). It is important to note that the centroid and shear center of the member's cross-section do not have to coincide. The location of the shear center is given with the MEMBER PROPERTIES command (Section 8.1). The local y- and z-axes coincide with the principal axes of the member cross-section as shown in Figure 3.3. Notice that either the local y or the local z-axis can be either the major or minor principal axis, depending only on the relative numerical values of the cross-section moments of inertias IY and IZ input by the MEMBER PROPERTIES command (Section 8.1). However, for TABLE members where the member properties are taken from prestored tables of section properties, the local y and z principal axes are as shown in Figure 3.4 for analysis processing. Additional considerations of member axes for design should be reviewed in the GTSTRUDL User Guide: Design.

3-4

General

Global and Local Coordinate Reference Frames

NOTES:

Centroid and shear center do not have to coincide. Member m goes from joint i to joint j. Local x axis is the straight centroidal axis. Local y and z axes are Principal Axes of the member's cross-section.

Figure 3.3 Local Member Reference Frame

3-5

Global and Local Coordinate Reference Frames

Figure 3.4

General

Orientation of Local y and z Principal Axes for Analysis as Stored in GTSTRUDL's Steel Section Tables

3-6

General

Figure 3.4

Global and Local Coordinate Reference Frames

Orientation of Local y and z Principal Axes for Analysis as Stored in GTSTRUDL's Steel Section Tables (continued)

3-7

Global and Local Coordinate Reference Frames

3.3

General

Orientation of Local Member Reference Frame (The BETA Angle) Although the specification of joint coordinates and member incidences are necessary in order to uniquely and precisely describe the position of members of a structure in space, they are not sufficient specifications for the unique description of the orientation of a member's principal axes. In particular, specification of joint coordinates and member incidences describe only the precise position of a member's local x-axis, but do not describe the position of a member's local principal cross-section axes (i.e., the local member y and z axes) as shown in Figure 3.3. Rather, the precise position of a member's local y and z principal axes is defined relative to the global cartesian reference frame by an angle called the BETA angle. As shown in Section 8.4, the BETA angle is measured in the cross-section plane of the member from some initially assumed reference position (i.e., the BETA = 0.0° position). Sections 8.4, 8.5, and 8.6 describe the BETA angle in detail.

3.4

Local and Planar Finite Element Reference Frames Two-dimensional (planar) finite elements in GTSTRUDL are associated with local, planar, and global reference frames, while three-dimensional (solid) finite elements are associated only with the global reference frame. With the exception of the rigidity matrix property, finite element properties are independent of the local and planar finite element reference frames. However, the rigidity matrix property is always referenced to the planar reference frame for 2D planar finite elements, and referenced to the global reference frame for 3D solid finite elements. Finite element applied loads may be referenced to the local, planar, or global reference frames depending on the element type. Finite element analysis results are output in the planar reference frame for 2D planar finite elements, and in the global reference frame for 3D solid finite elements. Sections 3.4.1 and 3.4.2 provide a short description of the 2D finite element local and planar reference frames.

3-8

General

3.4.1

Global and Local Coordinate Reference Frames

2D Finite Element Local Reference Frame Each 2D (planar) finite element has a local reference frame (Figure 3.5) with which it is associated and which is defined as follows (where references to the order of the nodes of an element are based on the direction (i.e., clockwise or counterclockwise) in which the element nodes were specified when defining the incidences of the element): 1.

The origin of the local reference frame is at the first node of the element, where the local x- and y-axes lie in the plane of the 2D element, and where the local zaxis is normal to the plane of the 2D element,

2.

The positive direction of the local x-axis (xL) is from the first node to the second node of the element,

3.

The positive direction of the local z-axis (zL) is determined by applying the righthand rule to the order in which the element nodes were input, and

4.

The positive direction of the local y-axis (yL) is determined by applying the righthand rule to the xL and zL axes.

It is important to note the following regarding 2D finite element local reference frames: 1.

The element's local x- and y-axes lie in the plane of the element, and their directions are dependent on the direction of the side of the element which goes from the first to the second node of the element (side 1).

2.

For all 2D elements that lie in the same plane, the local axes are all parallel to each other and in the same positive directions only if side 1 of all the elements are parallel to each other, and only if the order of input of nodal incidences are the same.

3.

It is often the case where the geometry of the finite element mesh is such that all 2D elements in the same plane do not have their first sides parallel to each other, resulting in local reference axes not being parallel to each other. In this case, it becomes extremely difficult to specify loadings applied to all elements which lie in the same plane, and to correctly interpret the finite element analysis results such as stresses (since stress results are referred to an element's reference axes). To solve this difficulty, GTSTRUDL provides a planar reference frame for all 2D finite elements which lie in the same plane.

3-9

Global and Local Coordinate Reference Frames

3.4.2

General

2D Finite Element Planar Reference Frame Each 2D finite element has a planar reference frame (Figure 3.6) with which it is associated and which is defined as follows: 1.

The origin of the planar reference frame is not of interest. Only the positive directions of the planar reference axes are of interest.

2.

The positive direction of the planar z-axis (zp) is determined by applying the righthand rule to the order (i.e., clockwise or counterclockwise) in which the element nodes were input (i.e., in the same positive direction as the local z-axis (zL)).

3.

The direction of the planar x-axis (xp) lies along a line which is parallel to the line of intersection of the plane of the element and the Global XY plane. The positive direction of xp is determined as follows:

4.

a.

If the planar z-axis (zp) does not lie in a plane which is parallel to the Global XZ plane, then the positive direction of the planar x-axis (xp) is such that its projection on the Global X-axis is in the positive direction of the Global X-axis.

b.

If the planar z-axis (zp) does lie in a plane which is parallel to the Global XZ plane, and if zp is parallel to the Global Z-axis, then the positive direction of the planar x-axis (xp) is in the same positive direction as the Global Xaxis. If zp is not parallel to the Global Z-axis, then the positive direction of the planar x-axis (xp) is in the same positive direction as the Global Y-axis.

The positive direction of the planar y-axis (yp) is determined by applying the righthand rule to the xp and zp axes.

3 - 10

General

Global and Local Coordinate Reference Frames

ELEMENT INCIDENCES 6 2 7 8 3

ELEMENT INCIDENCES 6 7 2 3 8

Figure 3.5 2D Finite Element Local Reference Frame

3 - 11

Global and Local Coordinate Reference Frames

Figure 3.6 2D Finite Element Planar Reference Frame

3 - 12

General

General

3.5

Global and Local Coordinate Reference Frames

Local Joint Reference Frame Each joint in a structure modeled with GTSTRUDL has a local joint reference frame and the global reference frame associated with it (Figures 3.7(a), (b), and (c)). Except for input describing certain structure boundary conditions, all other input joint data, and all output computed joint results, are referred to the global reference frame. The only time the local joint reference frame is not parallel and in the same positive direction as the global reference frame is at a support joint where the displacement restraints and releases are not parallel to the global reference frame axes. In this case, the local reference frame is oriented parallel to the restraint and released directions. The orientation of a non-parallel local joint reference frame is given by the JOINT RELEASES command (Section 7.3). Figure 3.7(d) shows a structure where only one support joint (joint 4) has a restraint direction non-parallel to global. Therefore, the only local joint reference frame which is non-parallel to global is at joint 4.

3 - 13

Global and Local Coordinate Reference Frames

Figure 3.7 Local Joint Reference Frames

3 - 14

General

General

4.

General Commands and File Management

General Commands and File Management This Chapter describes the concept of "list" processing, default command file processing, general commands, and files created by GTSTRUDL, as follows: Commands and Concepts

Description

4.1

"list" Processing

Forms of lists of names

4.2

STRUDL

Initiate execution

4.3

FINISH

Terminate execution and exit

4.4

CINPUT

Read an external input file

4.5

COUTPUT

Output to an external file

4.6

FLIST 1 and FLIST 2

Display system and user data files

4.7

SCAN Error Notice

Error notification control

4.8

BYPASS

Bypass following commands

4.9

UNITS

Specify current units

4.10

QUERY

Summarize current status

4.11

DEFINE GROUP

Assigns collections of joint, member, finite element, or loading names to GROUP names

4.12

PRINT GROUP

Print group data

4.13

DELETE GROUP

Delete group data

4.14

PRINT GENERATE

Controls output from automatic mesh generation commands

4.15.

CONSISTENCY CHECK

Perform a data consistency check

4.16

OPEN USERDATA FILE

Open new or existing user data set

4.17

Files Created by GTSTRUDL

Description of files created by GTSTRUDL

4-1

General Commands and File Management

General

4.18

The GTSTRUDL Batch Processor Run one or more GTSTRUDL command files in a batch mode

4.19

LARGE PROBLEM SIZE

Improve analysis performance for very large problems and speed of data base RESTORE processing

4.20

RUN

Run DOS commands from a GTSTRUDL command

4.21

ALIGN

Adjust coordinates to assure members are parallel to the global Y-axis

4.22

NOTES

Specify and store notes in connection with a structural model

4.23

PRINT COMMAND ARCHIVE

Print commands and comments that are archived in files associated with data base SAVE files.

4.24

ACTIVE SOLVER

Perform all subsequent static analyses using the GT64M or GTSES solvers, and Eigen solving using the GTSELANCZOS solver

4.25

DEFINE PHYSICAL MEMBER SMOOTH PHYSICAL MEMBER

Define and smooth the design of physical members

4-2

General Commands

4.1

"list" Options

"list" Options

Command elements:

Note:

The words JOINT or NODE and MEMBER or ELEMENT are synonymous and may be used interchangeably.

4-3

"list" Options

General Commands

Command elements: alphalist integerlist 'a1' ('a2')...

= = =

i1 (i2) ........ id1, id2

= =

n3

=

id4

=

id5, id6

=

n7

=

'a1' ('a2'). . . i1 (i2) . . . alphanumeric names each of from 1 to 8 characters enclosed in single quotes (apostrophes). positive integer names first and last names (integer or alphanumeric) of a name sequence. integer increment used to generate the name sequence. If not specified, n3 = 1 or -1 depending on the value of id1 and id2. the name (integer or alphanumeric) of a previously defined GROUP name (Chapter 4.13). first and last names (integer or alphanumeric) of a previously defined GROUP name (Chapter 4.13) sequence. integer increment used to generate the GROUP name sequence. If not specified, n7 = 1 or -1 depending on the value of id5 and id6.

Example DEFINE GROUP 'COLINE-A' MEMBERS 301 TO 320 DEFINE GROUP 'COLINE-B' MEMBERS 401 TO 420 MEMBER PROPERTIES EXISTING AX 100 IZ 10000 $ For ALL currently active members CONSTANTS BETA 90 MEMBERS 1 TO 31 BY 2 BETA 45 MEMBERS 101 107 200 TO 209 GRP LIST 'COLINE-A' 'COLINE-B' DENSITY EXISTING 490. BUT 301 305 GRP 'COLINE-B' LOADING 1 'APPLIED MEMBER LOADS' MEMBER LOADS EXISTING FOR Y UNIF W -1.5 $ Applied to all currently active members C C C STIFFNESS ANALYSIS LOAD LIST 1 2 3 LIST FORCES MEMBERS GRP 'COLINE-A' LIST FORCES MEMBERS GRP 'COLINE-B'

4-4

General Commands

"list" Options

Explanation In GTSTRUDL, all joints, members, finite elements, and independent and dependent loading conditions have names (id's) associated with them. These names can either be positive integer numbers, or they can be strings of from 1 to 8 alphanumeric characters (other than reserved characters such as the single quote or $ characters) enclosed in single quotes (apostrophes). The names are established and stored in the problem data base (Section 5.2) at the time a joint, member, finite element, or loading is referenced the first time in a GTSTRUDL execution, or during the creation of a finite element model using GTMenu. Where the word "list" appears in a command description in this User Guide, and unless otherwise described, it means that a list of names may be given in the form described above. Whenever a list of names is given in a command, the list may refer only to one type of entity (i.e., joints, members and finite elements, or loading conditions). Examples of different forms of "list" are presented after the following description of how the different forms of "list" operate: 1.

alphalist: This is a list of names where each name consists of a string of from 1 to 8 alphanumeric characters (other than reserved characters such as the single quote or $ characters) enclosed in single quotes (apostrophes).

2.

integerlist: This is a list of positive integer numbers in any sequence.

3.

id1 TO id2 BY n3: This is a list of consecutive names. The names are incremented or decremented as follows: a.

If the "BY n3" option is given, then n3 may be a positive or negative integer and the names are incremented or decremented accordingly.

b.

If the "BY n3" option is not given, then the names id1 TO id2 are incremented from id1 TO id2 by 1 if id1 is less than id2, or decremented from id1 TO id2 by -1 if id1 is greater than id2.

4-5

"list" Options

General Commands

c.

If id1 and id2 are alphanumeric names, then they are incremented or decremented as follows: (1)

The alphanumeric name must be composed of two parts which are an alphanumeric prefix and an integer suffix. The alphanumeric prefix consists of the first string of characters in the name where the last character in the prefix is a character other than the integers 0 9. For example: 'BEAM10' 'COLA-15' 'ABC*100' In the above names, the alphanumeric prefixes are "BEAM", "COLA", and "ABC*" respectively, while the integer suffixes are "10", "15", and "100" respectively.

(2)

4.

The integer suffix is then incremented/decremented according to the "BY n3" option.

GROUP or GRP: A GROUP (Section 4.12) is associated with a list of joint, member and finite element, and/or loading condition names. When the GROUP option is used, the group name is simply the name of a group which in turn is associated with a list of joint, member and finite element, and/or loading condition names. GROUP names may be specified as follows: (a)

id4: Only one GROUP name may follow the word GROUP or GRP. The GROUP name may be a positive integer number or an alphanumeric string of from 1 to 8 characters enclosed in single quotes. If several GROUP names are to be given, then the LIST option must be used.

(b)

LIST: This option allows one or more GROUP names to be given as described by "group-list". If additional joint, member and finite element, or loading condition names are to be given in the "listi", then the list of GROUP names must first be followed by the word JOINT, NODE, MEMBER, ELEMENT, or LOAD.

4-6

General Commands

5.

"list" Options

EXISTING: The "alphalist", "integerlist", "id1 TO id2 BY n3", and GROUP options of specifying names requires using explicit names. For example, you cannot use the word "ALL" to mean all the joints, members, finite elements, or both members and finite elements. The "EXISTING" option provides a means of specifying "ALL". The word "ALL" is not permitted as part of a "list" since it will conflict with its use in certain other commands. The use of EXISTING is context dependent. For example, it can mean all joints, or all members, or all finite elements, or all members and finite elements depending on the command in which EXISTING is used. Further, EXISTING only applies to the "structural components" referred to as joints, members, and finite elements, but not to loading conditions. EXISTING operates as follows: (a)

If the MEMBERS, ELEMENTS, NLS or CABLES ONLY option is not given, then EXISTING refers to joint names, or member and finite element names. ACTIVE is the default.

(b)

If the MEMBERS, ELEMENTS, NLS or CABLES ONLY option is given, then EXISTING refers ONLY to MEMBERS, ELEMENTS (i.e., finite elements), NLS (i.e., nonlinear springs), or CABLES (i.e., cable finite elements). ACTIVE is the default.

(c)

Only ACTIVE, INACTIVE, or both ACTIVE and INACTIVE structural components will be referenced depending on the use of the respective word. ACTIVE is the default.

(d)

Any name that is given in, or implied by, the "list2" or "BUT list3" options will be used as long as the name exists in the current GTSTRUDL data base (i.e., it has been referenced in a previous command and has not been previously deleted). Any name given or implied by list2 and list3 that does not exist in the current data base is ignored during the processing of these lists (i.e., such nonexistent names are neither created nor added to the data base).

(e)

If a "list2" has been given, then only the names that exist in the current GTSTRUDL data base are used (i.e., the names that have been referenced in previous commands and which have not been previously deleted are used). The other names in the "list2" are ignored.

(f)

If a "list2" has not been given, then all names that exist in the current GTSTRUDL data base for the particular structural component being referenced are used (i.e., all the names that have been referenced in previous commands and which have not been previously deleted are used).

4-7

"list" Options

General Commands

(g)

(h)

Any name that is from the "BUT list3" option operates as follows: (1)

If a "list2" has been given, then the names used from "list3" are subtracted from the names used from "list2". The remaining names are then sorted in the same order as is ordered by the OUTPUT ORDERED command (Section 13.2).

(2)

If a "list2" has not been given, then the names used from "list3" are subtracted from all names that currently exist in the data base for the particular structural component being referenced by the command in which EXISTING is used. The remaining names are then sorted in the same order as is ordered by the OUTPUT ORDERED command (Section 13.2).

Any name that is given in, or implied by, the "PLUS list4" option will be used if it exists in the current GTSTRUDL data base or, if it does not exist in the current data base, it will be created and placed in the data base as a new existing structural component.

Examples of Different Forms of "list" 4 or 'COLUMN1': A single name is a list. 'L2', 105, 'LOAD1' 'LOAD2' 4 5:

'J9' 6 TO 10 23 25:

Integer and alphanumeric names can be mixed, and spaces and commas are equivalent.

This list contains eight names which are: 'J9', 6, 7, 8, 9, 10, 23 and 25.

17, 18, 21, 2 TO 10 BY 2, 22 TO 13 BY -3, 33 TO 29: This list contains seventeen names which are: 17, 18, 21, 2, 4, 6, 8, 10, 22, 19, 16, 13, 33, 32, 31, 30 and 29.

4-8

General Commands

"list" Options

'JT-3' TO 'JT-7': This list contains seven names which are: 'JT-3' 'JT-4' 'JT-5' 'JT-6' 'JT-7' GRP 1 GRP 2 GRP 3 10 TO 15 This list will contain the names associated with GROUP 1, 2 and 3, and the structural component names 10, 11, 12, 13, 14 and 15. GRP LIST 1 TO 7 BY 2 4 10 This list will contain the names associated with GROUP 1, 3, 5, 7, 4 and 10. GROUP LIST 1 TO 4 7 JOINT 17 19 This list will contain the joint names associated with GROUP 1, 2, 3, 4 and 7, and the joint names 17 and 19 . EXISTING Depending on the context of the command, all names of currently active structural components are included in this list. For example, all active joints, or all active members and finite elements. EXISTING 1 TO 100 This list will contain the names of all currently active structural components whose names lie in the range of 1 to 100. Any names in the range of 1 to 100 that are the names of inactive structural components, or which do not exist in the current GTSTRUDL data base are ignored. For example, all active members and finite elements whose names lie in the range 1 to 100. EXISTING ELEMENTS ONLY This list will only contain the names of all currently active finite elements. EXISTING MEMBERS ONLY This list will only contain the names of all currently active members.

4-9

"list" Options

General Commands

EXISTING INACTIVE All names of currently inactive structural components are included in this list. EXISTING BUT 4 TO 12 BY 2 The names of all currently active structural components, except for those whose names are 4, 6, 8, 10, or 12, are included in this list. EXISTING MEMBERS ONLY 1 TO 20 BUT 5 TO 17 BY 3 The names of all currently active members whose names lie in the range 1 to 20, except those whose names are 5, 8, 11, 14 or 17, are included in this list. EXISTING PLUS 201 to 231 by 2 The names of all currently active structural components, plus those structural components whose names lie in the range 201 to 231 by 2, are included in this list. In addition, any structural components whose names do not appear in the range 201 to 231 by 2 are created and added to the currently active GTSTRUDL data base, and they are included in this list of names. 1 TO 11 BY 3 The sequence 1, 4, 7, 10 is generated, but a warning message is issued stating that the incrementation sequence does not terminate on the number 11. In this case, the number 11 is ignored. 'A1' TO 'B5' The alphanumeric prefixes in the range of names are not the same. The two names specified are ignored. GROUP LIST 1 TO 5 10 15 MEMBER 54 If the GROUP option is given in a command that references JOINT names, the word MEMBER will cause list processing for the joint list to terminate. The joint names 1, 2, 3, 4, 5, 10 and 15 may or may not be processed depending on the command in which this was given.

4 - 10

General Commands

4.2

STRUDL Command

STRUDL Command STRUDL ('a') ('title') Command elements: 'a'

= an optional problem name of from 1 to 8 characters.

'title'

= an optional problem title of from 1 to 64 characters.

Example STRUDL 'JOB-123' 'BRIDGE AT HIGHWAY I-85/I-285'

Explanation On PC’s, the STRUDL command is no longer required. However, if given within an existing execution of GTSTRUDL, it will initiate a new GTSTRUDL execution for which a problem data base does not currently exist. The RESTORE command (Section 5.3) is the first command in a GTSTRUDL problem for which a data base does exist. The STRUDL command causes the following to occur: 1.

Initialize a working GTSTRUDL problem data base (Section 5.2) which will contain information specified by the engineer in the commands that follow the STRUDL command, and will contain information created by GTSTRUDL such as the results of analysis and design,

2.

Unless the user modifies the default units, sets the default units as follows: INCHES, POUNDS, RADIANS, FAHRENHEIT, AND SECONDS, and

3.

Sets the ADDITIONS mode for subsequent processing of commands.

Following the STRUDL command, the user may specify any number of other commands (such as UNITS, GENERATE JOINTS, STIFFNESS ANALYSIS, LIST FORCES, etc.).

4 - 11

FINISH Command

4.3

General Commands

FINISH Command

FINISH

Explanation The FINISH command is used to terminate the execution of GTSTRUDL command processing and graphic al display. It should be noted that if it is desired to save all information in the current GTSTRUDL Data Base (Section 5), it is necessary to issue the SAVE command (Section 5.3) prior to the FINISH command.

4 - 12

Input

4.4

CINPUT Command

CINPUT Command

command element, ‘filename’

=

Any valid permanent file specification enclosed in single quotes. Filename is the file containing GTSTRUDL commands to be read.

Example CINPUT 'BRIDGE1.DAT' C C C GTMenu $ Enter the GTMenu Graphical User Interface to view the structure $ Exit GtMenu STIFFNESS ANALYSIS C C C

Explanation The CINPUT command is used to read subsequent commands from an alternate file, and it is used to cause GTSTRUDL to alternate reading of commands between the terminal keyboard or a batch file of commands, and an alternate file of commands.

4 - 13

CINPUT Command

Input

The CINPUT command operates as follows: 1.

CINPUT 'filename': This form of the command causes subsequent commands to be read from an alternate input file called 'filename'. 'filename' may be any valid file specification including references to directory and subdirectory names. The file 'filename' may contain any valid command that normally can be processed from a file of commands. The STRUDL command may be included in the file 'filename'.

2.

CINPUT STANDARD: This form of the command may be included in the alternate input file 'filename'. When this command is encountered during processing of commands in the file 'filename', GTSTRUDL will return control of command processing back to the primary input device from which subsequent commands will be read.

3.

CINPUT RESUME: This form of the command may be given from the primary input device. If it is given, GTSTRUDL will return control of command processing to the alternate file 'filename' beginning with the command in the alternate file immediately following the most recent CINPUT STANDARD command processed in the alternate input file. If another CINPUT STANDARD command is subsequently encountered in the alternate input file, control of command processing will be returned to the primary input device.

Figure 4.4-1 shows how the above three forms of the CINPUT command operate.

CHANGES, and DELETIONS Modes The CINPUT command is mode independent. That is, it operates the same in the ADDITIONS, CHANGES and DELETIONS modes.

4 - 14

Input

CINPUT Command

Figure 4.4-1 Operation of the CINPUT Command

4 - 15

CINPUT Command

Input

Extended Example In this example (Figure 4.4-2), the following commands are input from the keyboard, or from a file of commands: STRUDL $ $ Input joint coordinates, support boundary conditions, and finite $ element incidences from an alternate file 'GATEGEOM.DAT' $ CINPUT 'GATEGEOM.DAT' $ $ Input finite element and material properties from an alternate file $ 'GATEPROP.DAT' $ CINPUT 'GATEPROP.DAT' $ $ Input loading descriptions from an alternate file 'GATELOAD.DAT' $ CINPUT 'GATELOAD.DAT' $ QUERY GTMenu $ GTMenu can be entered from a menu pick C C $ Additional commands input from the primary input device C STIFFNESS ANALYSIS UNITS CM LIST DISPLACEMENTS UNITS MTON M LIST REACTIONS FINISH

4 - 16

Input

CINPUT Command

Figure 4.4-2 CINPUT Example 1 4 - 17

COUTPUT Command

4.5

Output

COUTPUT Command

command elements, 'filename'

=

Any valid permanent file specification of up to 256 alphanumeric characters and enclosed in single quotes. Filename is the file into which output caused by subsequent POL commands will be written.

Example STRUDL UNITS KN M C C $ Additional commands describing the structure model C STIFFNESS ANALYSIS UNITS CM MTONS COUTPUT 'DISPL.OUT' LIST DISPLACEMENTS COUTPUT 'FORCES.OUT' LIST FORCES COUTPUT STANDARD LIST SUM REACTIONS C C $ Additional commands C

4 - 18

Output

COUTPUT Command

Explanation The COUTPUT command causes output created by subsequent commands to be written to an alternate file, and it causes GTSTRUDL to alternate the writing of output between the screen and an output text file. The COUTPUT command operates as follows: 1.

COUTPUT APPEND 'filename': This form of the command causes output created by subsequent commands to be written to an alternate output file called 'filename'. If the file 'filename' does not currently exist, it will be automatically created by GTSTRUDL in the current working directory, or in a specified directory. If the file 'filename' currently exists, then subsequent output will be written beginning at the end of the current file (i.e., appended to the file).

2.

COUTPUT REPLACE 'filename': This form of the command causes output created by subsequent commands to be written to an alternate output file called 'filename'. If the file 'filename' does not currently exist, it will be automatically created by GTSTRUDL in the current working directory, or in a specified directory. If the file 'filename' currently exists, then the content of the file will be deleted, and subsequent output will be written from the beginning of the file (i.e., replace the current content of the file).

3.

COUTPUT STANDARD: This form of the command causes all output created by subsequent commands to be written to the primary output device (e.g., the text window). This is the default output function.

Figure 4.5-1 shows how the above two forms of the COUTPUT command operate.

CHANGES, and DELETIONS Modes The COUTPUT command is mode independent. That is, it operates the same in the ADDITIONS, CHANGES, and DELETIONS modes.

4 - 19

COUTPUT Command

Output

Figure 4.5-1 Operation of the COUTPUT Command

4 - 20

Output

4.6

FLIST 1/2 Command

FLIST 1 and FLIST 2 Commands

FLIST i command elements, i

=

1,

causes a display of file names in the User Data Set

=

2,

causes a display of file names in the GTSTRUDL System Data Set

Example FLIST 1 FLIST 2

Explanation GTSTRUDL maintains several special data sets on disk from which GTSTRUDL may read required data, or to which GTSTRUDL may write specified data. The FLIST 1 and FLIST 2 commands are used to output the names of the data files contained in two of such special data sets which are the: 1.

User Data Set: This data set (default name of userdat1234567.ds, where 1234567 is a multi-digit random integer) is a READ/WRITE data set that is created by the user of GTSTRUDL, and which contains files used by GTSTRUDL as follows: a.

User defined TABLES of steel rolled shapes used by the analysis and steel design features of GTSTRUDL. These user defined TABLES are created by using the GTTABLE software provided with GTSTRUDL. See the GTTABLE Users Manual for an explanation of the use of GTTABLE.

4 - 21

FLIST 1/2 Command

b.

Output

User defined files containing dynamic transient loading records and dynamic response spectra loading curves. This dynamic loading data is stored through the use of the GTSTRUDL dynamic analysis commands "STORE TIME HISTORY" and "STORE RESPONSE SPECTRA" commands (Chapter 15).

The GTSTRUDL Installation and Operations Guide, and the GTSTRUDL User Guide: Getting Started, describe how to make the Userdat.ds file a permanent file. 2.

GTSTRUDL System Data Set: This data set, called "strxx.ds", where "xx" is the GTSTRUDL version number (e.g., str29.ds), is a permanent READ ONLY data set that is included with GTSTRUDL, and which contains files used by GTSTRUDL as follows: a.

Prestored TABLES of steel rolled shapes used by the analysis and steel design features of GTSTRUDL.

b.

Various dynamic transient ground motion records (such as the ELCENTRO acceleration vs. time ground motion), and response spectra curves (such as several response spectra curves used in the dynamic analysis of bridge structures in the State of California).

c.

Steel and reinforced concrete design PARAMETER definitions.

d.

Finite element dictionary containing the names and processing rules for all finite element types used by GTSTRUDL.

e.

Other relevant data.

4 - 22

General

4.7

SCAN Error Flag Command

SCAN Error Flag Command

Example SCAN OFF

Explanation During the processing of commands, if GTSTRUDL detects an error condition, the SCAN error flag may be set (i.e., turned "ON"). If the SCAN flag is set, command processing will continue. However, if the SCAN flag is set, certain commands will not be executed such as: 1. 2. 3. 4. 5. 6.

DEAD LOAD, STIFFNESS ANALYSIS, DYNAMIC ANALYSIS, NONLINEAR ANALYSIS, the PERFORM commands, and other analysis commands, Certain LIST commands, SELECT and CHECK steel design commands, The PROPORTION reinforced concrete design command, and Several other commands which will be executed only if the SCAN flag is not set (i.e., turned "OFF).

The SCAN error flag can only be turned "OFF" by specifying the command "SCAN OFF". For example, if an error condition is detected which causes the SCAN error flag to be turned ON, and if the error is subsequently corrected, the SCAN flag may then be turned "OFF" by specifying the SCAN OFF command. It should be noted that although the analysis commands (such as STIFFNESS ANALYSIS or DYNAMIC ANALYSIS) will execute when the SCAN error flag is turned OFF, if an error is detected during the consistency check phase of analysis, then the SCAN error flag will be turned ON, consistency checking will continue until all data are checked, and then analysis processing will terminate with the error message "ERROR: Errors detected which preclude analysis. Scan mode entered."

4 - 23

SCAN Error Flag Command

General

Extended Example STRUDL UNITS M KN JOINT COORDINATES 1 0.0 2 10.0 3 20.0 STATUS SUPPORT JOINTS 1 TO 3 JOINT RELEASES 1 MOMENT Z 2 3 FORCE X MOMENT Z TYPE PLANE FRAME MEMBER INCIDENCES 112 223 MATERIAL STEEL LOAD 1 'LIVE LOAD' MEMBER LOADS 1 2 FORCE Y UNIFORM W -5000 STIFFNESS ANALYSIS $ $ A consistency check error will be issued which notes that member $ properties have not been specified, and the SCAN error flag is turned ON. $ Consistency checking will continue until the consistency of all data has $ been checked. Stiffness analysis processing will then terminate. $ The error is corrected by specifying the MEMBER PROPERTIES command, $ turning OFF the SCAN error flag, and respecifying the STIFFNESS $ ANALYSIS command. $ UNITS CM MEMBER PROPERTIES 1 2 AX 1000 IZ 20000 SCAN OFF $ 0.5, τb = 1.0 may be used for all members, provided that an additive notional load of 0.001Yi is added to the notional load required in (2).” So, for this example, the total notional load Ni = 0.003Yi, and therefore NLFACTOR 0.003 would be specified in the FORM NOTIONAL LOAD command. The lateral joint load components are applied only at the joints specified in list, the default being all active joints.

10 - 14

Input

10.2

Combinations of Static Analysis Results

Combinations of Static Analysis Results

Examples LOADING 1 C C LOADING 2 C C LOADING 3 C C FORM LOAD 10 FROM 1 1.3 2 1.7 C C LOAD COMBINATION 21 SPECIFICATION 1 1.0 2 1.0 LOAD COMBINATION 22 SPECIFICATION 21 -0.5 10 2.4 STIFFNESS ANALYSIS LOAD COMBINATION 31 SPEC 1 1.0 3 2.0 LOAD COMBINATION 32 SPEC 3 1.0 21 1.0 31 1.0 COMBINE 31 COMBINE 32 CREATE LOAD COMBINATION 41 SPECS 1 1.0 3 2.0 CREATE LOAD COMBINATION 42 TYPE ABSOLUTE SPECS 1 1.0 3 2.0 CREATE LOAD COMBINATION 43 TYPE RMS SPECS 1 1.0 3 2.0

Explanation Combinations of static analysis results are created and stored in dependent static loading conditions (also referred to as a loading combinations) which have the following three main characteristics: 1.

A dependent static loading condition does not contain any description of independent static loading types (e.g., it does not include any description of JOINT LOADS, MEMBER LOADS, etc.), but rather

2.

A dependent static loading condition (i.e., loading combination) only consists of some specified combination of static analysis results (i.e., combinations of joint displacements, support reactions, member end forces, finite element nodal stresses, etc.), and

10 - 15

Combinations of Static Analysis Results

3.

Input

A dependent static loading condition may be formed as a combination of the static analysis results of independent and other dependent loading conditions for which static analysis results exist.

Any number of dependent static loading conditions may be defined. GTSTRUDL places no artificial limitations on the number of dependent static loading conditions. There are three (3) commands which may be used to define a dependent static loading condition as follows: LOADING COMBINATION COMBINE CREATE LOADING COMBINATION In addition, there are two (2) ways in which dependent static loading conditions may be computed as follows: 1.

Loading combinations may be computed during a STIFFNESS ANALYSIS. This will occur automatically for any currently ACTIVE loading combination that was defined using the LOADING COMBINATION command, and which included combination specifications, prior to a STIFFNESS ANALYSIS. For example, the following STIFFNESS ANALYSIS command will compute analytical results for independent Loadings 1, 2, and 3, and then combine the analytical results according to the combination specifications as defined by the LOADING COMBINATION commands: LOAD COMBINATION 10 'GRAVITY LOADS' SPECS 1 1.0 2 1.0 LOAD COMBINATION 11 'GRAVITY+WIND' SPECS 10 0.75 3 0.75 STIFFNESS ANALYSIS

2.

Loading combinations may be computed following one or more STIFFNESS ANALYSES by using either or both of the following two command sequences: (a)

(b)

STIFFNESS ANALYSIS LOADING COMBINATION 20 SPECS 5 1.4 7 1.7 COMBINE 20 STIFFNESS ANALYSIS CREATE LOAD COMBINATION 20 SPECS 5 1.4 7 1.7

The LOADING COMBINATION, CREATE LOADING COMBINATION, and COMBINE commands are described in the following three Chapters.

10 - 16

Combinations of Static Analysis Results

LOADING COMBINATION Command

10.2.1 LOADING COMBINATION Command

command elements,

i, 'a'

=

the name of this dependent static loading condition expressed as a positive integer number, or as a string of from 1 to 8 characters.

'title'

=

the optional title of this dependent static loading condition expressed as a string of from 1 to 64 characters.

i1, i2..... = 'a1', 'a2',.....

v1, v2,.....

=

names of one or more independent and/or other dependent loading conditions.

linear combination factors which multiply the static analysis results of the corresponding independent or dependent loading condition respectively. These factors may be positive or negative, and they must include a decimal point (.).

10 - 17

LOADING COMBINATION Command

Combinations of Static Analysis Results

Examples LOADING 101 C LOADING 102 C FORM LOADING 'ABC' FROM 101 1.3 102 1.7 C LOADING COMBINATION 201 SPECIFICATIONS 101 1.0 'ABC' 2.0 LOADING COMB 'SPECIAL' SPECS 201 1.0 'ABC' 1.0 102 1.5 C STIFFNESS ANALYSIS C

Explanation In the ADDITIONS mode, the LOADING COMBINATION command is used to define a dependent static loading condition by establishing the existence of a dependent loading condition, by assigning a name and optional title to the loading condition, and by defining the linear combination factors which are used to form the loading combination. The loading name i or 'a' must be unique among all static and dynamic independent loading condition names, and among all static dependent loading condition names. If the loading condition name has been previously specified, then GTSTRUDL will issue an error message, set the SCAN error flag, and ignore the LOADING COMBINATION command. This command does not by itself cause the loading combination to be formed. Rather, the LOADING COMBINATION command simply defines the specification according to which a linear combination of the static analysis results computed for other independent and dependent loading conditions are to be formed. GTSTRUDL User Reference Manual provides a more complete description of the LOADING COMBINATION command. The loading combination can then be formed in one of two ways as follows: 1.

During the processing of a STIFFNESS ANALYSIS command, loading combinations will be formed for loading combinations that have been previously defined by a LOADING COMBINATION command, and which are currently ACTIVE (Section 5.5). Following the static analysis for the currently ACTIVE independent loading conditions, all currently ACTIVE loading combinations are computed. The linear combination factors specified in the LOADING COMBINATION command are used to multiply the static analysis 10 - 18

Combinations of Static Analysis Results

LOADING COMBINATION Command

results (i.e., joint displacements, support reactions, member end forces, finite element stresses, etc.) computed during the processing of the STIFFNESS ANALYSIS command, and then the multiplied results are added together and stored as the analysis results for the loading combination. 2.

If static analysis results have been previously computed in one or more prior STIFFNESS ANALYSIS commands, then following the STIFFNESS ANALYSIS commands, a loading combination can be defined by a LOADING COMBINATION command, and then it can be formed (i.e., computed) by the use of the COMBINE command (Section 10.2.3).

CHANGES Mode When the LOADING COMBINATION command is given in the CHANGES mode, all previously specified combination-specs are deleted and replaced by the newly specified combination-specs. However, if combined analysis results exist for the changed loading combination, such results will remain the same until a new STIFFNESS ANALYSIS or COMBINE command is given. At that time, the old combined results will be deleted and replaced by the new results which are formed according to the new combination-specs.

DELETIONS Mode A dependent loading condition (loading combination) may be deleted in the same way as an independent loading condition may be deleted (Section 9.3) by giving the name of the dependent loading following a LOADING command in the DELETIONS mode.

Extended Example Consider the PLANE TRUSS structure shown in Figure 10.2-1, and consider the following command sequence: LOADING 1 JOINT LOAD 2 FORCE X P1 $ P1 is some numerical value. JOINT DISPLACEMENT 3 DISPL Y -.1 LOADING 2 JOINT LOAD 2 FORCE Y -P2 $ P2 is some numerical value.

10 - 19

LOADING COMBINATION Command

Combinations of Static Analysis Results

FORM LOADING 3 FROM 1 2.0 2 1.0 LOADING COMBINATION 10 SPECS 1 1.0 2 4.0 3 0.7 LOADING COMBINATION 11 SPECS 10 1.0 2 -4.0 STIFFNESS ANALYSIS In the above example, the following should be noted: 1.

Loading 3 is an independent loading condition whose loading descriptions are formed from the loading descriptions of independent loadings 1 and 2. In other words, FORM LOAD 3 FROM 1 2.0 2 1.0 is identical to the following LOADING command: LOADING 3 JOINT LOADS ; 2 FORCE X 2P1 Y -P2 JOINT DISPLACEMENT ; 3 DISPL Y -.2

2.

During STIFFNESS ANALYSIS, static analysis results are computed for independent loadings conditions 1, 2 and 3. Then, these static analysis results are combined to form loading combinations 10 and 11 according to the specified combination-specs.

3.

