Femap Getting Started

FEMAP Getting Started

Version 10.3

MUF1000-GS-103

Proprietary and Restricted Rights Notice This software and related documentation are proprietary to Siemens Product Lifecycle Management Software Inc. © 2011 Siemens Product Lifecycle Management Software Inc. All Rights Reserved. Siemens and the Siemens logo are registered trademarks of Siemens AG. NX is a trademark or registered trademark of Siemens Product Lifecycle Management Software Inc. or its subsidiaries in the United States and in other countries. All other trademarks, registered trademarks or service marks belong to their respective holders.

Siemens PLM Web:

http://www.femap.com

Customer Support Phone: Web:

(714) 952-5444, (800) 955-0000 (In US & Canada) http://support.ugs.com

The following copyright refers only to the “bmp2raster.exe” executable distributed with FEMAP: NeuQuant Neural-Net Quantization Algorithm Copyright (c) 1994 Anthony Dekker NEUQUANT Neural-Net quantization algorithm by Anthony Dekker, 1994. See "Kohonen neural networks for optimal colour quantization" in "Network: Computation in Neural Systems" Vol. 5 (1994) pp 351-367 for a discussion of the algorithm. See also http://members.ozemail.com.au/~dekker/NEUQUANT.HTML Any party obtaining a copy of these files from the author, directly or indirectly, is granted, free of charge, a full and unrestricted irrevocable, world-wide, paid up, royalty-free, nonexclusive right and license to deal in this software and documentation files (the "Software"), including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons who receive copies from any such party to do so, with the only requirement being that this copyright notice remain intact.

Conventions This manual uses different fonts to highlight command names or input that you must type.

a:setup

Shows text that you should type.

OK, Cancel

Shows a command name or text that you will see in a dialog box.

Throughout this manual, you will see references to Windows. Windows refers to Microsoft® Windows XP, Windows Vista, and Windows 7 (32-bit and 64-bit versions). You will need one of these operating environments to run FEMAP for the PC. This manual assumes that you are familiar with the general use of the operating environment. If you are not, you can refer to the Windows User’s Guide for additional assistance. Similarly, throughout the manual all references to FEMAP, refer to the latest version of our software.

FEMAP Examples Proprietary and Restricted Rights Notice 1. Introduction Introduction to FEMAP . . . . Using the Examples in Getting Started . The FEMAP Documentation Set . .

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Hardware/Software Requirements . . . Installation - Stand Alone . . . . Network Installation - PC . . . . Starting FEMAP . . . . . . Improving Performance (RAM Management) Licensing Conversion Methods . . .

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2. Installing FEMAP

What’s New in FEMAP What’s New for version 10.3

User Interface . . . . . . . . . . Geometry . . . . . . . . . . Meshing . . . . . . . . . . . Elements . . . . . . . . . . . Materials . . . . . . . . . . . Properties . . . . . . . . . . Aeroelasticity - New for 10.3! . . . . . . Loads and Constraints . . . . . . . . Connections (Connection Region, Properties, and Connectors) Groups and Layers . . . . . . . . . Views . . . . . . . . . . . Output and Post-Processing . . . . . . . Geometry Interfaces . . . . . . . . Analysis Program Interfaces . . . . . . . Tools . . . . . . . . . . . OLE/COM API . . . . . . . . . Preferences . . . . . . . . . .

3. Analyzing Buckling for a Bracket Importing the Geometry . . Meshing the Model . . . Applying Constraints and Loads Post-processing the Results .

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4. Analyzing a Beam Model Importing the Geometry . . . Defining the Material and Property Meshing the Model . . . . Applying Constraints and Loads . Analyzing the Model . . . Post-Processing the Results . .

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5. Analyzing a Midsurface Model of an Electrical Box Importing the Geometry . . Creating the Midsurface Model Meshing the Model . . . Applying Loads and Constraints Analyzing the Model . . Post-processing the Results .

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6. Analysis of a Simple Assembly

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TOC-2 Importing the Geometry . . . . . . . Creating Connections . . . . . . . . Applying Loads and Constraints. . . . . . Meshing the Model . . . . . . . . Analyzing the “Glued Contact” Model . . . . Post-processing the Results of “Glued Contact” Analysis . Modifying the Connection Property . . . . . Applying additional Constraints for stability . . . Analyzing the “Linear Contact” Model . . . . Post-processing the Results of “Linear Contact” Analysis.

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1.

Introduction

This section introduces FEMAP and explains how to use the FEMAP Getting Started guide.

Introduction to FEMAP FEMAP is finite element modeling and post-processing software that allows you to perform engineering analyses both quickly and confidently. FEMAP provides the capability to develop sophisticated analyses of stress, temperature, and dynamic performance directly on the desktop. With easy access to CAD and office automation tools, productivity is dramatically improved compared to traditional approaches. FEMAP automatically provides the integration that is necessary to link all aspects of your analysis. FEMAP can be used to create geometry, or you can import CAD geometry. FEMAP provides powerful tools for meshing geometry, as well as applying loads and boundary conditions. You may then use FEMAP to export an input file to over 20 finite element codes. FEMAP can also read the results from the solver program. Once results are obtained in FEMAP, a wide variety of tools are available for visualizing and reporting on your results. With FEMAP you can: •

Import or Create Geometry

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Build a Finite Element Model

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Check Your Model

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Analyze Your Model

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Post-process Results

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Document Results

Import or Create Geometry FEMAP can directly import geometry from your CAD or design system. In fact, FEMAP can directly import a solid model from any ACIS-based or Parasolid-based modeling package. If your modeling package does not use either of these packages, you can use the FEMAP IGES or STEP reader. If you are using I-DEAS, you can bring a single part into FEMAP by exporting a Viewer XML (IDI) file from I-DEAS. These files can be read and then stitched together to form a solid. This typically requires using one command. If you do not have CAD geometry, you can create geometry directly in FEMAP using powerful wireframe and solid modeling tools. Solid modeling directly in FEMAP uses the robust Parasolid modeling engine. You can build or modify solid models using the Parasolid engine, and then export the geometry out of FEMAP. This is very convenient if you need to export geometry to CAD packages that are Parasolid-based.

Build a Finite Element Model Regardless of the origin of your geometry, you can use FEMAP to create a complete finite element model. Meshes can be created by many methods ranging from manual creation, to mapped meshing between keypoints, to fully automatic meshing of curves, surfaces and solids. FEMAP can even work with your existing analysis models. You can import and manipulate these models using the interfaces to any of the supported analysis programs. Appropriate materials and section properties can be created or assigned from FEMAP libraries. Many types of constraint and loading conditions can be applied to represent the design environment. You can apply loads/constraints directly on finite element entities (nodes and elements), or you can apply them to geometry. FEMAP will automatically convert geometric conditions to nodal/elemental values upon translation to your solver program. You may even convert these loads before translation to convince yourself that the loading conditions are appropriate for your model.

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Introduction

Check Your Model At every step of the modeling process, you receive graphical verification of your progress. You need not worry about making a mistake because FEMAP contains a multi-level undo and redo capability. FEMAP also provides extensive tools for checking your model before you analyze it to give you the confidence that you have properly modeled your part. It constantly examines input to prevent errors in the model, and provides immediate visual feedback. FEMAP also provides a comprehensive set of tools to evaluate your finite element model and identify errors that are often not obvious. For example, FEMAP can check for coincident geometry, find improper connections, estimate mass and inertia, evaluate your constraint conditions, and sum your loading conditions. Each of these methods can be used to identify and eliminate potential errors, saving you considerable time and money.

Analyze Your Model When your model is complete, FEMAP provides interface to over 20 popular programs to perform finite element analysis. You can even import a model from one analysis program and automatically convert it to the format for a different analysis program. The NX Nastran for FEMAP solver is a general finite element analysis program for structural and thermal analysis that is integrated with FEMAP.

Post-process Results After your analysis, FEMAP provides both powerful visualization tools that enable you to quickly interpret results, and numerical tools to search, report, and perform further calculations using these results. Deformation plots, contour plots, animations, and XY plots are just some of the post-processing tools available to the FEMAP user. FEMAP supports OpenGL, which provides even more capability for post-processing, including dynamic visualization of contours through solid parts. You can dynamically rotate solid contoured models with one push of your mouse button. Section cuts and isosurfaces can be viewed dynamically by simply moving your cursor.

Document Results Documentation is also a very important factor with any analysis. FEMAP obviously provides direct, high quality printing and plotting of both graphics and text. Frequently, however, graphics or text must be incorporated into a larger report or presentation. FEMAP can export both graphics and text to non-engineering programs with a simple Windows Cut command. You can easily export pictures to popular programs such as Microsoft Word, Microsoft Power Point, and Adobe Framemaker. You can export to spreadsheets, databases, word processors, desktop publishing software, and paint and illustration programs. These links enable you to create and publish a complete report or presentation, all electronically, right on your desktop. With support for AVI files, you can even include an animation directly in your Power Point Presentation or Word document. FEMAP also supports VRML and JPEG format so anyone can easily view results with standard viewers.

