steel-ec3 (1)

Version August 2013

Add-on Module

STEEL EC3 Ultimate Limit State, Serviceability, Fire Resistance, and Stability Analyses According to Eurocode 3

Program Description

All rights, including those of translations, are reserved. No portion of this book may be reproduced – mechanically, electronically, or by any other means, including photocopying – without written permission of der DLUBAL-SOFTWARE GMBH.

© Dlubal Software GmbH Am Zellweg 2 D-93464 Tiefenbach Tel.: Fax: E-Mail: Web:

+49 9673 9203-0 +49 9673 9203-51 [email protected] www.dlubal.com

Program STEEL EC3 © 2013 Dlubal Software GmbH

Contents Contents

Page

Contents

Page

1.

Introduction

4

4.2

Design by Cross-Section

53

1.1

Add-on Module STEEL EC3

4

4.3

Design by Set of Members

54

1.2

STEEL EC3 - Team

5

4.4

Design by Member

55

1.3

Using the Manual

6

4.5

Design by x-Location

55

1.4

Open the Add-on Module STEEL EC3

6

4.6

Governing Internal Forces by Member

56

2.

Input Data

8

4.7

Governing Internal Forces by Set of Members

57

2.1

General Data

8

4.8

Member Slendernesses

58

2.1.1

Ultimate Limit State

10

4.9

Parts List by Member

59

2.1.2

Serviceability

11

4.10

Parts List by Set of Members

60

2.1.3

Fire Resistance

12

2.1.4

National Annex (NA)

13

5.

Results Evaluation

61

2.2

Materials

17

5.1

Results in the RSTAB Model

62

2.3

Cross-Sections

19

5.2

Result Diagrams

64

2.4

Lateral Intermediate Supports

23

5.3

Filter for Results

65

2.5

Effective Lengths - Members

24

6.

Printout

67

2.6

Effective Lengths - Sets of Members

28

6.1

Printout Report

67

2.7

Nodal Supports - Sets of Members

29

6.2

STEEL EC3 Graphic Printout

67

2.8

Member End Releases - Sets of Members

31

7.

General Functions

69

2.9

Serviceability Data

32

7.1

Design Cases

69

Cross-Section Optimization

71

2.10

Specifications for Fire Resistance Design

33

7.2

2.11

Parameters - Members

34

7.3

Units and Decimal Places

73

2.12

Parameters - Sets of Members

41

7.4

Data Transfer

74

3.

Calculation

42

7.4.1

Export Material to RSTAB

74

3.1

Detail Settings

42

7.4.2

Export Effective Lengths to RSTAB

74

3.1.1

Ultimate Limit State

42

7.4.3

Export Results

74

3.1.2

Stability

44

8.

Examples

76

3.1.3

Serviceability

46

8.1

Stability

76

3.1.4

Fire Resistance

47

8.2

Fire Resistance

83

3.1.5

Other

49

A

Literature

86

3.2

Start Calculation

50

B

Index

87

4.

Results

51

4.1

Design by Load Case

52

Program STEEL EC3 © 2013 Dlubal Software GmbH

3

1 Introduction

1.

Introduction

1.1

Add-on Module STEEL EC3

The European Standard Eurocode 3 (EN 1993-1-1:2005) describes design, analysis, and construction of steel structures in the member states of the European Union. With the RSTAB addon module STEEL EC3, DLUBAL SOFTWARE provides a powerful tool for designing steel structures. Country-specific regulations are taken into account by National Annexes (NA). In addition to the parameters included in the program, you can define your own limit values or create new National Annexes. STEEL EC3 can carry out all typical ultimate limit state designs as well as stability and deformation analyses. The program is able to take into account various actions for the ultimate limit state design. Furthermore, you can choose between the interaction formulas given in the code. An important part of the analysis in STEEL EC3 is the categorization of the cross-sections into the Classes 1 through 4. In this way, you can check the limitation of the design capacity and of the rotational capacity due to local buckling for cross-section parts. Moreover, STEEL EC3 determines the c/t-ratios of the cross-section elements subjected to compression and classifies the cross-sections completely automatically. For the stability analysis, you can specify for each member or set of members whether flexural buckling occurs in y- and/or z-direction. Furthermore, you can define additional lateral supports in order to represent the model close to reality. In addition, the stabilizing effect of purlins and sheeting can be taken into account by rotational restraints and shear panels. STEEL EC3 determines the slendernesses and elastic critical buckling loads from the boundary conditions. The elastic critical moment for lateral torsional buckling required for the lateral torsional buckling analysis can be determined automatically or specified manually. In addition to this, it is possible to take into account the load application point of transverse loads, which is affecting the torsional resistance considerably. STEEL EC3 can also perform the fire resistance design according to EN 1993-1-2. The steel structure is designed on the bearing capacity level according to the simplified calculation method. As fire protection, you can select encasements with different physical properties. For structures with extremely slender cross-sections, the serviceability limit state represents an important design. The load cases, load combinations, and result combinations can be assigned to different design situations. The limit deformations are preset by the National Annexes and can be adjusted, if necessary. In addition, you can specify reference lengths and precambers that are considered accordingly in the design. STEEL EC3 also allows you to design structural components made of stainless steel according to EN 1993-1-4. If required, you can optimize cross-sections in the model, and then export the modified crosssections to RSTAB. Using the design cases, you can design separate structural components in complex structures or analyze variants. STEEL EC3 is integrated as an add-on module in RSTAB. Thus, the design relevant input data is already preset when you start the module. After the design, you can use the graphical RSTAB user interface to evaluate the results. Finally, you can document the design process in the global printout report, from determination of internal forces to design. We hope you will enjoy working with STEEL EC3. Your DLUBAL Team

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1 Introduction

1.2

STEEL EC3 - Team

The following people were involved in the development of STEEL EC3:

Program coordination Dipl.-Ing. Georg Dlubal

Dipl.-Ing. (FH) Younes El Frem

Programming Ing. Zdeněk Kosáček Dipl.-Ing. Georg Dlubal Dr.-Ing. Jaroslav Lain Ing. Martin Budáč

Mgr. Petr Oulehle Zbyněk Zámečník DiS. Jiří Šmerák

Cross-section and material database Ing. Ph.D. Jan Rybín Mgr. Petr Oulehle

Ing. Jiří Kubíček

Program design, dialog figures, and icons Dipl.-Ing. Georg Dlubal MgA. Robert Kolouch

Ing. Jan Miléř

Program supervision Ing. Martin Vasek

Dipl.-Ing. (FH) Wieland Götzler

Localization, manual Ing. Fabio Borriello Ing. Dmitry Bystrov Eng.º Rafael Duarte Ing. Jana Duníková Dipl.-Ing. (FH) René Flori Ing. Lara Freyer Alessandra Grosso Bc. Chelsea Jennings Jan Jeřábek Ing. Ladislav Kábrt Ing. Aleksandra Kociołek

Ing. Roberto Lombino Eng.º Nilton Lopes Mgr. Ing. Hana Macková Ing. Téc. Ind. José Martínez MA Translation Anton Mitleider Dipl.-Ü. Gundel Pietzcker Mgr. Petra Pokorná Ing. Michaela Prokopová Ing. Marcela Svitáková Dipl.-Ing. (FH) Robert Vogl Ing. Marcin Wardyn

Technical support and quality management M.Eng. Cosme Asseya Dipl.-Ing. (BA) Markus Baumgärtel Dipl.-Ing. Moritz Bertram Dipl.-Ing. (FH) Steffen Clauß Dipl.-Ing. Frank Faulstich Dipl.-Ing. (FH) René Flori Dipl.-Ing. (FH) Stefan Frenzel Dipl.-Ing. (FH) Walter Fröhlich Dipl.-Ing. (FH) Bastian Kuhn

Program STEEL EC3 © 2013 Dlubal Software GmbH

Dipl.-Ing. (FH) Ulrich Lex Dipl.-Ing. (BA) Sandy Matula Dipl.-Ing. (FH) Alexander Meierhofer M.Eng. Dipl.-Ing. (BA) Andreas Niemeier M.Eng. Dipl.-Ing. (FH) Walter Rustler M.Sc. Dipl.-Ing. (FH) Frank Sonntag Dipl.-Ing. (FH) Christian Stautner Dipl.-Ing. (FH) Lukas Sühnel Dipl.-Ing. (FH) Robert Vogl

5

1 Introduction

1.3

Using the Manual

Topics like installation, graphical user interface, results evaluation, and printout are described in detail in the manual of the main program RSTAB. The present manual focuses on typical features of the STEEL EC3 add-on module. The descriptions in this manual follow the sequence and structure of the module's input and results windows. In the text, the described buttons are given in square brackets, for example [View mode]. At the same time, they are pictured on the left. Expressions appearing in dialog boxes, windows, and menus are set in italics to clarify the explanations. At the end of the manual, you find the index. However, if you still cannot not find what you are looking for, please check our website www.dlubal.com where you can go through our FAQ pages by selecting particular criteria.

1.4

Open the Add-on Module STEEL EC3

RSTAB provides the following options to start the add-on module STEEL EC3.

Menu To start the program from the RSTAB menu bar, select Add-on Modules → Design - Steel → STEEL EC3.

Figure 1.1: Menu: Add-on Modules → Design - Steel → STEEL EC3

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1 Introduction

Navigator As an alternative, you can start the add-on module in the Data navigator by clicking Add-on Modules → STEEL EC3.

Figure 1.2: Data navigator: Add-on Modules → STEEL EC3

Panel If results from STEEL EC3 are already available in the RSTAB model, you can also open the design module in the panel: Set the relevant STEEL EC3 design case in the load case list of the RSTAB toolbar. Then, click the [Show Results] button to graphically display the design criterion on the members. When the results display is activated, the panel is available, too. Now you can click [STEEL EC3] in the panel to open the module.

Figure 1.3: Panel button [STEEL EC3]

Program STEEL EC3 © 2013 Dlubal Software GmbH

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2 Input Data

2.

Input Data

When you have started the add-on module, a new window opens. In this window, a Navigator is displayed on the left, managing the windows that can be currently selected. The drop-down list above the navigator contains the design cases (see chapter 7.1, page 69). The design relevant data is defined in several input windows. When you open STEEL EC3 for the first time, the following parameters are imported automatically: • Members and sets of members • Load cases, load combinations, result combinations, and super combinations • Materials • Cross-sections • Effective lengths • Internal forces (in background, if calculated) To select a window, click the corresponding entry in the navigator. To set the previous or next input window, use the buttons shown on the left. You can also use the function keys to select the next [F2] or previous [F3] window. To save the results, click [OK]. Thus, you exit STEEL EC3 and return to the main program. To exit the module without saving the new data, click [Cancel].

2.1

General Data

In the 1.1 General Data window, you select the members, sets of members, and actions that you want to design. The tabs are managing the load cases, load combinations, result combinations, and super combinations for the different designs.

Figure 2.1: Window 1.1 General Data

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2 Input Data

Design of

Figure 2.2: Design of members and sets of members

The design can be carried out for Members as well as for Sets of Members. If you want to design only selected objects, clear the All check box: Then you can access the input fields to enter the numbers of the relevant members or sets of members. To select the list of the numbers preset in the field, double-click in the field and overwrite the list by manually entering the data. Alternatively, you can select the objects graphically in the RSTAB work window after clicking []. When you design a set of members, the program determines the extreme values of the analyses of all members contained in the set of members and takes into account the boundary conditions of connected members for the stability analysis. The results are shown in the results windows 2.3 Design by Set of Members, 3.2 Governing Internal Forces by Set of Members, and 4.2 Parts List by Set of Members. Click [New] to create a new set of members. The dialog box that you already know from RSTAB appears where you can specify the parameters for a set of members.

National Annex (NA)

Figure 2.3: National Annex

In the selection field in the upper-right corner of the window, you define the National Annex whose parameters will be applied for the design and the limit values of the deformation. Use the [Edit] button to open a dialog box where you can check and, if necessary, adjust the parameters of the selected NA. The dialog box is described in chapter 2.1.4 on page 13.

Comment

Figure 2.4: User-defined comment

In this input field, you can type user-defined notes describing, for example, the current design case.

Program STEEL EC3 © 2013 Dlubal Software GmbH

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2 Input Data

2.1.1

Ultimate Limit State

Figure 2.5: Window 1.1 General Data, tab Ultimate Limit State

Existing Load Cases and Combinations This column lists all load cases, load combinations, result combinations, and super combinations created in RSTAB. To transfer selected entries to the Selected for Design list on the right, click []. Alternatively, you can double-click the items. To transfer the complete list to the right, click []. To transfer multiple entries at once, select them while pressing the [Ctrl] key, as common for Windows applications. Load cases marked by an asterisk (*), like load case 8 in Figure 2.5, cannot be designed: This happens when the load cases are defined without any load data or the load cases contain only imperfections. When you transfer the load cases, a corresponding warning appears. At the end of the list, several filter options are available. They will help you assign the entries sorted by load case, load combination, or action category. The buttons have the following functions: Selects all cases in the list. Inverts selection of load cases. Table 2.1: Buttons in the tab Ultimate Limit State

Selected for Design The column on the right lists the load cases, load combinations, and result combinations selected for design. To remove selected items from the list, click [] or double-click the entries. To transfer the entire list to the left, click []. The load cases, load combinations, and result combinations can be assigned to the following design situations:

10

•

Persistent and Transient

•

Accidental

Program STEEL EC3 © 2013 Dlubal Software GmbH

2 Input Data

This classification controls the partial safety factors γM0, γM1, and γM2 that are included in the determination of the resistances Rd for the cross-section and stability analyses (see Figure 2.10, page 13). To change the design situation, use the list at the end of the input field which you can open by clicking the drop-down arrow [].