Following the STIFFNESS ANALYSIS, static analysis results (joint displacements, support reactions, member end forces, finite element stresses, etc.) are stored in GTSTRUDL's data base for both the independent and dependent loadings 1, 2, 3, 10 and 11. However, only independent loading conditions have specific loading type descriptions associated with them (e.g., JOINT LOADS), while the dependent loading conditions have the combination-specs associated with them.

10 - 20

Combinations of Static Analysis Results

Form Loading 3 From

LOADING COMBINATION Command

=

(Load 1) ( 2.0 + (Load 2) ( 1.0

Loading Combination 10 Specs =

(Load 1) ( 1.0 + (Load 2) ( 4.0 + (Load 3) ( 0.7

Loading Combination 11 Specs =

(Load 10) ( 1.0 + (Load 2) ( (-4.0)

Figure 10.2-1 FORM LOAD and LOADING COMBINATION Processing

10 - 21

LOADING COMBINATION Command

Combinations of Static Analysis Results

In the above example, following the STIFFNESS ANALYSIS command, and assuming that the joint displacements and member end forces for independent loading conditions 1, 2 and 3 are as shown below, then the joint displacements and member end forces for Loading Combinations 10 and 11 are as follows:

Loading 1:

Loading 2: Displacements

Joint

X

Y

1

0

0

2

.5

3

0

Loading 3: Displacements

Joint

X

Y

1

0

0

0

2

0

-.1

3

0

Loading 10:

Displacements Joint

X

Y

1

0

0

-.3

2

1.0

-.3

0

3

0

-.2

Loading 11 Displacements

Joint

X

Y

1

0

0

2

1.2

3

0

Displacements Joint

X

Y

1

0

0

-1.41

2

1.2

-.21

-.24

3

0

-.24

AXIAL FORCE MEMBER

Load 1

Load 2

Load 3

Load 10

Load 11

1

5

-3

7

-2.1

9.9

2

-5

-3

-13

-26.1

-14.1

10 - 22

Combinations of Static Analysis Results

CREATE LOADING COMBINATION Command

10.2.2 CREATE LOADING COMBINATION Command

command elements,

i

=

the name of this dependent static loading condition expressed as a positive integer number.

'a'

=

the name of this dependent static loading condition expressed as a string of from 1 to 8 characters.

'title' =

the optional title of this dependent static loading condition expressed as a string of from 1 to 64 characters.

i1, i2..... = 'a1', 'a2',..... v1, v2,.....

=

names of one or more independent and/or other dependent loading condition names.

factors which multiply the static analysis results of the corresponding independent or dependent loading condition respectively. These factors may be positive or negative, and they must include a decimal point (.).

10 - 23

CREATE LOADING COMBINATION Command

Combinations of Static Analysis Results

Examples LOADING 101 C LOADING 102 C FORM LOADING 'ABC' FROM 101 1.3 102 1.7 C STIFFNESS ANALYSIS C CREATE LOADING COMBINATION 201 SPECS 101 1.0 'ABC' 2.0 CREATE LOADING COMB 'SPECIAL' ABSOLUTE SPECS 201 1.0 'ABC' 1.0 102 1.5 CREATE LOADING COMB '301' TYPE RMS SPEC 101 1.0 102 -0.5

Explanation The CREATE LOADING COMBINATION command is used to create a dependent loading condition by establishing the existence of a dependent loading condition, by assigning a name and optional title to the loading condition, and by causing the loading combination to be formed as an ALGEBRAIC, ABSOLUTE, or RMS sum of existing static analysis results. Consequently, this command can be processed only if it is given at some time after a STIFFNESS ANALYSIS command is given. Furthermore, any independent or dependent loading condition referred to by this command must have static analysis results existing for it such as computed by a previous STIFFNESS ANALYSIS, COMBINE, CREATE PSEUDO STATIC LOAD or CREATE LOADING COMBINATION command. If such static analysis results do not exist, the CREATE LOADING COMBINATION command will be ignored, an error message will be displayed, and the SCAN error flag will be set. The CREATE LOADING COMBINATION command is a much more powerful and robust command than the LOADING COMBINATION command. Not only can it cause a linear ALGEBRAIC combination of static analysis results to be formed, it can also cause a combination to be formed as the sum of ABSOLUTE values of static analysis results, and as a Root Mean Square (RMS) sum of static analysis results as follows: 1.

ALGEBRAIC - an algebraic sum (i.e., linear combination), of static analysis results which exist for other independent and dependent loading conditions referenced in the type-specs. This is formed according to the specified combination factors. The ALGEBRAIC sum will produce the same combined results as the LOADING COMBINATION and COMBINE commands.

10 - 24

Combinations of Static Analysis Results

CREATE LOADING COMBINATION Command

2.

ABSOLUTE - Static analysis results for other independent and dependent loading conditions referenced in the type-specs are first multiplied by the multiplication factors (v1, v2, .....). Then a sum of the ABSOLUTE value of the factored analysis results is performed.

3.

RMS - Static analysis results for other independent and dependent loading conditions referenced in the type-specs are first multiplied by the multiplication factors (v1, v2 .....). Then a Root Mean Square summation (i.e., square root of the sum of the squares) of the factored analysis results is performed.

The combination factors and combination method given in the CREATE LOADING COMBINATION command are only used at the time the command is processed, and the combination is formed. In addition, these combination factors are also available for use in subsequent calculations of internal member section results (i.e., from the LIST SECTION command). However, unlike the LOADING COMBINATION command, the CREATE LOADING COMBINATION combination factors are not stored for later use in order to reform the combination. Rather, the CREATE LOADING COMBINATION command must be specified again in order to reform the combination following another STIFFNESS ANALYSIS. With respect to the calculation of internal member section results such as member section forces (e.g. from the LIST SECTION command, the steel design SELECT and CHECK commands, the reinforced concrete PROPORTION command, etc.), if the member end forces are computed using the ABSOLUTE or RMS options of the CREATE LOADING COMBINATION command, the internal member section forces cannot be correctly computed from the ABSOLUTE or RMS member end force values. Therefore, in order to correctly compute internal member section forces (and other related internal section results) based on member end forces computed by the ALGEBRAIC, ABSOLUTE, or RMS options of the CREATE LOADING COMBINATION command, GTSTRUDL uses the following procedure: 1.

The CREATE LOADING COMBINATION loading is decomposed into its component independent loading conditions.

2.

For each component independent loading, member internal section results are computed at the specified sections along the member based on the member equilibrium equations, the member's end forces, and the applied member forces for each such independent loading.

10 - 25

CREATE LOADING COMBINATION Command 3.

Combinations of Static Analysis Results

Then, at each such section location, the internal section results for each of the component independent loading conditions are multiplied by its corresponding vi factor, and then combined according to the TYPE option (ALGEBRAIC, ABSOLUTE, or RMS) given in the CREATE LOADING COMBINATION command. This method of computing internal section results is the only correct way to obtain ABSOLUTE and RMS combination values of the member's internal section forces, envelopes, stresses, etc.

CHANGES Mode The CREATE LOADING COMBINATION command is mode independent. Whenever a CREATE LOADING COMBINATION command is given, it operates the same in both the ADDITIONS and CHANGES MODE.

DELETIONS Mode A dependent loading condition (loading combination) may be deleted in the same way as an independent loading condition may be deleted (Section 9.3) by giving the name of the dependent loading following a LOADING command in the DELETIONS MODE.

Extended Examples 1.

The following example is identical to the Extended Example shown for the LOADING COMBINATION command as shown in Figure 10.2-1, except that the CREATE LOADING COMBINATION command is used instead of the LOADING COMBINATION command: LOADING 1 JOINT LOAD 2 FORCE X P1 $ P1 is some numerical value. JOINT DISPLACEMENT 3 DISPL Y - 0.1 LOADING 2 JOINT LOAD 2 FORCE Y -P2 $ P2 is some numerical value. FORM LOADING 3 FROM 1 2.0 2 1.0 STIFFNESS ANALYSIS CREATE LOAD COMB 10 TYPE ALGEB SPEC 1 1.0 2 4.0 3 0.7 CREATE LOAD COMB 11 TYPE ALGEB SPEC 10 1.0 2 -4.0

10 - 26

Combinations of Static Analysis Results 2.

CREATE LOADING COMBINATION Command

The following two examples show some differences between the use of the CREATE LOADING COMBINATION and COMBINE commands. a.

Using the COMBINE command, only a linear combination of static analysis results can be formed as follows: STRUDL C LOAD 1 C C LOAD 2 C C STIFFNESS ANALYSIS C C LOAD COMBINATION 10 SPEC 1 1.0 2 1.0 COMBINE 10 C C

b.

Using the CREATE LOADING COMBINATION command, in addition to linear combinations (ALG), both absolute (ABS) and root mean square (RMS) combinations can be formed: STRUDL C LOAD 1 C LOAD 2 C STIFFNESS ANALYSIS C CREATE LOAD COMBINATION 10 ALG 1 1.0 2 1.0 CREATE LOAD COMBINATION 11 ABS 1 1.0 2 1.0 CREATE LOAD COMBINATION 12 RMS 1 1.0 2 1.0

10 - 27

CREATE LOADING COMBINATION Command 3.

Combinations of Static Analysis Results

The following example shows a more comprehensive use of the CREATE LOADING COMBINATION command: STRUDL C C LOADING 1 C C LOADING 2 C C LOADING 3 C C LOADING 4 C C LOAD LIST 1 2 $ INACTIVATE ALL LOADS EXCEPT 1 AND 2 STIFFNESS ANALYSIS C C LOAD LIST 3 $ INACTIVATE ALL LOADS EXCEPT 3 STIFFNESS ANALYSIS C C LOAD LIST ALL $ ACTIVATE ALL LOADS CREATE LOAD COMBINATION 10 SPECS 1 1.0 2 1.0 3 1.0 CREATE LOAD COMB 11 SPECS 1 -1.0 3 1.5 C SAVE > > > >

$$* ** Resultant sum of forces in the composite beam at $$* ** X = 40 ft., using the member and finite element nodal $$* ** forces at joints 41 to 45 of elements 29 to 32 and $$* ** member 56 $$* ** LIST SUM FORCES ELEMENTS 29 TO 32 56 JOINTS 41 TO 45

******************************** * RESULTS FROM LATEST ANALYSIS * ********************************

ACTIVE UNITS (UNLESS INDICATED OTHERWISE): LENGTH WEIGHT ANGLE FEET KIP DEG

TEMPERATURE DEGF

TIME SEC

Member and Finite Element Force Resultants ========================================== Title: Example LSF01 Sum of Forces and Moments about Local Axis Orientation Angles: Z Loading ------1

FX -----0.0000

40.0000 0.0000 FY ------100.0000

Y

0.0000 0.0000 FZ -----0.0000

0.0000 X

0.0000

MX -----0.0000

MY -----0.0000

Figure 13.10.2 Output From the LIST SUM FORCES Command, Example LSF01

13 - 80

MZ ------2000.0001

Static Analysis Results Output

Steel Takeoff Command

13.11 STEEL TAKE OFF Command

where,

Examples STEEL TAKE OFF STEEL TAKE OFF MEMBERS 1 TO 10 STEEL TAKE OFF ALL MEMBERS ITEMIZE STEEL TAKE OFF ALL INACTIVE MEMBERS STEEL TAKE OFF BY PROFILE NAMES STEEL TAKE OFF ITEMIZE BY PROFILE NAMES

Explanation The STEEL TAKE OFF command is used to compute the total weight and volume of the specified members (finite elements are not included). The specified members may be identified as a particular group of members with the 'active/inactive' option, or a more selective group of members may be defined with the 'list' option. When no choice is indicated in the command, ALL ACTIVE MEMBERS will be used as the default option.

13 - 81

Steel Takeoff Command

Static Analysis Results Output

The STEEL TAKE OFF command outputs the total effective length (as discussed below), weight, and volume of the specified members in the currently active units. The STEEL TAKE OFF BY PROFILE NAMES command outputs the total length, volume, and weight for each profile name (i.e., table shape name) and also the grand total length, weight, and volume of the specified members. The ITEMIZE BY MEMBERS option outputs the effective length, density, volume, and weight of each individual member specified, and final total length, volume, and weight in currently active units. The ITEMIZE BY PROFILE NAMES option outputs the same data as above but it will be ordered based on the profile names (e.g., W12x58, W14x61, W18x71). Members with the same profiles are output in a sequential order. This option also outputs the total length, volume, and weight for each profile name and the grand total length, weight, and volume of the specified members. The effective length of a member will be computed in accordance with the following rules: (1)

For all cases not described below, the joint-to-joint length of the member will be used. This is the usual case.

(2)

For members with eccentricities, the end-to-end length of the member will be used.

(3)

For variable members, the individual segment lengths will be used with a warning message being printed if the sum of the segments differs by more than 1.5% from its joint-to-joint or end-to-end length, whichever is appropriate.

(4)

For members with end joint sizes, the end joint sizes will be subtracted from the effective length which would otherwise be used (note that DEAD LOADING includes end joint sizes).

The cross-section area (i.e., AX) member property for members referred to in a STEEL TAKE OFF command must be given as either PRISMATIC, TABLE, or VARIABLE. The densities need not be given prior to the STEEL TAKE OFF command. However, if not given, GTSTRUDL uses a default value for DENSITY of 0.0. If any finite elements are included in the specified list of members, a warning will be printed once and the finite elements will be ignored. Only members are included in the weight calculations of the STEEL TAKE OFF command.

13 - 82

Steel Code Check Results Output

List Code Check Results Command

13.12 The LIST CODE CHECK RESULTS Command

⎧CODE (CHECK) ⎫ ⎪ ⎪ LIST ⎨PUNCHING (SHEAR) (CHECK) ⎬ (RESULTS) (MEMBERS list) ⎪ ALL (CHECK) ⎪ ⎩ ⎭ where: list

=

a list of members for which to print code check or punching shear check results. If a list is not given, all available results for all active and inactive members will be printed.

Examples LIST CODE CHECK RESULTS MEMBERS 1 TO 11 BY 2 LIST PUNCHING SHEAR CHECK RESULTS MEMBERS 101 TO 121

Explanation The List Code Check Results Command outputs previously computed steel design select/check code or check punching shear results. LIST CODE CHECK RESULTS The most recently computed code check results for the members that have been processed with a previously specified CHECK (Section 2.8, Volume 2A, GTSTRUDL Users Reference Manual) or SELECT (Section 2.6, Volume 2A, GTSTRUDL Users Reference Manual) command are printed. The printed output is the member name; a pass/fail flag(“P” or “F”); section location in current length units measured from the member’s start; load name; code provision name; actual/allowable ratio; and the profile name.

13 - 83

List Code Check Results Command

Steel Code Check Results Output

LIST PUNCHING SHEAR CHECK RESULTS This option prints results for a previously specified check punching shear command (Section 4.4 of the Volume 8). The output for this option is chord member name; joint name (joint connected to the chord); brace name (brace connected to the joint); load name; geometry type; provision name; highest actual/allowable; pass or fail status; and the profile name. LIST ALL CHECK RESULTS This command prints both code check and punching shear check results. Note: Code check and punching shear results are stored at the time the CHECK, SELECT, or CHECK PUNCHING SHEAR command is processed. If you change the structure (geometry, loadings, profiles, etc.), you must re-issue the appropriate CHECK, SELECT, or CHECK PUNCHING SHEAR command to update the stored results.

13 - 84

Steel Code Check Results Output

List Code Check Results Command

13.13 The CALCULATE PRESSURE Command

⎧X ⎫ ⎪ ⎪ CALCULATE PRESSURE PLANE ⎨ Y ⎬ (EQUAL) v1 ((PLANE) TOLERANCE v2) ⎪Z ⎪ ⎩ ⎭ ((PLANE) ANGLE (TOLERANCE) v3 ) (ELEMENTS list) ((SHOW) CALCS) (SUMMARY (ONLY)) where: v1

=

Global coordinate value of specified Global plane

v2

=

optional value of plane tolerance; element nodes must lie within this distance to be considered planar. Default is 2 inches (5 cm)

v3

=

optional value of normal angle; planar elements or selected element face normals must lie within this many angular units of the specified global axis to be considered in the plane. Default is 5 degrees

list

=

a list of finite element names for which to calculate pressure values. If a list is not given, all planar elements and faces of 3D elements on the plane will be included.

Example UNITS FT CALCULATE PRESSURE PLANE Y 13.3 PLANE TOL 0.1 ELEMENTS 101 TO 110 SHOW CALCS SUMMARY

Explanation CALCULATE PRESSURE will calculate and output a calculated pressure value based on the spring force and the tributary area for each joint to which the specified finite elements are incident and to which a spring is connected. This command approximates the pressure felt by a continuous supporting material, such as soil under a foundation or concrete bearing surface supporting a base plate. The sign of the reported pressure is the same sign as the reaction in the specified global X, Y, or Z direction. This corresponds to a positive pressure for a base plate at the bottom of a column under compression. 13 - 85

List Code Check Results Command

Steel Code Check Results Output

Only joints to which finite elements are incident can report a pressure. Pressure is calculated only for spring forces in linear elastic support springs (KFX, KFY or KFZ) created with the JOINT RELEASES command (Section 7.3 in this Analysis Guide), or nonlinear spring elements (Section 2.5.3.1, Volume 3, GTSTRUDL User Reference Manual). Therefore, joints with a fixed support in the direction specified will not have a pressure. Elastic springs (KFX, KFY or KFZ) should not be rotated with the TH option in the JOINT RELEASES command. Nonlinear spring elements should not be rotated with ORIENTATION option when they are created. When the CALCULATE PRESSURE command is issued, a list of elements (the specified list or all elements or faces in the specified plane) is examined and all incident joints are determined. These joints must lie within the PLANE TOLERANCE and ANGLE TOLERANCE of the specified plane. Each element type (SBHQ6, etc.) is then determined. If 3D elements are included, the appropriate face is chosen. For each planar element or appropriate 3D element face, a set of tributary area distribution factors is determined. These distribution factors depend on the element type and joint coordinates, and correspond to the way mass is distributed for the element type. Triangular elements or faces will have tributary area distribution factors of 1/3, 1/3, and 1/3 regardless of the joint coordinates of the joints on which they are incident. Important Note: Do not use the ELEMENT list to list the names of finite elements that are only a portion of a finite element mesh representing a single plate or foundation, since the reported pressure for a joint on which a listed element is incident, but which also has one or more other incident elements not in the list, will be incorrect due to incorrect tributary area calculations. The pressure is calculated by the following process: 1.

For each joint on which the list of finite elements is incident, determine the tributary area for that joint from each such finite element, and then sum the tributary areas for each such finite element to obtain a total tributary area for that joint. SHOW CALCS will detail this process.

2.

Sum the elastic spring reaction (if any) and nonlinear spring force (if any) to obtain a total force at each such joint for each currently active load condition.

3.

For each currently active load condition, divide the total force at each such joint by the total tributary area of the joint to determine the pressure at the joint for this load condition.

13 - 86

Steel Code Check Results Output

List Code Check Results Command

The CALCULATE PRESSURE command options are: PLANE TOLERANCE: All joints must lie within this distance of the specified global plane. The default value is 2 inches (5 cm). Note that the areas calculated for each element or face is a projected area in the specified global plane. ANGLE TOLERANCE: All joints in the spring plane (all nodes for 2D elements or the appropriate face for 3D elements) must lie within this tolerance of the specified direction. The default is 5 degrees (0.087 radians). Note that the areas calculated for each element or face is a projected area in the specified global plane. SHOW CALCS: Print the contribution of all incident elements to the tributary area for each joint. SUMMARY (ONLY): Print a summary for each joint or load and an overall summary for all joints and loads. The ONLY option suppresses the individual pressure output and prints only the summaries. ELEMENTS list: Calculate pressure values only for the joints on which the specified finite elements are incident. This option is included to allow processing of a single pressure area in a larger model (see the "Important Note" above). For example, a model may contain more than one column base plate on the plane Y = 0. This option would allow you to calculate the pressures for a single base plate instead of all the base plates in a single output. The finite element types for which the CALCULATE PRESSURE command will work are the following: 2D Plate bending: CPT, BPHT, BPR, BPHQ, IPBQQ 2D Plate: SBCT, SBCR, SBHQ, SBHQCSH, SBHT, SBHT6, SBHQ6 3D Tridimensional: TRIP, IPLS, IPQS, IPSL, IPSQ Output from the CALCULATE PRESSURE command will respect the BY LOADING, BY JOINT, DECIMAL, and FIELD options of a previously specified OUTPUT command (Section 13.2). Section 2.1.12.19 in Volume 3 of the GTSTRUDL User Reference Manual contains more details and examples.

13 - 87

List Code Check Results Command

Steel Code Check Results Output

Blank Page

13 - 88

Output

14.

Scope Environment Graphical Display Commands

Scope Environment Graphical Display Commands Since the Scope Environment is being phased out of GTSTRUDL (i.e., the GTMenu graphical User Interface is the primary graphics for GTSTRUDL), a detailed description of the Scope Environment is no longer provided in the User Documentation for GTSTRUDL 26 and later versions The use of GTMenu is described in the tutorials in the GTSTRUDL User Guide: Getting Started, and in the GTSTRUDL Release Guide, Volume 2.

14 - 1

Scope Environment Graphical Display Commands

Blank Page

14 - 2

Output

Dynamic Analysis

15.

Dynamic Analysis Commands

Linear Dynamic Analysis The GTSTRUDL User Reference Manual should be referred to for a more in-depth description of the details of both linear and nonlinear dynamic analysis commands in GTSTRUDL. This Chapter describes the more frequently used commands to perform linear dynamic analysis, output dynamic analysis results, and combine dynamic analysis results with static analysis results as follows: Description

Commands 15.1 Summary of Features

Summary of dynamic analysis features

15.2 Dynamic Data

Specify additional information required for dynamic analysis

15.3 Dynamic Analysis

Perform various dynamic analysis calculations

15.4 Dynamic Results Computation

Perform structure dynamic response calculations

15.5 Dynamic Data and Dynamic Analysis Results Output

Output dynamic data and results of dynamic analysis and structure dynamic response calculations

15.6 Examples

Example Sequences of Dynamic Analysis Commands

15 - 1

Dynamic Analysis Commands

15.1

Dynamic Analysis

Summary of Features GTSTRUDL performs linear dynamic analysis of frame and finite element structures. The types of dynamic analyses performed are as follows: 1.

Eigenvalue Analysis for the computation of natural frequencies and mode shapes performed by any of the following three Eigen solution procedures: LANCZOS (referred to as GTLANCZOS and GTSELANCZOS in GTSTRUDL) SUBSPACE ITERATION HOUSEHOLDER TRIDIAGONALIZATION

2.

Response Spectrum Analysis for earthquake loadings. Modal combinations may be performed by any one or combination of the following methods: RMS: PRMS:

Root Mean Square or Square Root of the Sum of the Squares Peak Root Mean Square (absolute value of the peak modal response, plus the square root of the sum of the squares of the remaining modal responses) ABS SUM: Absolute Sum CQC: Complete Quadratic Combination NRC GRP: Nuclear Regulatory Commission Grouping Method NRC TPM: Nuclear Regulatory Commission Ten Percent Method NRC DSM: Nuclear Regulatory Commission Double Sum Method Gupta Method: Sections 1.3.1 and 1.5.1 of NRC Regulatory Guide 1.92, Revision 2 3.

Transient Time History Analysis using modal superposition and direct integration of the equations of motion

4.

Steady State Analysis for harmonic loads

5.

Maximum Response Harmonic Analysis to compute peak steady state response

In order to perform a dynamic analysis, the finite element model must be defined in a manner similar to that which is defined for a static analysis, and then additional dynamic data, dynamic analysis requests, and output requests, must be provided. Figure 15.1-1 shows a flow chart which summarizes the overall process of static and dynamic analysis, and subsequent frame design.

15 - 2

Dynamic Analysis

Figure 15.1-1

Dynamic Analysis Commands

Overview of General Static and Dynamic Frame and Finite Element Analysis, and Frame Design

15 - 3

Dynamic Analysis Commands

Dynamic Analysis

For example, the finite element model, additional dynamic data, dynamic analysis requests, and dynamic result display are described and requested as follows: 1. 2. 3. 4. 5. 6. 7. 8.

9.

Geometry (joint coordinates) Topology (member and finite element incidences) Support boundary conditions Member and finite element boundary conditions Material properties Member and finite element properties Dynamic data (Table 15.2-1) Structure mass and damping Dynamic loadings Dynamic analysis (Tables 15.3-1 and 15.4-1) Dynamic analysis control parameters Rayleigh Ritz approximate frequency analysis Eigen solution for natural frequencies and mode shapes Dynamic participation factors Response spectrum analysis (Including Missing Mass, Base Shear, and Shear Wall Analysis calculations) Transient time history analysis Create pseudo static loading results from dynamic analysis results Dynamic analysis output (Table 15.5-1) Dynamic data output Eigen solution results output Response spectrum analysis results output Transient analysis results output

This Chapter describes the more commonly used commands provided by GTSTRUDL to perform dynamic analysis, output dynamic analysis results, and combine dynamic analysis results with static analysis results as follows: 15.2 Dynamic Data Commands 15.2.1 15.2.2 15.2.3 15.2.4 15.2.5 15.2.6 15.2.7 15.2.8 15.2.9 15.2.10 15.2.11 15.2.12

INERTIA OF JOINTS Command MEMBER ADDED INERTIA Command DAMPING RATIO and DAMPING PERCENT Commands STORE TIME HISTORY Command STORE RESPONSE SPECTRUM Command CREATE TIME HISTORY Command CREATE RESPONSE SPECTRUM Command DELETE TIME HISTORY and DELETE RESPONSE SPECTRUM Commands TRANSIENT LOADING with JOINT LOADS Command TRANSIENT LOADING with SUPPORT ACCELERATION Command RESPONSE SPECTRUM LOADING with SUPPORT ACCELERATION Command and the MODE FACTOR Gupta Method FORM STATIC EARTHQUAKE LOAD Command - Automatic Generation of Static Equivalent Earthquake Loads ( Section 3.3.3.2.C of NEHRP Guidelines for the Seismic Rehabilitation of Buildings FEMA Publication 273) 15 - 4

Dynamic Analysis

15.2.13 15.2.14

Dynamic Analysis Commands

FORM UBC97 LOAD Command -- Automatic Generation of Static Seismic Loads According to 1997 UBC FORM IS1893 STATIC SEISMIC LOAD Command - Automatic Generation of Static Earthquake Loads According to the Indian Standard IS 1893 Seismic Code

15.3 Dynamic Analysis Commands 15.3.0 15.3.1 15.3.2 15.3.3 15.3.4 15.3.5 15.3.6 15.3.7

15.3.8 15.3.9 15.3.10

ACTIVE SOLVER Command EIGEN PARAMETERS Command DYNAMIC PARAMETERS Command LIST RAYLEIGH LOADING Command DYNAMIC ANALYSIS EIGENVALUES Command LIST DYNAMIC PARTICIPATION FACTORS INACTIVE/ACTIVE MODES Command PERFORM RESPONSE SPECTRUM ANALYSIS Command 15.3.7.1 PERFORM RESPONSE SPECTRUM ANALYSIS Command 15.3.7.2 LIST RESPONSE SPECTRUM SPECTRAL ACCELERATIONS and LIST RESPONSE SPECTRUM PARTICIPATION FACTORS Commands (for Base Shear) 15.3.7.3 Base Shear Calculations 15.3.7.4 Designing Shear Walls Based on a Response Spectrum Earthquake Analysis 15.3.7.5 FORM MISSING MASS LOAD Command 15.3.7.6 Extended Example: RESPONSE SPECTRUM ANALYSIS, FORM MISSING MASS LOAD, and Base Shear Calc. PERFORM TRANSIENT ANALYSIS Command PERFORM PHYSICAL ANALYSIS Command PERFORM NUMBER OF MODES COMPUTATION Command

15.4 Dynamic Results Back Substitution Computation Commands 15.4.1 15.4.2 15.4.3

COMPUTE RESPONSE SPECTRUM Results Command COMPUTE TRANSIENT Results Command CREATE PSEUDO STATIC LOADING Command

15.5 Dynamic Data and Analysis Results Output Commands 15.5.1 15.5.2 15.5.3 15.5.4 15.5.5 15.5.6 15.5.7

PRINT DYNAMIC Data Command PLOT DYNAMIC FILE Command NORMALIZE EIGENVECTORS Command LIST DYNAMIC Eigen-Results and Mass Summary Command OUTPUT MODAL CONTRIBUTIONS Command LIST RESPONSE SPECTRUM Results Command LIST TRANSIENT Results Command

15.6 Example Sequences of Dynamic Analysis Commands

15 - 5

Dynamic Data Commands

15.2

Dynamic Analysis

Dynamic Data Commands This Section describes the more frequently used commands provided by GTSTRUDL to define additional information required for dynamic analysis as follows: 15.2.1

INERTIA OF JOINTS Command

15.2.2

MEMBER ADDED INERTIA Command

15.2.3

DAMPING RATIO and DAMPING PERCENT Commands

15.2.4

STORE TIME HISTORY Command

15.2.5

STORE RESPONSE SPECTRUM Command

15.2.6

CREATE TIME HISTORY Command

15.2.7

CREATE RESPONSE SPECTRUM Command

15.2.8

DELETE TIME HISTORY and DELETE RESPONSE SPECTRUM Commands

15.2.9

TRANSIENT LOADING with JOINT LOADS Command

15.2.10

TRANSIENT LOADING with SUPPORT ACCELERATION Command

15.2.11

RESPONSE SPECTRUM LOADING with SUPPORT ACCELERATION Command and the MODE FACTOR Gupta Method

15.2.12

FORM STATIC EARTHQUAKE LOAD Command - Automatic Generation of Static Equivalent Earthquake Loads ( Section 3.3.3.2.C of NEHRP Guidelines for the Seismic Rehabilitation of Buildings - FEMA Publication 273)

15.2.13

FORM UBC97 LOAD Command -- Automatic Generation of Static Seismic Loads According to 1997 UBC

15.2.14

FORM IS1893 STATIC SEISMIC LOAD Command - Automatic Generation of Static Earthquake Loads According to the Indian Standard IS 1893 Seismic Code

Table 15.2-1 contains a brief description of the commands for the specification of dynamic data. 15 - 6

Dynamic Analysis

Dynamic Data Commands

Table 15.2-1 Commands for Specification of Dynamic Data Command Name

INERTIA OF JOINTS

MEMBER ADDED INERTIA

Brief Description Define mass by: 1. Automatic calculation of mass of members and finite elements 2. Direct specification of mass corresponding to specific dynamic degrees-of-freedom 3. Automatic calculation of mass based on static loading concentrated joint forces Automatic calculation of member mass based on specified concentrated and uniformly distributed member masses.

FORM MISSING MASS LOAD (Section 15.3.7.5)

Computes a new independent static loading condition consisting of joint load components that reflect the total mass associated with all modes ignored in a prior Response Spectrum Analysis.

DAMPING RATIO DAMPING PERCENT

Specification of modal damping as a percent of critical damping

STORE TIME HISTORY

Input force or acceleration versus time loading values, and store the values on disk in the user data set (USERDAT) for future use.

STORE RESPONSE SPECTRUM

CREATE TIME HISTORY

Input response spectrum loading values (i.e., maximum displacement, velocity, or acceleration values versus frequency or period), and store the values on disk in the user data set (USERDAT) for future use. Create acceleration versus time loading values from the results of a prior dynamic transient analysis, and store the values on disk in the user data set (USERDAT) for future use.

CREATE RESPONSE SPECTRUM

Create displacement versus frequency response spectrum loading values from existing acceleration time history files, and store the values on disk in the user data set (USERDAT) for future use.

DELETE TIME HISTORY DELETE RESPONSE SPECTRUM

Delete a stored time history or response spectrum file from the user data set (USERDAT)

15 - 7

Dynamic Data Commands

Dynamic Analysis

Table 15.2-1 (Continued) Commands for Specification of Dynamic Data

Command Name

Brief Description

TRANSIENT LOADING JOINT LOADS INITIAL CONDITIONS INTEGRATE FROM/TO/AT END (OF TRANSIENT LOADING)

Define a dynamic transient loading condition consisting of: - Force and/or moment joint load values taken from a previously STOREd force/moment versus time loading file - Force and/or moment joint load values versus time as a Sine/Cosine function - Optional structure initial conditions - Initial, final, and increment time values to be used in a subsequent dynamic time history analysis

TRANSIENT LOADING SUPPORT ACCELERATION INITIAL CONDITIONS INTEGRATE FROM/TO/AT END (OF TRANSIENT LOADING)

Define a dynamic transient loading condition consisting of: - Support translation acceleration values taken from a displacement/velocity/acceleration versus time loading file that was previously STOREd - Support translation acceleration values versus time as a Sine/Cosine function - Optional structure initial conditions - Initial, final, and increment time values to be used in a subsequent dynamic time history analysis

RESPONSE SPECTRUM LOADING SUPPORT ACCELERATION TRANSLATION X/Y/Z FILE 'name' END (OF RESPONSE SPECTRUM LOADING)

FORM STATIC LOAD

Define a dynamic response spectrum loading condition consisting of: - Response spectrum values taken from a previously STOREd response spectrum file

Automatic Generation of Static Equivalent Earthquake Loads ( Section 3.3.3.2.C of NEHRP Guidelines for the Seismic Rehabilitation of Buildings - FEMA Publication 273)

15 - 8

Dynamic Analysis

Dynamic Data Commands

15.2.1 INERTIA OF JOINTS Command (1) Automatic Computation of Lumped or Consistent Mass:

(2) Direct Specification of Lumped Mass Using an Individual Format:

(3) Direct Specification of Lumped Mass Using a Tabular Format:

list (specs) C C C list (specs)

(4) Direct Specification of Lumped Mass from Static JOINT and MEMBER LOAD Conditions:

15 - 9

Dynamic Data Commands

Dynamic Analysis

where, specs

=

v1

=

Effective fractional member length for computing mass moments of inertia for frame members, values may range from 0. 0 to 1.0. v1 = 0.01 by default.

v2

=

Factor for computing torsional inertia. Values must be greater than 0. v2 = 1/3 by default.

v3

=

Acceleration of gravity in currently active units (default value is 386.08858 inch/sec2 or its equivalent in currently active units).

v4,v5,v6,v7

=

Values for mass, mass moment of inertia, or weight ("Rotational weight" must not be specified. Only “rotational mass” may be specified).

v8

=

decimal value of the mass damping factor that relates the joint inertia values v4 through v7 to corresponding joint mass damping coefficients. v8 is taken as 0.0 if not specified (see Section 15.2.3).

ALL

=

All global directions (i.e., the X, Y, and Z global translation directions).

list

=

List (Section 4.1) of joint names.

load-list

=

List of previously defined static loading condition names.

Example INERTIA OF JOINTS LUMPED UNITS KIPS INERTIA OF JOINTS WEIGHT 1 TO 100 TRANSLATION ALL 1.5 201 TO 300 BY 2, 'ABC' 'AB-3NW' 15 17 TRANSLATION ALL 0.75 INERTIA OF JOINTS FROM LOADS 101 TO 107 ALL DOF

15 - 10

Dynamic Analysis

Dynamic Data Commands

Explanation The inertial properties of the structure are defined by specifying a lumped mass distribution corresponding to all joint degrees-of-freedom throughout the structure. Lumped masses may be automatically computed based on the mass of the structural members and finite elements, and they may be specified as non-structural mass. 1.

Automatic Computation of Lumped or Consistent Mass The INERTIA OF JOINTS LUMPED and INERTIA OF JOINTS CONSISTENT commands specify that lumped masses are to be automatically computed based on the volume and weight density of all currently active structural members and finite elements. The LUMPED option specifies that a diagonal mass matrix is to be computed, while the CONSISTENT option specifies that a mass matrix is to be computed in a manner consistent with the banded form of the global structural stiffness matrix. For multiple Eigen solutions (repeated specification of the DYNAMIC ANALYSIS EIGENSOLUTION command), each specification of the LUMPED or CONSISTENT option will change the type of mass computation without the need for a CHANGES command. Repeated specification of the INERTIA OF JOINTS LUMPED or INERTIA OF JOINTS CONSISTENT is not cumulative. A.

For the LUMPED option for members, mass values are computed as follows: Translation Mass, MT, of a member is computed as one-half of the total mass of the member and is lumped at the ends of the member in the global translation degree-of-freedom directions or,

Bending Rotation Mass, MRB, of a member (i.e., bending rotation mass moment of inertia) is lumped at the ends of the member in the member bending rotation degree-of-freedom directions, where the effective fractional member length v1 (default value of v1 is 0.01) may be specified to control the magnitude of MRB or,

15 - 11

Dynamic Data Commands

Dynamic Analysis

Torsion Rotation Mass, MRT, of a member (i.e., torsion rotation mass moment of inertia) is lumped at the ends of the member in the member torsion rotation degree-of-freedom directions, where the torsional mass scale factor v2 (default value of v2 is 1/3) may be specified to control the magnitude of MRT or, MRT =

v2 m Ip / Ax

where,

dm

=

material mass density (weight density / v3)

Ax

=

member cross-sectional area

L

=

member length

v1

=

fraction of member length (v1 = 0.01 by default)

m

=

total member mass [dm Ax L]

Ip

=

polar moment of inertia (Iy + Iz)

Ax

=

member coss-section area

v2

=

torsional inertia factor (v2 = 1/3 by default)

v3

=

acceleration of gravity in currently active units (default value is 386.08858 inch/sec2 or its equivalent in currently active units)

B.

For the LUMPED option for finite elements, mass values are computed as described in the textbook entitled, Finite Element Analysis in Engineering by K. Bathe (published by Prentice Hall).

C.

For the CONSISTENT option for members and finite elements, mass values are computed as described in the textbook entitled, Finite Element Analysis in Engineering by K. Bathe (published by Prentice Hall).

D.