Using the Examples in Getting Started

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Using the Examples in Getting Started The FEMAP Getting Started guide is designed to teach new users the basics of using FEMAP. It contains a number of examples that take you step-by-step through the processes for building and using an FEA model.

Working through the Examples As there are many different types of real analysis problems, there are different types of example problems shown here. Generally, you should start with the first example in chapter 3 and work through the examples sequentially. Some of the later examples focus on specific techniques that you may not use in your work (beam modeling, axisymmetric modeling, midsurfacing). However, we recommend that you work through all the problems because they may contain some commands or techniques that you will find useful. •

Analyzing Buckling for a Bracket

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Analyzing a Beam Model

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Analyzing a Midsurface Model of an Electrical Box

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Analysis of a Simple Assembly

The examples in this manual should help you learn the basic FEA modeling process, general FEMAP commands, and the FEMAP command structure. For a more complete description of the FEMAP interface and modeling procedures, see the FEMAP User Guide. For an in-depth description of all the commands in FEMAP, see FEMAP Commands.

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Introduction

Using the Examples In general, italicized text identifies items in the user interface. For example: File, Preferences tells you to pick the File menu, then the Preferences command. The Examples also include some graphics to help you identify user interface (UI) items. They include: UI Graphic

Meaning Pick an option from a cascading menu.

Menu

Pick an item from a pull-down menu on a dialog box.

Pick an item from a list.

Pick an icon.

Enter a value into a field on a dialog box.

Pick a button.

Pick a radio button.

Check an item on or off in a dialog box.

Pick with the left mouse button.

Pick with the right mouse button.

Pick with middle mouse button if you have a three button mouse. Also can be the wheel of a wheel mouse.

Ctrl-A

Hold the Control key, then pick the letter key.

F5 key

Pick the function key.

The FEMAP Documentation Set

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The FEMAP Documentation Set FEMAP comes with a set of three printed manuals: FEMAP Examples, the FEMAP User Guide, and the FEMAP Commands reference manual. The FEMAP online help includes the contents of these manuals, as well as several additional books. The complete set includes: •

FEMAP Examples: Step-by-step examples for new users.

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FEMAP User Guide: General information on how to use FEMAP, including an overview of the finite element modeling process. Also contains reference information for the FEMAP analysis program and geometry interfaces.

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FEMAP Commands: Detailed information on how to use FEMAP commands.

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FEMAP API Reference: Information on how to write your own applications that work with FEMAP.

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What’s New: New features for this release.

When NX Nastran for FEMAP is installed, online help includes all of the above, as well as a full set of current NX Nastran documentation, to assist you during the solving portion of the analysis process.

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Introduction

2.

Installing FEMAP

This section will help you install and start using the FEMAP software. This section contains information specific to getting started on a PC, which includes 32-bit and 64-bit versions of Windows XP, Windows Vista, and Windows 7. A single DVD contains both the 32-bit version and 64-bit version of FEMAP. If you have a 32-bit system, you must install the 32-bit version. If you have a 64-bit system, you can choose to install either version, but will only get the benefits of using a 64-bit system by installing the 64-bit version. Note:

You MUST be logged in with Administrator privileges when installing FEMAP in order for the installation process to work properly.

Hardware/Software Requirements There are no special hardware/software requirements for FEMAP beyond those imposed by Windows operating systems. There are many types of hardware that will allow you to use FEMAP. Proper choice of hardware, however, can often make the difference between frustration and productivity. Here are a few suggestions: •

Memory, RAM

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Memory, (Hard Disk)

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Graphics Boards

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Browser

Memory, RAM You will need at least 128 Mbytes of RAM to run FEMAP and the Parasolid solid modeling engine, which is the default. Obviously, the more amount of RAM the better. Adding RAM can be one of the most cost effective means of increasing performance. If using the “Standard” geometry Engine in FEMAP, you can actually run with as little as 32 Mbytes of RAM. This is not a recommended configuration.

Memory, (Hard Disk) Required hard disk space is very difficult to estimate, but in general you will never have enough. Analysis results will be the main driver of any disk space requirement. Models are typically relatively small. A model with 1000 nodes and 1000 elements would typically be less than 1 Mbyte in size. Output from an analysis of that model, however, could be 5 Mbytes, 10 Mbytes or even larger, depending on the output you request. To estimate total disk space, you need to first estimate how many models you will have online simultaneously, the approximate size of those models, and the type of output you will request.

Graphics Boards Standard graphics adapters work very well with FEMAP. Specialized boards which contain support for OpenGL will provide increased graphical performance when dynamically rotating large, complex models. They also usually provide higher resolution and more colors, which make graphics easier to see and more realistic.

Browser To run the online help, you should have Internet Explorer, version 6.0 or later. Browsers such as Mozilla Firefox may also be used to access the HTML help system.

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Installing FEMAP

Installation - Stand Alone This section describes the procedure that you should follow to install the stand alone (security device) version of FEMAP on your PC. Security Device Computer

FEMAP

In order to run the Stand Alone (Security Device) version of FEMAP a Rainbow SuperPro Parallel Port (pictured on left) or USB Port dongle is required. In order for your PC to be able to see the dongle, a driver must first be installed. Installation of the driver requires Administrator privileges for your PC. During installation, if the current user has Administrator privileges, the installation program will automatically prompt for installation of this driver.

If the installer does not have Administrator privileges, someone with Administrator privileges will have to log in and install the driver manually. The driver installation program can be found in the SentinalDriver directory of the FEMAP CD. On 32-bit and 64-bit Windows platforms, run CD\SentinalDriver\SPI750.exe. It is highly recommended that you do not have any security devices attached to your computer while you are installing the driver. Once the driver has been installed, you can plug a USB security device directly into an open USB port and it should be recognized. For the Parallel Port security device, it is highly recommended that you shut your computer down and turn it off before installing the security device. After it is installed, turn the computer on begin using FEMAP. Printer

Setup Program Execution Windows XP/Vista/7 1. Log in to your computer as Administrator. As detailed above, this will make installation of the driver required to talk to the FEMAP dongle possible. 2. Insert the FEMAP CD into the drive. The setup should automatically begin within a few seconds. If it does not, manually run the SETUP.EXE program in the root directory of the FEMAP DVD. Once setup is running you will see a license agreement. Assuming that you agree with the license agreement, choose “I accept the terms of the license agreement” and press Next to continue and select the directory where you would like to have the FEMAP program files installed. You will be prompted for the selection of additional FEMAP options, please choose any optional modules and components that you wish to have installed.

Setup Program Execution

2-3

Notice that the installation will tell you the amount of disk space required for the chosen options to be installed and how much space is available on the drive where FEMAP will be installed. Note: If you plan on licensing FEMAP with a dongle (security key), not a network license, then you will probably want to UNCHECK the FLEXlm License Manager option as it is not used by the dongle. You will now be asked which type of installation to perform. Choose Nodelocked Dongle as the licensing method.

Setup Type

Description

Nodelocked Dongle

This is by far the most popular setup type used when installing FEMAP. It installs FEMAP for use with a Rainbow Parallel Port or USB dongle. If you have the dongle version of FEMAP, choose this setup type.

Network Client

Network Client Installs the Network Client version of FEMAP. This setup is for use where FEMAP is licensed via the FLEXlm license management software. With the Network Client version of FEMAP, one machine on your network will be designated as the license server. The following "Network License Server" setup will have to be run on that mac

Node-Limited Demo License

Installs the 300-Node demonstration version of FEMAP. This version requires no licensing, but is limited to very small models. It is intended for new users to try FEMAP and all its options.

After choosing Nodelocked Dongle and pressing Next, the program will be installed and then a driver required for the dongle will automatically be installed. Finally, if you are installing FEMAP with the NX Nastran option you will be prompted to specify a “scratch” directory for the solver. You will need to have read/write access to this directory to be able to properly use NX Nastran. FEMAP dongles are shipped good for 30 days from the first time they are run. In order to remove the time limit from your new FEMAP dongle, or upgrade an older dongle or network license, you must contact Siemens Product Lifecycle Management Software Inc. PLM's Global Technical Access Center (GTAC). In order to retrieve your FEMAP upgrade codes or your FLEXlm license file, you will need a GTAC WebKey account.

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Installing FEMAP

Obtaining a Webkey Account from Siemens Product Lifecycle Management Software Inc. To request a WebKey account, access the web page; then provide the following information: https://plmapps.ugs.com/webkey •

Your Installation ID

•

WebKey Access Code

Your Installation ID is directly under the "sold to" information on your shipping order. For dongle-based FEMAP customers, your WebKey Access code is the unique portion of your FEMAP serial number, i.e. 3H-NT-1234, which is displayed in your current FEMAP in the Help - About dialog box, for this license as 1000-3H-NT-1234, with the version information at the beginning of the serial number removed. If you have any problems determining your Installation ID, FEMAP Serial Number, or have trouble getting a WebKey account, please contact: Trish McNamara - [email protected] - 610-458-6508, or Mark Sherman - [email protected] - 610-458-6502

Obtaining Upgrade Codes or a new License File 1. Via the Web, using your WebKey Account -Upgrade codes or an updated license file can be e-mailed to you from the Customer Support (GTAC) web site http://support.ugs.com. Select the "License & Passwords" icon or select the "current license" option under the "License Retrieval" menu from the left side of the main GTAC screen. Select "Femap" as the Product and 10.0 as the Version, and fill in the LM Host with the unique portion of you FEMAP serial number (3H-NT-7878 in this case), or for FLEXlm network licenses, fill in the Ethernet address of your FEMAP license server. Your license will be e-mail to the address supplied during WebKey registration.