Figure 2.6: Assigning a design situation

For a multiple selection, press [Ctrl] and click the corresponding entries. Thus, you can change several entries at once. Result combination

The design of an enveloping max/min result combination is performed faster than the design of all contained load cases and load combinations. However, the analysis of a result combination has also disadvantages: First, the influence of the contained actions is difficult to discern. Second, for the determination of the elastic critical moment for lateral-torsional buckling Mcr, the envelope of the moment distributions is analyzed, from which the most unfavorable distribution (max or min) is taken. However, this distribution only rarely reflects the moment distribution in the individual load combinations. Thus, in the case of a RC design, more unfavorable values for Mcr, are to be expected, leading to higher ratios. Result combinations should be selected for design only for dynamic combinations. For "usual" combinations, load combinations are recommended, because here the actual moment distributions are taken for the determination of Mcr.

2.1.2

Serviceability

Figure 2.7: Window 1.1 General Data, tab Serviceability Limit State

Existing Load Cases and Combinations This section lists all load cases, load combinations, result combinations, and super combinations created in RSTAB.

Program STEEL EC3 © 2013 Dlubal Software GmbH

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2 Input Data

Selected for Design Load cases, load combinations, and result combinations can be added or removed as described in chapter 2.1.1. You can assign different deflection limit values to the individual load cases, load combinations, and result combinations. You can select from the following design situations: •

Characteristic

•

Frequent

•

Quasi-permanent

To modify the design situation, use the list, which you access at the end of the input field by clicking [] (see Figure 2.7). The limit values of the deformations are defined in the National Annex. To adjust these values according to the design situation, click [Nat. Annex]. The National Annex Settings dialog box appears (see Figure 2.10, page 13). The 1.9 Serviceability Data window manages the reference lengths governing for the deformation check (see chapter 2.9, page 32).

2.1.3

Fire Resistance

Figure 2.8: Window 1.1 General Data, tab Fire Resistance

Existing Load Cases and Combinations This section lists all load cases, load combinations, result combinations, and super combinations created in RSTAB.

Selected for Design Load cases, load combinations, and result combinations can be added or removed, as described in chapter 2.1.1. In this dialog section, you can select the actions that have been determined according to EN 1991-1-2 [2].

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2.1.4

National Annex (NA)

In the upper-right list of the 1.1 General Data window, you can select the National Annex whose parameters you want to apply to the design and the limit values of the deformation.

Figure 2.9: Selecting a National Annex

To check and, if necessary, adjust the preset parameters, click [Edit] (see the following figure). To create a user-defined National Annex, click [New]. In addition to that, you can use the [Nat. Annex] button in all input windows to open the National Annex Settings dialog box consisting of two tabs.

Base

Figure 2.10: Dialog box National Annex Settings - BS, tab Base

Program STEEL EC3 © 2013 Dlubal Software GmbH

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2 Input Data

In the dialog box sections, you can check the Partial Factors, the Serviceability Limits (Deflections), as well as the Parameters for Lateral-Torsional Buckling and adjust them, if necessary. In the dialog box section General Method Acc. to 6.3.4, you can specify whether you want to perform the stability analysis always in accordance with [1] clause 6.3.4. The option Enable also for non I-sections allows you to use the method also for other cross-sections. In addition, you can perform a stability analysis using the European lateral-torsional buckling curve according to NAUMES [8]. In his dissertation, NAUMES [9] expanded the "General method for buckling and lateral torsional buckling of structural components" according to [1] clause 6.3.4 for additional transverse bending and torsion. This expanded method is now available for designing unsymmetrical cross-sections as well as tapered members and sets of members with biaxial bending (torsion is currently not considered in STEEL EC3). According to [1] clause 6.3.4 (4), the reduction factor χop is to be calculated either a) as minimum value of the values for buckling according to 6.3.1 or χLT for lateral-torsional buckling according to 6.3.2 by means of the slenderness ratio χop, or b) as a value that is interpolated between χ and χLT – see also [1] Equation (6.66). Since the method acc. to NAUMES is based on the standardized European lateral-torsional buckling curve taking into account the modified imperfection factor α*, the interaction between local buckling and lateral-torsional buckling according to [1] equation (6.66) can be omitted.

Figure 2.11: Calculation run for the method according to NAUMES

In the first step, the calculation is carried out separately for the principal and the secondary load-bearing plane. In this step, the moment factor qmZ according to Figure 2.12 is determined. In the second step, the design criterion ∆nR is determined. Finally, the design is performed by summing up the design ratios for the principal and the secondary load-bearing plane and compared to the design criterion ∆nR.

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2 Input Data

Figure 2.12: Determination of the moment factor qMz

The buttons in the National Annex Settings dialog box have the following functions: Button

Function Resets the original settings of the program Imports user-defined default settings Saves modified settings as default Deletes a user-defined National Annex

Table 2.2: Buttons in the dialog National Annex Settings

Program STEEL EC3 © 2013 Dlubal Software GmbH

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2 Input Data

Stainless Steel STEEL EC3 also allows for the design of structural components made of stainless steel according to EN 1993-1-4 [4]. In the second tab of the National Annex Settings dialog box, you find the relevant Partial Factors and Parameters for Stability Design.

Figure 2.13: Dialog box National Annex Settings - BS, tab Stainless Steel (EN 1993-1-4)

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2.2

Materials

The window is subdivided into two parts. The upper part lists all materials created in RSTAB. The Material Properties section shows the properties of the current material, that is, the table row currently selected in the upper section.

Figure 2.14: Window 1.2 Materials

Materials that will not be used in the design are dimmed. Materials that are not allowed are highlighted in red. Modified materials are displayed in blue. The material properties required for the determination of internal forces are described in chapter 4.2 of the RSTAB manual (Main Properties). The material properties required for design are stored in the global material library. These values are preset (Additional Properties). To adjust the units and decimal places of material properties and stresses, select from the model's menu Settings → Units and Decimal Places (see chapter 7.3, page 73).

Material Description The materials defined in RSTAB are already preset, but you can always modify them: To select the field, click the material in column A. Then click [] or press function key [F7] to open the material list.

Figure 2.15: List of materials

Program STEEL EC3 © 2013 Dlubal Software GmbH

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2 Input Data

According to the design concept of the Standard [1], you can select only materials of the “Steel” category. When you have imported a material, the design relevant Material Properties are updated. If you change the material description manually and the entry is stored in the material library, STEEL EC3 will import the material properties, too. In principal, it is not possible to edit the material properties in the add-on module STEEL EC3.

Material Library Numerous materials are already available in the library. To open the corresponding dialog box, select Edit → Material Library or click the button shown on the left.

Figure 2.16: Dialog box Material Library

In the Filter section, Steel is preset as material category. Select the material quality that you want to use for the design in the Material to Select list. You can check the corresponding properties in the dialog section below. Click [OK] or press [↵] to transfer the selected material to window 1.2 of the module STEEL EC3. Chapter 4.2 in the RSTAB manual describes in detail how materials can be filtered, added, or rearranged. You can also select material categories like Cast Iron or Stainless Steel. Please check, however, whether these materials are allowed by the design concept of the Standard [1].

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2.3

Cross-Sections

This window manages the cross-sections used for design. In addition, the module window allows you to specify optimization parameters.

Figure 2.17: Window 1.3 Cross-Sections

Cross-Section Description The cross-sections defined in RSTAB are preset together with the assigned material numbers. To modify a cross-section, click the entry in column B selecting this field. Click [Cross-section Library] or [...] in the field or press function key [F7] to open the cross-section table of the current input field (see the following figure). In this dialog box, you can select a different cross-section or a different cross-section table. To select a different cross-section category, click [Back to cross-section library] to access the general cross-section library. Chapter 4.3 of the RSTAB manual describes how cross-sections can be selected from the library.

Program STEEL EC3 © 2013 Dlubal Software GmbH

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2 Input Data

Figure 2.18: IS cross-sections in the cross-section library

The new cross-section description can be entered in the input field directly. If the data base contains an entry, STEEL EC3 imports these cross-section parameters, too. A modified cross-section will be highlighted in blue. If cross-sections specified in STEEL EC3 are different from the ones used in RSTAB, both crosssections are displayed in the graphic on the right. The designs will be performed with the internal forces from RSTAB for the cross-section selected in STEEL EC3.

Cross-Section Type for Classification The cross-section type used for the classification is displayed. The cross-sections listed in [1] Table 5.2 can be designed plastically or elastically depending on the Class. Cross-sections that are not covered by this table are classified as General. These cross-sections can only be designed elastically (Class 3 or 4).

Max. Design Ratio This table column is displayed only after the calculation. It is a decision support for the optimization. By means of the displayed design ratio and colored relation scales, you can see which cross-sections are little utilized and thus oversized, or overloaded and thus undersized.

Optimize You can optimize every cross-section from the library: For the RSTAB internal forces, the program searches the cross-section that comes as close as possible to a user-defined maximum utilization ratio. You can define the maximum ratio in the Other tab of the Details dialog box, (see Figure 3.8, page 49). To optimize a cross-section, open the drop-down list in column D or E and select the desired entry: From Current Row or, if available, From favorites 'Description'. Recommendations for the cross-section optimization can be found in chapter 7.2 on page 71.

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Remark This column shows remarks in the form of footers that are described in detail below the crosssection list. A warning might appear before the calculation: Incorrect type of cross-section! This means that there is a cross-section that is not stored in the data base. This may be a user-defined crosssection or a SHAPE-THIN cross-section that has not been calculated yet. To select an appropriate cross-section for design, click [Library] (see description after Figure 2.17).

Member with tapered cross-section For tapered members with different cross-sections at the member start and member end, the module displays both cross-section numbers in two rows, in accordance with the definition in RSTAB. STEEL EC3 also designs tapered members, provided that the cross-section at the member's start has the same number of stress points as the cross-section at the member end. For example, the normal stresses are determined from the moments of inertia and the centroidal distances of the stress points. If the cross-sections at the start and the end of a tapered member have a different number of stress points, the intermediate values cannot be interpolated. The calculation is possible neither in RSTAB nor in STEEL EC3. The cross-section's stress points including numbering can also be checked graphically: Select the cross-section in window 1.3 and click [Info]. The dialog box shown in Figure 2.19 appears.

Info About Cross-Section In the dialog box Info About Cross-Section, you can view the cross-section properties, stress points, and c/t-parts.

Figure 2.19: Dialog box Info About Cross-Section

In the right part of the dialog box, the currently selected cross-section is displayed.

Program STEEL EC3 © 2013 Dlubal Software GmbH

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2 Input Data

The buttons below the graphic have the following functions: Button

Function Displays or hides the stress points Displays or hides the c/t-parts Displays or hides the numbering of stress points or c/t-parts Displays or hides the details of the stress points or c/t-parts (see Figure 2.20) Displays or hides the dimensions of the cross-section Displays or hides the principal axes of the cross-section Resets the full view of the cross-section graphic

Table 2.3: Buttons of cross-section graphic

Click [Details] to call up detailed information on stress points (distances to center of gravity, statical moments of area, normalized warping constants etc.) and c/t-parts.

Figure 2.20: Dialog box Stress Points of HE B 260

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2.4

Lateral Intermediate Supports

In window 1.4, you can define lateral intermediate supports for members. STEEL EC3 always assumes this kind of support as perpendicular to the minor z-axis of the cross-section (see Figure 2.19). Thus, you can influence the members' effective lengths which are important for the stability analyses for flexural buckling and lateral-torsional buckling.

Figure 2.21: Window 1.4 Lateral Intermediate Supports

In the upper part of the window, you can assign up to nine lateral supports to each member. The Settings section shows the input as column overview for the member selected above. To define the intermediate supports of a member, select the Lateral Supports check box in column A. To graphically select the member and to activate its row, click []. By selecting the check box, the other columns become available for entering the parameters. In column B, you can select the Support Type from the list. The fork support is preset. Furthermore, you can place the intermediate supports also at the lower or upper flange. The Userdefined option allows you to individually specify the support parameters (support in the direction of the member axis y, restraint about longitudinal member axis x, eccentricity of support) in the Settings section. In column D, you specify the number of the intermediate support. Depending on the specification, one or more of the following Lateral Intermediate Supports columns for the definition of the x-locations are available. If the Relatively (0 … 1) check box is selected, the support points can be defined by relative input. The positions of the intermediate supports are determined from the member length and the relative distances from the member start. If the Relatively (0 ... 1) check box is cleared, you can define the distances manually in the upper table. In case of cantilevers, avoid intermediate supports, because such supports divide the member into segments. For cantilevered beams, this would results in segments that are fork supported on one side and thus statically underdetermined (fork support on one end only, respectively).

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2.5

Effective Lengths - Members

The window is subdivided into two parts. The table in the upper part provides summarized information about the factors for the lengths of buckling and lateral-torsional buckling as well as the equivalent member lengths of the members to be designed. The effective lengths defined in RSTAB are preset. In the Settings section, you can see further information on the member whose row is selected in the upper section. Click [] to select a member graphically and to show its row. You can make changes in the table as well as in the Settings tree.