Availability of lumped and consistent mass for the finite elements described in the GTSTRUDL Finite Element Dictionary (see Section 6.4, Table 6.4-1) are listed in the following Table 15.2.1-1. Diagonal lumped mass matrices are available for all finite elements. Consistent mass matrices are not available for the PSRR or the hybrid elements (i.e., those elements in Table 15.2.1-1 whose consistent mass column is denoted by a “D”). If INERTIA OF JOINTS CONSISTENT is specified for a structure containing hybrid elements, then an element diagonal lumped mass matrix will be computed and used in the place of a consistent banded mass matrix for each hybrid element. 15 - 12

Dynamic Analysis

Dynamic Data Commands

Table 15.2.1-1 Element Mass Matrix Information

ELEMENT

CONSISTENT MASS

LUMPED MASS

BPHQ

D

A

BPHT

D

A

BPP

X

A

BPR

X

A

CPT

X

A

CSTG

X

A

IPBQQ

X

A

IPCQ

X

C

IPLQ

X

C

IPLS

X

C

IPQL

X

C

IPQLQ1

X

C

IPQLQ2

X

C

IPQLQ2B

X

C

IPQLQ3

X

C

(Continued on next page)

15 - 13

Dynamic Data Commands

Dynamic Analysis

Table 15.2.1-1 Element Mass Matrix Information (Continued)

ELEMENT

CONSISTENT MASS

LUMPED MASS

IPQLQ4

X

C

IPQQ

X

C

IPQS

X

C

IPSL

X

C

IPSQ

X

C

LST

X

C

PSHQ

X

B

PSHQCSH

X

B

PSHT

X

B

PSR

X

A

PSRR

0

A

SBCT

X

A

SBCR

X

A

SBHQ

D

A

(Continued on next page)

15 - 14

Dynamic Analysis

Dynamic Data Commands

Table 15.2.1-1 Element Mass Matrix Information (Continued)

ELEMENT

CONSISTENT MASS

LUMPED MASS

SBHQ6

D

A

SBHQCSH

D

A

SBHT

D

A

SBHT6

D

A

TRANS3D

X

C

TRIP

X

C

UTLQ1

X

A

WEDGE15

X

C

Legend for Table 15.2.1-1

0 - Element not used in dynamic analysis X - Consistent mass matrix available A - Conventional mass lumping at translation degrees-of-freedom, and .0001 times that value at rotational degrees-of-freedom if applicable B - Lumped mass matrix formed by summing the columns of the consistent mass matrix C - Lumped mass matrix formed from the consistent mass matrix by using the diagonal terms scaled such that they sum to 2 or 3 times the mass of the element for planar or tridimensional elements, respectively. This technique is applied to elements with translational degrees-offreedom only. D - Lumped mass matrix is used if consistent is specified

15 - 15

Dynamic Data Commands

2.

Dynamic Analysis

Direct Specification of Lumped Mass a.

The INERTIA OF JOINTS MASS or WEIGHT command specifies that additional lumped mass corresponding to specific joint degrees-of-freedom are to be added to the diagonal of the structural mass matrix. If the INERTIA OF JOINTS LUMPED/CONSISTENT is also specified, then the additional specified mass is added to the diagonal mass terms in the LUMPED or CONSISTENT structural mass matrix. Translation mass values corresponding to different joint degrees-of-freedom may be specified. However, the ALL option (i.e., the X, Y, and Z global translation directions) is more often used since mass is not usually direction dependent. Additional mass may be specified either in the form of weight (force units), or mass (force-time2/length and force-length-time2 units) . In the case of weight, only mass associated with translation degrees-of-freedom may be specified. In this case, the value of the acceleration of gravity (v3) which is used to convert weight to mass may also be specified (where the default value is 386.08858 in/sec2). Mass associated with rotation degrees-offreedom may not be specified using the WEIGHT option. Mass moments of inertia values which are specified at rotation degrees-of-freedom are assumed to have the units of force-length-time2. Mass moments of inertia should only be input under the MASS option and not the WEIGHT option.

b.

The INERTIA OF JOINTS FROM LOAD command causes the immediate computation of lumped mass from both applied concentrated translation (FORCE) JOINT and MEMBER LOADS, and applied uniform and linear distributed translation (FORCE) MEMBER and FINITE ELEMENT LOADS (but not rotation (MOMENT) joint, member, or finite element loads) in the specified loading conditions. This option converts the absolute value of translational joint forces and, in the case of member and finite element force loads, the absolute value of the translational fixed end force components contained in a static loading to their translational mass equivalents. Member temperature loads, member distortion loads, and joint temperature loads are not converted. Mass is computed by dividing the absolute value of the JOINT, MEMBER, and FINITE ELEMENT FORCES (in the internal GTSTRUDL units of pounds) by the default acceleration of gravity which is 386.08858 inch/sec2. The INERTIA OF JOINTS FROM LOAD command results in the immediate computation of mass by accumulating the mass converted from the translation forces defined by JOINT, MEMBER and finite ELEMENT LOADS contained in the specified loading conditions. Thus any loading specified must correspond to a previously defined static loading condition.

15 - 16

Dynamic Analysis

Dynamic Data Commands

In addition: (i)

In the case of static JOINT LOADS, CONCENTRATED translation forces are converted into mass in either the specified “ALL” joint global translation degree-of-freedom directions (i.e., global X, Y, and Z), or in the “SAME” global degree-of-freedom directions as specified in the JOINT LOADS commands.

(ii)

In the case of static MEMBER and ELEMENT LOADS, CONCENTRATED translation forces, and UNIFORM and LINEAR, GLOBAL and GLOBAL PROJECTED distributed translation forces, are converted into mass in either the specified “ALL” global translation degree-of-freedom directions (i.e., global X, Y, and Z), or in the “SAME” global degree-of-freedom directions (i.e., global X, Y, or Z, or local x, y, or z), as specified in the MEMBER and ELEMENT LOADS commands.

Converted joint load mass data can be listed by the PRINT DYNAMIC JOINT INERTIA command, and converted member and finite element added inertia data can be listed by the PRINT DYNAMIC MEMBER ADDED MASS command (Section 15.5).

Important Notes There are several important considerations to note in regard to the INERTIA OF JOINTS command as follows: 5.

In the ADDITIONS mode, any number of INERTIA OF JOINTS commands may be given, where all mass specified is accumulated (except that repeated specification of the INERTIA OF JOINTS LUMPED or INERTIA OF JOINTS CONSISTENT commands are not cumulative).

6.

There are several restrictions regarding zeroes on the diagonal of the mass matrix. which can be created by the INERTIA OF JOINTS command as follows: a.

If the INERTIA OF JOINTS LUMPED or CONSISTENT is specified, and if each member and finite element has a non-zero weight density, then no zero will appear on the diagonal of the mass matrix, and all three Eigen solvers (i.e., TRIDIAGONALIZATION, SUBSPACE ITERATION, and GTLANCZOS) will run without problem.

b.

If the INERTIA OF JOINTS commands result in one or more zeroes on the diagonal of the mass matrix, the TRIDIAGONALIZATION eigen solver will not operate (i.e., TRIDIAGONALIZATION requires that each dynamic degree-of-freedom must have nonzero mass). In this case, degrees-offreedom that have zero masses must be condensed (see the GTSTRUDL User Reference Manual, Volume 3, Section 2.4.5.1) in order for the TRIDIAGONALIZATION Eigen solver to be used.

15 - 17

Dynamic Data Commands

Dynamic Analysis

c.

If the INERTIA OF JOINTS commands result in one or more zeroes on the diagonal of the mass matrix, the number of modes computed by the SUBSPACE ITERATION and GTLANCZOS must be less than the number of degrees-of-freedom that have non-zero mass (i.e., the rank of the mass matrix).

d.

If a direct integration (PHYSICAL) analysis is to be performed, each dynamic degree-of-freedom must have non-zero mass only if initial conditions are specified, since a mass matrix decomposition is then required.

CHANGES Mode In the CHANGES mode, mass specified by the INERTIA OF JOINTS command replaces all mass previously specified or accumulated at each relevant degree-offreedom. The format of the INERTIA OF JOINTS command is the same in both the ADDITIONS and CHANGES mode.

DELETIONS Mode

where, list

=

list of joint names

In the DELETIONS mode, previously specified LUMPED or CONSISTENT mass can be deleted, while all mass associated with specified joints can also be deleted. New mass specifications could then be given for these joints in the ADDITIONS mode.

15 - 18

Dynamic Analysis

Dynamic Data Commands

Extended Examples (1)

UNITS KIPS INERTIA OF JOINTS LUMPED INERTIA OF JOINTS WEIGHT 1 TO 10 TRANSLATION ALL 10 11 TO 20 TRANSLATION ALL 20 A diagonal lumped mass matrix will be formed from contributions from all currently active members and finite elements. In addition, 10 Kips of weight are added to all translation degrees-of-freedom (i.e., global X, Y, and Z directions) at joints 1 to 10, and 20 Kips of weight are added to all translation degrees-offreedom at joints 11 to 20. The added weight will be automatically converted to mass by dividing the added weight by the acceleration of gravity.

(2)

UNITS POUNDS SECONDS INCHES LOADING 1 JOINT LOADS 'A' 'B' FORCE X -1000. INERTIA OF JOINTS FROM LOAD 1 ALL DOF PRINT DYNAMIC JOINT INERTIA The mass of the structure is computed from the joint loads previously defined in static loading 1, where the mass is specified to act in all global degree-offreedom directions. The PRINT command will show that joints 'A' and 'B' have translation mass of 2.59 pound-sec2/inch (1000.0 pounds / 386.08858 inch/sec2 = 2.59 pound-sec2/inch) in all global translation directions (i.e., global X, Y, and Z directions).

(3)

UNITS POUNDS SECONDS INCHES LOADING 1 JOINT LOADS 'A' 'B' FORCE X -1000. Y -500. INERTIA OF JOINTS FROM LOAD 1 ALL DOF PRINT DYNAMIC JOINT INERTIA The mass of the structure is computed from the joint loads previously defined in static loading 1, where the mass is specified to act in all global degree-offreedom directions. The PRINT command will show that joints 'A' and 'B' have translation mass of 2.59 pound-sec2/inch ([1000+500.0] pounds / 386.08858 inch/sec2 = 3.885 pound-sec2/inch) in all global translation directions (i.e., global X, Y, and Z directions).

(4)

UNITS POUNDS SECONDS INCHES 15 - 19

Dynamic Data Commands

Dynamic Analysis

LOADING 1 JOINT LOADS 'A' 'B' FORCE X -1000. MEMBER LOADS 100 TO 200 BY 2 FORCE Y GLOBAL UNIFORM W -100 LOADING 2 MEMBER LOADS 101 TO 201 BY 2 FORCE Y GLOBAL UNIFORM W -50 INERTIA OF JOINTS LUMPED INERTIA OF JOINTS FROM LOADS 1 2 ALL DOF PRINT DYNAMIC JOINT INERTIA PRINT DYNAMIC MEMBER ADDED MASS The mass of the structure is the accumulated mass computed from the joint and member loads previously defined in static loadings 1 and 2. (5)

UNITS MTONS INERTIA OF JOINTS WEIGHT 1 TO 20 TRANS X 2.5 Y 2.5 INERTIA OF JOINTS WEIGHT 30 TO 50 TRANS X 3.0 Y 3.0 Mass in weight units of MTONS is specified for the global X and Y translation degrees-of-freedom at joints 1 to 20 and 30 to 50.

(6)

UNITS MTONS INERTIA OF JOINTS WEIGHT 1 TO 20 TRANS X 2.5 Y 2.5 30 TO 50 TRANS X 3.0 Y 3.0 This example is equivalent to the previous example (5), but specified in a different syntax.

(7)

UNITS KIPS SECONDS INCHES INERTIA OF JOINTS LUMPED INERTIA OF JOINTS WEIGHT GRAVITY 250. 1 , 3 , 5 TO 12 TRANS ALL 200. 'A' 'B' TRANS ALL 300. DYNAMIC ANALYSIS EIGENVALUE $ #1 LIST DYNAMIC EIGENVALUE INERTIA OF JOINTS CONSISTENT DYNAMIC ANALYSIS EIGENVALUE $ #2 LIST DYNAMIC EIGENVALUE 15 - 20

Dynamic Analysis

Dynamic Data Commands

DELETIONS INERTIA OF JOINTS ALL INERTIA OF JOINTS CONSISTENT ADDITIONS INERTIA OF JOINTS LUMPED DYNAMIC ANALYSIS EIGENVALUE $ #3 LIST DYNAMIC EIGENVALUES The mass matrices for the dynamic analyses are computed as follows: Analysis #1: members and finite elements lumped mass + additional weight Analysis #2: members and finite elements consistent mass + additional weight Analysis #3: members and finite elements lumped mass only The "additional" weight is input in Kip units and will be converted to mass using the specified acceleration of gravity as 250.0 in/sec2. Note that weight density used to automatically compute lumped and consistent mass of members and finite elements will also be converted to mass density using the specified acceleration of gravity of 250.0 in/sec2.

15 - 21

Dynamic Data Commands

Dynamic Analysis

15.2.2 MEMBER ADDED INERTIA Command Additional non-structural member mass may be defined by the MEMBER ADDED INERTIA command as concentrated or uniformly distributed MASS or WEIGHT (where WEIGHT is the default) applied to members (not finite elements) in the members’ local reference system directions. However, this command is no longer needed since the INERTIA OF JOINTS FROM LOADS command (Section 15.2.1) will compute additional non-structural mass for both members and finite elements from previously defined static loading conditions. This command is described in more detail in the GTSTRUDL User Reference Manual, Volume 3.

15 - 22

Dynamic Analysis

Dynamic Data Commands

15.2.3 DAMPING RATIO and DAMPING PERCENT Commands Damping in GTSTRUDL may be specified in a variety of forms including: !

Rayleigh Damping Rayleigh damping is used in direct integration transient analyses where the effects of damping are to be included via a global system damping matrix. [C]

=

3ai [ki] + 3bi [mi]

where, [C] [ki] ai [mi] bi

= = = = =

global system damping matrix, stiffness of ith member, finite element, support spring, Rayleigh damping factor for [ki], mass of ith member, finite element, added joint mass, Rayleigh damping factor for [mi],

and where summation is performed over all members and finite elements, support springs, and added joint masses. !

Composite Modal Damping Composite modal damping can be used in mode superposition analysis where the modal damping ratios vary on an entity-by-entity basis. The term “entity” in this context refers to frame and truss members, finite elements, support springs, and added joint masses. Composite modal damping provides for the computation of modal damping ratios as a stiffness/mass weighted average of member modal damping ratios. Stiffness weighted average modal damping ratio: rj

=

{hj}T[C]{hj} / wj2

(where [C] = 3ai [ki]),

Mass weighted average modal damping ratio: rj

=

{hj}T[C]{hj}

(where [C] = 3bi [mi]),

15 - 23

Dynamic Data Commands

Dynamic Analysis

where, ai, bi = rj {hj} wj [C]

= = = =

damping ratios for the ith member (% of critical damping) (See ASCE Manual 4-98 for damping values for earthquake loads) computed modal damping ratio for the jth mode mode shape vector for the jth mode frequency (rad/sec) of the jth mode global system damping matrix, computed as above wherein ai and bi are modal damping ratios rather than Rayleigh damping factors

!

Direct specification of global system damping matrix [C] for direct integration.

!

Direct specification of modal damping ratios for response spectrum analysis and mode superposition transient analysis.

This Section will describe the direct specification of the modal damping ratios and percent of critical damping, while the GTSTRUDL User Reference Manual, Section 2.4.3.4, should be referred to for a complete description of all damping specification options.

where, v1, v2, ..... , vn

=

modal damping RATIO (or PERCENT of critical damping) used in response spectrum and modal superposition transient dynamic analysis. Values of vi must be decimal numbers with decimal points.

i1, i2, ..... , in

=

integer numbers indicating the number of modes in ascending order for which its corresponding modal damping value vj is assigned. The default value is 1 mode.

Example DAMPING PERCENTS 5.0 1, 3.5 4, 3.0 5 2.0 50

15 - 24

Dynamic Analysis

Dynamic Data Commands

Explanation The DAMPING command is used to specify the modal damping factors in the form of either ratios (in the range 0.0 to 1.0) or percent of critical damping (0.0% to 100.0%). These modal damping factors can be specified for any number of modes, and they are used in response spectrum and mode superposition transient analysis (as well as in Steady State and Maximum Response Harmonic Analysis as described in the GTSTRUDL User Reference Manual). If more modes are used in a response spectrum or mode superposition transient dynamic analysis than the modes specified in the DAMPING command, then the damping factors are assumed to have values of 0.0 for the modes not specified.

CHANGES and DELETIONS Modes The DAMPING command is mode independent. Whenever specified, all previously specified damping factors are deleted and replaced by the damping factors specified in the current DAMPING command.

Extended Example

MODE 1 6 11

INERTIA OF JOINTS LUMPED EIGEN PARAMETERS SOLVE USING GTLANCZOS NUMBER OF MODES 15 PRINT MAX END DAMPING PERCENTS 2.0 3, 3.0 5, 5.0 7 $ 15 modes specified PRINT DYNAMIC MODAL DAMPING RATIO MODE RATIO MODE RATIO MODE RATIO 0.020 2 0.020 3 0.020 4 0.030 0.030 7 0.030 8 0.030 9 0.050 0.050 12 0.050 13 0.050 14 0.050

MODE 5 10 15

MODE

DAMPING RATIOS .03 2, .02 3, 1.5 4 $ 9 modes specified PRINT DYNAMIC MODAL DAMPING RATIO MODE RATIO MODE RATIO MODE RATIO

MODE RATIO

1 6 11

0.030 0.015 0.000

5 10 15

2 7 12

0.030 0.015 0.000

3 8 13

15 - 25

0.020 0.015 0.000

4 9 14

0.020 0.015 0.000

RATIO 0.030 0.050 0.050

0.020 0.000 0.000

Dynamic Data Commands

Dynamic Analysis

15.2.4 STORE TIME HISTORY Command

v1 t1 v2 t2 v3 t3 ..............vi ti .................................................. ........................... vn-1 tn-1 vn tn

Elements: ‘name’ =

file name (up to 8 characters) which is associated with the time history

s

=

scale factor applied to all values vi at times ti ( vi x s is stored at time ti). If omitted, s is taken as 1.0.

v1,...,vn

=

values of the FORCE or ACCELERATION at the specified time points.

t1,...,tn=

corresponding time points.

Example UNITS KIPS SECONDS STORE TIME HISTORY FORCE TRANSLATION ‘FORCE-X’ 0.0 0.0 2.0 0 .2 -1.5 0.4 1.5 0.6 -1.0 0.7 1.0 0.8 -0.5 0.9 0.5 1.0 0.0 1.1 END TIME HISTORY

Explanation The STORE TIME HISTORY command is used to both define, and to store for future use in a file called ‘name’, dynamic time dependent loading function data in terms of (FORCE, ACCELERATION, VELOCITY, or DISPLACEMENT vs. Time) data pairs (vi ti). The data pairs may be continued to subsequent lines of input, except that data pairs may not be split between two lines of input. The FACTOR s is used as a scale factor to multiply the FORCE, ACCELERATION, VELOCITY, or DISPLACEMENT values vi.

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Dynamic Analysis

Dynamic Data Commands

The STORE TIME HISTORY command may be given during the same GTSTRUDL job in which the transient dynamic loading data file ‘name’ is referenced in a subsequent TRANSIENT LOADING command (Sections 15.2.9 and 15.2.10), or it may be given in a GTSTRUDL job for the sole purpose of storing the dynamic loading data file permanently for use in subsequent GTSTRUDL jobs. Note that a computed acceleration time history may also be stored for future use by using the CREATE TIME HISTORY command described in Section 15.2.6. Note again that the STORE TIME HISTORY and CREATE TIME HISTORY commands must appear before (i.e., in the same execution of GTSTRUDL or in a prior execution of GTSTRUDL where the time history file ‘name’ was permanently saved in a USERDAT file) the TRANSIENT LOADING command (Sections 15.2.9 and 15.2.10) in which the time history data file is referenced. The type of time history (i.e., FORCE, ACCELERATION, VELOCITY, or DISPLACEMENT) must be specified in order to make the proper units of conversion using the currently active units. TIME HISTORY loading data may be saved permanently in the Userdat file. This may be done by checking the Userdat file box**, and entering the name of the Userdat file by typing or by using the browse feature. In the example below, the Userdat file called “JobData.ds” is as: D:\User\JobData.ds. The Read Only option should not be checked when running the job which stores the TIME HISTORY loading data in the JobData.ds file. **NOTE:

A far more powerful means of controlling access to the Userdat file is to use the OPEN USERDATA FILE command (Section 4.16).

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Dynamic Data Commands

Dynamic Analysis

The stored time history may later be deleted from the USERDAT file using the DELETE command described in Section 15.2.8. For convenience, the N-S component of the 1940 El Centro Earthquake ACCELERATION vs. Time record is permanently stored in the GTSTRUDL Subsystem Data File (which is supplied with GTSTRUDL along with steel section tables and other related data) under the file name ‘ELCENTRO’. The file name ‘ELCENTRO’ need only be referenced in a TRANSIENT LOADING command in order to be used. For example: TRANSIENT LOADING 100 SUPPORT ACCELERATION TRANSLATION X FILE ‘ELCENTRO’ C C The TIME HISTORY dynamic loading data file may be subsequently plotted by using the PLOT DYNAMIC FILE command, or printed by using the PRINT DYNAMIC FILE command, as described in Sections 15.5.1 and 15.5.2.

Extended Example UNITS KIPS SECONDS STORE TIME HISTORY FORCE TRANSLATION ‘FORCE-X’ 0.0 0.0 2.0 0 .2 -1.5 0.4 1.5 0.6 -1.0 0.7 1.0 0.8 -0.5 0.9 0.5 1.0 0.0 1.1 The above command is used to input the following translation force time history:

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Dynamic Analysis

Dynamic Data Commands

15.2.5 STORE RESPONSE SPECTRUM Command

R 11 f 11 R 12 f 12 . . . . . . . . . . . . ......................... . . . . . . . . . . . . . . . . . . . . R 1n f 1n C C C

R i1 f i1 R i2 f i2 . . . . . . . . . . . . ......................... . . . . . . . . . . . . . . . . . . . . R in f in ( END (OF RESPONSE SPECTRUM ) ) Elements: ‘name’

=

name of the file (up to 8 characters) in which the response spectrum curve data are located

15 - 29

Dynamic Data Commands

Dynamic Analysis

v 1,...,v i

=

the ratios or percentages of critical damping for the corresponding response spectrum curves

s 1,...,s i

=

scale factors applied to all values R kj of the corresponding response spectrum curve (R kj x s k). If omitted, sk is taken as 1.0.

R I1,...,R im =

the maximum Displacement, Velocity, or Acceleration response spectrum values in current active units. The first response value in each line of input IMPORTANT NOTE: must have a decimal point.

f i1,...,f im

the value of the Frequency or Period corresponding to R i1,...,R im in current active units (unless the NATURAL option is specified causing the angular units to be CYCLES).

=

Example UNITS FT SECONDS CYCLES STORE RESPONSE SPECTRUM VELOCITY LINEAR vs PERIOD LINEAR ‘QUAKE’ DAMPING 0.00 $ 0% critical damping 0.60 0.2 1.0 1.1 1.3 2.2 1.4 3.0 1.45 3.8 DAMPING 0.02 $ 2% critical damping 0.35 0.2 0.8 1.1 1.0 2.2 1.15 3.0 1.2 3.8 DAMPING 0.03 $ 3% critical damping 0.20 0.2 0.6 1.1 0.8 2.2 0.90 3.0 0.9 3.8 END OF RESPONSE SPECTRUM

Explanation A response spectrum curve is a plot of maximum response (DISPLACEMENT, VELOCITY, or ACCELERATION) versus FREQUENCY or PERIOD of a single degreeof-freedom oscillator which has some particular damping, and which is subjected to some particular applied ground motion dynamic load. The plot consists of a series of curves, each associated with a different value of constant damping. An example is shown below as a linear-linear plot of maximum acceleration vs. period.

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Dynamic Analysis

Dynamic Data Commands

The STORE RESPONSE SPECTRUM command is used both to define, and to store for future use in a file called ‘name’, a family of response spectrum curves each corresponding to the same applied ground motion dynamic load, but each corresponding to a different damping value. The response spectrum curves are defined by a specified set of data pairs (R ij f ij). The maximum response data values and the frequency or period data may be given as linear or logarithmic values. The data pairs may be continued to subsequent lines of input, except that data pairs may not be split between two lines of input. The FACTOR sk is used as a scale factor that is applied to all values R kj of the corresponding response spectrum curve (R kj x s k). If omitted, sk is taken as 1.0. The STORE RESPONSE SPECTRUM command must be followed by one or more DAMPING commands, where each DAMPING command is followed by its associated response spectrum data pairs. Any number of damping curves may be input for a response spectrum, and they need not be in any order relative to their damping values. It is not necessary for the frequency or period values to coincide in any way between the curves. Note that no maximum response, or frequency or period, should have a value less than or equal to zero, since this would cause problems with the standard logarithmic interpolation or the conversion of period to frequency. If a zero value is given, however, it will be converted to a ‘small’ (1.E-30) positive number internally. Further, it is not necessary that the actual modal frequencies or periods of the structure coincide with the values stored in the response spectrum curve data. Rather, either linear or logarithmic interpolation between frequency or period values, and linear interpolation between the different damping curves, will automatically be performed. 15 - 31

Dynamic Data Commands

Dynamic Analysis

It is a good practice to place the END OF RESPONSE SPECTRUM command as the last command in the sequence, although it is not required unless the next command begins with the word “DAM....”. The STORE RESPONSE SPECTRUM command may be given during the same GTSTRUDL job in which the response spectrum dynamic loading data file ‘name’ is referenced in a subsequent RESPONSE SPECTRUM LOADING command (Section 15.2.11), or it may be given in a GTSTRUDL job for the sole purpose of storing the response spectrum dynamic loading data file permanently for use in subsequent GTSTRUDL jobs. Note that a computed response spectrum may also be stored for future use by using the CREATE RESPONSE SPECTRUM DISPLACEMENT VS FREQUENCY command described in Section 15.2.7. Note again that the STORE RESPONSE SPECTRUM and CREATE RESPONSE SPECTRUM DISPLACEMENT VS FREQUENCY commands must appear before (i.e., in the same execution of GTSTRUDL or in a prior execution of GTSTRUDL where the response spectrum file ‘name’ was permanently saved in a USERDAT file) the RESPONSE SPECTRUM LOADING command (Section 15.2.11) in which it is referenced. RESPONSE SPECTRUM loading data may be saved permanently in the Userdat file. This may be done by checking the Userdat file box**, and entering the name of the Userdat file by typing or by using the browse feature. In the example below, the Userdat file called “JobData.ds” is as: D:\User\JobData.ds. The Read Only option should not be checked when running the job which stores the RESPONSE SPECTRUM loading data in the JobData.ds file. **NOTE:

A far more powerful means of controlling access to the Userdat file is to use the OPEN USERDATA FILE command (Section 4.16).

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Dynamic Analysis

Dynamic Data Commands

The stored response spectrum may later be deleted from the USERDAT file using the DELETE command described in Section 15.2.8. The RESPONSE SPECTRUM dynamic loading data file may be subsequently plotted by using the PLOT DYNAMIC FILE command, or printed by using the PRINT DYNAMIC FILE command, as described in Sections 15.5.1 and 15.5.2.

Extended Example STRUDL UNITS FT SECONDS CYCLES STORE RESPONSE SPECTRUM VELOCITY LINEAR vs PERIOD LINEAR ‘QUAKE’ DAMPING 0.00 $ 0% critical damping 0.60 0.2 1.0 1.0 1.3 2.2 1.4 3.0 1.45 3.8 DAMPING 0.02 $ 2% critical damping 0.35 0.2 0.8 1.0 1.05 2.2 1.15 3.0 1.2 3.8 DAMPING 0.03 $ 3% critical damping 0.20 0.2 0.6 1.0 0.9 2.2 1.0 3.0 1.0 3.8 END OF RESPONSE SPECTRUM FINISH The above STORE RESPONSE SPECTRUM command is used to input and store the maximum velocity (linear) vs. period (linear) response spectrum curves shown below for three critical damping values.

15 - 33

Dynamic Data Commands

Dynamic Analysis

15.2.6 CREATE TIME HISTORY and Ramp Function Command

Elements: joint specs =

time segment specs = TIME SEGMENT (OF) FILE ‘filenamesrc’ START (TIME) vS END TIME vE RAMP (FUNCTION)

BUILD (TIME) vB

‘filenamenew’

=

name of created acceleration time history file (up to 8 characters),

‘a1’, i1

=

joint identifier when using joint specs

‘a2’, i2

=

load identifier when using joint specs

‘filenamesrc’

=

name of the existing time history file that is the source of the data from which the new time history file is created when using the time segment specs,

vS

=

starting time of the time history segment from file ‘filenamesrc’ that is used to create the new time history file when using the time segment specs,

vE

=

ending time of the time history segment from file ‘filenamesrc’ that is used to create the new time history file when using the time segment specs,

vB

=

the time period over which the ramp function scaling factor applies.

Example CREATE TIME HISTORY FILE ‘TH-1' FROM JOINT 250 TRANSLATION X ‘QUAKE’ CREATE TIME HISTORY FILE 'THSEG' FROM TIME SEGMENT FILE 'JFETest' START TIME 15.0 END TIME 50.0 RAMP COSINE BUILD 5.0 15 - 34

Dynamic Analysis

Dynamic Data Commands

Explanation The CREATE TIME HISTORY command is used to create a new dynamic loading file named ‘filenamenew’ of acceleration versus time and then store the file in a user data set (userdat.ds) where the name “userdat” may be any name specified by the user. Either RELATIVE or ABSOLUTE acceleration will be stored depending on options selected in the DYNAMIC PARAMETERS command described in Section 15.3.2. Two options are available which are the joint specs or the time segment specs. The joint specs option: Following a time-history dynamic analysis for dynamic loading ‘a2/i2', this option is used to extract the computed acceleration vs. time results associated with specified joint ‘a1/i1' in the specified Global X, Y or Z direction and store them in a new file named ‘filenamenew’ which is then stored in the userdat.ds file. This feature is particularly useful when it is required to compute response spectrum data for one or more floors in a building structure due to ground motion to which the building is subjected. The response spectrum data would be computed by the CREATE RESPONSE SPECTRUM command (Section 15.2.7) by using the computed acceleration results that were stored in the new dynamic loading file ‘filenamenew’. The time segment specs option: This option permits an engineer to perform a time-history analysis based on an existing time-history dynamic loading, but rather than beginning the calculation at time 0.0 seconds, the engineer can begin the calculation at some later start time vS in the timehistory loading. However, since the initial conditions at time vS are not known, they can be estimated by beginning the dynamic analysis computation at some specified time prior to time vS (i.e., at start time vS - vB), and continuing the dynamic analysis through the last time specified by vE. The time segment specs option of the CREATE TIME HISTORY command creates the new time-history loading file callled ‘filenamenew’ from the existing time-history loading file called ‘filenamesrc’ as follows: 1.

The acceleration vs. time values in the new file ‘filenamenew’ are the same as those in the existing file ‘filenamesrc’ in the time period between time points vS and vE.

2.

The acceleration vs. time values in the new file ‘filenamenew’ between start time point vS - vB and time point vS are computed over a time period vB called the Build Time and is based on a “ramping” function as follows:

15 - 35

Dynamic Data Commands

Dynamic Analysis

fnew(t) = R(t)fsrc(t), where, fnew(t) = new time history function value at time t, fsrc(t) = time history function value at time t from file ' filenamesrc' , R(t) = ramp function scaling factor, 0 ≤ t ≤ vE, The ramp function R(t) can be designated as either LINEAR or COSINE using the RAMP FUNCTION LINEAR or COSINE specification. The LINEAR ramp function has the following form,

⎧0.0, ⎪ t - (v − v ) ⎪ S B R(t) = ⎨ , v B ⎪ ⎪⎩1.0,

0 ≤ t ≤ (vS − vB) (vS − vB) ≤ t ≤ vS vS ≤ t ≤ vE

While the COSINE ramp function has the following form,

⎧0.0, ⎪ ⎪1 ⎡ ⎛ π ( t - (vS - vB)) ⎞ ⎤ R(t) = ⎨ ⎢1 − cos ⎜ ⎟ ⎥, ⎝ ⎠⎦ vB ⎪2 ⎣ ⎪⎩1.0,

0 ≤ t ≤ (vS - vB) (vS - vB) ≤ t ≤ vS vS ≤ t ≤ vE

Thereafter, the created file may be used as follows: 1.

The file may be plotted or printed (Sections 15.5.1 and 15.5.2).

2.

The file may be used as the time history input to in a transient loading condition (Sections 15.2.9 and 15.2.10).

3.

The file may be used to create a response spectrum file (Section 15.2.7).

4.

The file may be deleted from the userdat.ds user data set (Section 15.2.8). 15 - 36

Dynamic Analysis

Dynamic Data Commands

Extended Example The joint specs option: $ Define a ground acceleration transient loading TRANSIENT LOAD 1100 ‘GROUND MOTION ACCELERATION VS. TIME LOAD’ SUPPORT ACCELERATION TRANSLATION X FILE ‘ELCENTRO’ FACTOR 1.3 INTEGRATE FROM 0.0 TO 10.0 AT 0.01 END OF TRANSIENT LOAD $ Perform a transient analysis computing joint acceleration versus time PERFORM TRANSIENT ANALYSIS $ Use the computed joint acceleration versus time to create a time history $ acceleration versus time loading file name ‘TH-1' containing the computed translation $ acceleration in the global X degree-of-freedom direction at joint 250 $ ---------------------------------------------------------------------------------------------------------CREATE TIME HISTORY FILE ‘TH-1' FROM JOINT 250 TRANSL X LOAD 1100 $ ---------------------------------------------------------------------------------------------------------The time segment specs option: The following commands create the acceleration time history file ‘THR’ from the 'ELCENTRO' acceleration vs. time record between time points t = 20.0 seconds and t = 40.0 seconds from the ELCENTRO record, using the COSINE ramp function with a build time = 10.0 seconds. CREATE TIME HISTORY FILE 'THR' FROM TIME SEGMENT OF FILE 'ELCENTRO' START TIME 20.0 END TIME 40.0 RAMP COSINE BUILD 10.0 and using the LINEAR ramp function with a build time = 10.0 seconds: CREATE TIME HISTORY FILE 'THR' FROM TIME SEGMENT OF FILE 'ELCENTRO' START TIME 20.0 END TIME 40.0 RAMP LINEAR BUILD 10.0

15 - 37

Dynamic Data Commands

Dynamic Analysis

The following are plots of ELCENTRO time history and two new 0.0 to 40.0 second THR time histories using a Cosine and Linear ramp function respectively.

El-Centro Time History

Cosine ramp function between 10 and 20 seconds

Linear ramp function between 10 and 20 seconds

15 - 38

Dynamic Analysis

Dynamic Data Commands

The THR time history values are equal to 0.0 from 0.0 seconds to 10.0 seconds (the 20.0 second specified START TIME minus the 10.0 second specified BUILD TIME). The BUILD TIME in time history THR is from 10.0 to 20.0 seconds during which time period the THR time history values are computed by scaling the ELCENTRO time history values by the ramp function over this time period. Finally, the THR time history values are identical to the ELCENTRO time history values over the time period from 20.0 to 40.0 seconds. The most effective way to use the new THR time history file is illustrated by the following TRANSIENT LOADING command: UNITS FT KIPS RAD SEC TRANSIENT LOADING 101 SUPPORT ACCELERATION TRANSLATION X FILE 'THR' FACTOR 1.0 INTEGRATE FROM 0.0 TO 10.0 AT 10.0 FROM 10.0 TO 40.0 AT 0.01 END TRANSIENT LOAD Note that there are two integration spec entries given. The first one, FROM 0.0 TO 10.0 AT 10.0, covers the time period from 0.0 to 10.0 seconds during which the time history function values are all 0.0. The time step is specified as 10.0 seconds. The second integration spec covers the time period from 10.0 to 40.0 seconds during which time the time history values are those computed by the ramp function between 10.0 and 20.0 seconds, and those which are the same as the original ELCENTRO file between 20.0 and 40.0 seconds.

15 - 39

Dynamic Data Commands

Dynamic Analysis

15.2.7 CREATE RESPONSE SPECTRUM Command

(RANGE) FROM f1 [TO] t1 [AT] a1 FROM f2 [TO] t2 [AT] a2 • • • FROM fn [TO] tn [AT] an

INCLUDE (NATURAL STRUCTURAL FREQUENCIES) USE (ACCELERATION TIME HISTORY FILES) ‘th_file1’ (‘th_file2’ (‘th_file3’)) DIVISOR d END (OF CREATE RESPONSE SPECTRUM) where, ‘rs_file’ ‘th_file1’ ‘th_file2’ ‘th_file3’ f1,f2,...,fn t1,t2,...,tn a1,a2,...,an r1,r2,...,rm

= = = = = = = =

d

=

time increment

=

the response spectrum file name to be created the acceleration time history file used optional additional acceleration time history file optional additional acceleration time history file lower frequency bounds upper frequency bounds frequency increment list of damping ratio values for which damping curves are to be computed divisor used to compute time increment from natural period (default is 12) natural period / d 15 - 40

Dynamic Analysis

Dynamic Data Commands

Example CREATE RESPONSE SPECTRUM DISPLACEMENT LOG VS FREQUENCY LOG FILE ‘RS-1’ USE ACCELERATION TIME HISTORY FILE ‘TH-1’ UNITS CYCLES SECONDS DAMPING PERCENTS 0. 2. 4. 6. 8. FREQUENCY RANGE FROM 0.2 TO 3. AT 0.1 FROM 3. TO 3.6 AT FROM 3.6 TO 5. AT 0.2 FROM 5. TO 8.0 AT FROM 8.0 TO15. AT 0.5 FROM 15. TO 18.0 AT FROM 18.0 TO22. AT 2.0 FROM 22. TO 34.0 AT INCLUDE NATURAL FREQUENCIES END OF CREATE RESPONSE SPECTRUM

0.15 0.25 1.00 3.00

Explanation The CREATE RESPONSE SPECTRUM command is used to create a response spectrum file named ‘rs_file’ and store it in the user data set (USERDAT.ds). A maximum ACCELERATION, VELOCITY, or DISPLACEMENT response spectrum vs. Frequency or vs. Period file may be selected. Both the maximum response and frequency/period scales may be selected as LOG or LINEAR where LOG is the default. The response spectrum file is computed from one or more acceleration time history files which reside either in the user data set (i.e., as stored by the STORE TIME HISTORY ACCELERATION command, Section 15.2.4, or as created and stored by the CREATE TIME HISTORY FILE command, Section 15.2.6 ) or the GTSTRUDL subsystem data set . If more than one acceleration time history file is referenced in the USE option, the total maximum response will be computed by the root mean square technique. The frequencies or periods to be used for response spectrum calculation are specified in groups via the FREQUENCY/PERIOD RANGE option. The currently active frequencies/periods of the supporting structure will be included in the frequency list if the INCLUDE option is given. Only the supporting structure frequencies/periods within the specified FREQUENCY/PERIOD RANGE will be included. The levels of damping for which curves are to be generated are specified with the DAMPING option. The time integration technique used is the “Wilson Theta” method with a default time increment equal to the fundamental natural period divided by 12. The time increment may be changed with the DIVISOR option. However, times at which peak accelerations occur in the th_file1, th_file2, and th_file3 files are included automatically in the integration. 15 - 41

Dynamic Data Commands

Dynamic Analysis

The UNITS command may be given within this tabular command. After this command is issued, the created response spectrum file may be used as follows: 1.

The file may be plotted or printed (Sections 15.5.1 and 15.5.2).

2.

The file may be used as a support acceleration in a response spectrum loading condition (Section 15.2.11).

3.

The file may be deleted from the USERDAT user data set (Section 15.2.8).