2. Via the Phone - You can call GTAC at 714-952-5444 (US and Canada residents may use 800-955-0000) and enter option 1, 1, for your CSR or option 1,2, for Software Product Delivery (SPD). You should then request a copy of the license upgrade for a specific Installation ID and serial number or Ethernet Address. For dongle versions of FEMAP, the information returned to you to upgrade the dongle will be in the form of two case insensitive alpha numeric codes. They will appear something like:

Access Code 1: 08aeca3f0f52639179 Access Code 2: 362ff63c3426d943

Use the Help, About command, then click the Security button. Cut and paste (to avoid errors) or type these two codes in to the appropriate fields and press OK. The FEMAP dongle is an EPROM, and these codes are used to update the memory of the dongle. Once these codes have been entered, you will never need to enter them again, with changes made to the memory of the dongle, they will either be useless, or simply write the same thing to memory again.

Network Installation - PC

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Network Installation - PC The “Network Client” version of FEMAP utilizes the FLEXlm License Manager software from Globetrotter Software Inc. This licensing approach requires some software to be installed on a server machine and other software to be installed on one or more clients. The clients then request and obtain licenses from the server. In a simple situation, both the client and server could be the same computer, but more likely they are different systems connected by a network.

Obtaining a License File License files are obtained through the same procedure as defined above for getting the upgrade codes for a dongle license. Call GTAC, or use your WebKey account to request your FEMAP license file. The only difference in Network Licensed FEMAP is that you need to enter the LMHostID (Ethernet Address) of your license server when prompted instead of the FEMAP Serial Number. When you receive your license file information, you need to extract just the valid FLEXlm license entries, and copy them into a file called "license.dat". Please make sure that your license.dat looks something like the one show below. For FEMAP, you will have one SERVER line, one DAEMON line, and one or more FEATURE lines depending on how many options you have purchased with your FEMAP. A couple of things to make sure of: 1. Make sure that the entry immediately following the word "SERVER" is the name of the license server where you are installing the license server software. If it is a temporary name, i.e. ANY, or THISHOST, change it to the correct machine name. This is one of the two things in the license file that you can change. 2. Make sure that the third entry on the SERVER line matches the LMHostID of license server. This number is the key to the whole license file. If this does not match the LMHostID of the license server, then the licensing will not work. 3. The "DAEMON esplmd" line calls out the actual programs that hands out FEMAP licenses. If you have installed all the license server pieces in the same directory, it is fine as is. If the esplmd.exe program is not in the same directory as LMTOOLS.EXE, you will have to edit this line to tell LMTOOLS.EXE where to find it. This is the other part of a license file that you can change. SERVER PHLF10 00095b8e20ef DAEMON esplmd FEATURE femap esplmd 9.20 18-may-2007 1 0588B50324A5 \ VENDOR_STRING=920-FX-NT-20ef0001762070000 FEATURE femapthermal esplmd 9.20 18-may-2007 1 DBB2754C3B21 \ VENDOR_STRING=920-FX-NT-20ef0001762070000 FEATURE femapadvthermal esplmd 9.20 18-may-2007 1 7033101A44B2 \ VENDOR_STRING=920-FX-NT-20ef0001762070000 FEATURE femapflow esplmd 9.20 18-may-2007 1 0F1D6AB8AE56 \ VENDOR_STRING=920-FX-NT-20ef0001762070000 FEATURE femapnx_nas_basic_fep esplmd 9.20 18-may-2007 1 EE2DC8632354 \ VENDOR_STRING=920-FX-NT-20ef0001762070000 FEATURE femapnx_nas_nonlin_fep esplmd 9.20 18-may-2007 1 861F50768DA3 \ VENDOR_STRING=920-FX-NT-20ef0001762070000 FEATURE femapnx_nas_dyn_fep esplmd 9.20 18-may-2007 1 8ECB283B0927 \ VENDOR_STRING=920-FX-NT-20ef0001762070000

License Server This section provides instructions on installing the network license manager and configuring your server.

Installing the FLEXlm License Manager To begin the server installation, simply insert the FEMAP CD and allow it to AutoRun, or choose setup from the CD. FEMAP will ask which “features” should be installed. If you only want to install the license server, then UNCHECK all the options except “FLEXlm License Manager”. Once FEMAP has installed the software, copy

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Installing FEMAP

your license file (usually called "license.dat") to the same directory where you installed the license server components.

Configuring the FLEXlm License Manager You can run the LMTOOLS program from the FEMAP entry on your start -> All Programs - >FEMAP v10 -> FLEXlm License Manager, or manually run LMTOOLS.EXE from its installed directory.

Once LMTOOLS is running, select the "Config Services" Tab.

Fill in a Service Name, specify a path to the lmgrd.exe file (a required FLEXlm component) that can be found in the installation directory, and specify the path the license file. Finally, check the "Use Services" option, and then the "Start Server at Power Up". Press the "Save Service" button.

Answer "Yes" to:

You must start the license server manually the first time, press the "Start/Stop/Reread" tab.

Configuring the FLEXlm License Manager

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Select the FEMAP service that you just created, and press the "Start Server" button. At this point FLEXlm will be handing out FEMAP licenses on your network. To verify that everything is working fine from the license server standpoint, press the "Server Status" tab.

Press the "Perform Status Enquiry" button and the text window will be filled with status information about your FLEXlm license server. In the text window you will find information about how many licenses are available, and once user start checking out licenses, how many are in use.

2-8

Installing FEMAP

Configuring Network Client Machines Once your network license server is up and running, configuring FEMAP Network Client machines is very easy. Make sure that FEMAP is installed on the local machine using the "Network Client" setup type. To configure client machines to access the network license: You have two options for telling network client machines how to find licenses on the license server: 1. Place a copy of the "license.dat" file in the FEMAP directory on the client machine. FEMAP will extract the name of the license server from the license file, and check out a license and run. The only drawback to this approach is that you must remember to update every copy of the license file when you receive a new one from Siemens PLM Software, Inc. (updates, licensing changes, etc.). To avoid this problem, you can type in the full network path to the License File in the "License File" field used below for HostName/IP Address location of the license server. 2. Tell FEMAP the name or IP address of the License Server. a. Start FEMAP b. Go to Help - About - Security c. In the "License File" field, enter the name of the license server, preceded by an ampersand. In the example below, FEMAP is told to check out licenses from a network machine named PLSRV2: d. In order for this machine name approach to work, the client computer must be able to see the license server computer via TCP/IP networking. To verify this, you can open a Command Prompt and ping the license server. In this case, one would type "ping PHLSRV2". The ping command will let you know if it can talk to the machine name indicated. If the client computer cannot find the license server by its name, you can also enter the IP address of the license server, preceded by an ampersand and licensing should also work.

Monitoring Network Usage In a multi-user environment, sometimes you will not be able to get a license simply because all available licenses are in use. You can find out who is using licenses, which computers they are using and when they started their license simply by going to Help, About, and pressing the Security button. At the bottom of the dialog box you will find information that will give you this information. If you fail to get a license because none are available, you will not be able to work in FEMAP. You do not however, have to leave FEMAP. You can simply stay there and periodically try a command. Whenever a license becomes available it will be assigned to you and your command will succeed. If there are still no licenses available, you will simply get a message that says try again later.

Copying FEMAP from one machine to another In previous versions, the FEMAP directory created from a proper installation could simply be copied from one machine to another, and then with the proper licensing, could be run on the new machine. For FEMAP 9.3.1 and above, there is one additional step which must be done in order for a copied version of FEMAP to be able to run. Note: You must have Administrator privileges on the machine FEMAP is being copied to in order to complete this additional step. Once the FEMAP directory has been copied, you need to go into the directory find an executable file called “vcredist_x86.exe”, then run the executable. This will install a set of Microsoft Compiler Libraries needed for FEMAP 9.3.1 to run properly. On 64-bit operating systems, you will need to run “vcredist_x86.exe” and then run a 64-bit version of the executable called “vcredist_x64.exe”. You need to run both because FEMAP still uses some 32-bit applications in the 64bit versions. For instance, the FEMAP Neutral File translators are all 32-bit applications.

Errors Starting FEMAP

2-9

Errors Starting FEMAP Security Device Not Found Symptom: You see an error indicating that the security device cannot be found. Resolution: Go to Section , "Security Device", and confirm all steps have been followed. Try to run FEMAP again.