Figure 2.22: Window 1.5 Effective Lengths - Members

The effective lengths for buckling about the minor z-axis are aligned automatically with the entries of the 1.4 Lateral Intermediate Supports window. If lateral intermediate supports are dividing the member into member segments of different lengths, the program displays no value in the table columns G, K, and L of window 1.5. The effective lengths can be entered manually in the table and in the Settings tree, or defined graphically in the work window after clicking [...]. This button is enabled when you click in the input field (see figure above). The Settings tree manages the following parameters: • Cross-Section • Member Length • Buckling Possible for the member (cf. columns B, E, and H) • Buckling about Axis y Possible (cf. columns C and D) • Buckling about Axis z Possible (cf. columns F and G) • Lateral-Torsional Buckling Possible (cf. columns I through K) In this table, you can specify for the currently selected member whether to carry out a buckling or a lateral-torsional buckling analysis. In addition to this, you can adjust the Buckling Length Coefficient and the Warping Length Coefficient for the respective lengths. When a coefficient is modified, the equivalent member length is adjusted automatically, and vice versa.

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You can also define the buckling length of a member in a dialog box. To open it, click the button shown on the left. It is located on the right below the upper table of the window.

Figure 2.23: Dialog box Select Buckling Length Coefficient

For each direction, you can define the buckling length according to one of the four Euler buckling modes or as User-defined. If a RSBUCK case calculated according to the eigenvalue analysis is already available, you can also define a Buckling Shape to determine the factor.

Buckling Possible A stability analysis for flexural buckling and lateral-torsional buckling requires that members can resist compressive forces. Therefore, members for which such resistance is not possible because of the member type (for example tension members, elastic foundations, rigid couplings) are excluded from design in the first place. The corresponding rows appear dimmed and a note is displayed in the Comment column. The Buckling Possible check boxes in table row A and in the Settings tree offer you a control option for the stability analyses: They determine whether the analyses should or should not be performed for a member.

Buckling about Axis y or Axis z With the check boxes in the Possible table columns, you decide whether a member is susceptible to buckling about the y-axis and/or z-axis. These axes represent the local member axes, where the y-axis is the major and the z-axis the minor member axis. The buckling length coefficients kcr,y and kcr,z for buckling around the major or the minor axis can be selected freely. You can check the position of the member axes in the cross-section graphic in the 1.3 CrossSections window (see Figure 2.17, page 19). To access the RSTAB work window, click [View mode]. In the work window, you can display the local member axes by using the member's context menu or the Display navigator.

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Figure 2.24: Selecting the member axis systems in the Display navigator of RSTAB

If buckling is possible about one or even both member axes, you can enter the buckling length coefficients as well as the buckling lengths in the columns C and D as well as F and G. The same is possible in the Settings tree. To graphically specify the buckling lengths in the work window, click [...]. This button becomes available when you click in an Lcr input field (see Figure 2.22). When you specify the buckling length coefficient kcr, the program determines the effective length Lcr by multiplying the member length L by the buckling length coefficient. The input fields kcr and Lcr are interactive.

Lateral-Torsional Buckling Possible Table column H shows you for which members the program performs an analysis of lateraltorsional buckling.

Buckling Length Coefficient kz To determine Mcr by the eigenvalue calculation method, a member model with four degrees of freedom is created in the program background. The following definitions of kz and kw (see page 27) are possible to represent the degrees of freedom on the supports of such a model: kz = 1.0

fork support on both beam ends

kz = 0.7le

restrained on the left and fork support on the right

kz = 0.7ri

restrained on the right and fork support on the left

kz = 0.5

restraint on both girder ends

kz = 2.0le

restrained on the left and free member end on the right

kz = 2.0ri

restrained on the right and free member end on the left

A fork support with kz = 1.0 results in a support with a fixation in direction of the y-axis and a restraint to the torsion about the x-axis (longitudinal axis) of the member. In case a restraint is used, the torsion of the cross-section about the z-axis is prevented, too. The abbreviations le and ri refer to the left and right side. The description le always refers to the support conditions at the member start. Axis definition for kz and kw

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As the definitions for kz and kw always refer to member start and member end, particular attention must be paid when intermediate supports are taken into account: These supports divide the member into individual segments for the calculation. For cantilevered beams, segments with fork supports on one side would therefore result that are statically underdetermined (fork support respectively on one end only).

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Buckling Length Coefficient kw With the warping length coefficient kw, you define the support’s fourth degree of freedom, which is also included in the determination of the elastic critical moment for lateral torsional buckling Mcr. You must define whether the cross-section can be warped freely (support is free to warp) or a warping restraint is set. The definition follows the one of the buckling length coefficient kz (see above) but now it is a restraint that describes the prevention of warping. By default, STEEL EC3 applies the member length for the length of lateral-torsional buckling. When you have a structural component consisting of several members between the supports, it may be reasonable to define the length for lateral-torsional buckling manually. You can use the select function [...] for such a definition. kw = 1.0

support free to warp on both beam ends

kw = 0.7le

restrained on the left and fork support on the right

kw = 0.7ri

restrained on the right and fork support on the left

kw = 0.5

warping restraint on both beam ends

kw = 2.0le

restrained on the left and free member end on the right

kw = 2.0ri

restrained on the right and free member end on the left

Since the internal member model requires only four degrees of freedom, a definition of the remaining degrees of freedom (displacement in x- and z-direction) is unnecessary. Below the Settings table, you find the Set input for members No. check box. If selected, the settings entered afterwards will be applied to the selected or to All members. Members can be selected by typing the member number or by selecting them graphically using the [] button. This option is useful when you want to assign the same boundary conditions to several members. Please note that already defined settings cannot be changed subsequently with this function. It may happen that the length for lateral-torsional buckling Lw or the torsional buckling length LT differ from the member length or the effective length. In these cases, it is possible to define the lengths Lw and LT in the columns K and L manually.

Comment In the last table column, you can enter you own comments for each member to describe, for example, the selected equivalent member lengths.

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2.6

Effective Lengths - Sets of Members

This window appears only if you selected at least one set of members for design in the 1.1 General Data window (see Figure 3.2, page 44) and selected the Equivalent Member Method for sets of members in the dialog box Details. With these settings, however, the windows 1.7 and 1.8 will not be displayed. In this case, you can define the lateral intermediate supports by division points in window 1.4.

Figure 2.25: Window 1.6 Effective Lengths - Sets of Members

This window's concept is similar to the one of the previous 1.5 Effective Lengths - Members window. In this window, you can enter the effective lengths for the buckling about the two principal axes of the set of members as described in chapter 2.5.

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2.7

Nodal Supports - Sets of Members

This window is displayed only if you have selected at least one set of members for the design in the 1.1 General Data window. In STEEL EC3, the stability analysis for sets of members is performed usually according to [1], clause 6.3.4. If, however, the Equivalent Member Method is selected in the Details dialog box (see Figure 3.2, page 44), window 1.7 will not be displayed. In that case, you can define the lateral intermediate supports by using division points in window 1.4.

Figure 2.26: Window 1.7 Nodal Supports – Set of Members

According to [1], clause 6.3.4 (1), only monosymmetrical cross-sections that are loaded exclusively in their principal plane may be designed. For this analysis method, it is necessary to know the amplification factor αcr,op of the entire set of members. To determine this factor, a planar framework is created with four degrees of freedom for each node, which you have to define in window 1.7. This window refers to the current set of members (selected in the add-on module’s navigator on the left). The orientation of the axes in the set of members is important for the definition of nodal supports. The program checks the position of the nodes and internally defines, according to Figure 2.27 through Figure 2.30, the axes of the nodal supports for window 1.7.

Figure 2.27: Auxiliary coordinate system for nodal supports – straight set of members

If all members of a set of members are lying in a straight line as shown in Figure 2.27, the local coordinate system of the first member in the set of members corresponds to the equivalent coordinate system of the entire set of members.

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Figure 2.28: Auxiliary coordinate system for nodal supports – set of members in vertical plane

If members of a set of members are not lying in a straight line, they must at least lie in the same plane. In Figure 2.28, they are lying in a vertical plane. In this case, the X’-axis is horizontal and oriented in direction of the plane. The Y’-axis is horizontal as well and defined perpendicular to the X’-axis. The Z’-axis is oriented perpendicularly downwards.

Figure 2.29: Auxiliary coordinate system for nodal supports – set of members in horizontal plane

If the members of a buckled set of members are lying in a horizontal plane, the X’-axis is defined parallel to the X-axis of the global coordinate system. Thus, the Y’-axis is oriented in the opposite direction to the global Z-axis and the Z’-axis is directed parallel to the global Y-axis.

Figure 2.30: Auxiliary coordinate system for nodal supports – set of members in inclined plane

Figure 2.30 shows the general case of a buckled set of members: The members are not lying in one straight line but in an inclined plane. The definition of the X’-axis arises out of the intersection line of the inclined plane with the horizontal plane. Thus, the Y’-axis is defined perpendicular to the axis X’ and directed perpendicular to the inclined plane. The Z’-axis is defined perpendicular to the X’- and Y’-axis.

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2.8

Member End Releases - Sets of Members

This window is displayed only if you have selected at least one set of members for the design in the 1.1 General Data window . Here, you can define releases for members and sets of members that, due to structural reasons, do not transfer the locked degrees of freedom specified in window 1.7 as internal forces. This window refers to the current set of members (selected in the add-on module’s navigator on the left). Window 1.8 is not be displayed, if the Equivalent Member Method is selected in the dialog box Details (see Figure 3.2, page 44) for the sets of members.

Figure 2.31: Window 1.8 Member Releases – Set of Members

In table column B, you define the Member Side to which the release should be assigned. You can also connect the releases to both member sides. In the columns C through F, you can define releases or spring constants to align the set of members model with the support conditions in window 1.7.

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2.9

Serviceability Data

This input window controls several settings for the serviceability limit state design. It is only available if you have set the according entries in the Serviceability Limit State tab of window 1.1 (see chapter 2.1.2, page 11).

Figure 2.32: Window 1.9 Serviceability Data

In column A, you decide whether you want to apply the deformation to single members, lists of members, or sets of members. In table column B, you enter the numbers of the members or sets of members that you want to design. You can also click […] to select them graphically in the RSTAB work window. Then, the Reference Length appears in column D automatically. This column presets the lengths of the members, sets of members, or member lists. If required, you can adjust these values after selecting the Manually check box in column C. In table column E, you define the governing Direction for the deformation analysis. You can select the directions of the local member axes y and z (or u and v for unsymmetrical crosssections). In column F, you can consider a precamber wc. The Beam Type is of crucial importance for the correct application of limit deformations. In column G, you can specify whether there is a beam or a cantilever and which end should have no support. The settings in the Serviceability tab of the Details dialog box decide whether the deformations are related to the undeformed initial structure or to the shifted ends of members or sets of members (see Figure 3.3, page 46).

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2.10 Specifications for Fire Resistance Design The final input window manages the different fire resistance parameters. It is only available if you have set relevant entries in the Fire Resistance tab of window 1.1 (see chapter 2.1.3, page 12).

Figure 2.33: Window 1.10 Fire Protection – Members

Table column A contains the members that are taken into account for fire resistance design. Click […] to graphically select the members in the RSTAB work window. In column B, you define the number of cross-section sides that are exposed to fire. Fire Exposure has an effect on the determination of the section factors according to [2] window 4.2 and window 4.3. In case an encasement for fire resistance is used, you can select the Protection Type in column D. You can choose between a spray (contour) encasement that follows the geometry of the crosssection (for example intumescent coating) and a hollow encasements of the cross section. Then, you specify the corresponding parameters in table columns E through H. The general parameters for the fire resistance design are managed in the Fire Resistance tab of the Details dialog box (see Figure 3.4, page 47).

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2.11 Parameters - Members This window allows you to enter specifications for beams that laterally supported by sheeting or purlins (see [3] clauses 10.1 and 10.3). The upper section lists the members intended for design together with the parameters that are relevant for the lateral-torsional buckling design. These parameters interact with the specifications in the section Settings for Member No. below. To the right of the Settings table, you can see information or options in the form of graphics facilitating the definition of boundary conditions. The display is controlled by the currently selected parameters.

Figure 2.34: Window 1.11 Parameters - Members

Below the Settings table, you find the Set inputs for members No. check box. If selected, the settings entered afterwards will be applied to the selected or to All members. Members can be selected by typing the member number or by selecting them graphically using the [] button. This option is useful when you want to assign the same boundary conditions to several members. In the Comment column, you can enter user-defined comments for each member to describe, for example, a member's parameters relevant for lateral-torsional buckling.

Cross-Section In this column, the cross-section description is displayed. In the case of a tapered member, the description of the cross-section start and end is displayed.

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Shear Panel To enter the shear panel parameters, select the check box in column A or in the Settings table. The type of shear panel can be selected from the list.