The response spectrum is computed when the END command is given. Note that response spectrum files may be directly input and stored by using the STORE RESPONSE SPECTRUM command (Section 15.2.5).

Extended Example CREATE RESPONSE SPECTRUM DISPLACEMENT LOG VS FREQUENCY LOG FILE ‘RS’ USE ACCELERATION TIME HISTORY FILE ‘TH-1’ UNITS CYCLES SECONDS DAMPING PERCENTS 0. 2. 4. 6. 8. FREQUENCY RANGE FROM 0.2 TO 3. AT 0.1 FROM 3. TO 3.6 AT FROM 3.6 TO 5. AT 0.2 FROM 5. TO 8.0 AT FROM 8.0 TO 15. AT 0.5 FROM 15. TO 18.0 AT FROM 18.0 TO 22. AT 2.0 FROM 22. TO 34.0 AT INCLUDE NATURAL FREQUENCIES END OF CREATE RESPONSE SPECTRUM

0.15 0.25 1.00 3.00

In this example, Log-Log displacement vs. frequency response spectrum curves will be computed for five critical damping ratios (0%, 2%, 4%, 6%, and 8% critical damping) using the ground motion acceleration vs. time transient load stored in transient load file called ‘TH-1’. The transient load ‘TH-1’ from which the response spectrum curves are computed may be defined using the STORE TIME HISTORY ACCELERATION TRANSLATION ‘TH-1’ command (Section 15.2.4), or it may be computed using the CREATE TIME HISTORY FILE ‘TH-1' command (Section 15.2.6). Frequency intervals between 0.2 and 34.0 Hertz for this acceleration vs. frequency response spectrum calculation are those which are suggested in the US Nuclear Regulatory Commission Regulatory Guide 1.122. In addition, natural frequencies of the structure in the range of 0.2 and 34.0 Hertz will also be included. 15 - 42

Dynamic Analysis

Dynamic Data Commands

15.2.8 DELETE TIME HISTORY and DELETE RESPONSE SPECTRUM Commands

Elements: ‘name’

=

name of the file in which the response spectrum or time history dynamic loading data are stored (up to 8 alphanumeric characters)

Example DELETE RESPONSE SPECTRUM ‘QUAKE’

Explanation The DELETE command is used to delete stored time history or response spectra data files from the Userdat.ds file in which they were previously stored using the STORE command (Sections 15.2.4 and 15.2.5). In order to delete such files, the Userdat.ds file must be referenced in the GTSTRUDL Startup Wizard when starting GTSTRUDL**.

**NOTE:

A far more powerful means of controlling access to the Userdat file is to use the OPEN USERDATA FILE command (Section 4.16).

15 - 43

Dynamic Data Commands

Dynamic Analysis

15.2.9 TRANSIENT LOADING with JOINT LOADS Command

C C C

integrate-specs

END (OF TRANSIENT LOADING) where,

load-specs =

function-specs =

15 - 44

Dynamic Analysis

Dynamic Data Commands

integrate-specs = INTEGRATE

[FROM] t11 [TO] t12 [AT] t13 [FROM] t21 [TO] t22 [AT] t23 C C C [FROM] tn1 [TO] tn2 [AT] tn3

where, i ‘a’

= =

‘title’

=

list

=

‘filnam’ v1

= =

v2 v3 v4

= = =

t11, t21,...,tn1 = t12, t22,...,tn2 = t13,t23,...,tn3 =

unique integer loading condition identifier unique alphanumeric loading condition identifier (up to 8 characters) optional loading condition title (up to 64 characters) list of names of joints on which the dynamic transient load is applied previously stored time history (Section 2.4.4.1) factor to be multiplied times ordinates of the forcing function (default value = 1.0) amplitude of sine/cosine function loading in active units frequency of sine/cosine function loading in active units phase of sine/cosine function loading in active units (default value = 0.0) initial time values final time values values of time increments to be used in the integration

Example UNITS SECONDS TRANSIENT LOADING 1000 ‘TRANSIENT JOINT FORCES’ JOINTS 1 TO 21 BY 2, ‘A’ LOADS FORCE Y FILE ‘WIND-1' FACTOR 1.5. JOINTS 1, 2 LOAD MOMENT Z FUNCTION SINE AMPL 5.0 FREQ 1.0. INTEGRATE FROM 0.0 TO 10.0 AT .01 END TRANSIENT LOAD

15 - 45

Dynamic Data Commands

Dynamic Analysis

Explanation The TRANSIENT LOADING with JOINT LOADS command is used to describe transient (i.e., time dependent) force and moment loads acting on the joints of the structure. A mode superposition or direct integration (physical) transient dynamic analysis may then be performed based on these transient joint forces and moments. The transient joint loads may be applied in the global X, Y, or Z directions, and may be specified in either of the following two ways: 1.

Reference to a previously STOREd time history (Section 15.2.4), or A previously STOREd transient loading (Section 15.2.4) of type FORCE TRANSLATION or FORCE ROTATION may be applied as a JOINT LOAD with the FILE option. If the STOREd time history does not match the type specified in the TRANSIENT LOADING with JOINT LOADS command (i.e., type FORCE or MOMENT), an error message will be printed and the SCAN mode will be entered.

2.

Specification of a trigonometric (SINE/COSINE) function. A trigonometric function transient load may be applied as a JOINT LOAD by specifying the SINE or COSINE function’s amplitude (v2), frequency (v3), and phase angle (v4) in the following expression, where “t” represents time:

Integrate-specs (the INTEGRATE command) specifies the initial (ti1) and final (ti2) times, and the time increment (ti3) for which the mode superposition integration or direct integration (PHYSICAL) dynamic analysis will be performed. A variable time increment may be specified by a sequence of initial and final times with the associated time increments. The initial time of one time sequence must be greater than or equal to the final time of the previous time sequence. The time increment must be positive. The INTEGRATE command must be given within each specified TRANSIENT LOADING definition.

15 - 46

Dynamic Analysis

Dynamic Data Commands

Extended Example STRUDL $ Open a user data set containing user steel section tables $ and/or dynamic loading data files. OPEN USERDATA FILE 'ForcingFunctions.ds' WRITE EXISTING $ Read/Write UNITS KIPS SECONDS STORE TIME HISTORY FORCE TRANSLATION ‘FORCE-X’ 0.0 0.0 2.0 0 .2 -1.5 0.4 1.5 0.6 -1.0 0.7 1.0 0.8 -0.5 0.9 0.5 1.0 0.0 1.1 FINISH

The above commands store a "force vs. time" forcing function in a new file called 'FORCE-X' which is then stored in an existing user data file (Section 4.16) called 'ForcingFunctions.ds'.

STRUDL C C C OPEN USERDATA FILE 'ForcingFunctions.ds' READ $ Read Only UNITS CM CYCLES SECONDS TRANSIENT LOADING 1000 ‘TRANSIENT JOINT FORCES’ JOINTS 1 TO 21 BY 2, 105, ‘A’ LOADS FORCE X FILE ‘FORCE-X’ FACTOR 1.5. JOINTS 201 TO 210 LOAD FORCE Z FUNCTION SINE AMPL 5.0 FREQ 1.0. INTEGRATE FROM 0.0 TO 10.0 AT .01 END TRANSIENT LOAD C C C FINISH

The above commands define a new transient dynamic loading condition consisting of a "force vs. time" forcing function previously stored in a file called 'FORCE-X' and which was previously stored in an existing user data file (Section 4.16) called 'ForcingFunctions.ds'.

15 - 47

Dynamic Data Commands

Dynamic Analysis

15.2.10 TRANSIENT LOADING with SUPPORT ACCELERATION Command

SUPPORT (ACCELERATION)

C C C

where, load-specs = same as for JOINT LOAD Command (Section 15.2.9)

Example UNITS SECONDS TRANSIENT LOADING 1000 ‘Support Acceleration’ SUPPORT ACCELERATION TRANSLATION X FILE ‘ELCENTRO’ FACTOR 0.707 TRANSLATION Z FILE ‘ELCENTRO’ FACTOR 0.707 INTEGRATE FROM 0.0 TO 10.0 AT .01 END TRANSIENT LOAD

15 - 48

Dynamic Analysis

Dynamic Data Commands

Explanation The TRANSIENT LOADING with SUPPORT ACCELERATION command is used to specify time history support acceleration loads. The accelerations may only be of type TRANSLATION in the global X, Y, and/or Z directions. Up to three support accelerations (X and/or Y and/or Z) may be specified in a single TRANSIENT LOADING. All support joints are assumed to have the identical support accelerations and to move as one rigid body with no relative motion. The load-specs are identical to the load-specs for the JOINT LOAD command in Section 15.2.9, except that the loads are translation accelerations in the restrained (not released) directions at the support joints rather than forces and moments applied to unrestrained joint directions. If the FILE option is used, the referenced file must be a previously stored time history of type ACCELERATION as described in Section 15.2.4, or must have been created and stored with the CREATE TIME HISTORY command as described in Section 15.2.6. Otherwise, an error message will be printed, and the SCAN mode will be entered. Displacement and velocity results are computed relative to the supports, while acceleration results may be computed relative to the supports or as absolute values as described in Section 15.3.2.

Extended Example UNITS SECONDS TRANSIENT LOADING 1000 ‘Support Acceleration’ SUPPORT ACCELERATION TRANSLATION X FILE ‘ELCENTRO’ FACTOR 0.707 TRANSLATION Z FILE ‘ELCENTRO’ FACTOR 0.707 INTEGRATE FROM 0.0 TO 10.0 AT .01 END TRANSIENT LOAD The TRANSLATION X FILE ‘ELCENTRO’ FACTOR 0.707 specifies that the global Xdirection component of the El Centro earthquake time history ground motion acceleration record which is stored in file name ‘ELCENTRO’ (provided with GTSTRUDL) be applied as a support acceleration in a direction 45 degrees to the global X axis of the structure. The TRANSLATION Z FILE ‘ELCENTRO’ FACTOR 0.707 specifies that the global Zdirection component of the El Centro earthquake time history ground motion acceleration record which is stored in file name ‘ELCENTRO’ (provided with GTSTRUDL) be applied as a support acceleration in a direction 45 degrees to the global Z axis of the structure. 15 - 49

Dynamic Data Commands

15.2.11

Dynamic Analysis

RESPONSE SPECTRUM LOADING with SUPPORT ACCELERATION Command and the MODE FACTOR Gupta Method

SUPPORT ( ACCELERATION )

END (OF RESPONSE SPECTRUM LOADING) where, i

=

integer transient loading condition identifier

‘a’

=

alphanumeric transient loading condition identifier (up to 8 characters)

‘title’

=

optional transient loading condition title (up to 64 characters)

'filename'

=

name of previously stored response spectra (Section 2.4.4.2),

vx

=

positive or negative factor by which the ordinates of the specified response spectra ('filename') are scaled in order to define the global X response spectra component. The default value for vx is 1.0.

vy

=

positive or negative factor by which the ordinates of the specified response spectra ('filename') are scaled in order to define the global Y response spectra component. The default value for vy is 1.0.

vz

=

positive or negative factor by which the ordinates of the specified response spectra ('filename') are scaled in order to define the global Z response spectra component. The default value for vz is 1.0.

15 - 50

Dynamic Analysis

Dynamic Data Commands

vF1

=

when the COMPUTE RIGID/PERIODIC option is specified, this is the frequency, in active angle and time units, at which the peak response spectrum spectral acceleration occurs in the response spectrum file specified by the SUPPORT ACCELERATION command above

vF2

=

when the COMPUTE RIGID/PERIODIC option is specified, this is the lowest frequency, in active angle and time units, at which the responses of single degree-of-freedom oscillators become completely correlated with the input support motion used to create the response spectrum file specified by the SUPPORT ACCELERATION command above

vFZPA

=

when the COMPUTE RIGID/PERIODIC option is specified, this is the frequency, in active angle and time units, above which the response spectrum spectral acceleration returns to the Zero -Period Acceleration (ZPA)

r1, r2, . . ., rm =

additional modal weighting factor, must be a decimal number

i1, i2, . . ., im

optional repeat number, must be an integer; default = 1. Specifies the number of modes for which the weighting factor is applied

=

Extended Example When the Gupta Method is required, two groups of Response Spectrum loads are needed in each earthquake direction under consideration, where one group is used for periodic modal responses, and the other group is used for rigid body modal responses. For example, for the horizontal Global X and Z directions, and the vertical Global Ydirection of earthquake, the following sequence of commands can be used: UNITS CYCLES SECONDS $ Define Response Spectrum Loads for PERIODIC RESPONSE in the $ Global X, Y and Z directions RESPONSE SPECTRUM LOAD '101P' 'RESPONSE SPECTRUM: PERIODIC MODE' SUPPORT ACCELERATION TRANSLATION X 1.0 FILE 'ELCEN-RS' $ NRC Gupta Method Periodic Response Modal Weighting Factors at the $ ZPA (Zero Period Acceleration) Cutoff Freq. = 40 Hz MODE FACTORS COMPUTE PERIODIC RESPONSE FZPA 40.0 $ Hz END OF RESPONSE SPECTRUM LOAD

15 - 51

Dynamic Data Commands

Dynamic Analysis

RESPONSE SPECTRUM LOAD '102P' 'RESPONSE SPECTRUM: PERIODIC MODE' SUPPORT ACCELERATION TRANSLATION Z 1.0 FILE 'ELCEN-RS' $ NRC Gupta Method Periodic Response Modal Weighting Factors at the $ ZPA (Zero Period Acceleration) Cutoff Freq. = 40 Hz MODE FACTORS COMPUTE PERIODIC RESPONSE FZPA 40.0 $ Hz END OF RESPONSE SPECTRUM LOAD RESPONSE SPECTRUM LOAD '103P' 'RESPONSE SPECTRUM: PERIODIC MODE' SUPPORT ACCELERATION TRANSLATION Y 0.50 FILE 'ELCEN-RS' $ NRC Gupta Method Periodic Response Modal Weighting Factors at the $ ZPA (Zero Period Acceleration) Cutoff Freq. = 40 Hz MODE FACTORS COMPUTE PERIODIC RESPONSE FZPA 40.0 $ Hz END OF RESPONSE SPECTRUM LOAD $ ----------------------------------------------------------------------------------------$ Define Response Spectrum Loads for RIGID RESPONSE in the $ Global X, Y, and Z directions RESPONSE SPECTRUM LOAD '101R' 'RESPONSE SPECTRUM: RIGID MODE' SUPPORT ACCELERATION TRANSLATION X 1.0 FILE 'ELCEN-RS' $ NRC Gupta Method Rigid Response Modal Weighting Factors at the $ ZPA (Zero Period Acceleration) Cutoff Freq. = 40 Hz MODE FACTORS COMPUTE RIGID RESPONSE FZPA 40.0 $ Hz END OF RESPONSE SPECTRUM LOAD RESPONSE SPECTRUM LOAD '102R' 'RESPONSE SPECTRUM: RIGID MODE' SUPPORT ACCELERATION TRANSLATION Z 1.0 FILE 'ELCEN-RS' $ NRC Gupta Method Rigid Response Modal Weighting Factors at the $ ZPA (Zero Period Acceleration) Cutoff Freq. = 40 Hz MODE FACTORS COMPUTE RIGID RESPONSE FZPA 40.0 $ Hz END OF RESPONSE SPECTRUM LOAD RESPONSE SPECTRUM LOAD '103R' 'RESPONSE SPECTRUM: RIGID MODE' SUPPORT ACCELERATION TRANSLATION Y 0.50 FILE 'ELCEN-RS' $ NRC Gupta Method Rigid Response Modal Weighting Factors at the $ ZPA (Zero Period Acceleration) Cutoff Freq. = 40 Hz MODE FACTORS COMPUTE RIGID RESPONSE FZPA 40.0 $ Hz END OF RESPONSE SPECTRUM LOAD

15 - 52

Dynamic Analysis

Dynamic Data Commands

Explanation The RESPONSE SPECTRUM LOADING command is used to define a response spectrum loading as a family of curves, where each curve is associated with a different modal damping value, and where each curve represents either the maximum displacement, velocity, or acceleration as a function of period or frequency of the modes of the structure. The response spectrum curves must have been previously stored in a file by using either the STORE RESPONSE SPECTRUM command (Section 15.2.5), or by using the CREATE RESPONSE SPECTRUM command (Section 15.2.7). The subsequent corresponding RESPONSE SPECTRUM dynamic analysis will use a mode superposition method procedure. The response spectrum curves for different levels of modal damping must bound all levels of modal damping specified for the structure by the DAMPING PERCENT or RATIOS command (Section 15.2.3). However, the response spectrum curves are assumed to have zero value outside their domain of definition on the frequency or period scale. Further, it is not necessary that the actual modal damping, or frequencies or periods of the modes of the structure, coincide with the values stored in the response spectrum curve data. Rather, depending on how the response spectrum curves were defined, either linear or logarithmic interpolation between frequency or period values, and along the input response spectrum curves, will automatically be performed. Then, for particular values of frequency or period, and for particular values of damping, linear interpolation will be performed between the input response spectrum curves with different damping values. A RESPONSE SPECTRUM LOADING condition may contain up to three factored response spectrum translation components -- global X, Y, and/or Z as specified by the TRANSLATION command option. The factors, vx, vy, and vz, are assumed to have values of 1.0 if not directly specified. One interpretation of these factors is the direction cosines that define an arbitrary response spectrum direction with respect to the global reference system. For example, the figure below shows response spectrum 'RS-1' applied in a direction defined by an angle of 60 degrees from the global Z axis in the global X-Z plane. The following RESPONSE SPECTRUM LOADING command defines this response spectrum as Response Spectrum Loading 100: RESPONSE SPECTRUM LOADING 100 SUPPORT ACCELERATION TRANSLATION X 0.866 Z 0.50 FILE 'RS-1' END RESPONSE SPECTRUM LOAD 15 - 53

Dynamic Data Commands

Dynamic Analysis

MODE FACTOR Option and the Gupta Method The MODE FACTOR command option results in the response spectrum analysis results being scaled by the specified or computed modal weighting factor values. The modal weighting factors can be specified directly, or they can be computed when the response spectrum analysis is performed by specifying the COMPUTE option. The specified or computed weighting factors are used to scale all response spectrum results computed for the specified response spectrum loading condition. The intent behind the implementation of the MODE FACTORS COMPUTE option is to be able to form a complete response spectrum solution by computing and combining rigid response and periodic response components pursuant to the provisions of Sections 1.3.1 and 1.5.1 of NRC Regulatory Guide 1.92, Revision 2. Therefore, the COMPUTE option is used to specify that a set of either rigid response or periodic response modal weighting factors is to be computed for the specified response spectrum loading, thus associating the final results computed for that loading with either rigid response or periodic response respectively. When the COMPUTE option is specified and a response spectrum analysis is subsequently performed, the modal weighting factors are computed according to the provisions of Section 1.3.1 of the NRC Regulatory Guide 1.92, Revision 2. The detailed procedure implemented for this computation, known as the Gupta Method, is summarized in Section 2.4.4.6.3 in Volume 3 of the GTSTRUDL User Reference Manual. 15 - 54

Dynamic Analysis

15.2.12

Dynamic Data Commands

FORM STATIC EARTHQUAKE LOAD Command - Automatic Generation of Static Equivalent Earthquake Loads (Section 3.3.3.2.C of NEHRP Guidelines for the Seismic Rehabilitation of Buildings - FEMA Publication 273)

⎧'asl' ⎫ FORM STATIC (EARTHQUAKE) LOAD ⎨ ⎬ ('titlesl') ⎩ isl ⎭ ⎧MASS [X] vx [Y] vy [Z] vz ⎫ ⎪ ⎪ ⎪ ⎧→ RMS ⎫ ⎪ FROM ⎨ ⎪ ⎧'aRS' ⎫ ⎪ ⎬ ⎪ ⎨ CQC ⎬ (OF RESPONSE SPECTRUM) LOAD ⎨ i ⎬ (FAC TOR vRS) ⎪ ⎩ RS ⎭ ⎪⎩ ⎪⎩ SUM ⎪⎭ ⎪⎭ Elements: ‘asl’, isl

=

‘titlesl’ vx

= =

vy

=

vz

=

‘aRS’, iRS = vRS

=

alphanumeric or integer name for the generated static earthquake load. This name must be unique among all current loading names and is limited to 8 characters or digits. optional static load title of up to 64 characters in length. scaling factor for the mass load in the global X direction. vx is taken as 0.0 by default. scaling factor for the mass load in the global Y direction. vy is taken as 0.0 by default. scaling factor for the mass load in the global Z direction. vz is taken as 0.0 by default. alphanumeric or integer name of the response spectrum load to be used for the calculation of static earthquake load ‘asl’ or isl. scaling factor to be applied to the response spectrum static earthquake load ‘asl’ or isl.

Example $ Generate equivalent static earthquake loads and print the resulting joint loads. FORM STATIC EARTHQUAKE LOAD 'ERS1-G.1' 'Equivalent Static Earthquake Load 1-G.1, from RMS of RS Load 1-G.1' FROM RMS OF RESPONSE SPECTRUM LOAD '1-G.1' FORM STATIC EARTHQUAKE LOAD 'EM1-G.1' 'Equivalent Static Earthquake Load 1-G.1 from Total Mass' FROM MASS X 1.0 PRINT APPLIED JOINT LOADS

15 - 55

Dynamic Data Commands

Dynamic Analysis

Explanation The FORM STATIC LOAD command is used to compute an independent static loading condition consisting of a static joint load representation of either the structural mass or a response spectrum load. The calculation of a MASS-Equivalent static load conforms to the NEHRP guidelines for the calculation of the uniform pattern lateral load distribution, and the calculation of a Response Spectrum static load conforms to the NEHRP guidelines for the calculation of the modal pattern lateral load distribution using a Response Spectrum Analysis, as described in Section 3.3.3.2.C of NEHRP Guidelines for the Seismic Rehabilitation of Buildings (FEMA Publication 273). 1.

Mass-Equivalent Static Load Option MASS [ X ] vx [ Y ] vy [ Z ] vz The MASS option generates an independent loading condition containing joint loads which are statically equivalent to any factored combination of the structural mass in the global X, Y, and Z directions. Because the global direction scaling factors vx, vy, and vz are taken as 0.0 by default, it is necessary to specify a non-zero value for the appropriate scaling factor if joint load components are to be computed for a particular global direction. The MASS-equivalent static joint load vector is computed by the following equation: {FEM}

=

[M] {vXYZ} g

Eq. 5.17-1

{FEM} [M] {vXYZ}

= = =

g

=

MASS-equivalent joint load vector, system global mass matrix, vector of global direction scaling factors vx, vy, and vz , arranged in the appropriate joint degree-of-freedom locations, acceleration due to gravity, taken as 386.0886 inches/sec2 by default.

where,

According to Equation 5.17-1, it is necessary that the structural mass has been defined, and that, as a minimum, the PERFORM ASSEMBLY FOR DYNAMICS command (Section 2.4.5.5.1, Volume 3, GTSTRUDL User Reference Manual) has been executed prior the execution of this option.

15 - 56

Dynamic Analysis

2.

Dynamic Data Commands

RESPONSE SPECTRUM LOAD option ⎧→ RMS ⎫ ⎧' aRS ' ⎫ ⎪ ⎪ ⎨ CQC ⎬ ( OF RESPONSE SPECTRUM) LOA D ⎨ ⎬ (FAC TOR v RS ) ⎩ iRS ⎭ ⎪ SUM ⎪ ⎩ ⎭

The RESPONSE SPECTRUM LOAD option generates an independent loading condition consisting of joint loads that represent a measure of the total base shear computed for the response spectrum load ‘aRS’ or iRS. The additional RMS, CQC, and SUM options provide for the selection of the modal combination method to be used for the computation of the global joint loads from the modal joint load components. RMS and CQC indicate the Root Mean Square and Complete Quadratic Combination methods, respectively, as described in Section 15.4.1 of this Analysis Guide, and in Section 2.4.2.5, Volume 3 of the GTSTRUDL User Reference Manual. The SUM option indicates a direct algebraic summation of the modal joint load components. The equivalent response spectrum static joint loading in the ith active mode is computed by the following equation:

{ f RS } i

=

- v RS Γ i S ai [ M ] {Φ i }

Eq. 5.17-2

where, {fRS}i vRS [M]

Γi

Sai

= = = = = =

response spectrum static joint load vector for the ith mode, scaling factor as defined above, the global system mass matrix, the response spectrum participation factor for the ith mode, the response spectrum spectral acceleration for the ith mode, mode shape displacement vector for the ith mode.

The total response spectrum static joint load vector is computed by combining the {fRS}i for each active mode using the specified RMS, CQC, or SUM procedure. Because the values for Γ i and Sai are determined from the direction and response spectrum data of response spectrum load ‘aRS’ or iRS, a response spectrum analysis for this load must have been performed prior to the execution of FORM STATIC LOAD RESPONSE SPECTRUM option. However, a COMPUTE RESPONSE SPECTRUM command execution subsequent to the response spectrum analysis is not required.

15 - 57

Dynamic Data Commands

Dynamic Analysis

The independent loading conditions generated by the FORM STATIC LOAD command are conventional independent static loading conditions, and as such, may be used and manipulated in the same manner as independent loads defined by other means. Errors: The following messages indicate error or warning conditions that can occur during the execution of the FORM STATIC LOAD command: **** ERROR_STGELL -- System mass matrix does not exist. SCAN MODE entered. This message indicates that the mass matrix had not been assembled prior to the execution of the FORM STATIC LOAD command. SCAN MODE is set and may be removed by giving the SCAN OFF command. The minimum requirement for the MASS option is that the PERFORM ASSEMBLY FOR DYNAMICS command must be executed. **** ERROR_STGELL --

Specified response spectrum loading 1-G.2 does not exist. SCAN MODE entered.

This error message indicates that the specified response spectrum load has not been defined. SCAN MODE is set and may be removed by giving the SCAN OFF command. **** ERROR_STGELL --

Results do not exist for response spectrum loading 1-G.2. Response spectrum analysis has not yet been run or the specified loading is not a response spectrum load. SCAN MODE entered.

This error message indicates that while the specified response spectrum load is valid, the required response spectrum analysis for this load has not yet been executed. SCAN MODE is set and may be removed by giving the SCAN OFF command.

15 - 58

Dynamic Analysis

Dynamic Data Commands

Extended Example Figure 15.2-1 shows the plane frame structure of Example SEL-1 which illustrates the use of the FORM STATIC LOAD command to create two static lateral loads based on the structural mass and on a response spectrum load. Note that the structure model includes mid-member joints to insure that the effects of fundamental member modes are not overlooked in the response spectrum analysis. The effects of such modes may arise due to the presence of the added joint inertias at joints 14 TO 22 BY 2. The complete command input for this example is shown in Figure 15.2-2.

15 - 59

Dynamic Data Commands

Dynamic Analysis

UNITS INCHES KIPS Density = 0.00615 K/IN**3 AX 33.6 IZ 2000.0 AX 33.6 IZ 1000.0 AX 240.0 IZ 18000.0

Members 1 to 4 Members 5 to 20 Members 21 to 30

Figure 15.2-1 Static Earthquake Load Example (SEL-1): Geometry, Structure, and Material Properties 15 - 60

Dynamic Analysis

Dynamic Data Commands

STRUDL 'SEL-1' 'Example of static earthquake load generation' $ 4-story plane frame for static earthquake load generation. $ Geometry. PRINT GENERATE OFF UNITS FEET KIPS GEN 11 JOINTS ID 1 1 X 0.0 Y DIFF 0.0 2 AT 7.5 2 AT 6.0 2 AT 6.5 2 AT 7.5 2 AT 8.0 REPEAT 2 TIMES ID 11 X 20.0 TYPE PLANE FRAME GEN 10 MEMB ID 1 2 FROM 1 1 TO 2 1 REPEAT 1 TIME ID 1 FROM 22 TO 22 GEN 2 MEMB ID 21 1 FROM 3 11 TO 14 11 REPEAT 4 TIMES ID 2 FROM 2 TO 2 DELETIONS JOINTS 12 13 TO 21 BY 2 ADDITIONS STATUS SUPPORTS 1 23 $ Structural and material properties. UNITS INCHES KIPS MEMBER PROP PRISMATIC 1 TO 4 AX 33.6 IZ 2000.0 5 TO 20 AX 33.6 IZ 1000.0 21 TO 30 AX 240 IZ 18000 CONSTANTS E 3000000. DENSITY 0.00615

ALL ALL

$ Lumped mass plus added joint masses. INERTIA OF JOINTS LUMPED INERTIA OF JOINTS MASS 14 TO 22 BY 2 TRANSLATION X 2.0 Y 2.0

Figure 15.2-2 GTSTRUDL Commands for Example SEL-1

15 - 61

Dynamic Data Commands

Dynamic Analysis

$ For the static response spectrum load generation, use a constant 1-g acceleration spectrum. UNITS INCHES SECONDS STORE RESPONSE SPECTRA ACCEL LIN VS NAT FREQ LIN 'ONE-G' DAMPING 0.05 FACTOR 386.0886 1.0 0.0 1.0 10000.0 RESPONSE SPECTRA LOAD '1-G.1' SUPPORT ACCELERATIONS TRANS X FILE 'ONE-G' END OF RESPONSE SPECTRA LOADING DAMPING RATIOS 0.05 100 $ Perform eigenvalue analysis and response spectrum analysis. UNITS CYCLES SECS EIGEN PARAMETERS SOLVE USING GTLANCZOS NUMBER OF MODES 50 PRINT MAX END ASSEMBLE FOR DYNAMICS PERFORM EIGENVALUE ANALYSIS LIST DYNAMIC PARTICIPATION FACTORS LOAD LIST '1-G.1' PERFORM RESPONSE SPECTRUM ANALYSIS $ Generate the static earthquake loads and print the joint load contents. FORM STATIC EARTHQUAKE LOAD 'ERS1-G.1' 'Equivalent STATIC EARTHQUAKE load 1-G.1, RS load 1-G.1' FROM RMS OF RESPONSE SPECTRUM LOAD '1-G.1' FORM STATIC EARTHQUAKE LOAD 'EM1-G.1' 'Equivalent STATIC EARTHQUAKE load 1-G.1 from total mass' FROM MASS X 1.0 PRINT APPLIED JOINT LOADS $ FINISH

Figure 15.2-2

GTSTRUDL Commands for Example SEL-1 (Continued)

15 - 62

Dynamic Analysis

Dynamic Data Commands

The following 15.2-3 is the text output from the PRINT APPLIED JOINT LOADS command, showing the joint loads generated by the FORM STATIC EARTHQUAKE LOAD commands: { 68} { 69} { 70} { 71} { 72} { 73} Time to

> > $ Generate the static earthquake loads and print the joint load contents. > > FORM STATIC EARTHQUAKE LOAD 'ERS1-G.1' >_ 'Equivalent STATIC EARTHQUAKE load 1-G.1, RS load 1-G.1' >_ FROM RMS OF RESPONSE SPECTRUM LOAD '1-G.1' create equivalent static earthquake load = 0.00 Seconds

{ 74} > FORM STATIC EARTHQUAKE LOAD 'EM1-G.1' { 75} >_ 'Equivalent STATIC EARTHQUAKE load 1-G.1 from total mass' Time to create equivalent static earthquake load = 0.00 Seconds {

FROM MASS X 1.0

76} > PRINT APPLIED JOINT LOADS

**************************************** * PROBLEM DATA FROM INTERNAL STORAGE * **************************************** JOB ID - SEL-1 JOB TITLE - Example of static earthquake load generation ACTIVE UNITS -

LENGTH INCH

WEIGHT KIP

ANGLE CYC

TEMPERATURE DEGF

TIME SEC

********** LOADING DATA ********** LOADING - ERS1-G.1

Equivalent STATIC EARTHQUAKE load 1-G.1, RS load 1-G.1

STATUS - ACTIVE

JOINT LOADS-------------------------------------------------------------------------------/ JOINT STEP FORCE X Y Z MOMENT X Y Z 2 3 4 5 6 7 8 9 10 11 14 16 18 20 22 24 25 26 27 28 29 30 31 32 33

9.333 89.505 9.113 139.065 13.030 181.060 18.780 229.312 25.081 268.411 521.227 814.057 1049.344 1316.084 1616.943 9.333 89.505 9.113 139.065 13.030 181.060 18.780 229.312 25.081 268.411

0.187 3.684 0.225 3.717 0.354 5.447 0.460 6.484 0.558 5.655 0.000 0.000 0.000 0.000 0.000 0.187 3.684 0.225 3.717 0.354 5.447 0.460 6.484 0.558 5.655

0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000

15 - 63

0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000

0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000

0.000 0.018 0.000 0.006 0.000 0.005 0.001 0.005 0.001 0.004 0.018 0.006 0.005 0.003 0.002 0.000 0.018 0.000 0.006 0.000 0.005 0.001 0.005 0.001 0.004

Dynamic Data Commands

LOADING - EM1-G.1

Dynamic Analysis

Equivalent STATIC EARTHQUAKE load 1-G.1 from total mass

STATUS - ACTIVE

JOINT LOADS-------------------------------------------------------------------------------/ JOINT STEP FORCE X Y Z MOMENT X Y Z 2 18.598 0.000 3 193.858 0.000 4 14.878 0.000 5 192.618 0.000 6 16.118 0.000 7 194.478 0.000 8 18.598 0.000 9 196.338 0.000 10 19.837 0.000 11 187.039 0.000 14 1126.417 0.000 16 1126.417 0.000 18 1126.417 0.000 20 1126.417 0.000 22 1126.417 0.000 24 18.598 0.000 25 193.858 0.000 26 14.878 0.000 27 192.618 0.000 28 16.118 0.000 29 194.478 0.000 30 18.598 0.000 31 196.338 0.000 32 19.837 0.000 33 187.039 0.000 **************************************** * END OF DATA FROM INTERNAL STORAGE * ****************************************

0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000

0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000

0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000

Figure 15.2-3 PRINT APPLIED JOINT LOAD Results for Example SEL-1 (Continued)

15 - 64

0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000

Dynamic Analysis

15.2.13

Dynamic Data Commands

FORM UBC97 LOAD Command -- Automatic Generation of Static Seismic Loads According to 1997 UBC

⎧'asl ' ⎫ FORM UBC97 ( STATIC ) ( SEISMIC ) LOAD ⎨ ⎬ ( ' titlesl ' ) ⎩ isl ⎭ ⎧→ X ⎫ ⎧→ X ⎫ ⎪ ⎪ ⎪ ⎪ DIRECTION ⎨ Y ⎬ HEIGHT (DIRECTION) ⎨ Y ⎬ WEIGHT ⎪ Z⎪ ⎪ Z⎪ ⎩ ⎭ ⎩ ⎭

⎧1 ⎫ ⎪2A ⎪ ⎪ ⎪ ⎪2B ⎪ ZONE ⎨ ⎬ ⎪3 ⎪ ⎪4 ⎪ ⎪ ⎪ ⎩Z v z ⎭

⎧ ⎧ ⎫⎫ ⎪ ⎪ ⎪⎪ ⎪ ⎪ ⎪⎪ ⎪ ⎪ ⎪⎪ ⎪ ⎪ ⎪⎪ ⎪ ⎪SA ⎪ ⎪ ⎪SOIL ⎪⎨SB ⎪⎬ ⎪ ⎪ ⎪SC ⎪ ⎪ ⎪ ⎪ ⎪⎪ ⎪ ⎪SD ⎪ ⎪⎪ ⎪ ⎨ ⎪SE ⎪ ⎬ OCCUPANCY ( CATEGORY ) ⎪ ⎪ ⎪⎪ ⎪ ⎩⎪SF ⎭⎪ ⎪ ⎪ ⎪ ⎪ ⎪ ⎪CA v ⎪ CA ⎪ ⎪ ⎪CV v CV ⎪ ⎪ ⎪ ⎪NA v NA ⎪ ⎪⎩NV v NV ⎪⎭

⎧SMR ⎫ ⎪RCMR ⎪ ⎛ ⎪ ⎪ CT ⎨ R v R ⎜ ( WITH ) TOR SION ⎬ ⎝ ⎪OTHER ⎪ ⎪⎩ v CT ⎪⎭

⎧→ PLUS ⎫ ⎞ ⎨ ⎬⎟ ⎩ MINUS ⎭ ⎠

(LOAD )

⎧'a w ' ⎫ ⎨ ⎬ ⎩ iw ⎭

⎧ESSENTIAL (FACILITIES ) ⎫ ⎪ ⎪ ⎪HAZ ARDOUS (FACILITIES ) ⎪ ⎪ ⎪ ⎪SPECIAL ( STRUCTURES ) ⎪ ⎨ ⎬ ⎪STANDARD ( STRUCTURES ) ⎪ ⎪ ⎪ ⎪MISCELLANEOUS ( STRUCTURES ) ⎪ ⎪I v ⎪ ⎩ I ⎭

(FLOOR ( TOLERANCE) v ) TOL

where, ‘asl’/isl =

alphanumeric or integer name for the generated UBC 1997 static seismic load. This name must be unique among all current loading names and is limited to eight characters or digits.

‘titlesl’ =

optional static load title of up to 64 characters in length.

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Dynamic Analysis

and where, ‘aw’/iw =

alphanumeric or integer name of the independent loading that is used for the calculation of the weight distribution of the structure.

vZ

=

decimal value for the UBC 1997 seismic zone factor Z. This specified value supersedes the calculated value based on the seismic zone specified by the ZONE option.

vCA

=

decimal value for the UBC 1997 seismic coefficient Ca. This specified value supersedes the calculated value based on the seismic zone and soil profiles specified by the ZONE and SOIL options.

vCV

=

decimal value for the UBC 1997 seismic coefficient Cv. This specified value supersedes the calculated value based on the seismic zone and soil profiles specified by the ZONE and SOIL options.

vNA

=

decimal value for the UBC 1997 near-source factor Na used in the calculation of Ca when seismic zone 4 is selected using the ZONE option. The default value is taken as 1.0.

vNV

=

decimal value for the UBC 1997 near-source factor Nv used in the calculation of Cv when seismic zone 4 is selected using the ZONE option. The default value is taken as 1.0.

vI

=

decimal value for the UBC 1997 importance factor I, to be used instead of the calculated value based on the selection of one of the OCCUPANCE CATAGORY options: ESSENTIAL, HAZARDOUS, SPECIAL, STANDARD, or MISCELLANEOUS.

vCT

=

decimal value for the UBC 1997 numerical coefficient Ct, to be used instead of the calculated value based on the selection of one of the CT options: SMR, RCMR, or OTHER.

vR

=

decimal value for the UBC 1997 numerical coefficient R.

vTOL =

All active joints within this specified HEIGHT DIRECTION tolerance of one another are assumed to define the geometry of a single floor. The input of this value assumes length units. The default value for vTOL is taken as 6.0 inches (15.24 cm).