Choose Server or File Symptom: If you are attempting to start a network client and see the Error dialog box from FEMAP, FLEXlm cannot find a valid license file. Resolution: Press Cancel in this dialog box. Pick Help, About, Security to define the location of the license file, as instructed above in Section , "Configuring Network Client Machines"

Unable to get license message:

LM_LICENSE_FILE environmental variable error:

This error will ONLY occur when the environment variable LM_LICENSE_FILE has been set. For example, this environment variable may have been set by another application for licensing purposes. Be careful when removing or altering this environment variable as it may cause other applications to no longer function properly.

2-10

Installing FEMAP

Other Error Messages Symptom: If you receive an “Unable to access {directory path}. Either this directory does not exist or you do not have proper permissions. Check the directory and your preferences” error or have any other difficulty starting FEMAP where abnormal termination occurs, you either do not have enough disk space, or your Windows TEMP is not set to a valid, accessible directory. Resolution: You may either change your Windows TEMP directory environment variable, or specify a path for the FEMAP scratch files (which default to the Windows TEMP directory set by the environment variable) to a valid directory. This and all other FEMAP preferences are stored in a file called femap.ini that is typically located in the FEMAP executable directory. You will have to create this file or modify it to include the appropriate lines as shown below: DISKMODELSCR=C:\FEMAP93 where C:\FEMAP93 can be any valid path. The DISKMODELSCR parameter is case sensitive and must be defined exactly as above. Once you make these changes and FEMAP starts, you can use the File, Preferences, Database command to modify this path.

Starting FEMAP There are several command line options to launch FEMAP. The simplest method to launch FEMAP is to create a shortcut for FEMAP on your desktop and double-click the icon when you want to launch FEMAP. This will use the command line contained under the shortcut to launch FEMAP. You can modify this command line by right-clicking on the FEMAP icon, selecting properties, and changing the command line option on the shortcut. The command line will contain the executable (and its path). After the femap.exe, there are several options which may be used to determine the mode in which FEMAP will operate. A list of these command line options are provided below. c:\femap931\femap.exe [-R] [-NEU] [-NOSPL] [-D dxf_file] [-N neu_file] [-PRG program_file] [-SE Solid Edge_File] [-L port] [-SAT sat_file] [-XMT x_t file] [-SCA scale_factor] [-IGES iges_file] [model_file or ?]

where all of the arguments in [ ] are optional command line parameters. They are: The remaining parameters can be specified in any order. -R

Read Only Mode. With this option set, the Save, Save As and Timed Save commands are disabled. You will not be able to save changes to any model you access. All other commands remain active. Any changes you make will be made in the temporary scratch file, and will be lost when you exit FEMAP.

-NEU

Automatically writes a neutral file with the same name (just .NEU extension) as your .modfem file every time you save a model. In addition, when you open a model, if a neutral file exists with a newer date than the model, it will be read.

-NOSPL

Starts FEMAP without the splash screen.

-D dxf_file

This option automatically reads the specified DXF file when you start FEMAP. Make sure you leave at least one space between the two arguments.

-N neu_file

This option automatically reads the specified FEMAP neutral file when you start FEMAP.

-PRG program_file

This option allows you to run a specified FEMAP program file (*.PRO or *.PRG file) when FEMAP is started.

-SE Solid Edge_file

Automatically creates a new FEMAP file and calls the File, Import Geometry command to read the Solid Edge part file (*.prt file) or assembly file (*.asm file). When you use FEMAP with this command option, you will see the Solid Model Read Options dialog box, which will contain the title of the solid model file contained in the SAT file.

Improving Performance (RAM Management)

-L port

2-11

Specifies the parallel port where the FEMAP security device has been installed. This is not typically needed unless FEMAP has difficulty accessing the device. If you want to attach the security device to parallel port 1 (LPT1:), use -L 1, for parallel port 2 (LPT2:) use -L 2. If your system is non-standard, or uses some other parallel port convention, you can specify the actual parallel port address. For example, if your parallel port was at address 03BCH (hexadecimal), you would convert the address to a decimal value, in this case 956, and specify -L 956. If you need to specify the -L option, you can change the default command line associated with the FEMAP icon on the Desktop by selecting Properties. First, right-click on the FEMAP icon. Then choose the File, Properties command (or press Alt+Enter). Move down to the command line option, and just add the appropriate -L options. From then on FEMAP will look for the security device on the specified port.

-SAT sat_file

Automatically creates a new FEMAP file and calls the File, Import Geometry command to read the ACIS solid model file *.SAT file [sat_file]. When you use FEMAP with this command option, you will see the Solid Model Read Options dialog box, which will contain the title of the solid model file contained in the SAT file.

-XMT xmt_file

Automatically creates a new FEMAP file and calls the File, Import, Geometry command to read the Parasolid solid model file *.X_T file [xmt_file]. When you use FEMAP with this command option, you will see the Solid Model Read Options dialog box which will contain the title of the solid model file contained in the X_T file.

-SCA scale_value

This option is used in conjunction with the -XMT and -SAT to specify a scale factor for the solid model. If this option is used, FEMAP will automatically import and scale the solid model. The Solid Model Read Options dialog box will not be shown.

-IGES iges_file

Automatically creates a new FEMAP file and calls the File, Import, Geometry command to read the file [iges_file]. When you use FEMAP with this command option, you will see the IGES Read Options dialog box, where you can specify options for reading the file.

- INI filename

Specify a specific femap.ini file to use. The femap.ini file contains specific options which can be used to customize many aspects of the program, such as a specific set of values for File, Preferences.

model_file

Normally FEMAP will start with a new, unnamed model. If model_file is the filename of an existing model however, FEMAP will start using that model. If the file does not exist, you will see an error message, and FEMAP will start a new model with that name.

?

If you add a question mark to the command line instead of specifying a model name, FEMAP will automatically display the standard file access dialog box and ask you for the name of the model that you want to use. If you want to begin a new model, just press New Model or the Escape key. When you want to work on an existing model, just choose it from the dialog box, or type its name. You should never specify both the ? and model_file options.

Improving Performance (RAM Management) FEMAP determines the amount of available memory a machine and sets it to a default level automatically (20%). FEMAP performance may improve on Windows personal workstations by modifying the default settings that FEMAP uses to manage RAM. To view or change these settings, use the File, Preferences command, then click the “Database” tab.

Database Performance These options control how FEMAP uses your computer’s RAM. Setting these properly can greatly improve performance.

2-12

Installing FEMAP

Database Memory Limit The Database Memory Limit sets the maximum amount of system memory that FEMAP will use to hold parts of your model and results in memory. If your model is larger than the amount of memory that you choose, FEMAP will automatically read data from your disk as it is needed, replacing data that is not being used. While this “Swapping” process can slow down overall performance, it does let you work with much larger models than would otherwise fit into your available memory. The Database Memory Limit DOES NOT control the total amount of memory that FEMAP will be using. FEMAP uses memory for many different operations – this is just one of them. Almost every command temporarily uses some small amount of additional memory. Some commands, like meshing, node merging and reading results can temporarily use fairly significant amounts of memory. Other operations, like loading large amounts of data into the Data Table require memory for a longer period of time – in this case as long as the data is in the table. Finally, the largest use of additional memory, and one which normally persists the entire time you have a model open is for drawing your model. For optimal performance, FEMAP uses OpenGL graphics, and keeps copies of the data to be drawn in memory at all times. You must always have sufficient free memory available for all of these uses, or the operations will not be able to execute properly. In the very worst case scenario, running out of memory could cause FEMAP to crash. It is for this reason that the default Database Memory Limit is set fairly low – 20% of the memory in your computer (The 32-bit version is also restricted by the 2 GByte limit for any program). This does not mean that you can not increase the limit beyond its default, but the further into the yellow and red zones you push the slider, you are increasing the chance of running out of memory. Note:

Changing the Database Memory Limit does not change the amount of memory used for the current session. For this selection to take effect, you must exit and restart FEMAP.

Using the Control The slider control allows you to choose the amount of memory to use for the database. Move the slider to the left to reduce the limit, to the right to increase it. As you move the slider, the memory limit is updated and displayed above the slider. The colored bar below the slider gives you an indication of the risk of running out of memory if you use this setting. The yellow and red regions should be used with caution since there is a good chance of causing problems with other operations like meshing and graphics. The small line along the top edge of the green section indicates the default memory limit. It is simply displayed to make it easy for you to go back to that limit if you try other settings. The blue bar along the bottom edge indicates the amount of memory that the database is currently using. Note:

The blue bar in the above figure shows the amount of memory used by a 1,000,000 element model (4noded plate elements) on a 32-bit machine with 2 GB of RAM. Most potential problems with exceeding the 2 GB memory limit only occur with very large models.

With this option, you are simply setting the maximum amount of memory available for the database. If you are working with a smaller model, FEMAP will not use memory that it does not need and the blue bar will not extend the entire way to the slider setting. If you look at this control with an empty model, or if you have a small model and a large amount of memory in your system, the blue bar may not be visible – because it is too short to be seen along the bar.

Max Cached Label Sets the largest label that FEMAP will reserve memory for. This option must be set to a ID higher than any entity in the model. Default value is 5,000,000 for 32-bit FEMAP and 10,000,000 for 64-bit FEMAP.