Figure 2.35: Selection of shear panel type

Trapezoidal sheeting The application of a continuous lateral support is described in 1993-1-1 [1] Annex BB.2.1 and EN 1993-1-3 [3] clause 10.1.5.1. To determine the shear panel stiffness of a trapezoidal sheeting (corrugated sheet), the following specifications are required (see Figure 2.35): •

Shear panel length lS

• • • •

Beam spacing a Position of trapezoidal sheeting on section Trapezoidal sheeting description Fastening arrangement

The shear panel length and the beam spacing can be entered manually or selected graphically after clicking [...]. This button becomes available when you click in one of the two input fields. Then, you can select the two snap points in the RSTAB work window that define the shear panel or the beam spacing. The trapezoidal sheeting’s Position on section can be taken into account in different ways by using the list shown on the left. The selected point of torsion D is marked in the cross-section graphic, even in case of user-defined input. Here, the distance d is related to the centroid; the sign results from the z-axis of the cross-section. To access the corrugated sheet library, click the [...] button that becomes available after you click in the Trapezoidal sheeting description input field (see Figure 2.38, page 37). The RSTAB cross-section library appears (see Figure 2.36), where you can select the trapezoidal sheet by double-clicking it or clicking [OK]. Thus, the shear panel coefficient K1 and K2 (according to the approval certificate) is automatically entered in the Settings table. The basic width b of the trapezoidal sheeting has no influence on these coefficients. The Fastening arrangement of the trapezoidal section influences the shear stiffness that the sheeting provides to the beam. If the trapezoidal sheeting is fastened only in every second rib, the shear stiffness to be applied is reduced by a factor of 5.

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Figure 2.36: Cross-section library Rolled Cross-Sections - Corrugated Sheets

Bracing

Figure 2.37: Shear panel type Bracing

To determine the provided shear panel stiffness, the following specifications are required: • • • • • • •

Shear panel length lS Beam spacing a Position of the bracing on section Post spacing b Number of bracings Section of diagonals Section of posts

The Shear panel length, the Beam spacing, and the Post spacing can be entered manually or selected graphically after clicking [...]. This button becomes available when you click in one of these input fields. Then, you can select the two points defining the shear panel or the spacing in the RSTAB work window.

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The bracing’s position on section can be considered in different ways by using the list shown on the left. The selected point of torsion D is marked in the cross-section graphic, even in case of manual input. Here, the distance d is related to the centroid; the sign results from the z-axis of the cross-section. The easiest way to specify the cross-sectional area of the diagonals and posts is to select the Section Description for the RSTAB library. To access the library, click [...] at the end of the input field. Then, the CS-Area is imported automatically. It is also possible to enter this value directly.

Trapezoidal sheeting and bracing

Figure 2.38: Shear panel type Trapezoidal sheeting and bracing

To determine the provided shear panel stiffness due to trapezoidal sheeting and bracing, the following specifications are required: • • • • • • • • •

Shear panel length lS Beam spacing a Position of shear panel on section Trapezoidal sheeting description Fastening arrangement Post spacing b Number of bracings Section of diagonals Section of posts

This way of defining the shear panel combines the parameters of the aforementioned options Trapezoidal sheeting and Bracing.

Define Sprov

Figure 2.39: Defining S-prov

The value of the provided Shear panel stiffness Sprov can also be entered directly. In addition to this, you have to specify the shear panel’s Position on section.

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Rotational restraint To enter the rotational restraint parameters, select the check box in column B or in the Settings table. The type of rotational restraint can be selected in the list or by clicking the graphics to the right of the Settings.

Figure 2.40: Selection of the type of rotational restraint

Continuous rotational restraint To determine the stiffness components from a trapezoidal sheeting and the connection deformation, you need the following specifications (see Figure 2.40): • • • •

Material and description of the trapezoidal sheet Method of determining CD,A Beam spacing s Continuous beam effect

To access the corrugated sheet library, click the button [...] that becomes available when you click in the input field Component description. The RSTAB cross-section library appears where you can select a corrugated sheet by double-clicking it or clicking [OK]. The section parameters Sheeting thickness t, Position of sheeting, effective Second moment of area Is for the downward loading direction, Distance of ribs bR (corrugation width), and Width of the flange bT are imported automatically. In case of continuous rotational restraint, you have also to consider the deformation of the connection. You can specify the rotational spring stiffness C100 in the entry Method of determining CD,A or determined by the program according to [3] Table 10.3. Use the […] button for automatic calculation. To access the button [...], click in the input field of the row C100. Use this button to open a dialog box where you can select the appropriate coefficient (see the following figure). Click [OK] to assign this value to all load cases and load combinations that you want to design. A dialog box opens where you can specify the appropriate coefficient.

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Figure 2.41: Dialog box Import Coefficient C100 from Table 10, EN 1993-1-3

After you confirm the specification by clicking [OK], this values is assigned to all load cases and load combinations selected for the design. To assign by load case, open the dialog box Import Coefficient via the C100 input fields of the individual load cases and load combinations, click [OK]. The Beam spacing can also be specified manually or graphically after clicking [...]. To do this, click two nodes in the RSTAB work window that define the distance between the beams. The Continuous beam effect has an impact on the coefficient k of the rotational restraint CD,C, which you can define in the list of this row (End panel: k = 2, Internal panel: k = 4).

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Discrete rotational restraint

Figure 2.42: Type of rotational restraint Discrete rotational restraint

To determine the stiffness component from isolated columns (for example purlins), the following specifications are required: • • • •

Material and description of the cross-section Spacing of purlins e Beam spacing s Continuous beam effect

You can select the Material and Cross-section description in the RSTAB library, which you can access by clicking [...]. To do this, select the relevant input field by clicking it. The Spacing of the purlins and the Beam spacing can be entered manually or graphically after clicking [...]. To do this, select two nodes defining the spacing of the purlins or beams by clicking them in the RSTAB work window. The Continuous beam effect has an impact on the coefficient k of the rotational restraint CD,C, which you can define in the list of this row (End panel: k = 2, Internal panel: k = 4).

Cross-Sectional Area

Figure 2.43: Defining cross-sectional area for tension design

According to [1] clause 6.2.3, holes for fasteners must be taken into account in the tension design. The Net Cross-Sectional Area Anet can be defined separately for the Start and End of the member – fasteners are usually located at these two x-locations the. The gross cross-sectional area A is shown for control purposes.

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2.12 Parameters - Sets of Members This window is displayed only if you have selected at least one set of members for the design in window 1.1 General Data.

Figure 2.44: Window 1.12 Parameters - Sets of Members

This window's concept is similar to the one of the previous window 1.11 Parameters - Members. In this window, you can define the parameters of shear panels and rotational restraints for each set of members as described in chapter 2.11.

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3.

Calculation

3.1

Detail Settings

Before you start the [Calculation], it is recommended to check the design details. You can open the according dialog box in all windows of the add-on module by clicking [Details]. The Details dialog box contains the following tabs: • • • • •

Ultimate Limit State Stability Serviceability Fire Resistance Other

3.1.1

Ultimate Limit State

Figure 3.1: Dialog box Details, tab Ultimate Limit State

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Classification of Cross-Sections If stresses from compression and bending occur together in the cross-section, you can determine the stress-deformation ratio ψ in two ways (the factor ψ is required for the determination of the appropriate c/t-ratio according to [1] table 5.2): •

Fixed NEd, increase MEd to reach fyd Only the flexural stress component is increased to reach the yield strength.

•

Increase NEd and MEd uniformly The flexural stress components from axial force and bending are increased uniformly until the yield strength fyd is reached.

The check box For limit c/t of Class 3, increase material factor ε acc. to 5.5.2 (9) can be accessed if the stability analysis has been deactivated in the tab Stability. This is based on the specifications for classification in [1] clause 5.5.2 (10). If the stability analysis is deactivated, you can treat cross-sections classified as Class 4 like cross-sections of Class 3 by increasing the factor ε. If select the check box Use SHAPE-THIN for Classification of all supported cross-section types, the effective cross-section properties of Class 4 sections will be calculated according to the method used in SHAPE-THIN. If cross-sections are classified as 'general' (that is, belong neither to a rolled nor a parameterized cross-section table), the classification will generally be performed with SHAPE-THIN. These cross-sections can be designed only elastically as Class 3 or Class 4 cross-sections.

Options Cross-sections that are assigned to Class 1 or 2 are designed plastically in STEEL EC3. If you do not want to perform a plastic design, you can activate the Elastic Design for these cross-section classes, too.

Stability Analyses with Second-Order Internal Forces If the stability analyses are performed not with the equivalent member method according to [1] clause 6.3 but with second order internal forces, you can use this check box to specify if to use the partial safety factor γM1 (instead of γM0) for the cross-section design. The partial safety factor γM1 is relevant for the determination of resistance in case of instability (structural component check). The safety factor can be checked and, if necessary, modified in the dialog box National Annex Settings (see Figure 2.10, page 13).

Cross-Section Check for M+N With the check box Use linear interaction acc. to 6.2.1(7), you control if to use a linear addition of the utilization ratios for the moments and axial forces according to Eq. (6.2) or Eq. (6.44) as conservative approximation for the resistance verification of the cross-section.

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3.1.2

Stability

Figure 3.2: Dialog box Details, tab Stability

Stability Analysis The Use check box controls whether to run, in addition to the cross-section checks, a stability analysis. If you clear the check box, the input windows 1.4 through 1.8 will not be displayed. If the check box is selected, you can define the axes relevant for the determination of Flexural buckling. In addition to that, you can include Effects from 2nd order theory according to [1] clause 5.2.2 (4) by an increase factor for bending moments that can be defined manually. Thus when you design, for example, a frame whose governing buckling mode is represented by lateral displacement, you can determine the internal forces according to linear static analysis and increase them with the appropriate factors. If you increase the bending moment, this does not affect the flexural-buckling analysis according to [1] clause 6.3.1, which is performed by using the axial forces.

Determination of Elastic Critical Moment for LTB By default, STEEL EC3 determines the ideal critical moment for lateral-torsional buckling Automatically by Eigenvalue Method. For the calculation, the program uses a finite model to determine Mcr, taking into account the following items: • • • • •

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Dimensions of gross cross-section Load type and position of load application point Effective distribution of moments Lateral restraints (by support conditions) Effective boundary conditions

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The degrees of freedom can be controlled by the factors kz and kw (see chapter 2.5, page 26). The elastic critical moment is determined Automatically by comparison of moment courses and assignment of coefficient C1. To view the load courses and moment distributions, open the corresponding dialog box by clicking [Info]. The coefficients C2 and C3 are determined automatically by the eigenvalue method, if required. If you select the Manual definition in Table 1.5 option, the name of column J changes to Mcr, thus allowing you to enter the elastic critical moment for LTB manually.

Mcr user-defined

If transverse loads are available, it is important to define where these forces are acting on the cross-section: Depending on the Load application point, transverse loads can be stabilizing or destabilizing, and thus can decisively influence the elastic critical moment.

Model Type According to Table B.3 According to [1], Table B.3, the equivalent uniform moment factor for structural components with buckling in the form of lateral deflection should be taken as Cmy = 0.9 or Cmz = 0.9, respectively. The two check boxes are cleared by default. If you select the check boxes, the program determines the factors Cmy and Cmz according to the criteria given in Table B.3.

Limit Load for Special Cases To design non-symmetrical cross-sections for intended axial compression according to [1] 6.3.1, you can neglect small moments about the major and the minor axis using the settings defined in this dialog section. In the same way, according to [1] 6.3.2, you can switch off small compression forces for the pure check of bending by defining a limit ratio for N to Npl. For the design of Unsymmetric Cross-Sections, Tapered Members or Sets of Members according to [1] 6.3.4, only uniaxial bending in the principal plane and/or compression is allowed. To neglect a minor moment about the minor axis, you can define a limit for the moment ratio Mz,Ed / Mpl,z,Rd. Intended torsion is not clearly specified in EN 1993-1-1. If a torsional stress is available that does not exceed the shear stress ratio of 5 % preset by default, it is not considered in the stability design. In this case, the output shows results for flexural buckling and lateral-torsional buckling. If one of the limits in this dialog section is exceeded, a note appears in the results window. No stability analysis is carried out. However, the cross-section checks are run independently. These limit settings are not part of EN 1993-1-1 or any National Annex. Changing the limits is in the responsibility of the program user.

Stability Analysis Method of Sets of Members The stability behavior of sets of members can be analyzed according to two methods. According to 6.3.1 … 6.3.3 (Equivalent Member Method), it is possible to treat sets of members as one single member. To do this, the factors kz and kw have to be defined in the window 1.6 Effective Lengths - Sets of Members. They are used to determine the support conditions β, uy, φx, φz, and ω. If you apply these settings, however, the windows 1.7 and 1.8 will not be displayed. Please note that the factors kz and kw are identical for each section or member of the set of members. In general, the equivalent member method should be used only for straight sets of members. With the presetting 6.3.4 (General Method), the program performs a general analysis according to [1] clause 6.3.4, based on the coefficient αcr. In window 1.7, you define the support conditions for each set of members individually. The factors kz and kw from window 1.5 are not used.

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3.1.3

Serviceability

Figure 3.3: Dialog box Details, tab Serviceability

Deformation Relative to The option fields control whether the maximum deformations are related to the shifted ends of members or sets of members (connection line between start and end nodes of the deformed system) or to the undeformed initial system. As a rule, the deformations are to be checked relative to the displacements in the entire structural system. In the National Annex Settings dialog box, you can check and, if necessary, adjust the limit deformations (see Figure 2.10, page 13).

Limitation of Web Breathing In the serviceability limit state design of steel bridges, the plate slenderness ratio is to be restricted to avoid excessive rippling and breathing of plates as well as a reduction of stiffnesses due to plate buckling. The check box Design as steel bridge structure according to EN 1993-2, 7.4 controls whether the breathing (repeated out-of-plane deformation) is to be analyzed, which can result in fatigue at or adjacent to the web-to-flange connections. You have to select whether you design a Road bridge or a Railway bridge. In the design, it is necessary to limit the slenderness of stiffened and unstiffened plates.