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Dynamic Data Commands

Example FORM UBC97 LOAD 'UBCXNEW' DIR X WEIGHT LOAD 'DL' ZONE 2B SOIL SC CV 0.35 OCC CATEGORY I 1.5 CT SMR R 5.5 TORSION MINUS

Explanation The FORM UBC97 LOAD command is used to compute an independent loading condition consisting only of static joint loads in accordance with the provisions of Sections 1630.2, 1630.5 and 1630.6 of the 1997 Uniform Building Code, Vol.2. A very important aspect regarding the execution of this command is that all load computations are performed only on the currently active joints. The options used to define this loading condition are described as follows:

⎧→ X ⎫ ⎪ ⎪ DIRECTION ⎨ Y ⎬ ⎪ Z⎪ ⎩ ⎭ The DIRECTION option is used to specify the global coordinate direction of computed joint load components contained in the loading condition. The global X direction is the default.

HEIGHT (DIRECTION)

⎧ X⎫ ⎪ ⎪ ⎨→ Y ⎬ ⎪ ⎪ ⎩ Z⎭

The HEIGHT DIRECTION option specifies the global coordinate direction that defines the elevation coordinate for the structure. For example, HEIGHT DIRECTION Y specifies that the height of the building structure and the building floor elevations are defined with respect to the global Y axis. It is assumed that elevations are measured from 0 at the joint having the least HEIGHT DIRECTION joint coordinate value to the full height of the structure at the joint having the largest HEIGHT DIRECTION joint coordinate value.

The required WEIGHT LOAD command option is used to identify the static, independent loading from which the total weight of the building model is computed. The total weight is computed as the sum of the absolute values of all translation load components (FORCE X, FORCE Y, and FORCE Z). The specified loading must have been defined previous to the time that the FORM UBC97 command is given.

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Dynamic Analysis

⎧1 ⎫ ⎪2A ⎪ ⎪ ⎪ ⎪2B ⎪ ZONE ⎨ ⎬ ⎪3 ⎪ ⎪4 ⎪ ⎪ ⎪ ⎩Z v Z ⎭ This optional command is used to specify data about the relevant earthquake zone for the load calculations. Use the ZONE option to select zone 1, 2A, 2B, 3, 4, or to directly specify a value vZ for the seismic zone factor Z. One of the ZONE options 1 through 4 must be selected if one of the SOIL options SA through SF is also selected as described below.

These options are used to specify data about the seismic zone coil conditions. The SOIL option is used to specify the soil type: SA = SA, SB = SB, SC = SC, SD = SD, SE = SE, and SF = SF. The selected SOIL specification – SA through SF – is used in combination of the selected seismic ZONE specification – 1 through 4 – to calculate the values for seismic coefficients Ca and Cv according to 1997 UBC Tables 16-Q and 16R. Any values specified using the CA and CV parameters supersede the values computed from the ZONE and SOIL specifications. Values for CA and CV must be specified if the ZONE and/or SOIL specifications are not given. The values for NA and NV are taken as 1.0 unless otherwise specified. These values are the values for the near-source fractors Na and Nv respectively, which are used in the calculation of Ca and Cv respectively when the ZONE 4 specification above is given.

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Dynamic Data Commands

⎧ ESSENTIAL (FACILITIES) ⎫ ⎪ ⎪ ⎪ HAZARDOUS (FACILITIES) ⎪ ⎪ SPECIAL (STRUCTURES) ⎪ ⎪ ⎪ OCCUPANCY (CATEGORY ) ⎨ ⎬ ⎪ STANDARD (STRUCTURES) ⎪ ⎪ MISCELLANEOUS (STRUCTURES)⎪ ⎪ ⎪ ⎪⎩ I vI ⎪⎭

The seismic importance factor I is calculated based on the OCCUPANCY CATAGORY specified using this required option. The value I is calculated automatically by specifying one of the categories ESSENTIAL, HAZARDOUS, SPECIAL, STANDARD, or MISCELLANEOUS. A value for I can also be specified directly by giving the value vI.

The numerical coefficient Ct used for the calculation of the structure period according the 1997 UBC Section 1630.2.2, Method A is calculated using the specifications of this required option. The value for Ct is calculated automatically by specifying one of the categories SMR, RCMR, or OTHER. SMR stands for Steel Moment-Resting frames, RCMR stands for Reinforced Concrete Moment-Resting frames and eccentrically braced frames, and OTHER stands for all Other buildings. The value Ct can also be specified directly by giving a value for vCT. R vR This required option is used to specify the over-strength/ductility factor R according to 1997 UBC Tables 16-N or 16-P.

The optional WITH TORSION specification is used to specify that the calculation of the UBC97 joint loads shall include the effects of the rigid diaphram, torsional mass displacement described in 1997 UBC Sections 1630.6 and 1630.7. The default PLUS option indicates that each floor mass distribution for the load computation shall reflect the shift from the floor center of mass in a positive global direction perpendicular to the global load-application direction specified by the DIRECTION option. The MINUS option indicates that each floor mass distribution shall reflect the shift from the floor center of mass in a negative global direction perpendicular to the global loadapplication direction.

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FLOOR (TOLERANCE) vTOL The optional FLOOR TOLERANCE specification is used to specify the elevation neighborhood within which groups of joints comprise a particular floor for the calculation of the UBC97 load. All joints whose elevation is within the specified tolerance are assumed to comprise a floor. The value for vTOL must reflect active length units and is taken as 6 inches by default. Because the UBC97 load computations are performed only for the active joints, any joints that shall not be considered as part of any floor can be inactivated prior to issuing the FORM UBC97 command and then re-activate following the command: INACTIVE JOINTS... FORM UBC97 LOAD... ACTIVE JOINTS ALL

Errors: The following messages indicate warning conditions that can occur during the execution of the FORM UBC97 LOAD command. 1.

The following message is produced if the specified weight loading does not exist. **** WARNING_STUBC9 -- Specified WEIGHT loading DL1 does not exist. Command ignored.

2.

One or more of the following three messages are produced if seismic zone and soil profile data are not correctly specified: **** WARNING_STUBC9 -- Value for seismic coefficient Cv incorrectly specified. Command ignored. **** WARNING_STUBC9 -- Value for seismic coefficient Ca incorrectly specified. Command ignored. **** WARNING_STUBC9 -- Value for seismic zone factor Z incorrectly specified. Command ignored. The following is an example of a FORM UBC97 command that will produce these warning messages: FORM UBC97 LOAD 'TESTUBCZ' DIR X WEIGHT LOAD 'DL' SOIL SC CT SMR OCC I 1.5 R 5.5 While the SOIL SC specification is given, the ZONE/Z specification is missing, resulting in insufficient data for the calculation of the seismic coefficients Ca and Cv. 15 - 70

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3.

Dynamic Data Commands

The following message is produced if the required occupancy data are incorrectly specified. **** WARNING_STUBC9 -- Value for importance factor I incorrectly specified. Command ignored. The following is an example of a FORM UBC97 command that will produce this warning message: FORM UBC97 LOAD 'TESTUBCZ' DIR X WEIGHT LOAD 'DL' CA 0.24 CV 0.32 CT SMR R 5.5 The required OCCUPANCY option is not given.

4.

This warning message is given if a value for the over-strength/ductility factor R is not specified using the required R command option: **** WARNING_STUBC9 -- Value for R factor incorrectly specified. Command ignored.

5.

The following warning message is given if the value for the numerical coefficient Ct is not correctly specified using the required CT command option:

6. **** WARNING_STUBC9 -- Value for period coefficient Ct incorrectly specified. Command ignored.

Extended Example: The following UBC97 command example correctly defines a 1997 UBC static lateral load having the name UBCX: FORM UBC97 LOAD 'UBCX' DIR X WEIGHT LOAD 'DL' SOIL SC ZONE 2B CT SMR OCC I 1.5 R 5.5 The load is calculated using the following 1997 UBC parameter values: Ct Z I R Ca Cv Na Nv

= = = = = = = =

0.035 0.2 1.5 5.5 0.24 0.32 1.0 1.0

No torsion effects are included in the computation of loading UBCX. 15 - 71

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Dynamic Analysis

The following example is the same as the previous one, with the exception that the CV 0.35 parameter is added following the ZONE 2B option. The TORSION option is also added: FORM UBC97 LOAD 'UBCXNEW' DIR X WEIGHT LOAD 'DL' ZONE 2B SOIL SC CV 0.35 OCC CATEGORY I 1.5 CT SMR R 5.5 TORSION MINUS The 1997 UBC parameter values that are used to calculate loading UBCXNEW are the same as those that are used to calculate load UBCX in the previous example, with the exception that Cv = 0.35 rather than Cv = 0.32, by virtue of the fact that this is the value that is directly specified for Cv using the CV 0.35 parameter specification. The specified value for Cv takes precedence over the value that is computed according to the 1997 UBC provisions. Loading UBCXNEW also reflects a negative global Z offset of the floor masses with respect to each floor center of mass.

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Dynamic Analysis

15.2.14

Dynamic Data Commands

FORM IS1893 STATIC SEISMIC LOAD Command - Automatic Generation of Static Earthquake Loads According to the Indian Standard IS 1893 Seismic Code

⎧'asl ' ⎫ FORM IS1893 ( STATIC ) ( SEISMIC ) LOAD ⎨ ⎬ ( ' titlesl ' ) ⎩ isl ⎭ ⎧→ X ⎫ ⎧→ X ⎫ ⎪ ⎪ ⎪ ⎪ DIRECTION ⎨ Y ⎬ HEIGHT (DIRECTION ) ⎨ Y ⎬ WEIGHT ⎪ Z⎪ ⎪ Z⎪ ⎩ ⎭ ⎩ ⎭ ⎧II ⎫ ⎪III ⎪ ⎪⎪ ⎪⎪ ZONE ⎨IV ⎬ SOIL ( TYPE ) ⎪V ⎪ ⎪ ⎪ ⎪⎩Z v z ⎪⎭ ⎧SMR ⎫ ⎪RCMR ⎪ ⎪ ⎪ PERIOD ( TYPE ) ⎨ ⎬ OTHER ⎪ ⎪ ⎪ ⎪⎭ v where, ⎩ T ‘asl’/isl =

‘titlesl’ = ‘aw’/iw = vZ

=

vI vT

= =

= vR vTOL =

(LOAD )

⎧'a w ' ⎫ ⎨ ⎬ ⎩ iw ⎭

⎧I ⎫ ⎪ ⎪ ⎨II ⎬ IMPORTANCE (FACTOR ) VI ⎪III⎪ ⎩ ⎭

R vR

(FLOOR ( TOLERANCE) v ) TOL

alphanumeric or integer name for the generated IS 1893 static seismic load. This name must be unique among all current loading names and is limited to eight characters or digits. optional static load title of up to 64 characters in length. alphanumeric or integer name of the independent loading that is used for the calculation of the weight distribution of the structure. decimal value for the IS 1893 seismic zone factor Z. This specified value supersedes the calculated value based on the seismic zone specified by the ZONE option. decimal value for the IS 1893 importance factor I. decimal value for the building fundamental period in seconds, to be used for the calculation of the average response acceleration coefficient Sa/g. decimal value for the IS 1893 response reduction factor R. All joints within this specified HEIGHT DIRECTION tolerance of one another are assumed to define the geometry of a single floor. The input of this value assumes length units. The default value for vTOL is taken as 6.0 inches (15.24 cm).

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Dynamic Analysis

Example FORM IS1893 LOAD 'IS1893X' DIR X WEIGHT LOAD 'DL' SOIL TYPE II ZONE V PERIOD 1.00 IMPORTANCE 1.5 R 4.0

Explanation The FORM IS1893 LOAD command is used to compute an independent loading condition consisting of static joint loads only in accordance with the provisions of Sections 6 and 7, Indian Standard IS 1893 (Part I): 2002. A very important aspect regarding the execution of this command is that all load computations are performed only on the currently active joints. The options used to define this loading condition are described as follows:

⎧→ X ⎫ ⎪ ⎪ DIRECTION ⎨ Y ⎬ ⎪ Z⎪ ⎩ ⎭ The DIRECTION option is used to specify the global coordinate direction of computed joint load components contained in the loading condition. The global X direction is the default.

HEIGHT (DIRECTION)

⎧ X⎫ ⎪ ⎪ ⎨→ Y ⎬ ⎪ Z⎪ ⎩ ⎭

The HEIGHT DIRECTION option specifies the global coordinate direction that defines the elevation coordinate for the structure. For example, HEIGHT DIRECTION Y specifies that the height of the building structure and the building floor elevations are defined with respect to the global Y axis. It is assumed that elevations are measured from 0 at the joint having the least HEIGHT DIRECTION joint coordinate value to the full height of the structure at the joint having the largest HEIGHT DIRECTION joint coordinate value.

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Dynamic Data Commands

⎧'a W ' ⎫ WEIGHT (LOAD ) ⎨ ⎬ ⎩ iW ⎭ The required WEIGHT LOAD command option is used to identify the static, independent loading from which the total weight of the building model is computed. The total weight is computed as the sum of the absolute values of all translation load components (FORCE X, FORCE Y, and FORCE Z). The specified loading must have been defined previous to the time that the FORM IS1893 command is given.

⎧II ⎫ ⎪III ⎪ ⎪⎪ ⎪⎪ ZONE ⎨IV ⎬ ⎪V ⎪ ⎪ ⎪ Z v ⎩⎪ Z ⎭⎪ This required command is used to specify data about the relevant earthquake zone for the load calculations. Use the ZONE option to select zone II, III, IV, V or to directly specify a value vZ for the seismic zone factor Z.

⎧I ⎫ ⎪ ⎪ SOIL ( TYPE ) ⎨II ⎬ ⎪III⎪ ⎩ ⎭ These options are used to specify data about the seismic zone soil conditions for the calculation of the average response acceleration coefficient Sa/g.

This required command is used to specify the value for the seismic importance factor I.

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Dynamic Analysis

⎧SMR ⎫ ⎪RCMR ⎪ ⎪ ⎪ PERIOD ( TYPE ) ⎨ ⎬ ⎪OTHER ⎪ ⎪⎩ v T ⎪⎭ The required PERIOD command is used to select the equation for the calculation of the approximate building natural period Ta. SMR stands for Steel Moment-Resisting frames, RCMR stands for Reinforced Concrete Moment-Resisting frames and eccentrically braced frames, and OTHER stands for all Other buildings. The period in seconds also can be specified directly by specifying a decimal value vT. R vR This required option is used to specify the value for the response reduction factor. FLOOR (TOLERANCE) vTOL The optional FLOOR TOLERANCE specification is used to specify the elevation neighborhood within which groups of joints comprise a particular floor for the calculation of the IS1893 load. All joints whose elevation is within the specified tolerance are assumed to comprise a floor. The value for vTOL must reflect active length units and is taken as 6 inches by default. Because the IS1893 load computations are performed only for the active joints, any joints that shall not be considered as part of any floor can be inactivated prior to issuing the FORM IS1893 STATIC SEISMIC LOAD command and then re-activated following the command: INACTIVE JOINTS • • • • • • FORM IS1893 LOAD • • • • • • ACTIVE JOINTS ALL

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Errors: The following messages indicate warning conditions that can occur during the execution of the FORM IS1893 LOAD command. 1.

The following message is produced if the specified weight loading does not exist.

**** WARNING_STIS93 --

2.

Specified WEIGHT loading DL1 does not exist. Command ignored.

The following message is produced if seismic zone data are not correctly specified:

**** WARNING_STIS93 --Seismic zone factor Z incorrectly specified. Command ignored.

The following is an example of a FORM IS1893 command that will produce this warning message: FORM IS1893 LOAD 'TESTISX' DIR X WEIGHT LOAD 'DL' SOIL II PERIOD TYPE SMR IMP 1.5 R 4.0 The ZONE option is not specified in the command. 3.

The following message is produced if the soil type is not correctly specified:

**** WARNING_STIS93 --Soil type not correctly specified. Command ignored.

The following is an example of a FORM IS1893 command that will produce this warning message: FORM IS1893 LOAD 'TESTISX' DIR X WEIGHT LOAD 'DL' ZONE III PERIOD TYPE SMR IMP 1.5 R 4.0 The SOIL TYPE option is not specified in the command.

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4.

Dynamic Analysis

The following message is produced if the importance factor I is incorrectly specified.

**** WARNING_STIS93 -- Importance factor I incorrectly specified. Command ignored.

The following is an example of a FORM IS1893 command that will produce this warning message: FORM IS1893 LOAD 'TESTISX' DIR X WEIGHT LOAD 'DL' ZONE III SOIL TYPE III PERIOD TYPE SMR R 4.0 The required value of the importance factor I is not specified. 5.

This warning message is given if a value for the response reduction factor R is not specified using the required R command option:

**** WARNING_STIS93 --

6.

R factor incorrectly specified. Command ignored.

The following warning message is given if the PERIOD option is not specified.

. **** WARNING_STIS93 --

Building natural period incorrectly specified. Command ignored.

Example: The following FORM IS1893 command example correctly defines an IS 1893 static lateral load having the name IS1893X: FORM IS1893 LOAD 'IS1893X' DIR X WEIGHT LOAD 'DL' SOIL TYPE II ZONE V PERIOD 1.00 IMPORT 1.5 R 4.0 The period is directly specified as 1.0 seconds.

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Dynamic Analysis

15.3

Dynamic Analysis Commands

Dynamic Analysis Commands This Section 15.3 describes the commands provided by GTSTRUDL to perform linear dynamic analysis of frame and finite element structures as follows: 15.3.0

ACTIVE SOLVER Command

15.3.1

EIGEN PARAMETERS Command

15.3.2

DYNAMIC PARAMETERS Command

15.3.3

LIST RAYLEIGH LOADING Command

15.3.4

DYNAMIC ANALYSIS EIGENVALUES Command

15.3.5

LIST DYNAMIC PARTICIPATION FACTORS

15.3.6

INACTIVE/ACTIVE MODES Command

15.3.7

PERFORM RESPONSE SPECTRUM ANALYSIS Command 15.3.7.1 15.3.7.2

15.3.7.3 15.3.7.4 15.3.7.5 15.3.7.6

PERFORM RESPONSE SPECTRUM ANALYSIS Command LIST RESPONSE SPECTRUM SPECTRAL ACCELERATIONS and LIST RESPONSE SPECTRUM PARTICIPATION FACTORS Commands (for Base Shear) Base Shear Calculations Designing Shear Walls Based on a Response Spectrum Earthquake Analysis FORM MISSING MASS LOAD Command Extended Example: RESPONSE SPECTRUM ANALYSIS, FORM MISSING MASS LOAD, and Base Shear Calc.

15.3.8

PERFORM TRANSIENT ANALYSIS Command

15.3.9

PERFORM PHYSICAL ANALYSIS Command

15.3.10 PERFORM NUMBER OF MODES COMPUTATION Command Table 15.3-1 contains a brief description of the commands for the performance of various types of dynamic analysis. Table 15.3-2 contains a summary of results computed by the various types of dynamic analysis. 15 - 79

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Table 15.3-1 Commands for Performance of Dynamic Analysis Command Name

Brief Description

ACTIVE SOLVER GTSES

Perform all subsequent Eigen solving using the GTSELANCZOS solver and static analyses using the GTSES solver.

EIGEN PARAMETERS DYNAMIC PARAMETERS

Specify various parameters used to control the processing of the Eigen problem solution commands, and transient and response spectrum analysis commands, such as DYNAMIC ANALYSIS EIGENVALUE and PERFORM RESPONSE SPECTRUM ANALYSIS.

LIST RAYLEIGH LOADING

Computes and outputs the result of a Rayleigh approximate natural frequency analysis. The corresponding mode shape is approximated as the joint displacements computed in a prior STIFFNESS ANALYSIS where only translational joint forces (not moments) have been applied.

DYNAMIC ANALYSIS EIGENVALUES

LIST DYNAMIC PARTICIPATION FACTORS

Causes an Eigen solution analysis for the computation of natural frequencies and mode shapes to be performed consistent with parameters specified by the EIGEN PARAMETERS command. Computes and outputs the mass participation factors as a percentage of the total mass participating in each computed mode in each global X, Y, and Z axis direction.

ACTIVE/INACTIVE MODES

Identifies the active modes, from among all computed modes, that will be used in subsequent modal superposition transient and response spectrum analyses.

PERFORM RESPONSE SPECTRUM ANALYSIS

Causes a response spectrum analysis to be performed for each currently active computed mode, and for all active response spectrum loading conditions. Only modal participation factors, modal coefficients, and spectrum accelerations, velocities, and displacements, are computed by this command.

LIST RESPONSE SPECTRUM SPECTRAL ACCELERATIONS

Computes and outputs modal acceleration values that are taken from currently active Response Spectrum loading data which is needed for Base Shear Calculations.

LIST RESPONSE SPECTRUM PARTICIPATION FACTORS

Computes and outputs modal participation factors following a Response Spectrum Analysis which is needed for Base Shear Calculations.

FORM MISSING MASS LOAD

Computes a new independent static loading condition consisting of joint load components that reflect the total mass associated with all modes ignored in a prior Response Spectrum Analysis.

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Dynamic Analysis Commands

Table 15.3-1 Commands for Performance of Dynamic Analysis (Cont.) Command Name

Brief Description

PERFORM TRANSIENT ANALYSIS

Causes a modal superposition analysis to be performed using all currently active computed modes, and for all active dynamic transient loading conditions. Only time histories of joint accelerations, velocities, and displacements are computed by this command.

PERFORM MODAL SUPERPOSITION ANALYSIS

Causes a modal superposition analysis to be performed using all currently active computed modes, and for all currently active dynamic response spectrum and transient loading conditions. This command is equivalent to giving both the PERFORM RESPONSE SPECTRUM ANALYSIS and PERFORM TRANSIENT ANALYSIS commands. In addition, this command also performs a modal superposition for all active steady state and harmonic loading conditions.

PERFORM PHYSICAL ANALYSIS

PERFORM NUMBER OF MODES COMPUTATION

Causes a direct time integration transient analysis for all active dynamic transient loading conditions. Only time histories of joint accelerations, velocities, and displacements are computed by this command. Causes the total number of modes to be computed and output which lie in the frequency range from 0.0 to some specified maximum frequency.

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Dynamic Analysis

Table 15.3-2 Dynamic Analysis Options Dynamic Analysis Type: Load Type:

EIGENVALUE

PHYSICAL (Direct Integration)

MODAL SUPERPOSITION

-----

Response Spectrum

Transient

Steady State

Eigenvalues

X

X

X

X

X

-----

Eigenvectors

X

X

X

X

X

-----

Modal Coefficients

-----

X

-----

-----

X

-----

Time History of Displacements

-----

-----

X

X

-----

X

Time History of Velocities

-----

-----

O

O

-----

O

Time History of Accelerations

-----

-----

O

O

-----

O

X = results computed and stored O = option (see DYNAMIC PARAMETERS command in Section 15.3.2

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Harmonic

Transient

Dynamic Analysis

Dynamic Analysis Commands

15.3.0 The ACTIVE SOLVER Command

Example:

ACTIVE SOLVER GTSES

Explanation: The purpose of the ACTIVE SOLVER command is to designate that all subsequent static analyses shall use the GTSES solver and Eigen solving shall use the GTSELANCZOS solver. When the GTSES option is specified, all subsequent STIFFNESS ANALYSIS commands will use the GTSES high performance sparse equation solver (Section 11.1), and all subsequent dynamic eigenvalue analyses will use the high performance GTSELANCZOS Eigen solver, regardless of which method is specified in the EIGEN PARAMETERS command (Section 15.3.1). In addition, the GTSES option causes the results produced by these analysis procedures and related results processing procedures to be stored into files in the current GTSTRUDL working directory/folder on the computer's hard drive rather than in virtual memory. The GTSES option further implies that all analysis result postprocessing operations, both text report processing and graphical processing, assume that linear static and dynamic analysis results (with the exception of dynamic steady state analysis results) exist in said files. When the ACTIVE SOLVER GTSES command is given, the following message is reported: **** INFO_STIFFN -- The active solver is set to GTSES. Stiffness analysis solution is set to GTSES, eigenvalue analysis solution is set to GTSELANCZOS, and analysis results will be stored in external files. The STANDARD option is used to reset the linear static and dynamic analysis solvers to the original default solvers. When the ACTIVE SOLVER STANDARD is given, the following message is reported: **** INFO_ACT -- The active solver is set to STANDARD. Stiffness analysis solution is set to default, eigenvalue analysis solution is set to GTLANCZOS, and analysis results will be stored in virtual memory. For all practical purposes, the ACTIVE SOLVER command need only be given once, prior to the execution of the first analysis, and when the GTSES option is intended. Although not prevented, switching between the GTSES and STANDARD options within the same job is strongly discouraged and may cause problems with results processing and postprocessing due to inconsistencies between results that are stored in files and results that are stored in virtual memory. 15 - 83

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Dynamic Analysis

15.3.1 EIGEN PARAMETERS Command

EIGEN (PARAMETERS)

NUMBER (OF) MODES i1 FREQUENCY (SPECIFICATIONS) 0.0 (TO) r1

DUMP ORTHOGONALITY MAXIMUM (ITERATIONS) i3

END (OF EIGEN PARAMETERS)

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Dynamic Analysis Commands

Elements: r1

=

upper bound on frequency range in current units for use by the GTLANCZOS and GTSELANCZOS Eigen solvers.

i1

=

number of modes to be computed.

i2, v1 =

integer or alphanumeric load name for initial stress computations

i3

maximum number of iterations allowed (must be 5000 or less for GTLANCZOS and GTSELANCZOS).

=

v2, v3 =

eigenvalue and eigenvector tolerances.

Example EIGEN PARAMETERS SOLVE USING GTLANCZOS NUMBER OF MODES 50 INITIAL STRESS LOAD 10 PRINT MAX END

Explanation The EIGEN PARAMETERS command is used to specify parameters required by the Eigen problem solvers. If multiple eigenvalue analyses are to be performed, the parameters may be changed by respecifying the value or option in subsequent EIGEN PARAMETER commands. Otherwise, all parameters will remain unchanged. This command should not be given in the CHANGES mode. To change the data, respecify the command in the ADDITIONS mode. A summary of the EIGEN PARAMETERS command options and default values are presented in Table 15.3.3, and are described as follows: SOLVE USING: The SOLVE USING option permits the specification of one of four methods for the solution of eigenvalues (frequencies) and eigenvectors (mode shapes), two of which (GTLANCZOS AND GTSELANCZOS) are described in this Analysis User Guide. This option should be the first option specified under the EIGEN PARAMETERS command. Although not the default, the GTLANCZOS Eigen solver should be the preferred Eigen solver for most Eigen solutions. For very large problems, the GTSELANCZOS (GT Sparse Equation Lanczos) Eigen solver may be used.

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Dynamic Analysis

If the SOLVE USING option is not given prior to an eigenvalue analysis, the default Eigen solver is TRIDIAGONALIZATION (GTSTRUDL User Reference Manual, Volume 3, Section 2.4.5.2). NUMBER OF MODES: The NUMBER OF MODES option specifies the number of frequencies and mode shapes to be computed by a subsequent eigenvalue analysis. The maximum number that may be specified for use by GTLANCZOS and GTSELANCZOS must be less than the rank of the mass matrix. FREQUENCY SPECIFICATIONS: The FREQUENCY SPECIFICATIONS option specifies that frequencies in the range from 0.0 to r1 are to be computed. If both the NUMBER OF MODES and FREQUENCY SPECIFICATIONS options are given, the more restrictive option is used. PRINT: The PRINT option specifies whether or not certain Eigen solution statistics are to be printed such as the number of dynamic degrees-of-freedom, the number of modes requested, etc. PRINT MINIMUM is the default. INITIAL STRESS LOAD: The INITIAL STRESS LOAD option is used to specify an independent load or load combination for which a static analysis has been computed by a prior STIFFNESS ANALYSIS and whose analysis results are used to incorporate the effect of initial stress in a subsequent Eigen solution analysis. This option is limited to structure models consisting only of space frame, space truss, and plate finite elements. Further, the space frame members must not have member eccentricities or member end sizes specified. The OFF option turns off this specification. PERFORM: The PERFORM option is used to turn on or off one or more of the three checks on the accuracy of the Eigen solution. The default is for all three Eigen solution checks to be turned on, and which are the following: STURM SEQUENCE CHECK: This check is used to verify if the lowest requested frequencies and associated modes have been found, and within the specified frequency range if given. ERROR ESTIMATE: This error check computes a measure of error as a residual norm as follows: ei

[K]

=

error estimate for mode i, where

=

the computed eigenvector for mode i

=

the computed eigenvalue for mode i

=

the system stiffness matrix, 15 - 86

[M] = the system mass matrix

Dynamic Analysis

Dynamic Analysis Commands

ORTHOGONALITY CHECK:

This check verifies if all computed modes are orthogonal with respect to mass and stiffness, and is computed as follows:

=

matrix of computed eigenvectors stored column by column

=

identity matrix (diagonal matrix with each diagonal value = 1.0)

=

diagonal matrix where the diagonal values equal the eigenvalues

DUMP ORTHOGONALITY: The DUMP ORTHOGONALITY option specifies that the entire and matrices are to be output following the orthogonality check. MAXIMUM ITERATIONS: The MAXIMUM ITERATION limit option specifies the maximum number of iterations used to compute eigenvalues and eigenvectors. The default MAXIMUM ITERATION limit is adequate for most eigenvalue computations, but may not be sufficient in cases of slow convergence such as those caused by duplicate or closely spaced frequencies or where the value of the frequencies sought are relatively high (e.g., when the fundamental frequency is 30 Hz). TOLERANCE: The TOLERANCE option specifies the computational tolerance used in the eigenvalue and eigenvector computations. This option may be used to change the tolerance in order to achieve a more or less accurate solution than that produced by using the default value. The changing of this tolerance can have a major effect on solution times. The default eigenvalue tolerance is appropriate for most computations.

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Dynamic Analysis

Table 15.3.3 Eigen Parameter Options and Defaults

Keyword

Modifier

Solver GTLANCZOS and GTSELANCZOS

FREQUENCY SPECS

YES

PERFORM .......

ST, ER, OR

DUMP ORTHOGONALITY

YES

NUMBER OF MODES

0

ITERATION LIMIT

# 5000

TOLERANCE

EIGENVALUE

1.E-06

EIGENVECTOR

N/A

PRINT

MINIMUM

Legend: N/A YES ST ER OR

= = = = =

not applicable the option is available but there is no default Sturm sequence check performed by default error estimate performed by default orthogonality check performed by default

Otherwise, the entry is the default.

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Dynamic Analysis

Dynamic Analysis Commands

Extended Examples (1)

UNITS CYCLES SECOND EIGEN PARAMETERS SOLVE USING GTLANCZOS NUMBER OF MODES 200 FREQUENCY SPECS 0. TO 30. PRINT MAX END EIGEN PARAMETERS $ DYNAMIC ANALYSIS EIGENVALUE

The eigenvalue problem will be solved by GTLANCZOS. The number of modes computed will be the lesser of (a) the lowest 200 modes, or (b) all of the modes whose natural frequency is less than or equal to 30 Hz. Eigenvalue computation statistics will be output. (2)

SELF WEIGHT 1 'DEAD LOAD OF MEMBERS' DIRECTION -Y ALL MEMBERS • • STIFFNESS ANALYSIS • UNITS CYCLES SECONDS EIGEN PARAMETERS SOLVE USING GTLANCZOS NUMBER OF MODES 100 INITIAL STRESS LOAD 1 FREQ SPECS 0. TO 35. END

The eigenvalue problem will be solved by GTLANCZOS. No more than 100 modes will be extracted in the frequency range of 0 Hz to 35 Hz. Stresses computed from a prior STIFFNESS ANALYSIS for Load 1 are accounted for in the Eigen solution computation. (2)

UNITS CYCLES SECONDS EIGEN PARAMETERS INITIAL STRESS LOAD OFF END

The INITIAL STRESS LOAD option is turned off for subsequent eigenvalue problem solutions.

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Dynamic Analysis Commands

Dynamic Analysis

15.3.2 DYNAMIC PARAMETERS Command

DYNAMIC PARAMETERS

RESULTS FILE NAME ‘fln’

DURATION (OF EARTHQUAKE) v

END (OF DYNAMIC PARAMETERS) where, v

=

duration of earthquake to be used in a NRC Double Sum Method response spectrum combination. The default is taken as 10 seconds.

‘fln’

=

alphanumeric string to be used as the prefix in the construction of the dynamic analysis results file names when the USE EXTERNAL FILE SOLVER option is given. The length of the alphanumeric string is limited to 24 characters.

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Dynamic Analysis

Dynamic Analysis Commands

Example DYNAMIC PARAMETERS USE EXTERNAL FILE SOLVER RESULTS FILE NAME 'JOB1' STORE VELOCITY OFF STORE ACCELERATION OFF END

Explanation The DYNAMIC PARAMETERS command is used to specify miscellaneous parameters related to dynamic analysis. It is important to note that when used, the USE EXTERNAL FILE SOLVER and RESULTS FILE NAME commands must be given prior to the PERFORM RESPONSE SPECTRUM ANALYSIS (Section 15.3.7.1) or PERFORM TRANSIENT ANALYSIS (Section 15.3.8) commands. The USE EXTERNAL FILE SOLVER option specifies that results computed from a subsequent transient or response spectrum dynamic analysis, and by results generated by the COMPUTE command (Sections 15.4.1 and 15.4.2), are to be stored in dynamic analysis results files on disk outside of virtual memory rather than within virtual memory. For large transient analysis or response spectrum analysis problems, this may reduce the execution time dramatically over the use of virtual memory to compute and store dynamic analysis results. The execution time savings have been observed to be an order of magnitude or more. The USE INTERNAL FILE SOLVER command is used to revert back to the virtual memory storage of transient and response spectrum results if the USE EXTERNAL FILE SOLVER command had been previously specified. The RESULTS FILE NAME option specifies an alphanumeric string to be used as a file name prefix in the creation of the transient and response spectrum results file names when the USE EXTERNAL FILE SOLVER option is given. If this option is not given, then the file name prefix string ‘fln’ is taken as the problem “id” given in the STRUDL command (Section 4.2, GTSTRUDL User Guide: Analysis) or the CHANGE ID command (Section 2.1.2.5, Volume 1, GTSTRUDL User Reference Manual). If a problem “id” is not specified in either of these two commands, then ‘fln is taken as “GTS”. The convention for constructing the transient and response spectrum results file names is as follows:

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Dynamic Analysis Commands

Dynamic results file name =

Dynamic Analysis

fln||load id||.drt

where, || fln load id .drt

= = = =

indicates concatenation of alphanumeric character strings, file name prefix as described above, the name of the dynamic loading for which the results are computed, a three-character file name extension indicating the type of dynamic results stored in the file.

The values for .drt and the corresponding dynamic analysis result types are as follows: File Extension Description .dsp

Joint displacements computed automatically by a transient analysis (Section 15.3.8) or by the COMPUTE command for a response spectrum analysis (Section 15.4.1),

.vel

Joint velocities computed automatically by a transient analysis (Section 15.3.8) or by the COMPUTE command for a response spectrum analysis (Section 15.4.1),

.acc

Joint accelerations computed automatically by a transient analysis (Section 15.3.8) or by the COMPUTE command for a response spectrum analysis (Section 15.4.1),

.lmf

Linear member and finite element forces computed by the COMPUTE command for transient analysis (Section 15.4.2) and by the COMPUTE command for response spectrum analysis (Section 15.4.1),

.nmf

Nonlinear member and element forces computed automatically by a nonlinear dynamic transient analysis,

.les

Linear finite element stresses and strains, computed by the COMPUTE command for transient analysis (Section 15.4.2) and by the COMPUTE command for response spectrum analysis (Section 15.4.1),

.rea

Support reactions computed by the COMPUTE command for transient analysis (Section 15.4.2) and by the COMPUTE command for response spectrum analysis (Section 15.4.1),

.lds

Resultant joint loads, computed by the COMPUTE command for transient analysis (Section 15.4.2) and by the COMPUTE command for response spectrum analysis (Section 15.4.1).

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Dynamic Analysis

Dynamic Analysis Commands

The STORE command option specifies whether nodal velocities and accelerations will be stored in a transient or steady state analysis. If either or both are not required, then the OFF option will bypass their computation and storage, and will result in decreased execution times and the use of less disk file space. Note that only displacements are used in the back substitution computation of forces, stresses, and reactions. If the STORE command is not given, then both velocities and accelerations are computed and stored. In addition, the STORE command option is used to specify that ABSOLUTE or RELATIVE accelerations should be computed and stored during a support acceleration transient analysis. This choice will be important if the CREATE TIME HISTORY command (Section 15.2.6) is to be given. If the command is not given, then RELATIVE is assumed. The DURATION OF EARTHQUAKE option is used to specify the quantity needed in the NRC Double Sum Method of modal combination. The formula appears in Section 2.4.2.5. The END command is used to terminate the DYNAMIC PARAMETER command.

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Dynamic Analysis Commands

Dynamic Analysis

15.3.3 LIST RAYLEIGH LOADING Command

LIST RAYLEIGH (NATURAL FREQUENCY) LOADING list

where, list

=

list of independent static load names

Example LIST RAYLEIGH FREQUENCIES LOADINGS 1 2

Explanation The LIST RAYLEIGH FREQUENCY command is used to compute and to output the results of a Rayleigh Quotient analysis as described in Section 2.4.2.8 of the GTSTRUDL User Reference Manual. The Rayleigh Quotient procedure is an approximate method to compute a few natural frequencies (especially the first mode frequency) of a structure using the static deflected shape of the structure that approximates the shape of the mode for which the frequency is to be approximated. The independent static loading conditions referenced by the list should contain only applied joint forces as given by a JOINT LOADS command or as given by the ALL JOINTS or JOINTS list options of the DEAD LOAD command. If member loads and/or joint moments exist in a loading condition, those load components contribute to the displacements used in the Rayleigh computation, but only the joint forces (not moments) in the loading conditions identified in the list are used in the calculation of the Rayleigh frequencies as shown in Equation 8-6 in Section 2.4.2.8 of the GTSTRUDL User Reference Manual. A STIFFNESS ANALYSIS must have previously been performed for the loading conditions identified in the list. The joint displacements computed by the STIFFNESS ANALYSIS are the one used in the calculation of the Rayleigh frequencies as shown in Equation 8-6 in Section 2.4.2.8 of the GTSTRUDL User Reference Manual.

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Dynamic Analysis

Dynamic Analysis Commands

Extended Example STRUDL 'TEST' 'RAYLEIGH FREQUENCY TEST' C C DEAD LOAD 1 '1st Mode Approximated by Dead Load' DIRECTION X ALL JOINTS C C LOADING 2 '2nd Mode Approximated by Concentrated Joint Loads' JOINT LOADS 1 TO 100 FORCE X 20. 101 TO 150 FORCE X -20. C C STIFFNESS ANALYSIS C C LIST RAYLEIGH FREQUENCY LOADINGS 1 2 C C FINISH

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Dynamic Analysis Commands

Dynamic Analysis

15.3.4 DYNAMIC ANALYSIS EIGENSOLUTION Command

DYNAMIC ANALYSIS EIGENSOLUTION

Example DYNAMIC ANALYSIS EIGENSOLUTION

Explanation The DYNAMIC ANALYSIS EIGENSOLUTION command is used to initiate an Eigen solution for eigenvalues, eigenvectors (mode shapes), undamped natural frequencies, and periods. The Eigen solution will proceed on the basis of parameters (e.g., Eigen solution algorithm, number of modes, etc.) specified in the EIGEN PARAMETERS command (Section 15.3.1). A bandwidth reduction is automatically performed unless the WITHOUT REDUCE BAND option is specified. It is important to note that the mass properties of the structure must have been specified prior to the use of the DYNAMIC ANALYSIS EIGENSOLUTION command. Otherwise, an Eigen solution cannot be performed and an error message will be issued, and the SCAN error flag (Section 4.8) will be set.