Blocks/Page This value sets the “page” size. The optimum setting of this number often depends on the speed of your disk and controller. Note:

The default value of “4” was determined via testing to produce the best performance over a wide range of values for Database Memory Limit and using the default settings for a number of different types of disk drives. You may want to try other values from 1 to 15 if you have changed any speed/caching settings on your drive or have “high-speed” drives to determine if performance is improved.

For more information, see Section 3.4.2, "Improving Performance (RAM Management)" in the FEMAP User Guide.

Licensing Conversion Methods

2-13

Licensing Conversion Methods Please read this section very carefully before changing your licensing method. If you are going to convert your licensing method you MUST HAVE FEMAP AND NX NASTRAN CLOSED (not running) before you use the files described below. You can change your licensing method (i.e., from using a security key to using a network license) using specific “batch” files located in the FEMAP directory. The files are named “go_licensing method”.bat and require minimum user input to change your licensing method. In general, the “go” batch files change your current “auth_102.dll” to use the appropriate licensing method (auth_licensing method.dll) and may create or alter some other required files. FEMAP will open a “command prompt” and let you know if the conversion of the auth_102.dll has been successful. The various “go” files are explained in greater detail below: •

go_apionly.bat - converts your current licensing method to the “API Only” version of FEMAP

•

go_demo.bat - converts your current licensing method to the FEMAP Node-Limited Demonstration version.

•

go_dongle.bat - converts your current licensing method to use a security key.

•

go_network.bat - converts your current licensing method to use the FlexLM Network Client 11.8

•

go_network_11_9_1.bat - converts your current licensing method to use the FlexLM Network Client 11.9.1.. Note:

The default license server for FEMAP 10.3 is FlexLM 11.8. There are some known issues with certain timeout parameters and using FlexLM over a VPN in FlexLM 11.8. Using the FlexLM 11.9.1 Network Client after installing the FlexLM 11.9.1 License Server “may” help in reducing this issues.

2-14

Installing FEMAP

What’s New in FEMAP FEMAP 10.3 includes enhancements and new features, which are detailed below: “User Interface” on page 3 “Geometry” on page 13 “Meshing” on page 13 “Elements” on page 18 “Materials” on page 18 “Properties” on page 18 “Aeroelasticity - New for 10.3!” on page 19 “Loads and Constraints” on page 34 “Connections (Connection Region, Properties, and Connectors)” on page 34 “Groups and Layers” on page 34 “Views” on page 34 “Output and Post-Processing” on page 34 “Geometry Interfaces” on page 34 “Analysis Program Interfaces” on page 35 “Tools” on page 37 “OLE/COM API” on page 37 “Preferences” on page 39

10.3-2

Finite Element Modeling

What’s New for version 10.3

10.3-3

What’s New for version 10.3 User Interface General, Entity Select, Menu, Toolbars, Model Info tree, Data Table, Entity Editor, Data Surface Editor, Meshing Toolbox, PostProcessing Toolbox

General •

Added Filter Title and Clear Title Filter icon buttons to the Load Set, Constraint Set, Group, Layer, View, Solid, and Freebody Manager dialog boxes.

•

Only tabs of entity types which currently exist in the model will be displayed in the View, Visibility dialog box.

•

User created Toolbars will now transfer between versions of FEMAP.

•

Pressing Ctrl+M while in a dialog box field asking for a length will display the Select Curve to Measure dialog box, which will return the selected curves length.

•

Added the Locate Center to the Methods for specifying the a coordinate.

The Locate Center method requires three specified locations which are not colinear to determine a “circle”. The “center” location is then determined by finding the center point of the “circle”. A geometric circular curve is NOT created.

Center of ‘circle’ Location 3 Location 2 Location 1

Entity Select •

Added “on Property” and “on CSys” methods when selecting Coordinate Systems.

•

Added Tools, Toolbars, Aeroelasticity command. See Toolbars section.

•

Added Model, Aeroelasticity... commands (Panel/Body, Property, Spline, and Control Surface) to create the various entities used in Static Aeroelastic analysis and Aerodynamic Flutter analysis. See Aeroelasticity section.

•

Added Mesh, Geometry Preparation command. See Meshing section.

•

Added commands to Modify, Edit..., Modify, Color..., Modify, Layer..., and Modify Renumber... menus for the Aeroelasticity entities (Aero Panel/Body, Aero Property, Aero Spline, and Aero Control Surface).

Menu

10.3-4

Finite Element Modeling

•

Added Modify, Update Other, Aero Interference Group command. Allows modification of IGID on any number of selected Aero Panel/Body entities at the same time.

•

Added List, Output, Force Balance to Data Table and List, Output, Force Balance Interface Load to Data Table commands. Also, updated List, Output, Force Balance and List, Output, Force Balance Interface Load to use Freebody entities. See Freebody tool section.

•

Added commands to Delete, Model... menu to delete the Aeroelasticity entities (Aero Panel/Body, Aero Property, Aero Spline, and Aero Control Surface

•

Added Delete, Output, Freebody command to delete any number of selected Freebody entities.

•

Added Group, Coord Sys, on Property and Group, Coord Sys, on CSys commands to add additional methods to add Coordinate Systems to groups.

•

Added View, Align By, Surface and View, Align By, Normal to Plane commands to align the active view to either the normal of a selected planar surface or the normal of a specified plane, respectively.

Toolbars •

Added Aeroelasticity Toolbar. Contains overall visibility controls (Draw Entity check box) of the Aero Panel, Aero Mesh, Aero Spline, and Aero Control Surfaces options in the Labels, Entities and Color section of the View, Options command.

•

Added Mesh Geometry Preparation icon to Mesh Toolbar. See Meshing section.

Model Info tree •

Added Aero Model branch and underlying branches for Panels/Bodies, Properties, Splines, and Control Surfaces, which allow for creation, copying, editing, listing, and deleting of the various aeroelasticity entities. The color and layer may also be changed.

•

Added Visibility check boxes (on/off) for Aero Model - Planels/Bodies, Splines, and Control Surfaces.

•

Added Compare command to context-sensitive menu for Results. Provides that same functionality as the Model, Output, Compare command for the selected sets.

Data Table •

Added a “Skew” column when using the “Add Element Checks” command.

Entity Editor •

Added “Skew” field to Element Quality section when an element is loaded in the Editor.

Data Surface Editor •

Added “Mapping Tolerance” to the “Options” of the Output Map Data Surface.

When a “Target” location is projected onto the “Source” data surface and the distance to a discrete data point is less than the tolerance, the “Source” value of the "coincident" location is directly mapped to the “Target” without interpolation. If multiple nodes fall within this tolerance, then the first one encountered numerically will be directly mapped. Default value is the "Merge Tolerance" of the "Target” model.

Meshing Toolbox •

Added Add Surface Mesh Point check box to Feature Removal tool (Feature Type = “Loops” only). Will create a point at the “center” of the “loop”, then use that point as a “mesh point” on the surface. See Section 5.1.2.9, "Mesh, Mesh Control, Mesh Points on Surface..." for more information.

•

Performance improvements to Propagate by Mapped Approach option in Mesh Sizing tool. Also, if no “mesh sizing exists on a curve, now the number of nodes attached is used for the initial mesh sizing.

PostProcessing Toolbox •

Added Freebody tool to all facets of Freebody display post-processing.

PostProcessing Toolbox

10.3-5

The Freebody tool is the gateway to using freebody diagrams for post-processing. The freebody display can be performed at any time, whether you are showing a deformed and contour plot, or a simple undeformed plot. The “type” of freebody display, the output set and contributions used in the calculations, and many view options for freebody entities are all controlled via this tool. In order to use the Freebody tool fully, the “Grid Point Force” and “Grid Point Moment” results must have been recovered from Nastran. This is done in FEMAP by selecting the “Force Balance” option in the Nastran Output Requests dialog box found in the Analysis Set Manager. See Section 4.10.1.5, "Output Requests" for more information. Visibility icon button Freebody Manager icon button

A Freebody entity must be created before any additional options may be specified. To do this, use the Freebody Manager, which is accessed by pressing the Add Freebody icon button next to the drop-down list next to Freebody in the Freebody Properties section. Multiple Freebody entities may be created. Once Freebody entities have been created, each may be made visible or hidden individually in all views using the Is Visible check box in the Freebody Properties section or the check boxes in the Freebody tab of the Visibility dialog box (see Section 6.1.4, "View, Visibility..."). The “...” icon button next to Display Freebodies will give direct access to the Visibility dialog box with the Freebody tab selected. Options - Freebody tool The Freebody tool is divided into 3 sections. The top of the Freebody tool contains 3 options which affect all Freebody entities in a View. The options in the Freebody Properties section changes based on which Freebody entity is selected with the Freebody drop-down list. Options in View Properties section change depending on which View is currently active in the model. The three options at the top of the Freebody tool are used to control the overall visibility of all Freebody entities (Display Freebodies), which Output Set will be used to create the freebody display, and if data should be summed at nodes (Sum Data on Nodes). The arrow icons can be used to go to the Next or Previous output set or the Select Output Set icon button can be used to access the Select Output Set dialog box. See Select Output Set and Select Output Vector dialog boxes section for more information. When Sum Data On Nodes is on, the grid point force and moment data from all element corners attached to that node will be summed at each node. When off, the individual grid point forces and moments will be displayed at each element corner along with the element ID next to the value in parentheses.