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3.1.4

Fire Resistance

This tab manages the detail settings for the fire resistance check.

Figure 3.4: Dialog box Details, tab Fire Resistance

In addition to the Required time of fire resistance and the Time interval of analysis for the determination of the temperature change, you have to define the governing Temperature Curve for Determination of Temperature of Gases. You can select one of the three following curves:

Figure 3.5: Standard temperature-time curve

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Figure 3.6: External fire curve

Figure 3.7: Hydrocarbon curve

The Factors for determination of net heat flux are preset in accordance with EN 1991-1-2 and EN 1993-1-2, but you can adjust them to the given conditions. If you select the Define final temperature manually check box, you can define the temperature Θa in window 1.9 individually.

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3.1.5

Other

Figure 3.8: Dialog box Details, tab Other

Cross-Section Optimization The optimization is targeted to the maximum design ratio of 100 %. If necessary, you can specify a different limit value in this input field.

Check of Member Slendernesses In the two input fields, you can specify the limit values λlimit in order to define member slendernesses. You can enter specifications separately for members with pure tension forces and members with bending and compression. The limit values are compared to the real member slendernesses in window 3.3. This window is available after the calculation (see chapter 4.8, page 58 ) if the corresponding check box is selected in the Display Result Tables dialog box section.

Design of Welds To carry out designs of welds in the analysis, select this check box. The program performs the typical designs according to EN 1993-1-8. After the calculation, you can find the results under the cross-section designs.

Display Result Tables In this dialog section, you can select the results table including parts list that you want to be displayed. The tables are described in chapter 4 Results. The 3.3 Member Slendernesses window is inactive by default.

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3.2

Start Calculation

To start the calculation, click the [Calculation] button, which is available in all input windows of the STEEL EC3 add-on module. STEEL EC3 searches for the results of the load cases, load combinations, and result combinations to be designed. If these cannot be found, the program starts the RSTAB calculation to determine the design relevant internal forces. You can also start the calculation in the RSTAB user interface: The dialog box To Calculate (menu Calculate → To Calculate) lists design cases of the add-on modules like load cases and load combinations.

Figure 3.9: Dialog box To Calculate

If the STEEL EC3 cases are missing in the Not Calculated section, select All or Add-on Modules in the drop-down list below the section. To transfer the selected STEEL EC3 cases to the list on the right, use the button []. Click [OK] to start the calculation. To calculate a design case directly, use the list in the toolbar. Select the STEEL EC3 case in the toolbar list, and then click [Show Results].

Figure 3.10: Direct calculation of a STEEL EC3 design case in RSTAB

Subsequently, you can observe the design process in a separate dialog box.

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4 Results

4.

Results

Window 2.1 Design by Load Case is displayed immediately after the calculation.

Figure 4.1: Results window with designs and intermediate values

The designs are shown in the results windows 2.1 through 2.5, sorted by different criteria. The windows 3.1 and 3.2 list the governing internal forces. Window 3.3 informs you about the member slendernesses. The last two results windows, 4.1 and 4.2 show parts sorted by member and set of members. Every window can be selected by clicking the according entry in the navigator. To set the previous or next input window, use the buttons shown on the left. You can also use the function keys to select the next [F2] or previous [F3] window. To save the results, click [OK]. Thus you exit STEEL EC3 and return to the main program. Chapter 4 Results describes the different results windows one by one. Evaluating and checking results is described in chapter 5 Results Evaluation, page 61ff.

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4.1

Design by Load Case

The upper part of the window provides a summery, sorted by load cases, load combinations, and result combinations of the governing designs. Furthermore, the list is divided in ultimate limit state, serviceability, fire resistance, and stability designs. The lower part gives detailed information on the cross-section properties, analyzed internal forces, and design parameters for the load case selected above.

Figure 4.2: Window 2.1 Design by Load Case

Description This column shows the descriptions of the load cases, load combinations, and result combinations used for the designs.

Member No. This column shows the number of the member that bears the maximum stress ratio of the designed loading.

Location x This column shows the respective x-location where the member's maximum stress ratio occurs. For the table output, the program uses the following member locations x: • • • •

Start and end node Division points according to possibly defined member division (see RSTAB table 1.6) Member division according to specification for member results (RSTAB dialog box Calculation Parameters, tab Global Calculation Parameters) Extreme values of internal forces

Design Columns D and E display the design conditions according to EN 1993-1-1. The length of the colored scale represents the respective utilization ratio.

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Design According to Formula This column lists the code's equations by which the designs have been performed.

DS The final column provides information on the respective check-relevant design situation (DS): PT or AC for the ultimate state or one of three design situations for serviceability (CH, FR, QP) according to the specifications in the 1.1 General Data window (see Figure 2.7, page 11).

4.2

Design by Cross-Section

Figure 4.3: Window 2.2 Design by Cross-Section

This window lists the maximum ratios of all members and actions selected for design, sorted by cross-section. The results are sorted by cross-section design, stability analysis, serviceability limit state design, and fire resistance design. If there is a tapered member, both cross-section descriptions are displayed in the table row next to the section number.

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4.3

Design by Set of Members

Figure 4.4: Window 2.3 Design by Set of Members

This results window is displayed if you have selected at least one set of members for design. The window lists the maximum utilization ratios sorted by set of members. The Member No. column shows the number of the one member within the set of members that bears the maximum ratio for the individual design criteria. The output by set of members clearly presents the design for an entire structural group (for example a frame).

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4.4

Design by Member

Figure 4.5: Window 2.4 Design by Member

This results window presents the maximum utilization ratios for the individual designs sorted by member number. The columns are described in detail in chapter 4.1 on page 52.

4.5

Design by x-Location

Figure 4.6: Window 2.5 Design by x-Location

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This results window lists the maxima for each member at the locations x resulting from the division points in RSTAB: •

Start and end node

• •

Division points according to possibly defined member division (see RSTAB table 1.6) Member division according to specification for member results (RSTAB dialog box Calculation Parameters, tab Global Calculation Parameters)

•

Extreme values of internal forces

4.6

Governing Internal Forces by Member

Figure 4.7: Window 3.1 Governing Internal Forces by Member

For each member, this window displays the governing internal forces, that is, those internal forces that result in the maximum utilization in each design.

Location x At this x location of the member, the respective maximum design ratio occurs.

Loading This column displays the number of the load case, the load combination, or result combination whose internal forces result in the maximum stress ratio.

Forces / Moments For each member, this column displays the axial and shear forces as well as the torsional and bending moments producing maximum ratios in the respective cross-section designs, stability analyses, serviceability limit state designs, and fire resistance designs.

Design According to Formula The final column provides information on the types of checks and the equations by which the checks according to [1], [2], or [4] have been performed.

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4.7 Governing Internal Forces by Set of Members

Figure 4.8: Window 3.2 Governing Internal Forces by Set of Members

This window shows the internal forces that result in the maximum ratios of the design for each set of members.

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4.8

Member Slendernesses

Figure 4.9: Window 3.3 Member Slendernesses

This results window appears only if you select the respective check box in the Other tab of the Details dialog box (see Figure 3.8, page 49). The table lists the effective slendernesses of the designed members for both directions of the principal axes. They were determined depending on the type of load. At the end of the list, you find a comparison with the limit values that have been defined in the Details dialog box, tab Other (see Figure 3.8, page 49). Members of the member "Tension" or "Cable" type are not included in this window. This table is displayed only for information. No stability analysis of slendernesses is intended.

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4 Results

4.9

Parts List by Member

Finally, STEEL EC3 provides a summary of all cross-sections included in the design case.

Figure 4.10: Window 4.1 Parts List by Member

By default, this list contains only the designed members. If you need a parts list for all members of the model, select the corresponding option in Other tab of the Details dialog box (see Figure 3.8, page 49).

Part No. The program automatically assigns item numbers to similar members.

Cross-Section Description The column lists the cross-section numbers and descriptions.

Number of Members The column shows how many similar members are used for each part.

Length This column displays the respective length of an individual member.

Total Length This column shows the product determined from the two previous columns.

Surface Area For each part, the program indicates the surface area related to the total length. The surface area is determined from the Surface Area of the cross-sections that can be seen in windows 1.3 and 2.1 through 2.5 in the cross-section information (see Figure 2.19, page 21).

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Volume The volume of a part is determined from the cross-sectional area and the total length.

Unit Weight The Unit Weight of the cross-section is relative to the length of one meter. For tapered crosssections, the program averages both cross-section masses.

Weight The values of this column are determined from the respective product of the entries in column C and G.

Total Weight The final column indicates the total mass of each part.

Sum At the bottom of the list, you find a sum of the values in the columns B, D, E, F, and I. The last data field of the column Total Weight gives information about the total amount of steel required.

4.10 Parts List by Set of Members

Figure 4.11: Window 4.2 Parts List by Set of Members

The last results window is displayed if you have selected at least one set of members for design. The window summarizes an entire structural group (for example a horizontal beam) in a parts list. Details on the various columns can be found in the previous chapter. If there are different cross-sections in a set of members, the program averages the surface area, the volume, and cross-section weight.

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5 Results Evaluation

5.

Results Evaluation

You can evaluate the design results in different ways. The buttons below the first window part can help you to evaluate the results.

Figure 5.1: Buttons for results evaluation

The buttons have the following functions: Button

Description

Function

Ultimate Limit State Designs

Shows or hides the results of the ultimate limit state design

Serviceability Limit State Designs

Shows or hides the results of the serviceability limit state design

Fire Protection Designs

Shows or hides the results of the fire protection design

Show Color Bars

Shows or hides the colored relation scales in the results windows

Show Rows with Ratio > 1

Displays only the rows where the ratio is greater than 1, and thus the design is failed

Result Diagrams

Opens the window Result Diagram on Member  chapter 5.2, page 64

Excel Export

Exports the table to MS Excel / OpenOffice  chapter 7.4.3, page 75

Member Selection

Allows you to graphically select a member to display its results in the table

View Mode

Jumps to the RSTAB work window to change the view

Table 5.1: Buttons in results windows 2.1 through 2.5

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When evaluating the fire resistance design, you can check the steel temperature development graphically: To open the Fire Curves diagram shown in Figure 3.5 to Figure 3.7 on page 47 ff., click the button shown on the left (below the cross-section graphic in the results window).

5.1

Results in the RSTAB Model

To evaluate the design results, you can also use the RSTAB work window.

RSTAB background graphic and view mode The RSTAB work window in the background is useful for finding the position of a particular member in the model: The member selected in the STEEL EC3 results window is highlighted in the selection color in the background graphic. Furthermore, an arrow indicates the member's x-location that is displayed in the selected window row.

Figure 5.2: Indication of the member and the current Location x in the RSTAB model

If you cannot improve the display by moving the STEEL EC3 module window, click [Jump to Graphic] to activate the View Mode: Thus, you hide the module window so that you can modify the display in the RSTAB user interface. In the view mode, you can use the functions of the View menu, for example zooming, moving, or rotating the display. The pointer remains visible. Click [Back] to return to the add-on module STEEL EC3.

RSTAB work window You can also graphically check the design ratios in the RSTAB model: Click [Graphics] to exit the design module. In the RSTAB work window, the design ratios are now displayed like the internal forces of a load case. In the Results navigator, you can specify which design ratios of the service and ultimate limit state or fire resistance design you want to display graphically. To turn the display of design results on or off, use the [Show Results] button known from the display of internal forces in RSTAB. To display the result values, click the [Show Values] toolbar button to the right. The RSTAB tables are of no relevance for the evaluation of design results.

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You can set the design cases can be set by means of the list in the RSTAB menu bar. To adjust the graphical representation of the results, you can select Results → Members in the Display navigator. The display of the design ratios is Two-Colored by default.

Figure 5.3: Display navigator: Results → Members

If you select a multicolor representation (options With/Without Diagram or Cross-Sections), the color panel becomes available. It provides the common control functions described in detail in the RSTAB manual, chapter 3.4.6.

Figure 5.4: Design ratios with display option Without Diagram

The graphics of the design results can be transferred to the printout report (see chapter 6.2, page 67). To return to the STEEL EC3 module, click [STEEL EC3] in the panel.

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5.2

Result Diagrams

You can also graphically evaluate a member's result distributions in the result diagram. To do this, select the member (or set of members) in the STEEL EC3 results window by clicking in the table row of the member. Then, open the Result Diagram on Member dialog box by clicking the button shown on the left. The button is located below the upper results table (see Figure 5.1, page 61). To display the result diagrams, select the command from the RSTAB menu Results → Result Diagrams for Selected Members or use the button in the RSTAB toolbar shown on the left. A window opens, graphically showing the distribution of the maximum design values on the member or set of members.

Figure 5.5: Dialog box Result Diagram on Member

Use the list in the toolbar above to choose the relevant STEEL EC3 design case. The Result Diagram on Member dialog box is described in the RSTAB manual, chapter 9.5.

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5.3

Filter for Results

The STEEL EC3 results windows allow you to sort the results by various criteria. In addition, you can use the filter options for graphical evaluation of the results as described in chapter 9.7 of the RSTAB manual. You can use the Visibility option also for STEEL EC3 (see RSTAB manual, chapter 9.7.1) to filter the members in order to evaluate them.