Extended Example INERTIA OF JOINTS LUMPED EIGEN PARAMETERS SOLVE USING GTLANCZOS NUMBER OF MODES 500 PRINT MAX END DYNAMIC ANALYSIS EIGENSOLUTION

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Dynamic Analysis

Dynamic Analysis Commands

15.3.5 LIST DYNAMIC PARTICIPATION FACTORS Command

LIST DYNAMIC PARTICIPATION FACTORS

Example LIST DYNAMIC PARTICIPATION FACTORS

Explanation The LIST DYNAMIC PARTICIPATION FACTORS command computes and outputs ground motion Mass Participation Factors for the global X, Y and Z translation directions. The factors are expressed as a percentage of mass in each direction participating in each active mode. This command may be issued at any time after an Eigenvalue analysis (Section 15.3.4) has been performed. NOTE:

The Inactive Modes dialog (Results >>> Dynamic Analysis Results >>> Inactive Modes) displays additional options for printing dynamic participation factors.

Extended Example INERTIA OF JOINTS LUMPED EIGEN PARAMETERS SOLVE USING GTLANCZOS NUMBER OF MODES 500 PRINT MAX END DYNAMIC ANALYSIS EIGENSOLUTION C C C LIST DYNAMIC PARTICIPATION FACTORS

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Dynamic Analysis Commands

Dynamic Analysis

15.3.6 INACTIVE/ACTIVE MODES Command

where, list

=

list of integer mode numbers

Example INACTIVE MODES ALL BUT 1 2 3 5 10 TO 15 27 59 63

Explanation The INACTIVE/ACTIVE MODES command is used to designate previously computed modes as being active or inactive in regard to their contribution to subsequent response computations. All modes computed by the DYNAMIC ANALYSIS EIGENSOLUTION command (Section 15.3.4) are designated as being active, regardless of any previously specified ACTIVE/INACTIVE MODES command. Modes that have been inactivated can be reactivated. The LIST DYNAMIC EIGENVALUES command (Section 15.5.4) is used to output the value of all computed modes and the ACTIVE/INACTIVE status of all modes. NOTE:

The Inactive Modes dialog (Results >>> Dynamic Analysis Results >>> Inactive Modes) displays additional options for printing dynamic participation factors, and it provides a powerful tool to automatically select ACTIVE and INACTIVE modes.

Extended Example INERTIA OF JOINTS LUMPED EIGEN PARAMETERS SOLVE USING GTLANCZOS NUMBER OF MODES 500 PRINT MAX 15 - 98

Dynamic Analysis

Dynamic Analysis Commands

END DYNAMIC ANALYSIS EIGENSOLUTION LIST DYNAMIC PARTICIPATION FACTORS C C C INACTIVE MODES ALL BUT 1 2 3 5 10 TO 15 27 35 43 47 125 TO 150 LIST DYNAMIC PARTICIPATION FACTORS In the above example, 500 modes are computed and used in the computation of mass participation factors. After inspecting the mass participation factors, it is observed that all modes except modes 1 2 3 5 10 TO 15 27 35 43 47 and 125 TO 150 would contribute little or nothing to subsequent dynamic response calculations and are therefore inactivated. Thus, all modes are inactivated except modes 1 2 3 5 10 TO 15 27 35 43 47 and 125 TO 150 which will be used in subsequent dynamic response calculations such as those of the PERFORM RESPONSE SPECTRUM ANALYSIS (Section 15.3.7), PERFORM TRANSIENT ANALYSIS (Section 15.3.8), PERFORM PHYSICAL ANALYSIS (Section 15.3.9), COMPUTE RESPONSE SPECTRUM Results (Section 15.4.1), and COMPUTE TRANSIENT Results (Section 15.4.2) commands. The second LIST DYNAMIC PARTICIPATION FACTORS command will compute and display the mass participation factors only for the currently active modes 1 2 3 5 10 TO 15 27 35 43 47 and 125 TO 150 . The user is cautioned that although the use of a fewer number of modes than the total number computed may result in significant reductions of computer resource requirements, it may also result in a significant loss of accuracy.

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Dynamic Analysis

15.3.7 RESPONSE SPECTRUM ANALYSIS The Response Spectrum Analysis procedure provides a very efficient method for determining the maximum response of a structure in any or all of its normal modes of vibration due to a ground motion loading such as caused by an earthquake. The total response of the structure to the ground motion (e.g., earthquake) can be determined by a statistical summation (CQC, RMS, PRMS, ABSOLUTE SUM, NRC Ten Percent, etc.) of the maximum modal responses. In general, it is not feasible to compute all modes of vibration of a structure. Rather, a combination of a subset of the total number of modes is used to estimate the maximum total response of the structure. The subset consists of those modes whose total computed response (as computed by a modal combination such as CQC or RMS) involves a total modal mass equal to some minimum percent (e.g., 85%) of the total mass of the structure. This subset of modes may be determined from the LIST DYNAMIC PARTICIPATION FACTORS command (Section 15.3.5). Further, the subset of modes may be activated, and all other modes made inactive, by using the INACTIVE/ACTIVE MODES command (Section 15.3.6), and where the active modes will be used in a subsequent response spectrum analysis. Since only an estimate of the maximum response of the structure will be computed by using the subset of modes rather than all modes of the structure, it is useful to be able to estimate the influence of the mass of the structure not accounted for by the subset of modes used (i.e., the missing mass influence). GTSTRUDL performs such a missing mass computation by assuming that the response of the structure to ground motion is static in the missing modes (i.e., the modes with frequencies that are higher than the frequency of the highest mode used in the subset of modes). Thus, the missing mass is represented by an equivalent static joint loading condition which is computed from the mass of the structure, the ground motion response influence vector, the modal participation factors, the eigenvectors, and the zero period acceleration (approximated as the acceleration associated with the ground motion cutoff frequency). The missing mass equivalent static load is then used as the active loading in a subsequent static STIFFNESS ANALYSIS, the results of which can be summed with the response spectrum maximum response in order to create a more accurate estimate of the total response of the structure due to ground motion. The following Sections 15.3.7.1 to 15.3.7.6 describe response spectrum analysis, response spectrum spectral accelerations and participation factors needed for Base Shear calculations, and missing mass static analysis, while Section 15.4.3 (the CREATE PSEUDO STATIC LOADING Command) describes a method to combine response spectrum analysis and missing mass static analysis results.

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Dynamic Analysis

15.3.7.1

Dynamic Analysis Commands

PERFORM RESPONSE SPECTRUM ANALYSIS Command

PERFORM RESPONSE (SPECTRUM ANALYSIS)

Example PERFORM RESPONSE SPECTRUM ANALYSIS

Explanation The PERFORM RESPONSE SPECTRUM ANALYSIS command is used to initiate a response spectrum analysis for all currently active response spectrum loading conditions (Section 15.2.11), and using all previously computed (Section 15.3.4, the DYNAMIC ANALYSIS EIGENVALUES command) and currently active (Section 15.3.6, the INACTIVE/ACTIVE MODES command) eigenvalues and eigenvectors. Modal participation factors, spectral displacements, spectral accelerations, and spectral velocities are computed. However, no mode superposition response computations are computed by this command. Rather, such response computations are performed by the COMPUTE RESPONSE SPECTRUM (Section 15.4.1) and LIST RESPONSE SPECTRUM (Section 15.5.6) results commands.

Extended Example INERTIA OF JOINTS LUMPED EIGEN PARAMETERS SOLVE USING GTLANCZOS NUMBER OF MODES 500 PRINT MAX END

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Dynamic Analysis

DYNAMIC ANALYSIS EIGENSOLUTION LIST DYNAMIC PARTICIPATION FACTORS C C $ Review mass participation factors and select relevant modes C INACTIVE MODES ALL BUT 1 2 3 5 10 TO 15 27 35 43 47 125 TO 150 LIST DYNAMIC PARTICIPATION FACTORS UNITS SECONDS RESPONSE SPECTRUM LOADING 2001 ‘Support Acceleration at 45 degree Angle’ SUPPORT ACCELERATION TRANSLATION X 0.707 Z 0.707 FILE ‘ELCENTRO’ END RESPONSE SPECTRUM LOAD RESPONSE SPECTRUM LOADING 2002 ‘Support Acceleration in Global X-Direction’ SUPPORT ACCELERATION TRANSLATION X FILE ‘ELCENTRO’ END RESPONSE SPECTRUM LOAD RESPONSE SPECTRUM LOADING 2003 ‘Support Acceleration in Global Z-Direction’ SUPPORT ACCELERATION TRANSLATION Z FILE ‘ELCENTRO’ END RESPONSE SPECTRUM LOAD $ Perform response spectrum analysis based on response spectrum loads 2001, 2002, $ and 2003 PERFORM RESPONSE SPECTRUM ANALYSIS

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Dynamic Analysis Commands

15.3.7.2 LIST RESPONSE SPECTRUM SPECTRAL ACCELERATIONS LIST RESPONSE SPECTRUM PARTICIPATION FACTORS Commands UNITS INCH POUNDS LIST RESPONSE SPECTRUM SPECTRAL ACCELERATIONS LIST RESPONSE SPECTRUM PARTICIPATION FACTORS

Example PERFORM RESPONSE SPECTRUM ANALYSIS UNITS INCH POUNDS LIST RESPONSE SPECTRUM SPECTRAL ACCELERATIONS LIST RESPONSE SPECTRUM PARTICIPATION FACTORS

Explanation The LIST RESPONSE SPECTRUM command is used to output previously computed Response Spectrum Analysis results associated with currently active RESPONSE SPECTRUM loading conditions (Section 2.4.4.6). The "Spectral Accelerations" and "Participation Factors" versions of this command are often used to display the information needed to compute Total Base Shear (Section 15.3.7.3) corresponding to a Response Spectrum Analysis (Section 15.3.7.3). 1.

LIST RESPONSE SPECTRUM SPECTRAL ACCELERATIONS: The LIST RESPONSE SPECTRUM SPECTRAL ACCELERATION command computes and outputs modal acceleration values that are taken from currently active Response Spectrum loading data for which a Response Spectrum Analysis has been performed. The units of Spectral Accelerations should be (INCH/SECOND**2) when used to calculate Base Shear.

2.

LIST RESPONSE SPECTRUM PARTICIPATION FACTORS: The LIST RESPONSE SPECTRUM PARTICIPATION FACTORS command computes and outputs modal participation factors following a Response Spectrum Analysis. Response Spectrum Modal Participation Factors are only output in Inches, Pounds, and Seconds. The units of the these participation factors are output as SQRT [(POUND-SECOND**2) / INCH].

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Dynamic Analysis

Response Spectrum Participation Factors, Spectral Accelerations, Velocities, and Displacements, and modal coefficients are defined in Chapter 2.4.2.5 in the GTSTRUDL User Reference Manual, Volume 3. Note that the Participation Factors output via the LIST DYNAMIC PARTICIPATION FACTORS (Section 15.3.5) command are the normalized values expressed as a percentage participation of total mass, while the values output via the LIST RESPONSE SPECTRUM PARTICIPATION FACTORS are the actual numerical values of the factors as computed in Eq. 5-6 in Section 2.4.2.5.

Extended Example INERTIA OF JOINTS LUMPED EIGEN PARAMETERS SOLVE USING GTSELANCZOS NUMBER OF MODES 1000 PRINT MAX END DYNAMIC ANALYSIS EIGENSOLUTION INACTIVE MODES ALL BUT 1 2 3 5 10 TO 15 27 35 43 47 125 TO 150 300 513 LIST DYNAMIC PARTICIPATION FACTORS PERFORM RESPONSE SPECTRUM ANALYSIS UNITS INCH POUNDS SECONDS LIST RESPONSE SPECTRUM SPECTRAL ACCELERATIONS LIST RESPONSE SPECTRUM PARTICIPATION FACTORS

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Dynamic Analysis

15.3.7.3

Dynamic Analysis Commands

BASE SHEAR CALCULATIONS

NOTE:

GTSTRUDL can automatically compute base shear values as described in Section 15.5.6.

However, the total base shear corresponding to the earthquake direction for the full structure can be computed by hand as follows: 1.

Change currently active UNITS to INCHES, POUNDS, and SECONDS (the internal units of GTSTRUDL)

2.

Output the modal spectral acceleration values for the response spectrum loads using the "LIST RESPONSE SPECTRUM SPECTRAL ACCELERATIONS" command (Section 15.3.7.2).

3.

Output the response spectrum modal participation factors using the "LIST RESPONSE SPECTRUM PARTICIPATION FACTORS" command (Section 15.3.7.2).

4.

IMPORTANT NOTES: a.

If the RESPONSE SPECTRUM LOAD command includes a value of the FACTOR parameter not equal to 1.0, AND if only one direction ground motion is specified, then for each mode compute the following and continue to Step 5: M / Factor = (MODAL PARTICIPATION FACTOR)**2 / (RESPONSE SPECTRUM LOAD FACTOR)

b.

If the RESPONSE SPECTRUM LOAD command includes a value of the FACTOR parameter not equal to 1.0, AND if two or three directions of ground motion are specified, then either: i.

Do NOT perform this calculation for Base Shear, or

ii.

Specify the RESPONSE SPECTRUM LOAD command WITHOUT a FACTOR (i.e., Default Value = 1.0), and redefine the STORE RESPONSE SPECTRUM command including the desired FACTOR (i.e., the desired FACTOR will be applied to the response values in the response spectrum loading). For this case, and for each mode, compute the following and continue to Step 5: M / Factor = (MODAL PARTICIPATION FACTOR)**2 / 1.0 15 - 105

Dynamic Analysis Commands

Dynamic Analysis

5.

Multiply the above computed value of "M / Factor" by its corresponding modal spectral acceleration value. This is the modal base shear (i.e., the base shear for each mode in POUNDS, the internal force unit of GTSTRUDL)

6.

Perform an RMS (or CQC, etc.) combination of the modal base shears corresponding to the earthquake direction. This is the total base shear in POUNDS (the internal force unit of GTSTRUDL)

7.

Convert the total base shear ("TBS") force from POUNDS to the desired force unit (e.g., TBS (KN) = TBS (POUNDS) x 0.0044482)

Example Calculation The following is an example calculation of computing BASE SHEAR corresponding to an X-direction earthquake, and an RMS combination of modes. In addition, assume that when the RESPONSE SPECTRUM LOAD command was specified, no FACTOR parameter was given. For this case: M / Factor = (MODAL PARTICIPATION FACTOR)**2 / 1.0. In order to minimize the number of calculations in this example, only results for modes 2, 3, and 15 (e.g., the 3 modes with the 3 highest mass participation factors in the X-direction) are used. For Base Shear calculations, all currently active modes corresponding to the desired mass participation level (from a LIST DYNAMIC PARTICIPATION FACTORS command) should be used.

X-Direction Spectral Acceleration (In/Sec**2) (A) Mode 2 50.895 3 54.682 15 89.291

(M / Factor) Modal Participation Factor (P) 204.777 -34.677 42.930

Modal Base Shear (Pounds) [ A x (P**2) ] 2,134,211.576 (i) 65,754.795 (j) 164,561.965 (k)

Total Base Shear is the RMS (i.e., SRSS) of the Modal Base Shears: RMS = = = =

Total Base Shear =

SQRT (i**2 + j**2 + k**2) = BASE SHEAR in X-Direction SQRT (2,134,211.576**2 + 65,754.795**2 + 164,561.965**2) SQRT (4.5862634E12) 2,141,556.30 Pounds x 0.0044482 (Convert Pounds to Kilonewtons) 9,526.07 KN in X-Direction

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Dynamic Analysis Commands

15.3.7.4 DESIGNING SHEAR WALLS BASED ON A RESPONSE SPECTRUM EARTHQUAKE ANALYSIS When designing shear walls that are modeled as finite element meshes, it is often the case that the structural engineer uses resultant forces (i.e., axial, shear, and bending moment forces) on a free-body section of the wall for purposes of design calculations. The resultant forces can be obtained from the GTSTRUDL "LIST SUM FORCES" command (Section 13.10) or from hand calculated static equivalents of the finite element nodal forces along the free-body cut as output by the GTSTRUDL "LIST ELEMENT FORCE" command. For static analysis results, this procedure works well. However, for Response Spectrum Analysis results, the procedure of obtaining correct resultants is more complicated. Therefore, consider the following: 1.

For static analysis, the resultants computed from FE nodal force values output by the LIST ELEMENT FORCES command are identical to those output by the "LIST SUM FORCES" command, and may be used for design.

2.

For Response Spectrum analysis, the resultants computed from FE nodal force values are the same as output by the "LIST SUM FORCES" command. However, if the free-body cut joints along which the resultant forces are computed are support joints, the resultants computed from the reaction values are NOT the same as those computed from the FE nodal force values, and are NOT the same as output by the "LIST SUM FORCES" command. The reason for this is as follows: a.

FE nodal force values are the result of a specified modal combination over the currently active modes (e.g., an RMS combination over 100 modes).

b.

The LIST SUM FORCES command computes the static equivalent resultant of the FE nodal forces (i.e., the RMS combination over 100 modes).

c.

The support reactions are computed from the specified modal combination over the currently active modes (e.g., an RMS combination of each reaction component over 100 modes). The static equivalent resultant of RMS'ed reactions, in general, is NOT the same as the static equivalent resultant of the FE nodal forces.

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Dynamic Analysis Commands

3.

Dynamic Analysis

For any one single mode such as Mode 2, if the free-body cut joints along which the resultant forces are computed are support joints, the resultants computed from the FE nodal force values are identical to the resultants computed from the reaction values, and both are the same as output by the "LIST SUM FORCES" command.

Now, in order for finite element resultant force calculations to be consistent with the way in which member end forces, internal member section forces, FE nodal stresses, FE nodal forces, and support reaction components are computed, the following must be done in order to obtain consistent resultant forces at a free-body cut through a finite element shear wall: 1.

Calculate the FE nodal forces or support reactions on a MODE-BY-MODE basis. For example, if LOAD 1001 is a response spectrum load, and where modes 1, 2, 3, 4, and 5 are the five modes whose mass participation factors sum to an acceptably large value, the following sequence of commands can be used:

DYNAMIC ANALYSIS EIGENSOLUTION LIST DYNAMIC PARTICIPATION FACTORS PERFORM RESPONSE SPECTRUM ANALYSIS COMPUTE RESPONSE SPECTRUM DISPLACEMENTS FORCES STRESSES REACTIONS MODAL COMBINATIONS RMS CREATE PSEUDO STATIC LOAD 3001 'MODE 1 RESULTS' FROM MODE 1 OF LOAD 1001 $ X-DIRECTION CREATE PSEUDO STATIC LOAD 3002 'MODE 2 RESULTS' FROM MODE 2 OF LOAD 1001 $ X-DIRECTION CREATE PSEUDO STATIC LOAD 3003 'MODE 3 RESULTS' FROM MODE 3 OF LOAD 1001 $ X-DIRECTION CREATE PSEUDO STATIC LOAD 3004 'MODE 4 RESULTS' FROM MODE 4 OF LOAD 1001 $ X-DIRECTION CREATE PSEUDO STATIC LOAD 3005 'MODE 5 RESULTS' FROM MODE 5 OF LOAD 1001 $ X-DIRECTION

-

OUTPUT MODAL CONTRIBUTIONS ON LIST RESPONSE SPECTRUM REACTIONS MODAL COMB RMS OUTPUT MODAL CONTRIBUTIONS OFF LOAD LIST 3001 TO 3005 LIST REACTIONS LIST ELEMENT FORCES ELEMENTS 1 2 LIST SUM FORCES JOINTS 1 2 3 ELEMENTS 1 2

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Dynamic Analysis

2.

Dynamic Analysis Commands

For the static equivalent resultants of the FE nodal forces, or of the support reaction components, along some free-body cut, compute the desired modal combination (e.g., an RMS combination) of the modal resultants from EACH of the Loads 3001 TO 3005 (i.e., each of these loads contain the mode response for EACH of modes 1 to 5 respectively) by hand or by using a spreadsheet. This modal combination of the modal resultants is consistent with the same calculation procedure used to compute modal combinations for member end forces, member section forces, etc.

The following shows the GTSTRUDL commands for a very simple example of a static and response spectrum analysis of a shear wall: STRUDL UNITS INCH SECONDS CYCLES STORE RESPONSE SPECTRUM ACCELERATION LINEAR VS PERIOD LINEAR 'RS-Job-1' $ THE 0% CRITICAL DAMPING CURVE DAMPING RATIO 0.0 FACTOR 386.08 $ G = 386.08 IN/SEC**2 0.156,0.01 0.66,0.1 0.68,0.2 0.66,0.3 0.6,0.4 0.5,0.5 0.42,0.6 0.34,0.7 0.3,0.8 0.26,0.9 0.22,1.0 0.2,1.1 0.18,1.2 0.16,1.3 0.147,1.4 0.138,1.5 0.125,1.6 0.119,1.7 0.108,1.8 0.1,1.9 0.098,2.0 0.09,2.1 0.084,2.2 0.08,2.3 0.079,2.4 0.075,2.5 0.07,2.6 0.069,2.7 0.065,2.8 0.062,2.9 0.06,3.0 END RESPONSE SPECTRUM UNITS KIPS INCH GEN 3 JOI ID 1 1 X LIST 0 40 100 REP 3 ID 3 Y 100 STATUS SUPP JOI 1 2 3 TYPE PLATE GENERATE 2 ELEMENTS ID 1 1 F 1 1 T 2 1 T 5 1 T 4 1 REPEAT 2 ID 2 F 3 ELEMENT PROPERTIES EXISTING TYPE 'SBHQ6' THICK 10. MATERIAL CONCRETE LOAD 1 JOINT LOADS 10 FORCE X 100 QUERY STIFFNESS ANALYSIS

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Dynamic Analysis

$ SPECIFY THE DYNAMIC RESPONSE SPECTRUM INDEPENDENT LOADING CONDITION $ USING THE ABOVE RESPONSE SPECTRUM CURVES RESPONSE SPECTRUM LOAD 1001 'RESPONSE SPECTRUM: TRANSLATION X-DIRECTION' SUPPORT ACCELERATION TRANSLATION X 1.0 FILE 'RS-Job-1' END OF RESPONSE SPECTRUM LOAD INERTIA OF JOINTS LUMPED INERTIA OF JOINTS FROM LOAD 1 DAMPING RATIOS 0.0 10 $ -----------------------------------------$ PERFORM DYNAMIC EIGENSOLUTION ANALYSIS FOR $ 10 FREQUENCIES AND MODE SHAPES $ -----------------------------------------EIGEN PARAMETERS NUMBER OF MODES 10 SOLVE USING GTLANCZOS PRINT MAX END DYNAMIC ANALYSIS EIGENSOLUTION LIST DYNAMIC PARTICIPATION FACTORS PERFORM RESPONSE SPECTRUM ANALYSIS COMPUTE RESPONSE SPECTRUM DISPLACEMENTS FORCES STRESSES REACTIONS MODAL COMBINATIONS RMS $ X-DIRECTION CREATE PSEUDO STATIC LOAD 2001 'RMS RESULTS' FROM RMS OF LOAD 1001 CREATE PSEUDO STATIC LOAD 2002 'MODE 2 RESULTS' FROM MODE 2 OF LOAD 1001 OUTPUT MODAL CONTRIBUTIONS ON LIST RESPONSE SPECTRUM REACTIONS MODAL COMB RMS OUTPUT MODAL CONTRIBUTIONS OFF LOAD LIST 1 2001 2002 LIST REACTIONS LIST SUM REACTIONS LIST ELEMENT FORCES ELEMENTS 1 2 LIST SUM FORCES JOINTS 1 2 3 ELEMENTS 1 2 CINPUT

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Dynamic Analysis

Dynamic Analysis Commands

15.3.7.5 FORM MISSING MASS LOAD Command

where: imm or 'amm'

=

missing mass load name specified as an integer or an alphanumeric name of up to eight alphanumeric. The name imm or 'amm’ must be unique among all static and dynamic loading names.

'title'

=

missing mass loading description character string of up to 64 characters in length.

irs or 'ars'

=

integer, irs, or alphanumeric, 'ars', identifier of the response spectrum reference loading upon which the missing mass load computation is based.

vf

=

cutoff frequency. The Zero Period Acceleration (ZPA) corresponds to this frequency on the response spectrum curves associated with response spectrum load irs or 'ars'.

vd

=

optional damping RATIO or PERCENT which defines the damping level for the retrieval of the ZPA from the response spectrum curves. If not specified, vd is taken as 0.0 by default.

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Dynamic Analysis

Example UNITS CYCLES SECOND FORM MISSING MASS LOAD ‘MM-1' FROM RESPONSE SPECTRUM LOAD ‘RS-1’ CUTOFF FREQUENCY 57.9 DAMPING RATIO 10.0

Explanation The FORM MISSING MASS LOAD command computes a new independent static loading condition consisting of joint load components that reflect the total mass associated with all ignored modes. Ignored modes can be modes that were inactivated by the INACTIVE/ACTIVE MODES command (Section15.3.6), or modes that were not computed in a previous eigenvalue analysis. Care must be exercised to insure that the inactive or otherwise unavailable modes are the same for both the response spectrum analysis for the reference loading irs or 'ars', as well as for a subsequent execution of the FORM MISSING MASS LOAD command. The missing mass joint load components are computed for all dynamic degrees-offreedom that correspond to the global support acceleration directions specified in the response spectrum reference loading irs or 'ars'. For example, if the support acceleration is defined by translation in the global Z direction, then the computed missing mass loading will consist of translation force joint load components also in the global Z direction. Any dynamic degree-of-freedom that has no mass will, of course, have a corresponding missing mass joint load component equal to zero. The computation of the missing mass joint load components requires that the system mass matrix, mode shape vectors (eigenvectors), response spectrum modal participation factors for loading irs or 'ars' (i.e., the ground motion response influence vector) have been computed prior to the specification of the FORM MISSING MASS LOAD command. The following steps may serve as a guide for the use of the FORM MISSING MASS LOAD command in a response spectrum analysis sequence: 1.

DYNAMIC ANALYSIS EIGENSOLUTION (Section 15.3.4) Perform the Eigenvalue analysis which computes frequencies and mode shapes for the structure. The system mass matrix is assembled as part of this process.

2.

RESPONSE SPECTRUM LOADING (Section 15.2.11) Define the response spectrum load(s). 15 - 112

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3.

Dynamic Analysis Commands

PERFORM RESPONSE SPECTRUM ANALYSIS (Section15.3.7.1) A Response Spectrum Analysis will be performed, and which will compute the response spectrum participation factors and maximum response spectrum modal displacements.

4.

COMPUTE RESPONSE SPECTRUM results (Section 15.4.1) Joint displacements, support reactions, member end forces, and finite element nodal forces are computed using response spectrum analysis results.

5.

FORM MISSING MASS LOAD (Section15.3.7.5) The missing mass static joint loads are computed. The specified response spectrum reference loading irs or 'ars' must have been defined in Step 2, and the response spectrum analysis performed in Step 3, in order for the missing mass static joint loads to be correctly computed.

6.

STIFFNESS ANALYSIS (Chapter 11, GTSTRUDL User Guide: Analysis) Perform a static analysis for the missing mass load.

7.

CREATE PSEUDO STATIC LOAD (Section 15.4.3) Create a pseudo static loading condition by copying the results of the response spectrum dynamic analysis for joint displacements, support reactions, member end forces, and finite element stresses (Step 4) into a static loading condition (i.e., a “pseudo” static loading condition).

8.

Create a loading combination consisting of the sum of the results from the pseudo static loading condition created in Step 6 plus the static analysis results from the missing mass loading computed in Step 5 (Section 10.2.2).

CHANGES and DELETIONS Modes The loading condition results created by the FORM MISSING MASS command may be manipulated using the standard ADDITIONS, CHANGES, and DELETIONS operations as described in Chapter 9 of the GTSTRUDL User Guide: Analysis.

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Dynamic Analysis

15.3.7.6 Extended Example: RESPONSE SPECTRUM ANALYSIS, FORM MISSING MASS LOAD, and Base Shear Computation UNITS KIPS FEET SECONDS $ SPECIFY A DYNAMIC RESPONSE SPECTRUM INDEPENDENT LOADING CONDITION RESPONSE SPECTRUM LOAD 1001 'RESPONSE SPECTRUM: TRANSLATION X-DIRECTION' SUPPORT ACCELERATION TRANSLATION X 1.5 FILE 'RS-Job-1' END OF RESPONSE SPECTRUM LOAD $ PERFORM DYNAMIC ANALYSIS FOR 10 MODES INERTIA OF JOINTS LUMPED EIGEN PARAMETERS NUMBER OF MODES 30 SOLVE USING GTLANCZOS PRINT MAX END DYNAMIC ANALYSIS EIGENVALUES $ SPECIFY MODAL DAMPING CHARACTERISTICS AS FOLLOWS: $ MODE 1: 2% CRITICAL DAMPING $ MODES 2 TO 5: 5% CRITICAL DAMPING $ MODES 6 TO 100: 10% CRITICAL DAMPING DAMPING RATIOS 0.02 1, 0.05 4, 0.10 95 $ PERFORM A RESPONSE SPECTRUM ANALYSIS (MODAL RESPONSE RESULTS) $ USING THE SELECTED (ACTIVE) SUBSET OF MODES WHOSE $ MASS PARTICIPATION IN THE GLOBAL X DIRECTION IS AT LEAST $ 85% (MODES 1 2 5 6 9), AND BASED ON RESPONSE SPECTRUM LOAD 1101. LIST DYNAMIC PARTICIPATION FACTORS INACTIVE MODES ALL BUT 1 2 5 6 9 15 17 25 LIST DYNAMIC PARTICIPATION FACTORS

PERFORM RESPONSE SPECTRUM ANALYSIS $ BASE SHEAR COMPUTATION (UNITS OF OUTPUT MUST BE INCH POUNDS SECONDS $ AT THIS TIME) - SEE SECTIONS 15.3.7.3 and 15.5.6 FOR DETAILS OF BASE SHEAR $ COMPUTATION UNITS INCH POUNDS SECONDS LIST RESPONSE SPECTRUM SPECTRAL ACCELERATIONS LIST RESPONSE SPECTRUM PARTICIPATION FACTORS UNITS KIPS FEET SECONDS

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$ $ $ $

Dynamic Analysis Commands

COMPUTE RESPONSE SPECTRUM RESULTS FOR RESPONSE SPECTRUM LOAD 1001 USING BOTH THE RMS (ROOT MEAN SQUARE) AND CQC(COMPLETE QUADRATIC COMBINATION) TECHNIQUES OF COMBINING COMPUTED MODAL RESPONSES, AND FOR JOINT DISPLACEMENTS, MEMBER END FORCES, AND SUPPORT REACTIONS.

COMPUTE RESPONSE SPECTRUM DISPLACEMENTS FORCES REACTIONS MODAL COMBINATIONS RMS CQC $ $ $

COMPUTE ADDITIONAL FORCES DUE TO MISSING MASS EQUIVALENT LOADS, AND BASED ON THE RESPONSE SPECTRUM CURVE FOR THE CUTOFF FREQUENCY OF 41.35 Hz, AND A DAMPING OF 10% CRITICAL

UNITS CYCLES SECOND FORM MISSING MASS LOAD 999 'MISSING MASS LOAD' FROM RESPONSE SPECTRUM LOAD 1001 CUTOFF FREQUENCY 41.35, DAMPING RATIO 0.10 LOAD LIST 999 STIFFNESS ANALYSIS LOAD LIST ALL $ 1. SELECT THE RESPONSE SPECTRUM ANALYSIS CQC MODAL COMBINATION $ RESULTS FROM RESPONSE SPECTRUM LOAD 1001, AND FORM RESULTS $ IN A "PSEUDO STATIC LOADING CONDITION" CALLED LOAD 1100. $ $ 2. FORM THE TOTAL RESPONSE SPECTRUM ANALYSIS RESULTS AS LOAD 1101 BY $ PERFORMING AN RMS OF THE CQC PSEUDO STATIC ANALYSIS RESULTS (LOAD $ 1100) AND THE MISSING MASS ANALYSIS RESULTS (LOAD 999). $ $ 3. FORM DESIGN LOAD COMBINATIONS 1201 AND 1202, AS THE COMBINATION OF $ THE TOTAL RESPONSE SPECTRUM ANALYSIS RESULTS (LOADING 1101) WITH $ STATIC GRAVITY DEAD AND LIVE LOADS (LOADING 11).

CREATE PSEUDO STATIC LOAD 1100 'CQC RESULTS' FROM CQC OF LOAD 1001 CREATE LOAD COMBINATION 1101 'RS RESULTS' TYPE RMS SPECS 1100 1.0 999 1.0 CREATE LOAD COMBINATION 1201 '(DL+LL + X/RS) x 0.75' SPECS 11 0.75 1101 0.75 CREATE LOAD COMBINATION 1202 '(DL+LL - X/RS) x 0.75' SPECS 11 0.75 1101 -0.75

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15.3.8

Dynamic Analysis

PERFORM TRANSIENT ANALYSIS Command

PERFORM TRANSIENT (ANALYSIS)

Example PERFORM TRANSIENT ANALYSIS

Explanation The PERFORM TRANSIENT ANALYSIS command is used to initiate a mode superposition transient response analysis for all currently active transient loading conditions (Sections 15.2.9 and 15.2.10), and using all previously computed (Section 15.3.4, the DYNAMIC ANALYSIS EIGENVALUES command) and currently active (Section 15.3.6, the INACTIVE/ACTIVE MODES command) eigenvalues and eigenvectors. Joint displacement, velocity, and acceleration vs. time results are computed using a mode superposition procedure. Additional response computations are performed by the COMPUTE TRANSIENT (Section 15.4.2) and LIST TRANSIENT (Section 15.5.7) results commands.

Extended Example UNITS SECONDS TRANSIENT LOADING 1001 ‘Transient Joint Forces’ JOINTS 1 TO 21 BY 2, ‘A’ LOADS FORCE Y FILE ‘WIND-1' FACTOR 1.5. JOINTS 1, 2 LOAD MOMENT Z FUNCTION SINE AMPL 5.0 FREQ 1.0. INTEGRATE FROM 0.0 TO 10.0 AT .010 END TRANSIENT LOAD

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Dynamic Analysis Commands

TRANSIENT LOADING 1002 ‘Support Acceleration’ SUPPORT ACCELERATION TRANSLATION X FILE ‘ELCENTRO’ FACTOR 0.707 TRANSLATION Z FILE ‘ELCENTRO’ FACTOR 0.707 INTEGRATE FROM 0.0 TO 30.0 AT .025 END TRANSIENT LOAD INERTIA OF JOINTS LUMPED EIGEN PARAMETERS SOLVE USING GTLANCZOS NUMBER OF MODES 50 PRINT MAX END DYNAMIC ANALYSIS EIGENSOLUTION $ Perform transient analysis based on transient loadings 1001 and 1002 PERFORM TRANSIENT ANALYSIS

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Dynamic Analysis Commands

15.3.9

Dynamic Analysis

PERFORM PHYSICAL ANALYSIS Command

PERFORM ASSEMBLY (FOR) DYNAMICS

PERFORM PHYSICAL (ANALYSIS)

where, r1

=

Newmark BETA value (default = 0.25)

r2

=

Wilson THETA value (default = 1.40)

Example PERFORM ASSEMBLY FOR DYNAMICS PERFORM PHYSICAL ANALYSIS

Explanation The PERFORM ASSEMBLY FOR DYNAMICS command causes the structural global stiffness ([K]) and mass ([M]) matrix portions of the dynamic equilibrium equations to be assembled. Then, the PERFORM PHYSICAL ANALYSIS command causes a transient response analysis for all currently active transient loading conditions (Sections 15.2.9 and 15.2.10) to be performed using a direct time integration of the following dynamic equations of motion:

[M] [C]

{X (t)} {P (t)}

= = = = = =

mass matrix damping matrix acceleration vector (function of time) velocity vector (function of time) joint displacement vector (function of time) load vector (function of time)

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Dynamic Analysis Commands

Joint displacement, velocity, and acceleration vs. time results are computed. Additional response computations are performed by the COMPUTE TRANSIENT (Section 15.4.2) and LIST TRANSIENT (Section 15.5.7) results commands.

Extended Example INERTIA OF JOINTS LUMPED UNITS SECONDS TRANSIENT LOADING 1001 ‘Transient Joint Forces’ JOINTS 1 TO 21 BY 2, ‘A’ LOADS FORCE Y FILE ‘WIND-1' FACTOR 1.5. JOINTS 1, 2 LOAD MOMENT Z FUNCTION SINE AMPL 5.0 FREQ 1.0. INTEGRATE FROM 0.0 TO 10.0 AT .010 END TRANSIENT LOAD TRANSIENT LOADING 1002 ‘Support Acceleration’ SUPPORT ACCELERATION TRANSLATION X FILE ‘ELCENTRO’ FACTOR 0.707 TRANSLATION Z FILE ‘ELCENTRO’ FACTOR 0.707 INTEGRATE FROM 0.0 TO 30.0 AT .025 END TRANSIENT LOAD $ Perform physical analysis (direct integration of the dynamic equations of motion) $ based on transient loadings 1001 and 1002 PERFORM ASSEMBLY FOR DYNAMICS PERFORM PHYSICAL ANALYSIS

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Dynamic Analysis Commands

15.3.10

Dynamic Analysis

PERFORM NUMBER OF MODES COMPUTATION Command

PERFORM ASSEMBLY (FOR) DYNAMICS PERFORM NUMBER (OF MODES COMPUTATION)

Example PERFORM ASSEMBLY FOR DYNAMICS PERFORM NUMBER OF MODES COMPUTATION

Explanation The PERFORM ASSEMBLY FOR DYNAMICS command causes the structural global stiffness ([K]) and mass ([M]) matrix portions of the dynamic equilibrium equations to be assembled. Then, the PERFORM NUMBER OF MODES COMPUTATION command causes the total number of modes to be computed and output which lie in the frequency range from 0.0 to some specified maximum frequency. The frequency range is specified by the FREQUENCY SPECIFICATIONS option in the EIGEN PARAMETERS command (Section15.3.1). The dynamic system matrices must have been previous assembled such as by a PERFORM ASSEMBLY FOR DYNAMICS command or by a DYNAMIC ANALYSIS EIGENSOLUTION command (Section 15.3.4).