Freebody Properties Freebody - This drop-down is used to select which options are currently available for use in the Freebody Properties section. To create a new Freebody entity or edit an existing one, click the Add Freebody icon button to access the Freebody Manager.

10.3-6 •

Finite Element Modeling

Freebody Manager - Used to create, edit, renumber, copy, and delete Freebody entities.

Title Filter

Clear Title Filter

New Freebody - When clicked, the New Freebody dialog box will appear.

In this dialog box, specify an ID and Title (optional) along with some “top-level” options for the new Freebody entity, such as Display Mode , Vector Display Freebody Contributions, and Load Components in Total Summation. These options will be described later in this section Update Title - Highlight a Freebody entity in Available Freebodies list, then click this button to enter a new Title. Renumber - Highlight a Freebody entity in Available Freebodies list, then click this button to change the ID. Delete - Highlight a Freebody entity in Available Freebodies list, then click this button to delete it from the model. Delete All - Deletes all Freebody entities in the model. Copy - Highlight a Freebody entity in Available Freebodies list, then click this button to make a copy. None Active - When clicked, there is no longer an “Active” Freebody entity.

PostProcessing Toolbox

10.3-7

Default Settings - When clicked, the following options are set: Display Mode: “Freebody Only” Vector Display: “Nodal Forces” displayed as Components, “Nodal Moments” Off Freebody Contributions: “Applied”, “Reaction”, “MultiPoint Reaction”, and “Peripheral Elements” On, “Freebody Elements” and “Nodal Summation” Off. More - Click this button to create another new Freebody entity. Freebody Tools - This section contains four icon buttons used for sending the data used in the calculations to create the freebody display to the Messages window or the Data Table.

Freebody to Messages Freebody to Data Table

•

Summation to Data Table Summation to Messages

List Freebody to Messages Window - Lists all contributions used to create the display of the Freebody entity currently selected in the Freebody tool to the Messages window. ID is the node ID where the Nodal Force and Nodal Moment vectors are being calculated and Source is the Element ID which is providing the force and moment contributions.

10.3-8

Finite Element Modeling

•

List Freebody to Data Table - Reports all contributions used to create the display of the Freebody entity currently selected in the Freebody tool to the Data Table. The ID is the node ID where the Nodal Force and Nodal Moment vectors are being calculated and Source is the Element ID which is providing the force and moment contributions

•

List Freebody Summation to Messages Window (Display Mode set to “Interface Load” only) - Lists all contributions used to create the display of the Total Summation Vector for the Freebody entity currently selected in the Freebody tool to the Messages window. The “Header” above the listing contains information about the “Components included in summation”, “Contributions included in the summation”, and “location” of the summation. The (F) and (P) designators in the listings indicate contributions from Freebody Elements (F) and contributions from Peripheral Elements (P). The d1, d2, and d3 fields represent the distance from the X, Y, and Z location of the node (Node ID) to the location where the summation is taking place

PostProcessing Toolbox •

10.3-9

List Freebody Summation to Data Table (Display Mode set to “Interface Load” only) - Reports all the same information as List Freebody Summation to Messages Window, but sends it to the Data Table. One difference is that the “Header” information is still sent to the Messages window, as there is no logical place to report this information in the Data Table.

Is Visible - When On, the Freebody entity currently in the Freebody drop-down will be visible in the graphics window in all views. Display of Freebody entities may also be controlled via the Freebody tab of the Visibility dialog box. Coordinate System - Drop-down list specifies which coordinate system should be used to display the freebody vectors. You can create a new coordinate system by using the New Coord Sys icon button. Display Mode - Each Freebody entity can be displayed in two different modes, Freebody or Interface Load. •

Freebody - Only Freebody Elements may be selected in the Entities section and only the vectors in the Nodal Vector(s) section can be displayed and controlled.

•

Interface Load - Both Freebody Nodes and Freebody Elements must be selected in the Entities section and vectors in both the Nodal Vector(s) and the Total Summation Vector sections can be displayed and controlled. Additionally, a Location must be selected when using this option.

Note: Only entities which can be displayed and controlled by the selected Display Type will be available in the Freebody Entity Colors section, while setting the View Properties for all the different freebody vector types and nodes markers is available at all times. Entities - Allows you to specify which Freebody Elements (Display Mode = “Freebody”) or Freebody Nodes and Freebody Elements (Display Mode = “Interface Load”) are used by a Freebody entity. Based on the Entity Selection Mode, elements and nodes may be selected for the Freebody entity directly or by using a pre-defined group. •

Entity Selection Mode - When set to Entity Select, elements and nodes are selected, highlighted in the graphics widow, or deleted from the Freebody entity using the icon buttons below. An additional icon button exists for placing the summation location at the center of the selected nodes. Display Mode = Freebody

Select Elements for Freebody

Display Mode = Interface Load

Delete Elements from Freebody

Highlight Elements in Freebody

Select Nodes for Interface Load Highlight Selected Nodes for Interface Load

Place Summation point at center of Selected Nodes Delete Elements from Freebody

When set to Group Select, elements and nodes are determined by selecting a group from the Group drop-down list. If Group is set to “-1..Active”, then the elements will be retrieved from the Active group in the model. The Group Manager dialog box may also be accessed by the icon button next to the Group drop-down (see Section 6.4.3.1, "Group, Create/Manage..." for more information). Total Summation Vector (Display Mode set to “Interface Load” only) - Allows you to specify the Location of the Total Force Vector and Total Moment Vector, along with how these vectors are displayed and what components will be summed to create these vectors. •

Location - Allows you to specify the location of summation for the Total Summation Vector. Click the icon button next to location to pick a location from the graphics window. Additionally, the individual coordinates may be entered or edited below the Location, when expanded.

10.3-10

Finite Element Modeling

When nodes are selected in the Entities section, the user will be prompted to answer the following question: Auto-locate total summation vector at center of freebody nodes (“X-coordinate”, “Y-coordinate”, “Z-coordinate” in coordinate system “ID of Coordinate System specified in Freebody Properties”)? If you click Yes, the Location will be specified at the center of the selected nodes. If you click No, the Location will be at (0.0, 0.0, 0.0) or the Location last used by the Freebody entity currently in the Freebody tool. •

Force Vector Display - This option controls how the “Force vector” (single arrow head) of the Total Summation Vector will be displayed. When set to “Off”, the force vector will be not be displayed. When set to “Display Components”, the force vector will be displayed in X, Y, and/or Z Components (individual components may be toggled on/off using the FX, FY, and FZ check boxes for Displayed Forces). When set to “Display Resultant”, the force vector will be displayed as a single resultant vector based on the components currently “on” in Displayed Forces.

•

Moment Vector Display - This option controls how the “Moment vector” (double arrow head) of the Total Summation Vector will be displayed. When set to “Off”, the moment vector will be not be displayed. When set to “Display Components”, the moment vector will be displayed in X, Y, and/or Z Components (individual components may be toggled on/off using the MX, MY, and MZ check boxes for Displayed Moments). When set to “Display Resultant”, the moment vector will be displayed as a single resultant vector based on the components currently “on” in Displayed Moments.

•

Summed Components - This option controls which Force and Moment components will be used to calculate the Total Summation Vector. Turning individual Force components on/off is also very likely to affect the Moment values, so keep that in mind.

Following figures show the Total Summation Vector. Freebody Node Markers are “On”, Node Vector(s) not displayed, Element Transparency set to 75%, and Element Shrink View Option is “On”.

Display Mode = Interface Load Total Summation Vector Force and Moment set to “Display Resultant”

Display Mode = Interface Load Total Summation Vector Force set to “Off” and Moment set to “Display Components”

Nodal Vector(s) - Allows you to control how the Force and Moment vectors are displayed at each node (Sum Data on Nodes in View Properties section “On”) or each “element corner” (Sum Data on Nodes “Off”). •

Force Vector Display - This option controls how the “Force vectors” (single arrow head) are displayed. When set to “Off”, the force vectors will be not be displayed. When set to “Display Components”, the force vector at each node/element corner will be displayed in X, Y, and/or Z Components (individual components may be tog-

PostProcessing Toolbox

10.3-11

gled on/off using the FX, FY, and FZ check boxes for Displayed Forces). When set to “Display Resultant”, the force vector at each node/element corner will be displayed as a single resultant vector based on the components currently “on” in Displayed Forces. •

Moment Vector Display - This option controls how the “Moment vectors” (double arrow head) are displayed. When set to “Off”, the moment vectors will be not be displayed. When set to “Display Components”, the moment vector at each node/element corner will be displayed in X, Y, and/or Z Components (individual components may be toggled on/off using the MX, MY, and MZ check boxes for Displayed Moments). When set to “Display Resultant”, the moment vector at each node/element corner will be displayed as a single resultant vector based on the components currently “on” in Displayed Moments..