Filtering designs The design ratios can easily be used as filter criteria in the RSTAB work window, which you can access by clicking [Graphics]. To apply this filter function, the panel must be displayed. If it is not shown, select View → Control Panel (Color Scale, Factors, Filter) or use the toolbar button shown on the left. The panel is described in the RSTAB manual, chapter 3.4.6. The filter settings for the results must be defined in the first panel tab (Color spectrum). Since this register is not available for the two-colored results display, you have to use the Display navigator and set the display options Colored With/Without Diagram or Cross-Sections first.

Figure 5.6: Filtering design ratios with adjusted color spectrum

As the figure above shows, the color spectrum can be set in such a way that only ratios higher than 0.50 are shown in a color range between blue and red. If you select the Display Hidden Result Diagram option in the Display navigator (Results → Members), you can display all design ratio diagrams that are not covered by the color spectrum. Those diagrams are represented by dotted lines.

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Filtering members In the Filter tab of the control panel, you can specify the numbers of particular members to display their results exclusively, that is, filtered. This function is described in detail in the RSTAB manual, chapter 9.7.3.

Figure 5.7: Member filter for the stress ratios of a hall frame

Unlike the partial view function (Visibilities), the graphic displays the entire model. The figure above shows the design ratios of a hall frame. The remaining members are displayed in the model but are shown without design ratios.

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6 Printout

6.

Printout

6.1

Printout Report

Similar to RSTAB, the program generates a printout report for the STEEL EC3 results, to which you can add graphics and descriptions. The selection in the printout report determines what data from the design module will be include in the printout. The printout report is described in the RSTAB manual. In particular, chapter 10.1.3.5 Selecting Data of Add-on Modules describes how to select input and output data from add-on modules for the printout report. For complex structural systems with many design cases, it is recommended to split the data into several printout reports, thus allowing for a clearly-arranged printout.

6.2

STEEL EC3 Graphic Printout

In RSTAB, you can add every picture that is displayed in the work window to the printout report or send it directly to a printer. In this way, you can prepare the design ratios displayed on the RSTAB model for the printout, too. The printing of graphics is described in the RSTAB manual, chapter 10.2.

Designs on the RSTAB model To print the currently displayed graphic of the design ratios, click File → Print Graphic or use the toolbar button shown on the left.

Figure 6.1: Button Print Graphic in RSTAB toolbar

Result Diagrams You can also transfer the Result Diagram on Member to the report by using the [Print] button or print it directly.

Figure 6.2: Button Print Graphic in the dialog box Result Diagram on Member

The Graphic Printout dialog box appears (see the following page).

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Figure 6.3: Dialog box Graphic Printout, tab General

This dialog box is described in the RSTAB manual, chapter 10.2. The RSTAB manual also describes the Options and Color Spectrum tab. You can move a graphic anywhere within the printout report by using the drag-and-drop function. To adjust a graphic subsequently in the printout report, right-click the relevant entry in the navigator of the printout report. The Properties option in the context menu opens the Graphic Printout dialog box, offering various options for adjustment.

Figure 6.4: Dialog box Graphic Printout, tab Options

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7 General Functions

7.

General Functions

This chapter describes useful menu functions as well as export options for the designs.

7.1

Design Cases

Design cases allow you to group members for the design: In this way, you can combine groups of structural components or analyze members with particular design specifications (for example changed materials, partial safety factors, optimization). It is no problem to analyze the same member or set of members in different design cases. To calculate a STEEL EC3 design case, you can also use the load case list in the RSTAB toolbar.

Create New Design Case To create a new design case, use the STEEL EC3 menu and click File → New Case. The following dialog box appears:

Figure 7.1: Dialog box New STEEL EC3 Case

In this dialog box, enter a No. (one that is still available) for the new design case. The corresponding Description will make the selection in the load case list easier. Click [OK] to open the STEEL EC3 window 1.1 General Data where you can enter the design data.

Rename Design Case To change the description of a design case, use the STEEL EC3 menu and click File → Rename Case. The following dialog box appears:

Figure 7.2: Dialog box Rename STEEL EC3 Case

In this dialog box, you can specify a different Description as well as a different No. for the design case.

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Copy Design Case To copy the input data of the current design case, select from the STEEL EC3 menu File → Copy Case. The following dialog box appears:

Figure 7.3: Dialog box Copy STEEL EC3 Case

Define the No. and, if necessary, a Description for the new case.

Delete a Design Case To delete design cases, select from the STEEL EC3 menu File → Delete Case. The following dialog box appears:

Figure 7.4: Dialog box Delete Case

The design case can be selected in the list Available Cases. To delete the selected case, click [OK].

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7 General Functions

7.2

Cross-Section Optimization

The design module offers you the option to optimize overloaded or little utilized cross-sections. To do this, select in column D or E of the relevant cross-sections in the 1.3 Cross-Sections window whether to determine the cross-section From the current row or the user-defined Favorites (see Figure 2.17, page 19). You can also start the cross-section optimization in the results windows by using the context menu.

Figure 7.5: Context menu for cross-section optimization

During the optimization process, the module determines the cross-section that fulfills the analysis requirements in the most optimal way, that is, comes as close as possible to the maximum allowable stress ratio specified in the Details dialog box (see Figure 3.8, page 49). The required cross-section properties are determined with the internal forces from RSTAB. If another crosssection proves to be more favorable, this cross-section is used for the design. Then, the graphic in window 1.3 shows two cross-sections: the original cross-section from RSTAB and the optimized one (see Figure 7.7). For a parameterized cross-section, the following dialog box appears after you select 'Yes' from the drop-down list.

Figure 7.6: Dialog box Welded Cross-Sections - I symmetric : Optimize

By selecting the check boxes in the Optimize column, you decide which parameter(s) you want to modify. This enables the Minimum and Maximum columns, where you can specify the upper and lower limits of the parameter. The Increment column determines the interval in which the size of the parameter varies during the optimization process.

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If you want to Keep current side proportions, select the corresponding check box. In addition, you must select at least two parameters for optimization. Cross-sections built up from rolled cross-sections cannot be optimized. Please note that the internal forces are not automatically recalculated with the changed crosssections during the optimization: It is up to you to decide which cross-sections should be transferred to RSTAB for recalculation. As a result of optimized cross-sections, internal forces may vary significantly because of the changed stiffnesses in the structural system. Therefore, it is recommended to recalculate the internal forces of the modified cross-section data after the first optimization, and then to optimize the cross-sections once again. You can export the modified cross-sections to RSTAB: Go to the 1.3 Cross-Sections window, and then click Edit → Export All Cross-Sections to RSTAB. Alternatively, you can use the context menu in window 1.3 to export optimized cross-sections to RSTAB.

Figure 7.7: Context menu in window 1.3 Cross-Sections

Before the modified cross-sections are transferred to RSTAB, a security query appears as to whether the results of RSTAB should be deleted.

Figure 7.8: Query before transfer of modified cross-sections to RSTAB

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By confirming the query, and then starting the [Calculation] in the STEEL EC3 add-on module, the RSTAB internal forces as well as the designs will be determined in one single calculation run. If the modified cross-sections have not been exported to RSTAB yet, you can reimport the original cross-sections in the design module by using the options shown in Figure 7.7. Please note that this option is only available in the 1.3 Cross-sections window. If you optimize a tapered member, the program modifies the member start and end. Then it linearly interpolates the second moments of area for the intermediate locations. Because these moments are considered with the fourth power, the analyses may be inaccurate if the depths of the start and end cross-section differ considerably. In such a case, it is recommended to divide the taper into several members, thus modeling the taper layout manually.

7.3

Units and Decimal Places

Units and decimal places for RSTAB and the add-on modules are managed in one dialog box. To define the units in STEEL EC 3, select Settings → Units and Decimal Places. The following dialog box familiar from RSTAB appears. STEEL EC3 will be preset in the Program / Module list.

Figure 7.9: Dialog box Units and Decimal Places

You can save the settings as user profile to reuse them in other models. These functions are described in the RSTAB manual, chapter 11.1.3.

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7.4

Data Transfer

7.4.1

Export Material to RSTAB

If you have adjusted the materials in STEEL EC3 for design, you can export the modified materials to RSTAB in a similar way as you export cross-sections: Open the 1.2 Materials window, and then click Edit → Export All Materials to RSTAB. You can also export the modified materials to RSTAB using the context menu of window 1.2.

Figure 7.10: Context menu in window 1.2 Materials

Before the modified materials are transferred to RSTAB, a security query appears as to whether the results of RSTAB should be deleted. When you have confirmed the query and then start the [Calculation] in STEEL EC3, the RSTAB internal forces and designs are determined in one single calculation run. If the modified materials have not been exported to RSTAB yet, you can transfer the original materials to the design module, using the options shown in Figure 7.10. Please note, however, that this option is only available in the 1.2 Materials window.

7.4.2

Export Effective Lengths to RSTAB

If you have adjusted the materials in STEEL EC3 for design, you can export the modified materials to RSTAB in a similar way as you export cross-sections: Open the 1.5 Effective Lengths Members window, and then select Edit → Export All Effective Lengths to RSTAB. or use the corresponding option on the context menu of window 1.5.

Figure 7.11: Context menu of window 1.5 Effective Lengths - Members

Before the modified materials are transferred to RSTAB, a security query appears as to whether the results of RSTAB should be deleted. If the modified effective lengths have not been exported to RSTAB yet, you can reimport the original effective lengths to the design module by using the options shown in Figure 7.11. Please note, however, that this option is only available in the windows 1.5 Effective Lengths Members and 1.6 Effective Lengths - Sets of Members.

7.4.3

Export Results

The STEEL EC3 results can also be used by other programs.

Clipboard To copy cells selected in the results windows to the Clipboard, press the keys [Ctrl]+[C]. To insert the cells, for example in a word-processing program, press [Ctrl]+[V]. The headers of the table columns will not be transferred.

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Printout report You can print the data of the STEEL EC3 add-on module into the global printout report (see chapter 6.1, page 67) for export. Then, in the printout report, click File → Export to RTF. The function is described in the RSTAB manual, chapter 10.1.11.

Excel / OpenOffice STEEL EC3 provides a function for the direct data export to MS Excel, OpenOffice.org Calc, or the file format CSV. To open the corresponding dialog box, click File → Export Tables. The following export dialog box appears.

Figure 7.12: Dialog box Export - MS Excel

Once you have selected the relevant options, you can start the export by clicking [OK]. Excel or OpenOffice will be started automatically, that is, the programs do not have to be opened first.

Figure 7.13: Result in Excel

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8 Examples

8.

Examples

8.1

Stability

In our example, we perform the stability analyses for flexural buckling and lateral-torsional buckling for a column with double-bending, taking into account the interaction conditions.

Design values System and loads N

Design values of the static loads

qz

2m

Nd

= 300 kN

qz,d = 5.0 kN/m = 7.5 kN

4m

Fy,d

2m

Fy

HEB160

z y

Figure 8.1: System and design loads (γ times)

Internal forces according to linear static analysis

N

My

Figure 8.2: Internal forces

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Mz

Vy

Vz

8 Examples

Design location (decisive x-location) The design is performed for all x-locations (see chapter 4.5) of the equivalent member. The governing location is x = 2.00 m. RSTAB determines the following internal forces: My = 10.00 kNm

N = –300.00 kN

Mz = 7.50 kNm

Vy = 3.75 kN

Vz = 0.00 kN

Cross-section properties HE-B 160, S 235 Property

Symbol

Value

Unit

Cross-section area

A

54.30 cm2

Moment of inertia

Iy

2490.00 cm4

Moment of inertia

Iz

889.00 cm4

Governing radius of gyration

ry

6.78 cm

Governing radius of gyration

rz

4.05 cm

Polar radius of gyration

ro

7.90 cm

Polar radius of gyration

ro,M

41.90 cm

Cross-section weight

wt

42.63 kg/m

Torsional constant

J

31.40 cm4

Warping constant

Cw

47940.00 cm6

Elastic section modulus

Sy

311.00 cm3

Elastic section modulus

Sz

111.00 cm3

Plastic section modulus

Zy

354.00 cm3

Plastic section modulus

Zz

169.96 cm3

Buckling curve

BCy

b

Buckling curve

BCz

c

Flexural buckling about minor axis (⊥ to z-z axis) Ncr , z =

λz =

21000 ⋅ 889.00 ⋅ π2 400.002

A ⋅ fy Ncr ,z

=

= 1151.60 kN

54.30 ⋅ 23.5 = 1.053 1151.60

λ z = 1.053 > 0.2

→ Design for flexural buckling must be performed.