Extended Example UNITS CYCLES SECOND EIGEN PARAMETERS SOLVE USING GTLANCZOS FREQUENCY SPECS 0. TO 50. $ CYC/SEC PRINT MAX PERFORM ASSEMBLY FOR DYNAMICS PERFORM NUMBER OF MODES COMPUTATION

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15.4

Dynamic Results Back Substitution Commands

Dynamic Results Back Substitution Commands This Section 15.4 describes the commands provided by GTSTRUDL to perform dynamic response back substitution computations in addition to those computed by the PERFORM (Sections 15.3.7 and 15.3.8) commands as follows: 15.4.1

COMPUTE RESPONSE SPECTRUM Results Command

15.4.2

COMPUTE TRANSIENT Results Command

15.4.3

CREATE PSEUDO STATIC LOADING Command

Table 15.4-1 contains a brief description of the commands for the computation of various types of structure dynamic response results.

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Dynamic Analysis

Table 15.4-1 Commands for Computation of Structure Dynamic Response

Command Name

COMPUTE RESPONSE SPECTRUM - results

COMPUTE TRANSIENT results

CREATE PSEUDO STATIC LOADING

Brief Description When used, this command must be given after a "PERFORM RESPONSE SPECTRUM ANALYSIS" or "PERFORM MODAL SUPERPOSITION ANALYSIS" command in which modal spectral results were computed. This command then computes requested modal responses and total structure responses (e.g., joint displacements, reactions, member end forces, finite element nodal forces, finite element stresses, etc.) based on specified modal combination methods using all currently active computed modes, and for all currently active response spectrum loads. When used, this command must be given after a "PERFORM TRANSIENT ANALYSIS", "PERFORM MODAL SUPERPOSITION ANALYSIS", or "PERFORM PHYSICAL ANALYSIS" command in which joint acceleration, velocity, and displacement time histories were computed. This command then computes requested structure responses for member end forces, finite element nodal forces, finite element stresses, support reactions, and free joint force resultants, for all currently active transient loads. Transforms dynamic analysis results into pseudo static loading results which then can be manipulated in a manner similar to real static analysis results. For example, by using the "CREATE PSEUDO STATIC LOADING", "CREATE LOAD COMBINATION", and "LIST SECTION FORCE" commands, pseudo static loading results (created from dynamic transient, response spectrum, etc. analysis results) can be combined with real static analysis results, and member internal section force and moment results can then be computed.

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15.4.1

Dynamic Results Back Substitution Commands

COMPUTE RESPONSE SPECTRUM Results Command

Note: The Gupta mode combination procedure is described in Section 15.2.11 and in the GTSTRUDL User Reference Manual, Volume 3.

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Dynamic Analysis

where:

and where, jlist

=

list of joint names for which response spectrum results are to be computed (default is ALL active and inactive joints)

mlist =

list of member and finite element names for which response spectrum results are to be computed (default is ALL active and inactive members)

Example COMPUTE RESPONSE SPECTRUM DISPLACEMENTS MODAL COMBINATIONS RMS CQC JOINTS 101 TO 111 BY 2 COMPUTE RESPONSE SPECTRUM FORCES REACTIONS MODAL COMBINATIONS RMS CQC

Explanation The COMPUTE RESPONSE SPECTRUM results command performs dynamic response back substitution result computations and modal combinations in addition to the dynamic result computations performed by the PERFORM RESPONSE SPECTRUM ANALYSIS command (Section 15.3.7.1) in which only modal weighting factors are computed. The COMPUTE RESPONSE SPECTRUM results command may be given any number of times, but it must be given at any time following the PERFORM RESPONSE SPECTRUM ANALYSIS command since the modal weighting factors must have previously been computed. Response spectrum result computations are computed for all currently active response spectrum loading conditions, while modal response computations and combinations will be performed only for previously computed (Section 15.3.4, DYNAMIC ANALYSIS EIGENVALUES) and currently active (Section 15.3.6, INACTIVE/ACTIVE MODES) modes.

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Dynamic Analysis

Dynamic Results Back Substitution Commands

If no members, finite elements, or joints are specified, the default of all active and inactive members, finite elements, or joints are used. If no modal combination method is specified, the default is that only individual modal contributions are computed. Result computation options are shown in Table 15.4.1-1, and modal combination options are shown in Table 15.4.1-2.

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Dynamic Analysis

Table 15.4.1-1 COMPUTE RESPONSE SPECTRUM Result Options

COMPUTE RESPONSE SPECTRUM Result Options

DISPLACEMENTS, VELOCITIES and ACCELERATIONS FORCES STRESSES

REACTIONS

Brief Description Joint displacements, velocities, and accelerations.

Member end forces and finite element nodal forces. Finite element generalized strains and stresses. Joint support reactions. Note that REACTIONS are computed as the resultant of the sum of the FORCE contributions of members and finite elements incident on the support joints. In order that the contributions are non-zero, the incident FORCES must be calculated in a preceding or in the same COMPUTE RESPONSE SPECTRUM REACTIONS command.

Table 15.4.1-2 COMPUTE RESPONSE SPECTRUM Modal Combination Options

COMPUTE RESPONSE SPECTRUM Modal Combination Options

Brief Description

RMS

Root Mean Square (i.e., Square Root of the Sum of the Squares) of the modal responses

PRMS

Peak Root Mean Square (Peak response plus the RMS of the remaining modal responses)

CQC

Complete Quadratic Combination of modal responses

ABS

Absolute Sum of modal responses

(NRC) TPM

U.S. Nuclear Regulatory Commission Ten Percent Method combination of modal responses

(NRC) GRP

U.S. Nuclear Regulatory Commission Grouping Method combination of modal responses

(NRC) DSM

U.S. Nuclear Regulatory Commission Double Sum Method combination of modal responses

ALL

All of the above seven modal combination methods

GUPTA

Gupta (Section 15.2.11 & Reference Manual, Vol. 3)

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Dynamic Analysis

15.4.2

Dynamic Results Back Substitution Commands

COMPUTE TRANSIENT Results Command

where,

t1,...,t5 i1,...,i5

= =

jlist

=

mlist

=

decimal value of time in active units time point number (e.g., 5 would mean the 5th time point of the integration time points) list of joint names for which transient results are to be computed (default is all active and inactive joints) list of member and finite element names for which transient results are to be computed (default is all active and inactive members and finite elements)

Example UNITS SECONDS COMPUTE TRANSIENT FORCES REACTIONS LOADS TIMES FROM 0.0 TO 100.0

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Dynamic Analysis

Explanation The COMPUTE TRANSIENT results command performs dynamic response back substitution result computations in addition to the dynamic result computations performed by the PERFORM TRANSIENT ANALYSIS command (Section 15.3.8) in which a time history of joint displacements, velocities, and accelerations are computed. The COMPUTE TRANSIENT results command may be given any number of times, but it must be given at any time following the PERFORM TRANSIENT ANALYSIS command since joint displacements must have previously been computed. Transient response result computations are computed for all currently active transient loading conditions, and will perform modal superposition only for previously computed (Section 15.3.4, DYNAMIC ANALYSIS EIGENVALUES) and currently active (Section 15.3.6, INACTIVE/ACTIVE MODES) modes. If no members, finite elements, or joints are specified, the default of all active and inactive members, finite elements, or joints are used. It should be noted that the LOADS option should always be given in order to avoid warning messages that would otherwise be issued by the CREATE PSEUDO STATIC LOAD command (Section 15.4.3). It is important to note that the COMPUTE TRANSIENT command does not honor the ACTIVE/INACTIVE MODES commands since transient forces and finite element stresses are computed from transient displacements which are not stored on a mode-by-mode basis. Only the PERFORM TRANSIENT and the DYNAMIC ANALYSIS MODE SUPERPOSITION (for Transient Loads) commands which compute transient displacements honor the ACTIVE/INACTIVE MODE commands. Transient result computation options are as follows: Transient Result Options

FORCES

Brief Description Member end forces and finite element nodal forces.

STRESSES

Finite element generalized strains and stresses.

REACTIONS

Joint support reactions. Note that REACTIONS are computed as the resultant of the sum of the FORCE contributions of members and finite elements incident on the support joints. In order that the contributions are non-zero, the incident FORCES must be calculated in a preceding or in the same COMPUTE TRANSIENT command.

LOADS

Summation of internal member end forces and finite element nodal forces acting on joints, and used in joint force equilibrium checks.

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15.4.3

Dynamic Results Back Substitution Commands

CREATE PSEUDO STATIC LOADING Command

where, i, ‘a’ =

integer or alphanumeric name for the pseudo static loading condition

‘title’ =

optional title for the pseudo static loading condition

i1,i2,...in

=

a1,a2,...an

=

integer name of an existing dynamic loading condition

alphanumeric name of an existing dynamic loading condition

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Dynamic Analysis

j

=

the jth mode of a response spectra loading, the results of which are to be copied

k

=

the kth time point of a transient load, the results of which are to be copied (INTEGER number required)

t

=

time point t in current time units of a transient load, the results of which are to be copied (DECIMAL number required)

m

=

the mth forcing frequency from a harmonic loading, the results of which are to be copied

f

=

forcing frequency in currently active units of a harmonic load, the results of which are to be copied

Example UNITS SECONDS CREATE PSEUDO STATIC LOAD ‘RMS-EQ-1’ FROM RMS OF LOAD ‘EQ-1’ CREATE PSEUDO STATIC LOAD 10 ‘Time=1.3 Sec’ FROM TIME 1.3 OF LOAD ‘ELCENTRO’

Explanation It is often necessary to operate on the analysis results of dynamic loads in the same manner as the analysis results of static loads. Examples of such operations include the calculation of internal member section force and moment values based on the dynamic analysis results, the combination of dynamic analysis results with static analysis results, the text and graphical output of dynamic analysis results, etc. The PSEUDO STATIC LOADING command is used to transform analysis results of dynamic loading conditions into the form of analysis results of static loading conditions, which can then be operated upon in a manner similar to static analysis results (such as being used in loading combinations). The transformed analysis results is called a pseudo static loading condition. It is important to note that a pseudo static loading condition is not an applied loading condition (i.e., it contains no applied loads). Rather, it contains a set of previously computed dynamic analysis results that may be referred to, and operated upon, by referencing the name of the pseudo static loading condition.

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Thus, any pseudo static loading condition should be INACTIVATED (Section 5.5) or DELETED (Sections 5.4 and 9.3) prior to a subsequent STIFFNESS ANALYSIS. The PSEUDO STATIC LOADING command can perform this transformation function in six different ways: (1)

Previously computed response spectrum dynamic analysis results which were computed on the basis of a specified modal combination method for a specified response spectrum loading condition are copied into, and become the analysis results of, a pseudo static loading condition. For example:

CREATE PSEUDO STATIC LOAD ‘RMS-EQ’ FROM RMS OF LOAD ‘EQ-1’ (2)

If two or more response spectrum loading conditions are specified, a pseudo static loading condition is created by performing an RMS (i.e., square root of the sum of the squares) calculation over previously computed response spectrum dynamic analysis results which were computed on the basis of a specified modal combination method (e.g., an RMS, CQC, or TPM method). The RMS’ed results are then copied into, and become the analysis results of, a pseudo static loading condition. For example:

CREATE PSEUDO STATIC LOAD 110 FROM CQC OF LOADINGS 101 102 (3)

Previously computed response spectrum dynamic analysis results for a specified natural MODE of a particular response spectrum loading are copied into, and become the analysis results of, a pseudo static loading condition. For example:

CREATE PSEUDO STATIC LOAD 120 FROM MODE 5 OF LOADING ‘EQ-1' (4)

Previously computed transient dynamic analysis results which were computed at a specified point in TIME for a specified transient loading condition are copied into, and become the analysis results of, a pseudo static loading condition. These results represent a “snapshot” of the structure’s response at the specified point in time. For example:

CREATE PSEUDO STATIC LOAD 10 ‘Time=1.3 Sec’ FROM TIME 1.3 OF LOADING ‘ELCENTRO’ (5)

Maximum response dynamic analysis results associated with a specified forcing FREQUENCY for which the maximum response was previously computed in a maximum response harmonic analysis are copied into, and become the analysis results of, a pseudo static loading condition. The specified forcing frequency must match one of the forcing frequencies given in a harmonic loading condition, and for which the maximum response harmonic analysis was performed.

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For example: UNITS CYCLES SECONDS CREATE PSEUDO STATIC LOAD 200 FROM FREQ 60. OF LOAD ‘ROTATE’

This command copies the maximum response dynamic analysis results associated with a forcing frequency of 60 Hertz into pseudo static loading 200. The maximum response must have been previously computed in a maximum response harmonic dynamic analysis for harmonic loading condition ‘ROTATE’ in which a frequency of 60 Hertz was specified. (6)

The MAXIMUM absolute value of response previously computed over all time points given in the specified transient loading conditions, or the MAXIMUM absolute value of response previously computed over all forcing frequencies given in the specified maximum response harmonic loading conditions, are copied into, and become the analysis results of, a pseudo static loading condition. For example:

CREATE PSEUDO STATIC LOAD ‘MAX’ FROM MAXIMUM OF LOAD 300 This command determines the maximum response over time (if load 300 is a transient load), or over all forcing frequencies given in loading 300 (if load 300 is a maximum response harmonic load), and copies such maximum response dynamic results into pseudo static loading ‘MAX’. Maximum absolute values of the results are stored. All previously computed dynamic analysis results (e.g., joint displacements, member end forces, support reactions, finite element nodal forces and stresses, etc., computed by the COMPUTE command) are included in the creation of the pseudo static loading condition. Any dynamic analysis results that have not been previously computed are set to zero in the pseudo static loading condition. Pseudo static loading conditions that contain response spectrum modal combination results, maximum response harmonic analysis results, or maximum absolute value of dynamic analysis results, do not represent force equilibrium or compatible deformation states since they contain only peak (i.e., positive) results. When such pseudo static analysis results are combined with static analysis results (e.g., as computed by the STIFFNESS ANALYSIS command), the combined results satisfy neither equilibrium nor compatibility conditions. If the results stored in a pseudo static loading condition is both added to and subtracted from the results stored in a static loading condition, the combination of results represent estimated bounds on the combined response.

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Dynamic Results Back Substitution Commands

Extended Example STRUDL ‘TEST’ ‘STATIC + DYNAMIC LOAD’ • • LOADING 1 ‘STATIC’ • • STIFFNESS ANALYSIS • • DYNAMIC LOADING 2 ‘RESPONSE SPECTRUM’ • • DYNAMIC ANALYSIS EIGENVALUES PERFORM RESPONSE SPECTRUM ANALYSIS OUTPUT MODAL CONTRIBUTIONS OFF COMPUTE DYNAMIC DISPLACEMENTS FORCES REACTIONS MODAL COMB RMS CREATE PSEUDO STATIC LOADING 10 ‘RMS OF LOADING 2' FROM RMS OF LOADING 2 LOADING COMBINATION 21 ‘STATIC + RMS’ SPECS 1 1.0 10 1.0 LOADING COMBINATION 22 ‘STATIC - RMS’ SPECS 1 1.0 10 -1.0 COMBINE 21 COMBINE 22 $ THE ACTIVE STATIC LOADING 1 AND PSEUDO STATIC LOADING 10, AND $ LOADING COMBINATIONS 21 AND 22 RESULTS FOR DISPLACEMENTS, $ FORCES AND REACTIONS ARE OUTPUT LIST DISPLACEMENTS FORCES REACTIONS

This job first calculates (STIFFNESS ANALYSIS) the response of the structure due to a static LOADING 1. After the dynamic structural properties have been given and the response spectrum DYNAMIC LOADING 2 is specified, an Eigen solution is performed by the DYNAMIC ANALYSIS EIGENVALUE command, and a response spectrum analysis is performed by the PERFORM RESPONSE SPECTRUM ANALYSIS command. an RMS modal combination for joint displacements, member end forces, and support reactions is then performed by the COMPUTE DYNAMIC command. The pseudo static LOADING 10 is then created by copying the RMS joint displacements, member end forces, and support reactions of DYNAMIC LOADING 2 into pseudo static LOADING 10. The results of LOADING 1 and 10 are then combined to form LOADING COMBINATIONS 21 and 22 Then, joint displacements, member end forces, and support reactions for loadings 1, 10, 21 and 22 are output.

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15.5

Dynamic Analysis

Dynamic Data and Analysis Results Output Commands This Section 15.5 describes the commands provided by GTSTRUDL to output dynamic data and dynamic analysis results as follows: 15.5.1

PRINT DYNAMIC Data Command

15.5.2

PLOT DYNAMIC RESULTS / FILE Command

15.5.3

NORMALIZE EIGENVECTORS Command

15.5.4

LIST DYNAMIC Eigen Results and Mass Summary Command

15.5.5

OUTPUT MODAL CONTRIBUTIONS Command

15.5.6

LIST RESPONSE SPECTRUM Results Command

15.5.7

LIST TRANSIENT Results Command

Table 15.5-1 contains a brief description of the commands for the output of dynamic data and the output of structure dynamic response results. Additional commands that cause output of dynamic data and dynamic analysis results can be found in Volume 3 of the GTSTRUDL User Reference Manual.

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Table 15.5-1 Commands for Output of Dynamic Data and Dynamic Analysis Results Command Name

Brief Description

PRINT DYNAMIC FILE data

Output data previously specified by the user (e.g., joint inertias and modal damping values), or computed by GTSTRUDL (e.g., mass and stiffness matrices), for purposes of dynamic analysis.

PLOT DYNAMIC FILE data

Plot dynamic loading file data.

NORMALIZE EIGENVECTORS

Specifies if eigenvectors are to be output normalized on maximum amplitude or normalized to unit mass.

LIST DYNAMIC Eigen-results

Output dynamic analysis results which are independent of dynamic loading conditions. These are the: - Eigenvalues (natural frequencies) - Eigenvectors (mode shapes) - Mass modal participation factors, and - Summary of total mass and mass distribution.

OUTPUT MODAL CONTRIBUTIONS

LIST RESPONSE SPECTRUM results

Used to set a switch which will permit a subsequent "LIST RESPONSE SPECTRUM results" command to output individual modal responses in addition to outputting modal combination total response values. Output results of dynamic response spectrum analyses as computed by prior "PERFORM RESPONSE SPECTRUM ANALYSIS", "PERFORM MODAL SUPERPOSITION ANALYSIS", and "COMPUTE RESPONSE SPECTRUM results" commands. Results include: - Modal participation factors - Spectral displacements, velocities, and accelerations - Modal coefficients - Joint displacements, velocities, and accelerations, member end forces, and support reactions for each currently active mode (if the "OUTPUT MODAL CONTRIBUTIONS ON" command was previously specified) - Total response that was previously computed on the basis of one or more modal combination methods. *NOTE: - Finite element response spectrum nodal forces, stresses, and strains are not output with this command. Rather, these finite element results must be copied into a pseudo static loading using the "CREATE PSEUDO STATIC LOADING" command, and then output by a "LIST finite element results" command.

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Table 15.5-1 (Continued)

Dynamic Analysis

Commands for Output of Dynamic Data and Dynamic Analysis Results

Command Name

LIST TRANSIENT results

Brief Description Output results of dynamic transient analyses as computed by prior "PERFORM TRANSIENT ANALYSIS", "PERFORM MODAL SUPERPOSITION ANALYSIS", "PERFORM PHYSICAL ANALYSIS", and "COMPUTE TRANSIENT results" commands. Results include: - Joint displacement, velocity, and acceleration total response (as computed by the "PERFORM" commands) - Member end force and support reaction total response (as computed by the "COMPUTE TRANSIENT" command) *NOTE: - Finite element transient nodal forces, stresses, and strains are not output with this command. Rather, these finite element results must be copied into a pseudo static loading using the "CREATE PSEUDO STATIC LOADING" command, and then output by a "LIST finite element results" command.

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15.5.1

Dynamic Data and Analysis Results Output Commands

PRINT DYNAMIC DATA Command

where, 'filename'

=

name of a response spectrum or time history data file

Example PRINT DYNAMIC MODAL DAMPING PRINT DYNAMIC PARAMETERS PRINT DYNAMIC LOAD DATA PRINT DYNAMIC FILE ‘ELCENTRO’ PRINT DYNAMIC DATA

Explanation The PRINT DYNAMIC command is used to output information concerning the dynamic characteristics of the structure for all active and inactive joints, members, finite elements, and loads. The command causes the text output of information previously specified by the user. If the results of a dynamic analysis are to be output in text form, the LIST DYNAMIC command must be used (Sections 15.5.4, 15.5.6, and 15.5.7, and Volume 3 of the GTSTRUDL Reference Manual). 15 - 137

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The PRINT DYNAMIC command may be given at any time and as often as desired. In addition, only one output option may be used per command. The output of dynamic data is subject to its existence. Further, note that all matrix data will be output in GTSTRUDL’s internal units of inches, pounds, seconds, and radians. Options of the PRINT DYNAMIC command are given in Table 15.5.1-1.

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Table 15.5.1-1 Options of the PRINT DYNAMIC Command

PRINT DYNAMIC Command Options

Description

DATA

All existing dynamic structural and loading data except the LOAD DATA and STRUCTURAL below will be output.

MATRICES

All existing system matrices ([K], [C] and [M]), and the CORRESPONDENCE TABLE, will be output in GTSTRUDL’s internal units of inches, pounds, seconds, and radians.

MATRIX ADDED DATA MASS MATRIX MEMBER ADDED MASS

The mass data specified in the MATRIX ADD command. Mass matrix [M] contents. Additional member mass data specified by the MEMBER ADDED INERTIA command.

DAMPING MATRIX

Damping matrix [C] contents.

STIFFNESS MATRIX

Stiffness matrix [K] contents.

CORRESPONDENCE TABLE

A table relating internal and external degrees-offreedom.

LOAD DATA

All dynamic loading data will be output including acceleration and force time loadings, initial conditions, integration time increments, etc.

STRUCTURAL DATA DEGREES OF FREEDOM JOINT INERTIAS MODAL DAMPING

FILE

PARAMETERS

DEGREES OF FREEDOM, JOINT INERTIAS, and MODAL DAMPING data. Dynamic degree-of-freedom data. All joint inertia data. Modal damping percents. Contents of the specified response spectrum or time history data file as stored in the userdat.ds file, or if not in userdat.ds, then as stored in the GTSTRUDL system data file. A summary of the Eigen problem solution parameters and other available dynamic analysis parameters, such as number of degrees-offreedom, will be output.

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15.5.2

Dynamic Analysis

Graphical Display of Dynamic Analysis Loading Data and Dynamic Analysis Results 1.

Dynamic Load Data Graphical display of dynamic load data files is used to: a.

Plot files of dynamic Transient Loading Data previously stored in file name ‘id1' using the STORE TIME HISTORY command (Section 15.2.4) or the CREATE TIME HISTORY command (Section 15.2.6), and to

b.

Plot files of dynamic Response Spectrum Loading Data previously stored in file name ‘id1' using the STORE RESPONSE SPECTRUM command (Section 15.2.5) or the CREATE RESPONSE SPECTRUM command (Section 15.2.7).

The graphical display is created by using the following menu selections: From the Modeling menu selection

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From the Results menu selection

For example, A plot of a Response Spectrum Family of Curves:

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A plot of El Centro Ground Motion Earthquake:

2.

Dynamic Analysis Results Graphical display of dynamic analysis results is used to: a.

Plot results (joint displacements, velocities, and accelerations, support joint reactions, and member end forces and moments) of dynamic analysis as a function of time, and to

b.

Plot results of dynamic analysis (joint displacements, velocities, and accelerations, support joint reactions, and member end forces and moments) as functions of joint displacement or rotation parameters.

The graphical display is created by using the following menu selections:

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From the Results menu selection

For example, a plot of Member 106 Axial Force vs. Time:

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15.5.3

Dynamic Analysis

Normalization of Eigenvectors Command

Example NORMALIZE EIGENVECTORS OFF LIST DYNAMIC EIGENVECTORS NORMALIZE EIGENVECTORS ON LIST DYNAMIC EIGENVECTORS The above command sequences cause the eigenvectors to first be printed normalized to unit mass and then normalized to unit maximum amplitude .

Explanation This command determines the manner in which the eigenvectors are normalized for output. If the ON option is used, each eigenvector is normalized to unit maximum amplitude. The eigenvectors are stored internally normalized to unit mass [Φ]T [M] [Φ] = [I], where [Φ] is a matrix of eigenvectors, [M] is the system mass matrix, and [I] is the unit matrix. If the OFF option is given, the eigenvectors are output normalized to unit mass. If the command is not given the eigenvectors will be normalized to unit maximum amplitude for output.

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15.5.4

Dynamic Data and Analysis Results Output Commands

LIST DYNAMIC Eigen Results and Mass Summary Command

where, i1

=

number of eigenvalues to be listed; default is all

i2

=

number of eigenvectors to be listed; default is all

jlist

=

list of joint names for which mass properties are to be computed and output; default is all

Example LIST DYNAMIC EIGENVALUES LIST DYNAMIC PARTICIPATION FACTORS LIST DYNAMIC MASS SUMMARY

Explanation The LIST DYNAMIC command is used to output certain computed dynamic analysis results that are computed by the DYNAMIC ANALYSIS EIGENVALUES command (Section 15.3.4), or that are computed on the basis of information created by the DYNAMIC ANALYSIS EIGENVALUES command. Options of the LIST DYNAMIC command are given in Table 15.5.4-1.

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Table 15.5.4-1 Options of the LIST DYNAMIC Command LIST DYNAMIC Command Options

Description

EIGENVALUES

The EIGENVALUE option is used to list eigenvalues and associated undamped natural frequencies and periods as computed by the DYNAMIC ANALYSIS EIGENVALUES command (Section 15.3.4), and the current active/inactive status of each mode. Eigenvectors are listed only for active modes.

EIGENVECTORS

The EIGENVECTORS option is used to list currently active eigenvectors as computed by the DYNAMIC ANALYSIS EIGENVALUES command (Section 15.3.4).

PARTICIPATION FACTORS

The PARTICIPATION FACTORS option (also described in Section 15.3.5) computes and outputs ground motion Mass Participation Factors for the global X, Y and Z translation directions. The factors are expressed as a percentage of mass in each direction participating in each active mode. This command may be issued at any time after an eigenvalue analysis (Section 15.3.4) has been performed.

MASS SUMMARY (JOINTS jlist)

The MASS SUMMARY option is used to compute and list information determined from the global mass matrix including the center of gravity, the total mass and weight in each translational global direction, and the mass moment of inertia of the translational masses about axes parallel to the global axes and passing through the center of gravity. The JOINTS option identifies a subset of joints for which the mass summary information is computed (i.e., only the mass associated with the specified joints are included in the computation). The JOINTS option is particularly useful for computing the mass properties of a floor in a building by specifying only the joints that are included in the plane or volume of the floor of interest. Note that only ACTIVE joints in jlist are processed and all ACTIVE joints are assumed when the JOINTS option is not given. This command may be issued after the global mass matrix has been assembled by the DYNAMIC ANALYSIS EIGENVALUES command (Section 15.3.4), or by the PERFORM ASSEMBLY FOR DYNAMICS command (Section 2.4.5.5.1, Volume 3, GTSTRUDL User Reference Manual). Note that mass at supported degrees-of-freedom is not contained in the global mass matrix. The condensed mass matrix is used if DYNAMIC DEGREES OF FREEDOM have been specified (Section 2.4.5.1, Volume 3, GTSTRUDL User Reference Manual).

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Extended Example DYNAMIC ANALYSIS EIGENVALUES LIST DYNAMIC PARTICIPATION FACTORS LIST DYNAMIC MASS SUMMARY LIST DYNAMIC MASS SUMMARY JOINTS GROUP 'Floor1' INACTIVE MODES ALL BUT 1 3 5 LIST DYNAMIC EIGENVALUES EIGENVECTORS LIST DYNAMIC PARTICIPATION FACTORS The above commands compute and output eigenvalues, frequencies, periods, and mass participation factors for all modes, and mass summary data, and then output the eigenvalues, eigenvectors, and mass participation factors for modes 1, 3, and 5.

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15.5.5

Dynamic Analysis

OUTPUT MODAL CONTRIBUTIONS Command

Example OUTPUT MODAL CONTRIBUTIONS

Explanation Dynamic response computed for response spectrum loadings can be output in the form of modal combinations (e.g., RMS, CQC, etc.), and/or modal contributions (the response in the individual modes). If the OUTPUT MODAL CONTRIBUTIONS command is not specified, then only the modal combinations will be output by the LIST RESPONSE SPECTRUM Results Command (Section 15.5.6). If the OUTPUT MODAL CONTRIBUTIONS command is specified (i.e., the ON option), then the modal combinations as well as individual modal contributions will be output by the LIST RESPONSE SPECTRUM Results Command (Section 15.5.6). The OFF option may be given to negate a previously specified ON option.

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15.5.6

Dynamic Data and Analysis Results Output Commands

LIST RESPONSE SPECTRUM Results Command

where:

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and where, jlist

=

list of joint names for which response spectrum results are to be computed (default is ALL active and inactive joints)

mlist =

list of member and finite element names for which response spectrum results are to be computed (default is ALL active and inactive members)

Example LIST RESPONSE SPECTRUM DISPLACEMENTS MODAL COMBINATIONS RMS CQC JOINTS 101 TO 111 BY 2 LIST RESPONSE SPECTRUM FORCES REACTIONS MODAL COMBINATIONS RMS CQC LIST RESPONSE SPECTRUM BASE SHEAR JOINTS ALL

Explanation The LIST RESPONSE SPECTRUM command is used to output participation factors, spectral displacements, velocites, accelerations and modal coefficients that are defined in Section 2.4.2.5, Volume 3 of the GTSTRUDL User Reference Manual. The participation factor output via the LIST DYNAMIC PARTICIPATION FACTOR command is a normalized value expressed as a percentage, while the value output via this LIST RESPONSE SPECTRUM PARTICIPATION FACTORS command is the actual factor as computed in Equation 5-6 in Section 2.4.2.5, Volume 3 of the GTSTRUDL User Reference Manual. The BASE/STORY SHEAR option lists the global X, Y, and Z components of the total response spectrum inertia forces computed for each active mode and summed over the joints specified in the list (restrained force components at support joints included in the joint list are ignored). Modal combinations are also computed and listed if specified. These results are computed and listed completely for each active response spectrum loading condition. For example, consider a building structure for which base shear with respect to all joints above the level for which base shear is to be computed and for each mode based on an RMS modal combination is needed for the top 10 stories, and where joint names 101 to 200 are the joints in the top 10 stories above the level for which base shear is to be computed. Base shear will be computed and output by the following command: LIST RESPONSE SPECTRUM BASE SHEAR MODAL COMB RMS JOINTS 101 TO 200

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Another example is a building structure where the total base shear is to be computed with respect to all support joints at the bottom of the structure for each mode and based on an RMS modal combination. Base shear will be computed and output by the following command: LIST RESPONSE SPECTRUM BASE SHEAR MODAL COMB RMS JOINTS ALL IMPORTANT NOTE REGARDING BASE SHEAR: Base shear calculations are performed on a mode-by-mode basis, where for each mode, the algebraic sum of reaction components is performed, thus respecting equilibrium in each mode, and which is the correct procedure for such a calculation. However, the base shear calculation is NOT equal to the output from the LIST SUM REACTIONS command since LIST SUM REACTIONS calculates a sum of reactions from the pseudo static load results which are not a set of forces in equilibrium (i.e., they are the result of modal combinations which eliminate sign, and thus cannot be a set of forces in equilibrium). NOTE:

Total base shear corresponding to the earthquake direction for the full structure can be computed by hand as described in Section 15.3.7.3.

The LIST RESPONSE SPECTRUM command is also used to output response spectrum dynamic analysis results (joint displacements, velocities, and accelerations, and member end forces and support reactions) for all currently active response spectrum loading conditions (Section 15.2.11). The requested results must have been previously computed by the PERFORM RESPONSE SPECTRUM command (Section 15.3.7.1), or the COMPUTE RESPONSE SPECTRUM results command (Section 15.4.1). Note that finite element nodal forces and generalized stresses and strains can be computed but cannot be output via the LIST RESPONSE SPECTRA command. However, these finite element results may be copied into static loading conditions using the CREATE PSEUDO STATIC LOADING (Section 15.4.3) command and then output using the LIST (Section 13.3) command. Member section forces and stresses can also be output in a similar manner with the CREATE PSEUDO STATIC LOAD and LIST SECTION (Section 13.8) commands. Other commands which affect the LIST RESPONSE SPECTRUM results command are as follows: OUTPUT MODAL CONTRIBUTIONS (Section 15.5.4) OUTPUT DECIMAL (Section 13.2) OUTPUT FIELD (Section 13.2) If no members, finite elements, or joints are specified, the default of all active and inactive members, finite elements, or joints are used.

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If no members, finite elements, or joints are specified, the default of all active and inactive members, finite elements, or joints are used. If no modal combination method is specified, the default is that only individual modal contributions are computed. LIST RESPONSE SPECTRUM result options are shown in Table 15.5.6-1, and LIST RESPONSE SPECTRUM modal combination options are shown in Table 15.5.6-2.

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Table 15.5.6-1 LIST RESPONSE SPECTRUM Result Options LIST RESPONSE SPECTRUM Result Options DISPLACEMENTS, VELOCITIES and ACCELERATIONS

FORCES

REACTIONS

Brief Description Joint displacements, velocities, and accelerations. Member end forces (finite element nodal forces and generalized stresses and strains cannot be output by the LIST RESPONSE SPECTRUM command). Joint support reactions. Note that REACTIONS are computed as the resultant of the sum of the FORCE contributions of members and finite elements incident on the support joints. In order that the contributions are non-zero, the incident FORCES must be calculated in a preceding or in the same COMPUTE RESPONSE SPECTRUM FORCES REACTIONS command.

Table 15.5.6-2 LIST RESPONSE SPECTRUM Modal Combination Options LIST RESPONSE SPECTRUM Modal Combination Options

Brief Description

RMS

Root Mean Square (i.e., Square Root of the Sum of the Squares) of the modal responses

PRMS

Peak Root Mean Square (Peak response plus the RMS of the remaining modal responses)

CQC

Complete Quadratic Combination of modal responses

ABS

Absolute Sum of modal responses

(NRC) TPM

U.S. Nuclear Regulatory Commission Ten Percent Method combination of modal responses

(NRC) GRP

U.S. Nuclear Regulatory Commission Grouping Method combination of modal responses

(NRC) DSM

U.S. Nuclear Regulatory Commission Double Sum Method combination of modal responses

ALL

All of the above seven modal combination methods

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15.5.7

LIST TRANSIENT Results Command

where,

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and where, t1,...,tn

=

i1,...,in

decimal value of times in active units =

time point numbers (e.g., 5 would mean the 5th time point of the integration time points)

jlist

=

list of joint names for which response spectrum results are to be computed (default is ALL active and inactive joints)

mlist

=

list of member and finite element names for which response spectrum results are to be computed (default is ALL active and inactive members)

Example PERFORM TRANSIENT ANALYSIS LIST TRANSIENT DISPL JOINT 50 101 TO 115 BY 2 LIST TRANSIENT MAXIMUM DISPLACEMENTS UNITS KN M SECONDS COMPUTE TRANSIENT FORCES REACTIONS TIMES FROM 0.0 TO 30.0 AT 0.10 LIST TRANSIENT FORCES TIMES 5.0 TO 20.0 AT 0.20 LIST TRANSIENT MAXIMUM FORCES TIMES ALL LIST TRANSIENT MAXIMUM REACTIONS TIMES ALL

Explanation The LIST TRANSIENT results command is used to output transient (i.e., time history) dynamic analysis results for all currently active transient loading conditions and at the specified or default time points, and for the specified or default joints and members. Transient joint displacements, velocities, and accelerations computed by the PERFORM TRANSIENT ANALYSIS command (Section 15.3.8), and transient support reactions and member end forces computed by the COMPUTE TRANSIENT results command (Section 15.4.2), may be output. LIST TRANSIENT result options are shown in Table 15.5.7-1.

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Table 15.5.7-1 LIST TRANSIENT Result Options LIST TRANSIENT Result Options

DISPLACEMENTS, VELOCITIES and ACCELERATIONS

FORCES

REACTIONS

Brief Description

Joint displacements, velocities, and accelerations.

Member end forces (finite element nodal forces and generalized stresses and strains cannot be output by the LIST TRANSIENT result command). Joint support reactions. Note that REACTIONS are computed as the resultant of the sum of the FORCE contributions of members and finite elements incident on the support joints. In order that the contributions are non-zero, the incident FORCES must be calculated in a preceding or in the same COMPUTE TRANSIENT FORCES REACTIONS command.

The LIST TRANSIENT command causes no computations, other than determining maximums if the MAXIMUM option has been given. Thus, any result to be listed must have been previously computed. If the MAXIMUM option is given, the maximum response and its corresponding time of occurrence are determined and are listed for each requested response quantity. The search for the maximum value occurs only among values that have been previously computed. The TIMES option permits the output of a subset of the computed transient dynamic analysis results at specified time points. TIMES ALL is the default. Note that finite element nodal forces, and generalized stresses and strains, can be computed by the COMPUTE TRANSIENT results command (Section 15.4.2), but they cannot be output by the LIST TRANSIENT command. Rather, finite element dynamic analysis results may be copied by CREATE PSEUDO STATIC LOADING command (Section 15.4.3), and subsequently output by the LIST (Section 13.3) and CALCULATE AVERAGE (Section 13.9) commands. Member section forces and stresses also can be output by using the CREATE PSEUDO STATIC LOADING (Section 15.4.3) and LIST SECTION (Section 13.8) commands.