When Sum Data on Nodes is “On”, the Nodal Vector(s) will be at each node:

Display Mode = Freebody Nodal Vector(s): Force Set to “Display Components”, Moment set to “Off”

Display Mode = Freebody Nodal Vector(s): Force Set to “Off”, Moment set to “Display Resultant”

When Sum Data on Nodes is “Off”, the Nodal Vector(s) at each element corner will include the Element ID

Forces shown using “Display Components” at “element corners”

Moments shown using “Display Components” at “element corners”

Freebody Contributions From - Allows you to control the calculation of the Freebody entity by choosing which contributions should be included. Available contributions are from Applied Loads, from Reaction Forces and Moments at single point constraints and/or constraint equations, from the selected elements (Freebody Elements), and from the elements surrounding the Freebody Elements (Peripheral Elements). Toggling various options on/off can drastically alter the values and appearance of a Freebody entity, so be sure to have the proper contributions included for your particular needs. •

Applied - When On, includes contributions from all loads applied to the model used to produce the results in the selected Output Set.

•

Reaction - When On, includes contributions from all reaction forces and moments at single point constraints in the model used to produce the results in the selected Output Set.

•

MultiPoint Reaction - When On, includes contributions from all reaction forces and moments from constraint equations, rigid elements, and interpolation elements in the model used to produce the results in the selected Output Set.

10.3-12

Finite Element Modeling

•

Peripheral Elements - When On, includes grid point force and moment contributions from the selected Output Set for the elements surrounding the Freebody Elements selected in Entities section.

•

Freebody Elements - When On, includes grid point force and moment contributions from the selected Output Set for the elements selected in Entities section.

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Nodal Summation - When On, includes force and moment contributions from nodal summation. Typically, these are very small numbers, unless there is a “non-balanced” force or moment in the model.

Contributions = Applied, Reaction, and Peripheral Elements Freebody Elements = 75% Transparent in figure Sum Data on Nodes = On, Freebody Node Markers = On

Contributions = Applied, Reaction, and Freebody Elements Peripheral Elements = 75% Transparent in figure Sum Data on Nodes = Off, Freebody Node Markers = On

Freebody Entity Colors - Allows you to specify colors for Node Marker(s), Total Force Vector, Total Moment Vector, Nodal Force Vector(s), and/or Nodal Moment Vector(s) for each Freebody entity. Click the icon button to select a color from the Color Palette. These colors will only be used when the “Color Mode” for any of these items is set to “Freebody Entity Color” in the View Properties section of the Freebody tool or via the Freebody... options in the View Options dialog box, PostProcessing category (See Section 8.3.25, "Freebody options"). View Properties The View Properties control the visibility, style, color, and labeling for Freebody display. Each view in the model can have different options set in the section. When a different view is activated, the values from that view will fill the View Properties section. Show Node Markers - controls the visibility, symbol size, and color of the “node markers” for Freebody entities. Having the node markers visible is a good way to visually inspect the nodes or element corners being used in the freebody calculations. The Symbol Size can be entered directly or increased/decreased using the “slider bar”. When Color Mode is set to “Freebody Entity Color”, the node markers will use the color specified for Freebody Node Marker(s) in the Freebody Properties section. Vector Options - controls the Label Mode, Length, and Label Format of the Freebody vectors. Label Mode allows you to display No Labels, the Value of each freebody vector, or the value using exponents. For Label Format, the number of digits may be entered directly or increased/decreased using the “slider bar”. This will chance the number of significant digits being displayed. When Label Format is set to “0”, this is an “automatic mode” and FEMAP will determine the number of significant digits to display. When Adjust Length is “off”, the length of each freebody vector “type” is controlled by a combination of the entered Length value and the Factor value entered for the Freebody Total Force, Freebody Total Moment, Freebody Nodal Force, and Freebody Nodal Moment view options. When Adjust Length is “on”, the length of the freebody vectors will be adjusted based on the vector’s value (i.e., larger values = longer vectors). The Units/Length value is an additional parameter used to control the length of the vectors when in this mode. Essentially, the Units/Length value is used in the following manner: If Units/Length value is 250, then a freebody vector value of 500 would be shown using a length of “2*Factor” on the screen. For the same freebody vector value of 500, entering a Units/Length value of 100 would display the vector using a length of “5*Factor” on the screen. Min Vector Magnitude - allows you to set a tolerance below which the vectors are not displayed. Using the default value of 1.0E-8, this option will basically remove vectors from the display that are not zero just due to numerical round-off. The value can also be used as a cut-off value, so if it is set to 10, only vector values above 10 will be displayed.

Geometry

10.3-13

Total Force Vector/Total Moment Vector - controls the Vector Style, Color Mode, and Factor for the Total Summation Force and Moment vectors. The Total Summation vectors are only visible when the Display Mode of a Freebody entity is set to “Interface Load”. When Vector Style is set to Arrow or Center Arrow, the vectors will be displayed as lines. When set to Solid Arrow or Center Solid Arrow, the vectors will be “thicker, filled-in solids”. Factor is an additional scale factor which can be entered to change the size of the selected vector type. When Color Mode is set to Freebody Entity Color, the “Freebody Entity Colors” specified for each Freebody entity in the Freebody tool is used. This allows multiple Freebody entities to be displayed at one time using unique colors for clarity. RGB Color uses Red to display the X component, Green for the Y component, and Blue for the Z component of each vector. Nodal Force Vector/Nodal Moment Vector - offers the same options as Freebody Total Force/Freebody Total Moment, but these options control the Nodal Vector(s). One difference is in Color Mode, where an additional option, Source Color exists. When set to Source Color, this selected vector type uses the color of the “source” elements, the color of the load for Applied loads, and/or the color of the constraint for Reaction forces and moments. When the Sum Data on Nodes option is “on” and Source Color is selected, the View Color will be used.

Geometry •

Enhanced Geometry, Solid, Embed to allow embedding of multiple solids into the base solid all at once.

Meshing •

Enhanced “Suppress Short Edges” option in Mesh, Mesh Sizing, Size on Surface and Mesh, Mesh Sizing, Size on Solid to be a percentage of Mesh Size instead of a percentage of “average curve length” on selected geometry.

•

Added Mesh, Geometry Preparation command

This command uses a set of parameters to find situations in geometry which typically result in poor element quality, then uses a combination of automatic curve/surface splitting, creation of Combined Curves/Boundary Surfaces, and feature suppression to likely improve mesh quality. In addition, this command will “prepare” some parts to a degree which will allow FEMAP to successfully mesh the part. Note: If FEMAP is successful when meshing a solid with acceptable mesh quality for your application, then using “Mesh, Geometry Preparation” is probably not necessary. Also, please be aware when using this process, it is quite common for certain small features to be ignored or removed completely. In most cases, this automatic process will be all that is need to produce a good quality mesh. However, even if it cannot fully automatically produce an acceptable mesh, it will still provide a good starting point for using the other interactive geometry cleanup tools, and greatly reduce the amount of work required.

Note: It is recommended to use the “Mesh, Geometry Preparation” command BEFORE manually creating additional Combined Curves /Boundary Surfaces for meshing purposes. Surfaces and Curves which have loads or boundary conditions applied will be ignored. By default, the command goes through two steps, Prepare Geometry and Mesh Sizing. You can choose to skip either step by simply un-checking the box next to Prepare Geometry or Mesh Sizing. The value for size shown for

10.3-14

Finite Element Modeling

both Prepare Geometry and Mesh Sizing is the “Default Mesh Size” calculated by FEMAP (uses the same algorithm as "Mesh, Geometry, Solids"). Prepare Geometry The value for Prepare Geometry is simply used as a baseline value for the various Prepare Options. Therefore, it is typically a good idea to change the Prepare Geometry value instead of the individual Prepare Options values. Prepare Options button Opens the Geometry Preparation Options dialog box. In general, the "Prepare Geometry" process has been developed to function most effectively using the default values in the "Maximum Sizes and Angles" section and all of the "Preparation Options" set to "on", except "Combine Small Surfaces". These values should only be changed and/or options turned off if you run into a problem.

Surfaces, Curves and Points to Ignore - allows you to choose a group containing Surfaces, Curves, and/or Points to exclude from the "Prepare Geometry" process. Maximum Sizes and Angles - allows you to specify “percentage of prepare size” and angle tolerances to help control the “Prepare Geometry” process. There are 5 values to set: •

Narrow Region Factor (default = 10%) - If distance between two locations on a region of a surface is less than n% of "Prepare Size", the surface will be split. The locations where distance is checked are automatically determined by faceting the curves based on a percentage of "Prepare Size" (the faceting percentage cannot be changed by the user).

For example, this simple part has a “narrow region”. Without going through the “Prepare Geometry” process, the worst elements in the resulting mesh have a “Tet Collapse Ratio” of 16.437 and a “Jacobian” of 0.8386167..

Meshing

10.3-15

Zoomed-in view of “narrow region” at the corner of the part:

After the “Prepare Geometry” process using the defaults, the “narrow region” has been split from the original surface, then combined with surfaces from the “base”. Also, two short curves at the split locations have been suppressed. Finally, 2 Combined Curves have been created to allow larger elements in an area that used to be restricted by the “narrow region” Worst elements now have “Tet Collapse Ratio” of 5.67 and “Jacobian” of 0.694 .