Cross-sectional geometry:

h = 1.00 ≤ 1.2 b

structural steel S 235

t ≤ 100 mm

[1], Table 6.2, row 3, column 4: Buckling curve c ⇒ αz = 0.49 (Table 6.1)

[

Φ = 0.5 ⋅ 1+ 0.49 ⋅ (1,053 − 0.2 ) + 1.0532 χz =

1 1.263 + 1.2632 − 1.0532

] = 1.263

= 0.510

NEd 300 = = 0.461 χ z ⋅ A ⋅ fy / γ M1 0.510 ⋅ 54.30 ⋅ 23.5 / 1.0

Program STEEL EC3 © 2013 Dlubal Software GmbH

77

8 Examples

Result values from STEEL EC3 calculation Second moment of area

Iz

889.00

cm4

Effective member length

Lcr,z

4.000

m

1151.60

kN

Elastic flexural buckling force Ncr,z Slenderness

λz

1.053

> 0.2 6.3.1.2(4)

Buckling curve

BCz

c

Tab. 6.2

Imperfection factor

αz

0.490

Tab. 6.1

Auxiliary factor

Φz

1.263

6.3.1.2(1)

Reduction factor

χz

0.510

Eq. (6.49)

Flexural buckling about major axis (⊥ to y-y axis) Ncr ,y =

λy =

21000 ⋅ 2490.00 ⋅ π 2 400.00 2

A ⋅ fy Ncr ,y

=

= 3225.51 kN

54.30 ⋅ 23.5 = 0.629 3225.51 → Design for flexural buckling must be performed.

λ y = 0.629 > 0.2

Cross-sectional geometry:

h = 1.00 ≤ 1.2 b

structural steel S 235

t ≤ 100 mm

[1], Table 6.2, row 3, column 4: Buckling curve b ⇒ αy = 0.34

(Table 6.1)

[

]

Φ = 0.5 ⋅ 1+ 0.34 ⋅ (0.629 − 0.2 ) + 0.6292 = 0.771 χY =

1 0.771+ 0.7712 − 0.629 2

= 0.822

NEd 300 = = 0.286 χ Y ⋅ A ⋅ fy / γ M1 0.822 ⋅ 54.30 ⋅ 23.5 / 1.0

Result values from STEEL EC3 calculation

78

Second moment of area

Iy

2490.00

cm4

Effective member length

Lcr,y

4.000

m

Elastic flexural buckling force

Ncr,y

3225.51

kN

Cross-section area

A

54.30

cm2

Yield strength

fy

23.50

kN/cm2

Slenderness

λ_y

0.629

Buckling curve

BCy

b

Tab. 6.2

Imperfection factor

αy

0.340

Tab. 6.1

Auxiliary factor

Φy

0.771

6.3.1.2(1)

Reduction factor

χy

0.822

Eq. (6.49)

Program STEEL EC3 © 2013 Dlubal Software GmbH

3.2.1 > 0.2 6.3.1.2(4)

8 Examples

Lateral-torsional buckling Elastic critical moment In this example, the elastic critical moment for lateral torsional buckling is determined according to the Austrian National Annex, assuming hinged supports . The point of load application is assumed to be in the shear center. The application point for transverse loads can be adjusted in Details dialog box (see chapter 3.1.2, page 44).

Mcr = C1 ⋅

π2 ⋅ E ⋅ Iz 2

L

Mcr = 1.13 ⋅

⋅

Iω L2 ⋅ G ⋅ It + Iz π2 ⋅ E ⋅ Iz

π2 ⋅ 21000 ⋅ 889 400

2

47940 4002 ⋅ 8100 ⋅ 31.40 + 2 = 215.71kNm 889 π ⋅ 21000 ⋅ 889

⋅

The program also shows Mcr,0, which is determined assuming a constant moment distribution. For the results by x-location, the program also shows the Mcr,x values, that is, the elastic critical moments at the x-locations relative to the elastic critical moment at the location of the maximum moment. With Mcr,x, the program calculates the relative slenderness λ LT .

Slenderness for lateral-torsional buckling Calculation according to [1], clause 6.3.2.2, for location with maximum moment at x = 2.00 m: HEB-160, cross-section Class 1: Sy ⇒ Zy = 354.0cm³

λLT =

Sy ⋅ fy Mcr

=

354 ⋅ 23.5 = 0.621 215.71

Reduction factor χLT Calculation according to [1], section 6.3.2.3 HEB-160: d/w = 1.0 < 2.0 ⇒ buckling curve "b" according to Table 6.5

[ ] ( ) = 0.5 ⋅ [1+ 0.34 ⋅ (0.621− 0.40 ) + 0.75 ⋅ 0.621 ] = 0.682

Φ LT = 0.5 ⋅ 1+ α LT ⋅ λLT − λLT ,0 + β ⋅ λ2LT

Auxiliary factor:

Φ LT

Limiting slenderness:

2

λLT ,0 = 0.40

β = 0.75

Parameter (minimum value): Imperfection factor:

χLT =

α LT = 0.34

1 2

Φ LT + Φ LT − β ⋅ λLT

2

=

(Table 6.3)

1 0.682 + 0.682 2 − 0.75 ⋅ 0.6212

= 0.908

In accordance with [1], clause 6.3.2.3, the reduction factor may be modified as follows:

χLT ,mod =

χLT f

χLT ,mod =

0.908 = 0.934 0.972

where f = 1− 0.5 ⋅ (1− k c ) ⋅ [1− 2.0 ⋅ ( λLT − 0.82 )]

Program STEEL EC3 © 2013 Dlubal Software GmbH

79

8 Examples

For a parabolic moment diagram, we obtain the following correction factor kc: kc = 0.94

(Table 6.6)

f = 1− 0.5 ⋅ (1− k c ) ⋅ [1− 2.0 ⋅ ( λLT − 0.8 )2 ] = 1− 0.5 ⋅ (1− 0.94 ) ⋅ [1− 2.0 ⋅ (0.621− 0.8 )2 ] = 0.972

Interaction factors kyy and kyz Determination according to [1], Annex B, Table B2, for structural components susceptible to torsional deformations. The equivalent moment factor CmLT according to Table B3 for ψ= 0 is obtained as: Cmy = CmLT = 0.95 + 0.05 ⋅ αh = 0.95 where

α h = Mh / Ms = 0 / 10 = 0

    NEd NEd  ≤ C my ⋅ 1+ 0.8 ⋅  k yy = C my ⋅ 1+ ( λ y − 0 ,2) ⋅     χ ⋅ N / γ χ ⋅ N / γ y Rk M 1 y Rk M 1     k yy = 0.95 ⋅ (1+ (0.629 − 0.2) ⋅ 0.286 ) ≤ 0.95 ⋅ (1+ 0.8 ⋅ 0.286 ) = 1.067 ≤ 1.167 k yz = 0.60 ⋅ k zz = 0.60 ⋅1.481 = 0.888

Interaction factors kzy and kzz Determination according to [1], Annex B, Table B2, for structural components susceptible to torsional deformations The equivalent moment factor CmLT according to Table B3 for ψ = 0 is obtained as:

Cmz = 0.90 + 0.01⋅ αh = 0.90 where

α h = Mh / Ms = 0 / 10 = 0

    NEd NEd 0.1⋅ λ z 0.1  ≥ 1−  k zy = 1− ⋅ ⋅     (C mLT − 0.25) χ z ⋅ NRk / γ M1   (C mLT − 0.25) χ z ⋅ NRk / γ M1  0.1⋅1.053 0.1     k zy = 1 − ⋅ 0.461 ≥ 1− ⋅ 0.461 = 0.892 ≤ 0.934  (0.95 − 0.25)   (0.95 − 0.25)  k zy = 0.934

    NEd NEd   ≤ C mz ⋅ 1+ 1.4 ⋅ k zz = C mz ⋅ 1+ (2 ⋅ λ z − 0 ,6 ) ⋅ χ z ⋅ NRk / γ M1  χ z ⋅ NRk / γ M1   

k zz = 0.90 ⋅ (1+ (2 ⋅1.053 − 0.6 ) ⋅ 0.461) ≤ 0.90 ⋅ (1+ 1.4 ⋅ 0.461) = 1.525 ≥ 1.481 k zz = 1.481

Interaction design for buckling around major axis and lateral-torsional buckling M y ,Ed M NEd + k yy ⋅ + k yz ⋅ z ,Ed ≤ 1 according to [1], Eq. (6.61) N M y ,Rk M z ,Rk χ y ⋅ Rk χLT ⋅ γ M1 γ M1 γ M1 M y ,Rk = Wpl,y ⋅ f y = 354 ⋅ 23.5 = 8319 kNcm = 83.19 kNm M z ,Rk = Wpl,z ⋅ fy = 169.96 ⋅ 23.5 = 3994.1kNcm = 39.94 kNm

300 10.0 7.50 + 1.067 ⋅ + 0.888 ⋅ = 0.594 ≤ 1 1276.05 83.19 39.94 0.822 ⋅ 0.908 ⋅ 1.0 1.0 1.0

80

Program STEEL EC3 © 2013 Dlubal Software GmbH

8 Examples

Interaction design for buckling around minor axis and lateral-torsional buckling M y ,Ed M NEd + k zz ⋅ z ,Ed ≤ 1 according to [1], Eq. (6.62) + k zy ⋅ M z ,Rk M y ,Rk N χ z ⋅ Rk χLT ⋅ γ M1 γ M1 γ M1

7.50 10.0 300 = 0.863 ≤ 1 + 1.481⋅ + 0.934 ⋅ 39.94 83.19 1276.05 0.908 ⋅ 0.510 ⋅ 1.0 1.0 1.0

Result values from STEEL EC3 calculation Section depth

h

160.0

mm

Section width

b

160.0

mm

Criterion

h/b

1.00

Buckling curve

BCLT

b

Imperfection factor

αLT

0.340

Shear modulus

G

8100,00

Length factor

kz

1.000

Length factor

kw

1.000

Length

L

4.000

m

Warping constant

Cw

47940.00

cm6

Torsional constant

J

31.40

cm4

190.90

kNm

Ideal elastic critical moment for lateral-torsional buckling for determination of related slenderness Mcr,0

≤ 2 Tab. 6.5 Tab. 6.5 Tab. 6.3 kN/cm

2

Moment distribution

Diagr My

Maximum field moment

My,max

10.00

kNm

Boundary moment

My,A

0.00

kNm

Moment ratio

Ψ

0.000

Moment factor

C1

1.130

Ideal elastic critical moment

Mcr

215.71

kNm

Elastic section modulus

Sy

354.00

cm3

Slenderness

λ_LT

0.621

6.3.2.2(1)

Parameters

λ_LT,0

0.400

6.3.2.3(1)

Parameters

β

0.750

6.3.2.3(1)

Auxiliary factor

ΦLT

0.682

6.3.2.3(1)

Reduction factor

χLT

0.908

Eq. (6.57)

Correction factor

kc

0.940

6.3.2.3(2)

Modification factor

f

0.972

6.3.2.3(2)

Reduction factor

χLT,mod

0.934

Eq. (6.58)

Moment distribution

Diagr My

3) Max in field

Tab. B.3

Moment factor

Ψy

1.000

Tab. B.3

Moment

Mh,y

0.00

Program STEEL EC3 © 2013 Dlubal Software GmbH

6) Parabola

[2]

kNm

Tab. B.3

81

8 Examples

82

Moment

Ms,y

10.00

Ratio Mh,y / Ms,y

αh,y

0.000

Tab. B.3

Load type

Load z

Uniform load

Tab. B.3

Moment factor

Cmy

0.950

Tab. B.3

Moment distribution

Diagr Mz

3) Max in field

Tab. B.3

Moment factor

Ψz

1.000

Tab. B.3

Moment

Mh,z

0.00

kNm

Tab. B.3

Moment

Ms,z

7.50

kNm

Tab. B.3

Ratio Mh,z / Ms,z

αh,z

0.000

Tab. B.3

Load type

Load y

Concentr. load

Tab. B.3

Moment factor

Cmz

0.900

Tab. B.3

Moment distribution

Diagr My,LT

3) Max in field

Tab. B.3

Moment factor

Ψy,LT

1.000

Tab. B.3

Moment

Mh,y,LT

0.00

kNm

Tab. B.3

Moment

Ms,y,LT

10.00

kNm

Tab. B.3

Ratio Mh,y,LT / Ms,y,LT

αh,y.LT

0.000

Tab. B.3

Load type

Load z

Uniform load

Tab. B.3

Moment factor

CmLT

0.950

Tab. B.3

Component type

Structural member

Interaction factor

kyy

1.067

Tab. B.2

Interaction factor

kyz

0.888

Tab. A.1

Interaction factor

kzy

0.934

Tab. A.1

Interaction factor

kzz

1.481

Tab. A.1

Axial force (compression)

NEd

300.00

kN

Governing cross-section area

Ai

54.30

cm2

Tab. 6.7

Compression resistance

NRk

1276.05

kN

Tab. 6.7

Partial factor

γM1

1.000

Design component for N

γNy

0.29

≤ 1 Eq. (6.61)

Design component for N

hNz

0.46

≤ 1 Eq. (6.62)

Moment

My,Ed

10.00

kNm

Moment resistance

My,Rk

83.19

kNm

Moment component

ηMy

0.13

Moment

Mz,Ed

7.50

kNm

Elastic section modulus

Sz

169.96

cm3

Moment resistance

Mz,Rk

39.94

kNm

Moment component

ηMz

0.19

Eq. (6.61)

Design 1

η1

0.59

≤ 1 Eq. (6.61)

Design 2

η2

0.86

≤ 1 Eq. (6.62)

Program STEEL EC3 © 2013 Dlubal Software GmbH

kNm

Tab. B.3

Susceptible to torsional deformation

6.1

Tab. 6.7 Eq. (6.61)

Tab. 6.7

8 Examples

8.2

Fire Resistance

This example presents the fire design of a steel column.