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15.6

Example Sequences of Dynamic Analysis Commands

Example Sequences of Dynamic Analysis Commands Tables 15.6-1 to 15.6-3 in this Section 15.6 summarize examples of commands provided by GTSTRUDL for dynamic analysis, and ordered according to several examples of dynamic analysis functional requirements. The commands and orderings shown in this Chapter are not intended to be complete. Rather, they are merely intended to provide an example of command groups that may be used to achieve several common types of dynamic analysis results. There are numerous other ways in which all the dynamic analysis commands may be used. The examples included in this Chapter are as follows: Table 15.6-1 Example Commands to Perform the Eigen solution for Structure Frequencies and Mode Shapes Without Initial Stress Considerations Table 15.6-2 Example Commands to Perform Response Spectrum Analysis Table 15.6-3 Example Commands to Perform Transient (Time History) Analysis by Modal Superposition

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Dynamic Analysis

Table 15.6-1 Example Commands to Perform the Eigen solution for Structure Frequencies and Mode Shapes Without Initial Stress Considerations

Dynamic Analysis Functional Requirements

Examples of Commands That May be Used

1. Structural mass

1. INERTIA OF JOINTS MEMBER ADDED INERTIA

2. Eigen solution control parameters

2. EIGEN PARAMETERS SOLVE USING GTLANCZOS NUMBER OF MODES PRINT MAX END

3. Compute structure frequencies and mode shapes WITHOUT consideration of initial stress

3. DYNAMIC ANALYSIS EIGENSOLUTION

4. Output structure natural frequencies

4. LIST DYNAMIC EIGENVALUES

5. Output dynamic modal mass participation factors

5. LIST DYNAMIC PARTICIPATION FACTORS

15 - 158

Dynamic Analysis

Example Sequences of Dynamic Analysis Commands

Table 15.6-2 Example Commands to Perform Response Spectrum Analysis Dynamic Analysis Functional Requirements

Examples of Commands That May be Used

1. Define one or more response spectrum curves, and store into the USERDAT.DS data set under file name 'rs-fln' 2. Define one or more response spectrum loading conditions based on the previously defined response spectrum curves 3. Structural mass 4. Eigen solution control parameters 5. Compute structure frequencies and mode shapes WITHOUT consideration of initial stress 6. Output structure natural frequencies 7. Output dynamic modal mass participation factors 8. Activate only those modes, from among those computed, whose mass participation totals to some desired percent of the total structure mass participation 9. Specify modal damping factors 10. Perform a response spectrum analysis using the currently active modes, and based on all currently active and previously defined response spectrum loading conditions 11. Compute response spectrum results based on one or more modal combination methods 12. Output response spectrum analysis results 13. Create pseudo static loading results from response spectrum analysis results 14. Combine pseudo static load results with static analysis results 15. Output member section forces for loading combinations which include response spectrum analysis and static

1. STORE RESPONSE SPECTRUM 'rs-fln' DAMPING RATIO END (OF RESPONSE SPECTRUM) 2. RESPONSE SPECTRUM LOAD 'rs-ldn' SUPPORT ACCELERATION TRANSL X/Y/Z FILE 'rs-fln' FACTOR END (OF RESPONSE SPECTRUM LOAD) 3. INERTIA OF JOINTS INERTIA OF JOINTS FROM LOADING 4. EIGEN PARAMETERS SOLVE USING GTLANCZOS NUMBER OF MODES PRINT MAX END (OF EIGEN PARAMETERS) 5. DYNAMIC ANALYSIS EIGENSOLUTION 6. LIST DYNAMIC EIGENVALUES 7. LIST DYNAMIC PARTICIPATION FACTORS 8. INACTIVE MODES ALL BUT list 9. DAMPING RATIO or DAMPING PERCENT 10. PERFORM RESPONSE SPECTRUM ANALYSIS 11. COMPUTE RESPONSE SPECTRUM results MODAL COMBINATION comb-methods 12. LIST RESPONSE SPECTRUM results 13. CREATE PSEUDO STATIC LOAD 'name' FROM comb-methods OF LOAD 'rs-ldn' 14. CREATE LOAD COMBINATIONS 15. SECTION FRACT DS/NS LIST SECTION FORCES

15 - 159

Example Sequences of Dynamic Analysis Commands

Table 15.6-3

Dynamic Analysis

Example Commands to Perform Time History Transient Analysis by Modal Superposition

Dynamic Analysis Functional Requirements

Examples of Commands That May be Used

1. Define one or more transient loading curves, and store into the USERDAT.DS data set under file name 'tr-fln' 2. Define one or more transient loading conditions based on the previously defined transient loading curves 3. Structural mass 4. Eigen solution control parameters 5. Compute structure frequencies and mode shapes WITHOUT consideration of initial stress 6. Output structure natural frequencies 7. Output dynamic modal mass participation factor 8. Activate only those modes, from among those computed, whose mass participation totals to some desired percent of the total structure mass participation 9. Specify modal damping factors 10. Perform a modal superposition time history response analysis using the currently active modes, and based on all currently active and previously defined transient loading conditions 11. Compute transient time history results 12. Output transient time history analysis results 13. Create pseudo static loading results from transient time history analysis results 14. Combine pseudo static load results with static analysis results 15. Output member section forces for loading combinations which include transient time history analysis and static analysis results

1. STORE TIME HISTORY ACCEL 'tr-fln' acceleration-data 2. TRANSIENT LOAD 'tr-ldn' SUPPORT ACCELERATION TRANS X/Y/Z FILE 'tr-fln' FACTOR INTEGRATE FROM/TO/AT END (OF TRANSIENT LOAD) 3. INERTIA OF JOINTS MEMBER ADDED INERTIA 4. EIGEN PARAMETERS SOLVE USING GTLANCZOS NUMBER OF MODES PRINT MAX END (OF EIGEN PARAMETERS) 5. DYNAMIC ANALYSIS EIGENSOLUTION 6. LIST DYNAMIC EIGENVALUES 7. LIST DYNAMIC PARTICIPATION FACTORS 8. INACTIVE MODES ALL BUT list 9. DAMPING RATIO or DAMPING PERCENT 10. PERFORM TRANSIENT ANALYSIS 11. COMPUTE TRANSIENT FORCES REACTIONS TIMES FROM/TO/AT 12. LIST TRANSIENT results TIMES time-list LIST TRANSIENT MAX DISPL JOINTS list COMPUTE TRANSIENT results TIMES time-list 13. CREATE PSEUDO STATIC LOAD 'name' FROM TIME time-point OF LOAD 'tr-ldn' 14. CREATE LOAD COMBINATIONS 15. SECTION FRACT DS/NS LIST SECTION FORCES

15 - 160

Appendices

APPENDICES

Appendix A

Subset of GTSTRUDL Commands Ordered by Functional Area, and Ordered by Processing Requirements in Each Area

Appendix B

Subset of GTSTRUDL Commands Ordered by Functional Area, and Ordered by Command in Each Area

Appendices - 1

Appendices

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Appendices - 2

Appendix A Commands Ordered by Functional Area and by Processing Requirements

Appendix A Subset of GTSTRUDL Commands Ordered by Functional Area, and Ordered by Processing Requirements in Each Area

This Appendix summarizes a subset of GTSTRUDL commands that may be used to perform various types of information processing. The GTSTRUDL User Reference Manual (Table 1.2) should be referred to for a complete description of all available commands and Graphical User Interface (GTMenu) features. The commands summarized in this Appendix are ordered by functional area, and in each functional area are ordered by processing requirements, as follows: Table A-1 Subset of General Input/Output and Static Analysis Commands Ordered by Processing Requirements Table A-2 Subset of Dynamic Analysis Commands Ordered by Processing Requirements

A-1

APPENDIX A Commands Ordered by Functional Area and by Processing Requirements

Table A-1

Subset of General Input/Output and Static Analysis Commands Ordered by Processing Requirements

Engineering Requirement Starting GTSTRUDL

Data Base Management

Input/Output Control Current Units Geometry

Examples of GTSTRUDL Commands STRUDL 'job-id' 'job-title' RESTORE 'filename.gts' ADDITIONS CHANGES DELETIONS ACTIVE INACTIVE LOAD LIST OPEN USER DATA FILE SAVE 'filename.gts' RESTORE 'filename.gts' CINPUT 'filename.dat' COUTPUT 'filename.lis' UNITS JOINT COORDINATES GENERATE JOINTS/REPEAT/REPEAT DEFINE OBJECT COPY/MOVE OBJECT

Supports

STATUS SUPPORT

Support Boundary Conditions

JOINT RELEASES

Member and Finite Element Types

TYPE

Topology

MEMBER/ELEMENT INCIDENCES GENERATE MEMBERS/REPEAT/REPEAT GENERATE ELEMENTS/REPEAT/REPEAT DEFINE OBJECT COPY/MOVE OBJECT

A-2

Appendix A Commands Ordered by Functional Area and by Processing Requirements

Table A-1

Subset of General Input/Output and Static Analysis Commands Ordered by Processing Requirements (Continued)

Engineering Requirement

Member Boundary Conditions Member Principal Axis Orientation Member and Finite Element Properties Material Properties

Independent Loading Conditions

Applied Static Loading Types

Dependent Static Loading Conditions

Examples of GTSTRUDL Commands MEMBER RELEASES MEMBER ECCENTRICITIES MEMBER END JOINT SIZE CONSTANTS BETA BETA REFERENCE JOINT CALCULATE MEMBER ORIENTATION MEMBER PROPERTIES ELEMENT PROPERTIES CONSTANTS MATERIAL LOADING DEAD LOADING SELF WEIGHT LOADING FORM LOADING MOVING LOAD GENERATOR JOINT LOADS JOINT DISPLACEMENTS MEMBER LOADS MEMBER TEMPERATURE LOADS MEMBER DISTORTIONS ELEMENT LOADS SURFACE FORCES EDGE FORCES BODY FORCES JOINT TEMPERATURE LOADS LOADING COMBINATION COMBINE CREATE LOADING COMBINATION CREATE AUTOMATIC LOAD COMBINATIONS

A-3

APPENDIX A Commands Ordered by Functional Area and by Processing Requirements

Table A-1

Subset of General Input/Output and Static Analysis Commands Ordered by Processing Requirements (Continued)

Engineering Requirement

Problem Statistics

Selective Display of Problem Descriptive Information

Static Analysis

Examples of GTSTRUDL Commands

QUERY STEEL TAKEOFF

PRINT

STIFFNESS ANALYSIS

Static Analysis Result Display

LIST joint and member results SECTION Command LIST internal member results GTMenu $ Graphical Display

Problem Termination

FINISH

A-4

Appendix A Commands Ordered by Functional Area and by Processing Requirements

Table A-2 Subset of Dynamic Analysis Commands Ordered by Processing Requirements

Engineering Requirement

Dynamic Data

Dynamic Analysis

Dynamic Results Computation

Dynamic Analysis Output

Examples of GTSTRUDL Commands INERTIA OF JOINTS MEMBER ADDED INERTIA DAMPING RATIO and DAMPING PERCENT STORE TIME HISTORY STORE RESPONSE SPECTRUM CREATE TIME HISTORY CREATE RESPONSE SPECTRUM DELETE TIME HISTORY DELETE RESPONSE SPECTRUM TRANSIENT LOADING with JOINT LOADS TRANSIENT LOADING with SUPPORT ACCELERATION RESPONSE SPECTRUM LOADING with SUPPORT ACCELERATION EIGEN PARAMETERS and DYNAMIC PARAMETERS LIST RAYLEIGH LOADING DYNAMIC ANALYSIS EIGENVALUES LIST DYNAMIC PARTICIPATION FACTORS INACTIVE/ACTIVE MODES PERFORM RESPONSE SPECTRUM ANALYSIS PERFORM TRANSIENT ANALYSIS PERFORM MODAL SUPERPOSITION ANALYSIS PERFORM PHYSICAL ANALYSIS COMPUTE RESPONSE SPECTRUM COMPUTE TRANSIENT COMPUTE PSEUDO STATIC LOADING PRINT DYNAMIC LIST DYNAMIC OUTPUT MODAL CONTRIBUTIONS LIST RESPONSE SPECTRUM LIST TRANSIENT GTMenu $ Graphical Display Various Graphical Display Menus

A-5

APPENDIX A Commands Ordered by Functional Area and by Processing Requirements

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A-6

Appendix B Commands Ordered by Functional Area and by Command in Each Area

Appendix B Subset of GTSTRUDL Commands Ordered by Functional Area, and Ordered by Command in Each Area

This Appendix summarizes a subset of GTSTRUDL commands that may be used to perform various types of information processing. The GTSTRUDL User Reference Manual (Table 1.2) should be referred to for a complete description of all available commands and Graphical User Interface (GTMenu) features. The commands summarized in this Appendix are ordered by functional area, and in each functional area are ordered by command, as follows: Table B-1 Subset of General Input/Output and Static Analysis Commands Ordered by Command Table B-2 Subset of Dynamic Analysis Commands Ordered by Command

B-1

Appendix B Commands Ordered by Functional Area and by Command in Each Area

Table B-1 Subset of General Input/Output and Static Analysis Commands Ordered by Command

Command Name STRUDL

Brief Description Initiates the processing of all subsequent POL commands except the RESTORE command.

RESTORE

Restores an existing problem data base SAVE file, and initiates the processing of all subsequent commands.

UNITS

Specifies the currently active units.

JOINT COORDINATES GENERATE JOINTS

Specifies joint coordinate geometry data.

STATUS SUPPORT JOINTS

Identifies which joints are support joints.

JOINT RELEASES JOINT RELEASES with Springs

Specifies the boundary conditions between support joints and the external world (ground).

DELETIONS; JOINTS

Deletes joints, and all associated joint information, from the FEM data base.

TYPE

Specifies the type (e.g., SPACE FRAME, PLANE STRESS, etc.) of members or finite elements identified in subsequent INCIDENCE and GENERATE commands.

MEMBER INCIDENCES GENERATE MEMBERS ELEMENT INCIDENCES GENERATE ELEMENTS

Specifies the member and finite element topology of the structure (i.e., what member or finite element connects to which joints).

MEMBER PROPERTIES ELEMENT PROPERTIES

Specifies member cross-section properties. Specifies finite element properties.

B-2

Appendix B Commands Ordered by Functional Area and by Command in Each Area

Table B-1 Subset of General Input/Output and Static Analysis Commands Ordered by Command (Continued)

Command Name MEMBER RELEASES MEMBER RELEASES with Springs

MEMBER ECCENTRICITIES DELETIONS; MEMBERS CONSTANTS material BETA angle damping

Brief Description Specifies the boundary conditions between the start and end faces of members and the joints upon which they are incident. Specifies the eccentricity of the start and end of the member's centroidal axis from the joint upon which the member is incident. Deletes members, and all associated member information, from the FEM data base. Specifies linear elastic material properties. Specifies member BETA angles. Specifies member composite damping factors.

MATERIAL

Specifies material by name from which default material properties are obtained.

BETA REFERENCE JOINT

Specifies a joint from which the member BETA angle is automatically computed. Specifies an orientation vector that is used to calculate a BETA angle for a list of members.

CALCULATE MEMBER ORIENTATION LOADING

Specifies the name and title of an independent static loading condition.

DEAD LOADING SELF WEIGHT LOADING

Specifies the name, title and direction of an independent static loading condition, and causes the automatic calculation of the self-weight of all members in the FEM.

FORM LOADING

MOVING LOAD GENERATOR

Specifies the name and title of an independent static loading condition, and creates a new loading from a linear combination of previously specified loadings. Moves loads (i.e., AASHTO trucks, user defined trucks, lane loads) along a user defined path (superstructure) on a structure.

B-3

Appendix B Commands Ordered by Functional Area and by Command in Each Area

Table B-1 Subset of General Input/Output and Static Analysis Commands Ordered by Command (Continued)

Command Name JOINT LOADS

Brief Description Specifies concentrated forces and moments applied to joints.

JOINT DISPLACEMENTS

Specifies known joint translation and rotation displacements at the support joints. (e.g., support settlements).

MEMBER LOADS

Specifies concentrated, uniformly distributed, and linearly distributed forces and moments applied to members.

MEMBER TEMPERATURE LOADS

Specifies distributed axial and bending temperature loads on members.

MEMBER DISTORTIONS

Specifies concentrated and distributed initial strains (all six components of strain) as initial member conditions.

ELEMENT LOADS

Specifies distributed forces applied to the edges, and pressures applied to the surfaces, of finite elements.

JOINT TEMPERATURE LOADS

Specifies concentrated extension and bending temperature loads at the nodal points of finite elements.

CREATE PSEUDO STATIC LOADING

Creates an equivalent set of static analysis results (i.e., joint displacements, member forces, element stresses, etc.) from dynamic analysis results.

B-4

Appendix B Commands Ordered by Functional Area and by Command in Each Area

Table B-1 Subset of General Input/Output and Static Analysis Commands Ordered by Command (Continued)

Command Name

LOADING COMBINATION COMBINE

CREATE LOADING COMBINATION

Brief Description Specifies the name and title of a dependent static loading condition, and specifies the linear combination factors. Creates loading combination analysis results for a previously defined loading combination. Specifies the name and title of a dependent static loading condition, and creates loading combination analysis results based on either Linear, Absolute, or RMS combination factors.

CREATE AUTOMATIC LOAD COMBINATIONS

Automatically creates large numbers of LOADING COMBINATION commands

DELETIONS; LOADS

Deletes loading condition definitions and all associated analysis results from the current problem data base.

ACTIVE/INACTIVE

Activates and inactivates joints, members, finite elements, or loading conditions in the current problem data base.

LOAD LIST

Activates and inactivates loading conditions in the current problem data base.

ADDITIONS

Sets all subsequent command processing to the ADDITIONS mode.

CHANGES

Sets all subsequent command processing to the CHANGES mode.

DELETIONS

Sets all subsequent command processing to the DELETIONS mode.

B-5

Appendix B Commands Ordered by Functional Area and by Command in Each Area

Table B-1 Subset of General Input/Output and Static Analysis Commands Ordered by Command (Continued)

Command Name

PRINT STEEL TAKEOFF

QUERY

Brief Description Outputs requested information previously specified by the engineer from the current problem data base. The engineer may specify the units, order, amount, and type of information to be displayed. Computes and outputs the length, volume, and weight of members. Outputs current status information including the current total number of active and inactive joints, members, finite elements, superelements, and independent and dependent loading conditions.

STIFFNESS ANALYSIS

Causes a static analysis to be performed on the currently active FEM.

OUTPUT DECIMAL

Specifies the number of digits following the decimal point for certain types of output results.

OUTPUT ORDERED

Specifies that the output shall be ordered by ascending order of joint, member, and finite element names.

OUTPUT BY MEMBER/JOINT

Specifies that analysis result output should be ordered by member and by joint.

OUTPUT BY LOADING

Specifies that analysis result output should be ordered by loading.

B-6

Appendix B Commands Ordered by Functional Area and by Command in Each Area

Table B-1 Subset of General Input/Output and Static Analysis Commands Ordered by Command (Continued)

Command Name LIST joint, member, and finite element analysis results

SECTION

LIST internal member analysis results

Brief Description Outputs previously computed analysis results from the current problem data base. The engineer may specify the units, order, amount, and type of analysis results to be output. Specifies section locations along members at which internal member analysis results are to be computed, or at which steel design code checks are to be performed. Causes internal member results to be computed at specified section locations and then output (e.g., moment diagrams and envelopes). The engineer may specify the units, order, amount, and type of results to be computed and output.

SAVE

Causes the current problem data base to be saved in a specified file in the users's directory from which GTSTRUDL is initiated.

FINISH

Terminates the current GTSTRUDL job.

B-7

Appendix B Commands Ordered by Functional Area and by Command in Each Area

Table B-2 Subset of Dynamic Analysis Commands Ordered by Command Command Name

INERTIA OF JOINTS

MEMBER ADDED INERTIA

FORM MISSING MASS LOAD

Brief Description Define mass by: 1. Automatic calculation of mass of members and finite elements 2. Direct specification of mass corresponding to specific dynamic degrees-of-freedom 3. Automatic calculation of mass based on static loading concentrated joint forces Automatic calculation of member mass based on specified concentrated and uniformly distributed member masses. Computes a new independent static loading condition consisting of joint load components that reflect the total mass associated with all modes ignored in a prior Response Spectrum Analysis.

DAMPING RATIO DAMPING PERCENTS

Specification of modal damping as a percent of critical damping

STORE TIME HISTORY

Input force or acceleration versus time loading values, and store the values on disk in the user data set (USERDAT) for future use.

STORE RESPONSE SPECTRUM

Input response spectrum loading values (i.e., maximum displacement, velocity, or acceleration values versus frequency or period), and store the values on disk in the user data set (USERDAT) for future use.

CREATE TIME HISTORY

Create acceleration versus time loading values from the results of a prior dynamic transient analysis, and store the values on disk in the user data set (USERDAT) for future use.

CREATE RESPONSE SPECTRUM

Create displacement versus frequency response spectrum loading values from existing acceleration time history files, and store the values on disk in the user data set (USERDAT) for future use.

DELETE TIME HISTORY DELETE RESPONSE SPECTRUM

Delete a stored time history or response spectrum file from the user data set (USERDAT)

Table B-2 Subset of Dynamic Analysis Commands Ordered by Command (Continued)

B-8

Appendix B Commands Ordered by Functional Area and by Command in Each Area

Command Name

Brief Description

TRANSIENT LOADING JOINT LOADS INITIAL CONDITIONS INTEGRATE FROM/TO/AT END (OF TRANSIENT LOADING)

Define a dynamic transient loading condition consisting of: - Force and/or moment joint load values taken from a previously STOREd force/moment versus time loading file - Force and/or moment joint load values versus time as a Sine/Cosine function - Optional structure initial conditions - Initial, final, and increment time values to be used in a subsequent dynamic time history analysis

TRANSIENT LOADING SUPPORT ACCELERATION INITIAL CONDITIONS INTEGRATE FROM/TO/AT END (OF TRANSIENT LOADING)

Define a dynamic transient loading condition consisting of: - Support translation acceleration values taken from a previously STOREd displacement/velocity/acceleration versus time loading file - Support translation acceleration values versus time as a Sine/Cosine function - Optional structure initial conditions - Initial, final, and increment time values to be used in a subsequent dynamic time history analysis

RESPONSE SPECTRUM LOADING SUPPORT ACCELERATION TRANSLATION X/Y/Z FILE 'name' MODE FACTORS END (OF RESPONSE SPECTRUM LOADINGS)

FORM STATIC LOAD

Define a dynamic response spectrum loading condition consisting of: - Response spectrum values taken from a previously STOREd response spectrum file

Automatic Generation of Static Equivalent Earthquake Loads ( Section 3.3.3.2.C of NEHRP Guidelines for the Seismic Rehabilitation of Buildings - FEMA Publication 273)

Table B-2 Subset of Dynamic Analysis Commands Ordered by Command (Continued)

B-9

Appendix B Commands Ordered by Functional Area and by Command in Each Area

Command Name

Brief Description

EIGEN PARAMETERS DYNAMIC PARAMETERS

Specify various parameters used to control the processing of the eigenproblem solution commands, and transient and response spectrum analysis commands, such as DYNAMIC ANALYSIS EIGENVALUE and PERFORM RESPONSE SPECTRUM ANALYSIS.

LIST RAYLEIGH LOADING

Computes and outputs the result of a Rayleigh approximate natural frequency analysis. The corresponding mode shape is approximated as the joint displacements computed in a prior STIFFNESS ANALYSIS where only translational joint forces (not moments) have been applied.

DYNAMIC ANALYSIS EIGENVALUES

LIST DYNAMIC PARTICIPATION FACTORS

ACTIVE/INACTIVE MODES

PERFORM RESPONSE SPECTRUM ANALYSIS

PERFORM TRANSIENT ANALYSIS

Causes an eigensolution analysis for the computation of natural frequencies and mode shapes to be performed consistent with parameters specified by the EIGEN PARAMETERS command. Computes and outputs the mass participation factors as a percentage of the total mass participating in each computed mode in each global X, Y, and Z axis direction. Identifies the active modes, from among all computed modes, that will be used in subsequent modal superposition transient and response spectrum analyses. Causes a response spectrum analysis to be performed for each currently active computed mode, and for all active response spectrum loading conditions. Only modal participation factors, modal coefficients, and spectral accelerations, velocities, and displacements, are computed by this command. Causes a modal superposition analysis to be performed using all currently active computed modes, and for all active dynamic transient loading conditions. Only time histories of joint accelerations, velocities, and displacements are computed by this command.

B - 10

Appendix B Commands Ordered by Functional Area and by Command in Each Area

Table B-2 Subset of Dynamic Analysis Commands Ordered by Command (Continued)

Command Name

PERFORM MODAL SUPERPOSITION ANALYSIS

PERFORM PHYSICAL ANALYSIS

COMPUTE RESPONSE SPECTRUM results

COMPUTE TRANSIENT results

CREATE PSEUDO STATIC LOADING

Brief Description Causes a modal superposition analysis to be performed using all currently active computed modes, and for all active dynamic response spectrum and transient loading conditions. This command is equivalent to giving both the PERFORM RESPONSE SPECTRUM ANALYSIS and PERFORM TRANSIENT ANALYSIS commands. In addition, this command also performs a modal superposition for all active steady state and harmonic loading conditions. Causes a direct time integration transient analysis for all active dynamic transient loading conditions. Only time histories of joint accelerations, velocities, and displacements are computed by this command. When used, this command must be given after a "PERFORM RESPONSE SPECTRUM ANALYSIS" or "PERFORM MODAL SUPERPOSITION ANALYSIS" command in which modal spectral results were computed. This command then computes requested modal responses and total structure responses (e.g., joint displacements, reactions, member end forces, finite element nodal forces, finite element stresses, etc.) based on specified modal combination methods using all currently active computed modes, and for all active response spectrum loads. When used, this command must be given after a "PERFORM TRANSIENT ANALYSIS", "PERFORM MODAL SUPERPOSITION ANALYSIS", or "PERFORM PHYSICAL ANALYSIS" command in which joint acceleration, velocity, and displacement time histories were computed. This command then computes requested structure responses for member end forces, finite element nodal forces, finite element stresses, support reactions, and free joint force resultants, for all active transient loads. Transforms dynamic analysis results into pseudo static results which then can be manipulated in a manner similar to real static analysis results. For example, by using the "CREATE PSEUDO STATIC LOADING", "CREATE LOAD COMBINATION", and "LIST SECTION FORCE" commands, pseudo static loading results (created from dynamic transient or response spectrum analysis results) can be combined with real static analysis results, and member force and moment diagrams can then be computed.

B - 11

Appendix B Commands Ordered by Functional Area and by Command in Each Area

Table B-2 Subset of Dynamic Analysis Commands Ordered by Command (Continued)

Command Name

Brief Description

PRINT DYNAMIC data

Output data previously specified by the user (e.g., joint inertias and modal damping values), or computed by GTSTRUDL (e.g., mass and stiffness matrices), for purposes of dynamic analysis.

LIST DYNAMIC eigen-results

Output dynamic analysis results which are independent of dynamic loading conditions. These are the: - Eigenvalues (natural frequencies) - Eigenvectors (mode shapes) - Mass modal participation factors, and - Summary of total mass and mass distribution.

OUTPUT MODAL CONTRIBUTIONS

Used to set a switch which will permit a subsequent "LIST RESPONSE SPECTRUM results" command to output individual modal responses in addition to outputting modal combination total response values.

LIST RESPONSE SPECTRUM results

Output results of dynamic response spectrum analyses as computed by prior "PERFORM RESPONSE SPECTRUM ANALYSIS", "PERFORM MODAL SUPERPOSITION ANALYSIS", and "COMPUTE RESPONSE SPECTRUM results" commands. Results include: Modal participation factors Spectral displacements, velocities, and accelerations Modal coefficients Displacements, velocities, accelerations, member end forces, and support reactions for each currently active mode (if the "OUTPUT MODAL CONTRIBUTIONS ON" command was previously specified) Total response that was previously computed on the basis of one or more modal combination methods. Base shear at any level of a building *NOTE: Finite element response spectrum nodal forces, stresses, and strains are not output with this command. Rather, these finite element results must be copied into a pseudo static loading using the "CREATE PSEUDO STATIC LOADING" command, and then output by a "LIST finite element results" command.

B - 12

Appendix B Commands Ordered by Functional Area and by Command in Each Area

Table B-2 Subset of Dynamic Analysis Commands Ordered by Command (Continued)

Command Name

Brief Description

LIST TRANSIENT results

Output results of dynamic transient analyses as computed by prior "PERFORM TRANSIENT ANALYSIS", "PERFORM MODAL SUPERPOSITION ANALYSIS", "PERFORM PHYSICAL ANALYSIS", and "COMPUTE TRANSIENT results" commands. Results include: Displacement, velocity, and acceleration total response (as computed by the "PERFORM" commands) Member end force and support reaction total response (as computed by the "COMPUTE TRANSIENT" command) *NOTE: Finite element transient nodal forces, stresses, and strains are not output with this command. Rather, these finite element results must be copied into a pseudo static loading using the "CREATE PSEUDO STATIC LOADING" command, and then output by a "LIST finite element results" command.

B - 13

Appendix B Commands Ordered by Functional Area and by Command in Each Area

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B - 14

Index of Commands

Index of Commands ACTIVE and INACTIVE Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-14 ACTIVE SOLVER Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-56 & 11-11 ADDITIONS, CHANGES, and DELETIONS Commands . . . . . . . . . . . . . . . . . . . . . . . . . . 5-12 ALIGN Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-49 Analysis Errors Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-1 AREA LOAD Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-108 ASSEMBLE FOR STATICS Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-12 AUTOMATIC BACKUP Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-11 BASE SHEAR CALCULATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-105 BETA REFERENCE JOINT Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-42 BETA Angle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-34 BOUNDARY CONDITION COMMANDS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-1 BYPASS Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-25 CALCULATE AVERAGE Finite Element Results Command . . . . . . . . . . . . . . . . . . . . . . 13-61 CALCULATE MEMBER ORIENTATION Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-49 CALCULATE PRESSURE Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-85 CALCULATE SOIL SPRING VALUES Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-17 CHARACTERISTICS OF THE STRUCTURAL ANALYTICAL MODEL . . . . . . . . . . . . . . . . 2-1 CINPUT Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-13 Combinations of Static Analysis Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-15 COMBINATIONS OF INDEPENDENT LOAD COMPONENTS AND STATIC ANALYSIS RESULTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-1 COMBINE Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-29 Commands and the Graphical User Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1 Computation of Member Dead Loads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-11 COMPUTE GROSS RESULTS Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-12 COMPUTE RESPONSE SPECTRUM Results Command . . . . . . . . . . . . . . . . . . . . . . 15-123 COMPUTE TRANSIENT Results Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-127 CONSISTENCY CHECK Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-38 CONSTANTS Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-30 CONVERT LOAD COMBINATIONS TO/FROM FORM LOADS Command . . . . . . . . . . . 10-9 COPY OBJECT Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-91 COUTPUT Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-18 CREATE RESPONSE SPECTRUM Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-40 CREATE TIME HISTORY Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-34 CREATE AUTOMATIC LOAD COMBINATIONS Command . . . . . . . . . . . . . . . . . . . . . . 10-33 CREATE PSEUDO STATIC LOADING Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-129 CREATE LOADING COMBINATION Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-23 DAMPING RATIO and DAMPING PERCENT Commands . . . . . . . . . . . . . . . . . . . . . . . 15-23 Data Base Management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-2 Index - 1

Index of Commands

DATA BASE MANAGEMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-1 DEAD LOADING Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-19 DEFINE GROUP Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-31 DEFINE OBJECT Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-82 DELETE OBJECT Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-85 DEFINE PHYSICAL MEMBER Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-60 SMOOTH PHYSICAL MEMBERS Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-60 DELETE TIME HISTORY and DELETE RESPONSE SPECTRUM Commands . . . . . . . 15-43 DELETION of GROUPS Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-36 DELETION of JOINTS Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-31 DELETION of MEMBERS and ELEMENTS Command . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-80 Dependent Loading Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-9 DESIGNING SHEAR WALLS BASED ON A RESPONSE SPECTRUM EARTHQUAKE ANALYSIS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-107 DETERMINE PLANAR JOINTS Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-3 Dynamic Analysis Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-79 DYNAMIC ANALYSIS EIGENSOLUTION Command . . . . . . . . . . . . . . . . . . . . . . . . . . 15-96 Dynamic Data Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-6 Dynamic Data and Analysis Results Output Commands . . . . . . . . . . . . . . . . . . . . . . . 15-134 DYNAMIC PARAMETERS Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-90 Dynamic Results Back Substitution Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-121 EIGEN PARAMETERS Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-84 ELEMENT LOADS Command for Non-Isoparametric Elements . . . . . . . . . . . . . . . . . . . . 9-90 ELEMENT LOADS Command for Isoparametric Elements . . . . . . . . . . . . . . . . . . . . . . . . 9-93 ELEMENT PROPERTIES Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-25 END LOAD GENERATOR Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-79 Example Sequence of Dynamic Analysis Commands . . . . . . . . . . . . . . . . . . . . . . . . . . 15-157 Extended Example: RESPONSE SPECTRUM ANALYSIS, FORM MISSING MASS LOAD, and Base Shear Computation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-114 External World . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3 Files Created by GTSTRUDL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-40 Finite Element Planar Reference Frame . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-10 Finite Element Local Reference Frame . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-9 FINISH Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-12 FLIST 1 and FLIST 2 Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-21 FORM IS1893 STATIC SEISMIC LOAD Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-73 FORM LOAD REFORM Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-7 FORM LOADING Command (Combinations of Independent Loading Condition Components) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-2 FORM MISSING MASS LOAD Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-111 FORM STATIC EARTHQUAKE LOAD Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-55 FORM UBC97 LOAD Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-65 Format of the Descriptions of Commands in This Guide . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4 GENERAL COMMANDS AND FILE MANAGEMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1 Index - 2

Index of Commands

GENERATE LOAD Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-77 GENERATE m ELEMENTS Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-69 GENERATE n JOINTS Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-12 GENERATE m MEMBERS Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-60 GEOMETRY AND TOPOLOGY COMMANDS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-1 Global Reference Frame . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1 GLOBAL AND LOCAL COORDINATE REFERENCE FRAMES . . . . . . . . . . . . . . . . . . . . . 3-1 GRAPHICAL DISPLAY COMMANDS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14-1 Graphical Display of Dynamic Analysis Loading Data and Dynamic Analysis Results . 15-140 GROUP Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-31 GT64M and GTSES Stand-Alone Solvers for Linear Static Analysis . . . . . . . . . . . . . . . . . 11-12 INACTIVE / ACTIVE MODES Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-98 Independent Loading Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-9 Independent Static Loading Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-5 INDEPENDENT STATIC LOADING CONDITION COMMANDS . . . . . . . . . . . . . . . . . . . . 9-1 INERTIA OF JOINTS Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-9 Internal Member Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-40 INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1 Joints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1 JOINT LOADS Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-25 JOINT DISPLACEMENTS Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-32 JOINT RELEASES Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-6 JOINT TEMPERATURE Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-102 JOINT COORDINATES Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-3 LANE LOAD Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-71 LARGE PROBLEM Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-46 Linear Dynamic Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-1 “list” Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-3 LIST Internal Member Results Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-46 LIST MAXIMUM JOINT DISPLACEMENT Command . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-35 LIST RAYLEIGH LOADING Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-94 LIST DYNAMIC PARTICIPATION FACTORS Command . . . . . . . . . . . . . . . . . . . . . . . . 15-97 LIST Joint, Member, and Finite Element Results Command . . . . . . . . . . . . . . . . . . . . . . 13-11 LIST DYNAMIC Eigen Results Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-145 LIST MAXIMUM REACTION ENVELOPE Command . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-38 LIST TRANSIENT Results Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-154 LIST RESPONSE SPECTRUM Results Command . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-149 LIST RESPONSE SPECTRUM SPECTRAL ACCELERATIONS and LIST RESPONSE SPECTRUM PARTICIPATION FACTORS Commands . . . . . . 15-103 LIST SUM FORCES Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-72 LOAD LIST Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-17 LOADING COMBINATION Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-17 LOADING Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-7 Local and Planar Finite Element Reference Frames . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-8 Index - 3

Index of Commands

Local Joint Reference Frame . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-13 Local Member Reference Frame . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-4 LOCATE INTERFERENCE JOINTS Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-97 LOCATE DUPLICATE JOINTS Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-98 LOCATE DUPLICATE MEMBERS Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-100 MATERIAL Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-28 MEMBER ADDED INERTIA Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-22 MEMBER and ELEMENT INCIDENCES Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-49 Member and Finite Elements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1 Member and Finite Element Boundary Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-6 MEMBER and MATERIAL PROPERTIES, and MEMBER BETA ANGLE Commands . . . . 8-1 MEMBER DIMENSIONS Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-21 MEMBER DISTORTIONS Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-52 MEMBER ECCENTRICITIES Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-29 MEMBER LOADS Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-37 MEMBER PROPERTIES Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-2 MEMBER RELEASES Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-21 MEMBER TEMPERATURE LOAD Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-49 MOVE OBJECT Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-87 Moving Load Generator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-55 MOVING LOAD GENERATOR Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-56 Moving Load Generator Examples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-80 Normalization of Eigenvectors Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-144 NOTES Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-52 OPEN USERDATA FILE Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-39 Orientation of Local Member Reference Frame (The BETA Angle) . . . . . . . . . . . . . . . . . . . 3-8 OUTPUT Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-7 OUTPUT MODAL CONTRIBUTIONS Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-148 PERFORM TRANSIENT ANALYSIS Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-116 PERFORM PHYSICAL ANALYSIS Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-118 PERFORM NUMBER OF MODES COMPUTATION Command . . . . . . . . . . . . . . . . . . 15-120 PERFORM NUMERICAL INSTABILITY ANALYSIS Command . . . . . . . . . . . . . . . . . . . . 12-2 PERFORM RESPONSE SPECTRUM ANALYSIS Command . . . . . . . . . . . . . . . . . . . 15-101 PERFORM RESPONSE SPECTRUM ANALYSIS, FORM MISSING MASS LOAD, and Base Shear Computation (Extended Example) . . . . . . . . . . . . . . . . . . . . 15-101 Graphical Display of Dynamic Analysis Loading Data and Dynamic Analysis Results . 15-140 PRINT GENERATE Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-37 PRINT DYNAMIC DATA Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-133 PRINT Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-2 PRINT OBJECT Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-86 PRINT GROUP Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-35 Printed Output Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-1 QUERY Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-30 RESPONSE SPECTRUM LOADING with SUPPORT ACCELERATION Command . . . 15-50 Index - 4

Index of Commands

RESPONSE SPECTRUM ANALYSIS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-100 ROTATE LOAD Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-105 RUN Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-47 SAVE and RESTORE Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-8 SCAN Error Flag Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-23 Scope Environment Graphical Display Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14-1 SECTION Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-41 SELF WEIGHT LOADING RECOMPUTE Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-18 SELF WEIGHT LOADING Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-13 Static Loading Classes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-2 STATIC ANALYSIS COMMAND . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-1 STATUS Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-2 STEEL TAKE OFF Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-81 STIFFNESS ANALYSIS Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-2 STORE RESPONSE SPECTRUM Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-29 STORE TIME HISTORY Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-26 Structure Support Boundary Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-6 STRUDL Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-11 Subset of GTSTRUDL Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-5 Summary of Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-2 SUPERSTRUCTURE Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-57 The GTSTRUDL Batch Processor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-43 The GTSTRUDL Data Base . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-5 The LIST CODE CHECK RESULTS Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-83 TRANSIENT LOADING with SUPPORT ACCELERATION Command . . . . . . . . . . . . . . 15-48 TRANSIENT LOADING with JOINT LOADS Command . . . . . . . . . . . . . . . . . . . . . . . . . 15-44 TRUCK / VEHICLE LOAD Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-62 TYPE Command for Members and Finite Elements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-33 UNITS Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-26

Index - 5

Index of Commands

Blank Page

Index - 6

Reader Comment Form

Reader Comment Form Your comments can help the CASE Center improve its manuals and software. Please take a little time to fill out this comment sheet. Tell us what you did or did not like about this document. We will consider your suggestions as we continually review and update our software and user documentation. Thank you. Title:

GTSTRUDL User Guide: Analysis, Revision 6, April 2009.

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COMPUTER AIDED STRUCTURAL ENGINEERING CENTER School of Civil and Environmental Engineering Georgia Institute of Technology Atlanta, Georgia 30332-0355 U.S.A. Tel: +1-404-8942260 FAX: +1-404-8948014 email: [email protected]

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