System and loads Column cross-section:

HEB 300, steel S 235

System:

hinged column, β = 1.0

Height of system:

3.00 m

Loading:

GK = 1200 kN QK = 600 kN

Figure 8.3: System and loads

Ultimate limit state design for room temperature Flexural buckling about minor axis (⊥ to z-z axis) Ncr ,z =

21000 ⋅ 8560.00 ⋅ π2 300.00 2

A ⋅ fy

λz =

Ncr ,z

=

= 19712.90 kN

149.0 ⋅ 24.0 = 0.426 19712.90

λ z = 0.426 > 0.2

→ Design for flexural buckling must be performed.

Cross-sectional geometry:

h = 1.00 ≤ 1.2 b

structural steel S 235

t ≤ 100 mm

[1], Table 6.2, row 3, column 4: Buckling curve c ⇒ αz = 0.49 (Table 6.1)

[

]

Φ = 0.5 ⋅ 1+ 0.49 ⋅ (0.426 − 0.2 ) + 0.426 2 = 0.646 χz =

1 0.646 + 0.646 2 − 0.426 2

= 0.884

NEd = 1.35 * Gk + 1.5 * Q k = 1.35 * 1200 + 1.5 * 600 = 2520 kN Check

NEd 2520 = = 0.877 ≤ 1.0 χ z ⋅ A ⋅ fy / γ M1 0.884 ⋅149.0 ⋅ 24.0 / 1.1

Program STEEL EC3 © 2013 Dlubal Software GmbH

83

8 Examples

Result values from STEEL EC3 calculation Second moment of area

Iz

8560.00

cm4

Effective member length

Lcr,z

3.000

m

Elastic flexural buckling force

Ncr,z

19712.9

kN

Slenderness

λ_,z

0.4259

Buckling curve

BCz

c

Tab. 6.2

Imperfection factor

αz

0.490

Tab. 6.1

Auxiliary factor

Φz

0,646

6.3.1.2(1)

Reduction factor

χz

0,884

Eq. (6.49)

Nb,z,Rd

2872.27

η

0.877

Flexural buckling resistance Design

> 0.2 6.3.1.2(4)

kN

Eq. (6.47) ≤ 1.0

Eq. (6.46)

Fire resistance design After a fire exposure of 90 min, according to the standard temperature-time curve, the mean steel temperature is 524 °C.

A box-shaped GRP encasement (glass-reinforced plastic) is used as fire resistance material with the following characteristics: kg ρp = 945.0 3 Specific weight: m W λ p = 0.20 Thermal conductivity: k J Specific heat capacity: c p = 1700 kg * K dp = 18 mm

Thickness:

Determination of reduction factors k y ,Θ = 0.703

according to [2], Table 3.1

k E ,Θ = 0.528

according to [2], Table 3.1

Design in fire situation according to [2], 4.2.3.2 Imperfection factor α:

α = 0.65 *

235 235 = 0.65 * = 0.643 fy 240

Non-dimensional relative slenderness λ Θ :

k  λ Θ = λ *  y ,Θ k  Θ E ,  

84

0.5

[

]

0.5 = 0.426 * 0.703 0.528 = 0.491

Program STEEL EC3 © 2013 Dlubal Software GmbH

8 Examples

Auxiliary factor:

Φθ =

[

]

[

]

1 1 * 1 + α * λ θ + λ θ 2 = * 1 + 0.643 * 0.491 + 0.4912 = 0.778 2 2

Reduction factor for flexural buckling in the fire design situation:

χ fi =

1 2

ϕθ + ϕθ − λ θ

2

=

1 0.778 + 0.778 2 − 0.4912

= 0.723

Buckling resistance of structural component subjected to compression:

Nb ,fi,Rd =

χ fi * A * k y ,θ * fy γ M,fi

=

0.723 * 149.0 * 0.703 * 24 = 1817.83 1.0

Loading in case of fire: Nfi,Ed = 1.0 * Gk + 0.9 * Qk = 1.0 * 1200 + 0.9 * 600 = 1740 kN

Design

η=

Nfi,Ed 1740 = = 0.957 ≤ 1.0 Nb ,fi,Rd 1817.83

Result values from STEEL EC3 calculation Reduction factor

ky,Θ

0.703

EN 1993-1-2, Tab. 3.1

Reduction factor

kE,Θ

0.528

EN 1993-1-2, Tab. 3.1

Slenderness

λ_z,Θ

0.4915

EN 1993-1-2, Eq. (4.7)

α

0.6432

EN 1993-1-2,4.2.3.2(2)

Auxiliary factor

Φz,Θ

0.778

EN 1993-1-2, 4.2.3.2(2)

Reduction factor

χz,fi

0.723

EN 1993-1-2, Eq. (4.6)

Nb,fi,z,Θ,Rd

1817.83

η

0.957

Imperfection factor

Flexural buckling resistance Design criterion

Program STEEL EC3 © 2013 Dlubal Software GmbH

kN ≤ 1.0 EN 1993-1-2, Eq. (4.1)

85

A Literature

A Literature

86

[1]

EN 1993-1-1: Design of steel structures Part 1-1: General rules and rules for buildings, 2005

[2]

EN 1993-1-2: Design of steel structures Part 1-2: General rules - Structural fire design, 2006

[3]

EN 1993-1-3: Design of steel structures Part 1-3: General rules - Supplementary rules for cold-formed members and sheeting, 2006

[4]

EN 1993-1-4: Design of steel structures Part 1-4: General rules - Supplementary rules for stainless steels, 2006

[5]

Tragwerke aus Stahl nach Eurocode 3, Werner, 1. Auflage 1996

[6]

The Behaviour and Design of Steel Structures to EC3 , TRAHAIR N.S., BRADFORD M.A., NETHERCOT D.A., GARDNER L., Taylor & Francis Ltd 2007

[7]

Rules for Member Stability in EN 1993-1-1, ECCS Technical Committee 8 – Stability

[8]

Die neuen Stabilitätsnachweise im Stahlbau nach Eurocode 3, NAUMES J., STROHMANN I., UNGERMANN D., SEDLACEK G., Stahlbau 77 (2008) Heft 10, Ernst & Sohn

[9]

Biegeknicken und Biegedrillknicken von Stäben auf einheitlicher Grundlage, NAUMES J., FELDMANN M., SEDLACEK G., Heft 70, Schriftenreihe Stahlbau, RWTH Aachen, Shaker Verlag 2010

Program STEEL EC3 © 2013 Dlubal Software GmbH

B Index

B Index A

Detail settings ................................................................. 42

Accidental ......................................................................... 10

Diagonal............................................................................ 37

Axis ...................................................................................... 25

Discrete rotational restraint ....................................... 40

B

Display navigator .................................................... 63, 65

Background graphic ...................................................... 62

E

Beam spacing .................................................... 35, 36, 39

Effective length .......................................... 24, 25, 28, 74

Beam type ......................................................................... 32

Elastic critical moment for LTB .................................. 44

Boundary conditions..................................................... 34

End panel .......................................................................... 39

Bracing ............................................................................... 36

Equivalent member length ........................................ 24

Buckling ............................................................................. 25

Equivalent member method.........................28, 29, 45

Buckling length ........................................................ 24, 27

European lateral-torsional buckling ........................ 14

Buckling length coefficient ......................................... 26

Excel ................................................................................... 75

Button ................................................................................ 61

Exit STEEL EC3 .................................................................... 8

C

Expanded method......................................................... 14

Calculation........................................................................ 42 Cantilever ................................................................... 23, 32 Characteristic ................................................................... 12 Classification .................................................................... 43

Export ................................................................................ 74 Export cross-section...................................................... 72 Export effective length ................................................ 74 Export material ............................................................... 74

Clipboard .......................................................................... 74

F

Color spectrum ............................................................... 65

Fastening arrangement ............................................... 35

Colored design ................................................................ 65

Favorites ........................................................................... 71

Comment ............................................................................ 9

Filter ................................................................................... 65

Connection deformation ............................................. 38

Filtering members ......................................................... 66

Continuous beam effect .............................................. 39

Fire exposure ................................................................... 33

Continuous rotational restraint ................................. 38

Fire resistance ................................................................. 12

Control panel ................................................................... 65

Fire resistance check ..................................................... 47

Cross-section ............................................................ 19, 71

Fire resistance design ............................................ 33, 61

Cross-section class ......................................................... 43

Flexural buckling...............................................23, 25, 44

Cross-section design ..................................................... 53

Fork support .......................................................23, 26, 27

Cross-section library ...................................................... 19

Frequent ........................................................................... 12

Cross-section optimization ......................................... 71

G

Cross-section type ......................................................... 20

General data ....................................................................... 8

Cross-sectional area ...................................................... 40

General method ............................................................. 45

D

Graphic .............................................................................. 62

Decimal places ......................................................... 17, 73

Graphic printout............................................................. 67

Deflection ......................................................................... 12

H

Deformation analysis .................................................... 32

Hidden result diagram ................................................. 65

Design ....................................................... 9, 20, 51, 52, 53

Hollow encasement ...................................................... 33

Design case ........................................................ 63, 69, 70

I

Design combination...................................................... 12

Increase factor ................................................................ 44

Design of welds .............................................................. 49

Info about cross-section .............................................. 21

Design situation....................................................... 10, 53

Installation .......................................................................... 6

Program STEEL EC3 © 2013 Dlubal Software GmbH

87

B Index

Interaction ........................................................................ 43

Parts list ...................................................................... 59, 60

Intermediate support ................................................... 23

Persistent and transient............................................... 10

Internal forces........................................................... 56, 72

Post ..................................................................................... 37

Internal panel .................................................................. 39

Precamber ........................................................................ 32

L

Print .................................................................................... 67

Lateral intermediate support ..................................... 23

Printout report ......................................................... 67, 68

Lateral support ................................................................ 23

Protection type ............................................................... 33

Lateral-torsional buckling ............................. 14, 23, 26

Purlins ................................................................................ 40

Length ......................................................................... 24, 59

Q

Limit deformation .......................................................... 46

Quasi permanent ........................................................... 12

Limit load .......................................................................... 45

R

Limit values ........................................................... 9, 12, 13

Ratio ................................................................................... 52

List of members .............................................................. 32

Reference length............................................................ 12

Load application ............................................................. 45

Relation scales ................................................................ 61

Load case ............................................................ 10, 11, 56

Relatively .......................................................................... 23

Load combination.......................................................... 10

Remark .............................................................................. 21

Location x ......................................................................... 52

Rendering ......................................................................... 65

M

Result combination ................................................ 10, 11

Material ....................................................................... 17, 74

Result diagram ......................................................... 64, 67

Material description ...................................................... 17

Results evaluation ......................................................... 61

Material library ................................................................ 18

Results representation ................................................. 63

Material properties ........................................................ 17

Results values .................................................................. 62

Member release .............................................................. 31

Results window .............................................................. 51

Member slendernesses ......................................... 49, 58

Rotational restraint ....................................................... 38

Members ............................................................................. 9

RSBUCK.............................................................................. 25

Model type ....................................................................... 45

RSTAB graphic................................................................. 67

N

RSTAB work window ..................................................... 62

National Annex ...........................................................9, 13

S

Naumes.............................................................................. 14

Selecting windows ........................................................... 8

Navigator ............................................................................ 8

Serviceability ............................................................ 11, 46

Net cross-sectional area ............................................... 40

Serviceability limit state ....................................... 32, 61

Net flow of heat .............................................................. 48

Set of members ... 9, 28, 29, 31, 32, 41, 45, 54, 57, 60

Nodal support ................................................................. 29

SHAPE-THIN ..................................................................... 43

Nonlinear method (second order theory).............. 43

Shear panel ...................................................................... 35

Non-linear method (second order theory) ............ 44

Shear panel length ................................................. 35, 36

O

Shear panel stiffness ..................................................... 37

OpenOffice ....................................................................... 75

Shifted ends of members ............................................ 46

Optimization ............................................... 20, 49, 71, 72

Slenderness...................................................................... 58

P

Special cases .................................................................... 45

Panel ........................................................................7, 63, 65 Parameter ......................................................................... 34 Parameterized cross-section ...................................... 71 Part ...................................................................................... 59 Partial safety factor ........................................................ 14

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Program STEEL EC3 © 2013 Dlubal Software GmbH

Spring stiffness C100 ....................................................... 38 Stability analysis ........................... 14, 23, 43, 44, 45, 53 Stainless steel ........................................................... 16, 18 Start calculation ............................................................. 50 Start program ..................................................................... 6

B Index

Start STEEL EC3 ................................................................. 6

Undeformed system ..................................................... 46

Steel bridge ...................................................................... 46

Units ............................................................................ 17, 73

Stress point....................................................................... 22

User profile ....................................................................... 73

Sum ..................................................................................... 60

V

Surface area...................................................................... 59

View mode ................................................................ 61, 62

T

Visibilities .......................................................................... 65

Tapered cross-section................................................... 21

Volume .............................................................................. 60

Tapered member.............................................. 45, 53, 73

W

Temperature curve ........................................................ 47

Warping length coefficient......................................... 27

Tension design ................................................................ 40

Warping restraint ........................................................... 27

Torsion ............................................................................... 45

Web breathing ................................................................ 46

Transverse load ............................................................... 45

Weight ............................................................................... 60

Trapezoidal sheet ........................................................... 38

Windows .............................................................................. 8

Trapezoidal sheeting .................................................... 35

X

U

x-location ................................................................... 52, 56

Ultimate limit state .......................................... 10, 42, 61

Program STEEL EC3 © 2013 Dlubal Software GmbH

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