Close-up of “narrow region” split “Split Curve” is suppressed

Close-up of Combined Curve and Boundary Surfaces at Corner

10.3-16

Finite Element Modeling

A surface which has a “narrow region” that connects two other larger regions is also a good candidate for splitting, then combination to other surfaces. A surface may be split multiple times if needed to isolate the “narrow region”.

Before “Prepare Geometry” process When meshed, Worst Tet Collapse = 15.72 Worst Jacobian = 0.793

After “Prepare Geometry” process When meshed, Worst Tet Collapse = 4.642 Worst Jacobian = 0.458

•

Curve Suppression Factor (default = 5%)- If curve is less than n% of "Prepare Size", it will be suppressed. Also, if all curves on a surface are less than n% of "Prepare Size", the surface will also be suppressed and the surface "collapsed to a single point".

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Narrow Angle (default = 15 degrees) - If a surface has a narrow region, but the tangent vectors of the bounding curves at the locations where the "narrowness" occurs are not within this value, then the split will not occur. See description of "Detect Close Points" in the "Preparation Options" section for some exceptions.

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Feature Edge Angle (default = 15 degrees) - If angle of a feature is more than this value, then the "Prepare Geometry" process will look for other surfaces which are not above this threshold to combine with surfaces which will benefit from being combined. If no other suitable surface can be located, then surfaces which are over this value may still be combined when needed.

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Combined Curve Angle (default = 30 degrees) - If angle if larger than this value, curves will not be combined. Unlike combining curves via the Meshing Toolbox, which has the option to create boundary surfaces while creating combined curves, this command only deals with combined curves. This is because the surfaces to combine have already been determined earlier in the "Prepare Geometry" process.

Preparation Options - allows you to toggle 6 different options of the “Prepare Geometry” process on/off. •

Geometry Cleanup - When on, applies a subset of options found in the "Geometry, Solid, Cleanup" command to attempt cleanup of any numerical issues which may exist in the geometry. Many times, these types of issues arise during translation of the geometry.

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Detect Close Points - When on, detects when a point between two bounding curves of a surface is very close to a location on a third bounding curve on the surface (i.e., "knife edge"), then splits the surface at these locations and suppresses the "split curve". Using the default values for "Narrow Region Factor" and "Narrow Angle", this case would be ignored.

For example, the angles of the curves at the “narrow region” location on the part below are not within the “Narrow Angle” tolerance value. If “Detect Close Points” is “off”, this portion of the geometry will not be “prepared”..

“Detect Close Points” Set to “Off” Nothing split or suppressed

“Detect Close Points” Set to “On” Surface split and “split line” suppressed

Meshing

10.3-17

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Cut Slivers - When on, will review all surfaces considered "slivers" and determine if they should be "cut" again to allow for more effective combining with adjacent surfaces.

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Process Blends - When on, attempts to combine small fillet surfaces in a "fillet chain" to larger surfaces in the "fillet chain" to create Boundary Surfaces in hopes of creating a better surface mesh.

For example, this simple part has a “fillet chain” with a small surface near larger surfaces:

Before “Prepare Geometry” process

After “Prepare Geometry” process Smaller fillet surface combined to larger surface in “Fillet chain”

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Combine Small Surfaces - In many cases, suppressing very small surfaces entirely is a better option, therefore this option is off by default. When on, attempts to combine very small surfaces to surrounding surfaces instead of suppressing them.

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Delete Previous Mesh - When on, deletes any existing surface and/or solid mesh currently on the solid which was selected for the "Prepare Geometry" process.

Mesh Sizing and Sizing Options button The value for Mesh Sizing and the options found when the Sizing Options button is pressed are mostly the same as options found in the "Mesh, Mesh Control, Size on Solid" command (see Section 5.1.2.4, “Mesh, Mesh Control, Size on Surface...”). The one exception is that Max Size of Small Feature is entered as a percentage of the Mesh Sizing value entered in the Geometry Preparation and Sizing dialog box instead of being entered as an actual value. Interior Growth Factor Same as Growth Factor in the “Surfaced Interior Mesh Growth” section of the "Mesh, Mesh Control, Surface" and "Mesh, Mesh Control, Solid" (see Section 5.1.2.4, “Mesh, Mesh Control, Size on Surface...”). Value (1.0 by default) may be changed using the slider bar or by manually typing in a value (must be between 1.0 and 10.0). Sync Prepare and Size When on (default), the values for Prepare Geometry and Mesh Sizing will change at the same time to the same value when the slider is moved left or right or the value is entered manually into either field. Suppress Internal Voids When on (default), suppress any volumes which are completely contained within the solid (for example, a cube with an internal sphere). Note: There is no "limiting size" on an internal void, so if you have a mostly hollow structure (i.e., pressure vessel or fully enclosed tank), and this option is on, the entire “internal void” will be suppressed. Remove Combined Curves/Surfaces When on (default after “Mesh, Geometry Preparation” command has been used once), will remove Combined Curves/Boundary Surfaces on the geometry currently selected before starting the "Prepare Geometry" process. Sizing Type Same as "Sizing Type" of the "Mesh, Mesh Control, Surface" and "Mesh, Mesh Control, Solid" commands (see Section 5.1.2.4, “Mesh, Mesh Control, Size on Surface...”). "2..Parametric/Equal Length" is the default. Remove Previous button Removes all Combined Curves/Boundary Surfaces, along with any "surface splits" created by the most recent use of the "Mesh, Geometry Preparation" command on the selected geometry. Exits the command after completion.

10.3-18 •

Finite Element Modeling

Added Improve Collapsed Tets option to the Solid Automeshing Options dialog box of the Mesh, Geometry, Solid command, which is accessed by click the Options button.

When this option is “on” (default), the mesher will locate elements with a “Tet Collapse Ratio” higher than the specified value (default is 100), then attempt to improve the mesh quality by moving “internal nodes” to new locations. Once the nodes have been moved, the new “triangular seed mesh” is sent through the tet mesher again. •

Renamed the Length Based Sizing option in the Mesh, Mesh Control, Size on Surface and Mesh, Mesh Control, Size on Solid commands to Sizing Type and added the “2..Parametric/Equal Length” option, which is also now the default.

When this option is set to “0..Parametric”, all sizing along curves is done in the parametric space of the curves. In many cases this is desirable resulting in a finer mesh in areas of high curvature. In some cases however - with unstitched geometry, or geometry that has curves with unusual parameterization - “1..Equal Length” spacing along the curves will yield much better results. Especially when dealing with unstitched geometry, “equal length” spacing will produce meshes with matching nodal locations far more reliably than “parametric” spacing. The default is "2..Parametric/Equal Length", which sizes all curves using the "Parametric" option, then determines an "average distance" between each of the "mesh locations" on each curve. If the distance between any of the mesh locations is more than 1% different than the "average distance", then that curve is resized using "Equal Length" sizing. •

Improved the Surface Interior Mesh Growth option in the Mesh, Mesh Control, Size on Surface and Mesh, Mesh Control, Size on Solid commands to allow mapped meshing on surface where it was applied. Previously, mapped meshing was not available on these surfaces.

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Improved Mesh, Mesh Control, Custom Size Along Curve command to remove the limitation on number of custom points which can be assigned.

Elements •

Updated the Spring/Damper element to use the Type, either CBUSH or Other (NASTRAN CROD/CVISC), specified on the Property referenced by the element to determine if a CBUSH or a combination of CROD and/or CVISC elements will be exported to Nastran. Formally, this was done by setting the element formulation. Also, the Define Spring/Damper Element dialog box will now change to show the appropriate inputs based on the Type of the referenced Property. Finally, CBUSH elements will now use a circular symbol for display, while Other (NASTRAN CROD/CVISC) elements will use a rectangular symbol.

Materials •

Added Mullins Effect (MATHEM) and Viscoelastic Effect (MATHEV) support for NX Nastran Hyperelastic materials fpr SOL 601/701 in Other Types. The additional options are accessed using the Next button when defining Mooney-Rivlin, Hyperfoam, Ogden, Arruda-Boyce, or Sussman-Bathe types.

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Added Viscoelasitc Material (MATVE) in Other Types for NX Nastran SOL 601.

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Added NITONAL material type in Other Types for NEi Nastran..

Properties •

Added Mean Dilatational Formulation option to Plane Strain Property. This option is for NX Nastran only and is for properties which do not reference a hyperelastic material for Plane Strain or Plane Stress Elements. The formulation of the elements also must be set to “1..CPLSTN3, CPLSTN4, CPLSTN6, CPLSTN8” (Plane Strain) or “2..CPLSTS3, CPLSTS4, CPLSTS6, CPLSTS8” (Plane Stress) in order to export this property type. The “Mean Dilatational Formulation” switch on the property may be used for nearly incompressible materials, but is ignored for SOL 601. Also, Nonstructural mass/are is ignored for SOL 601.

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Added Type in Spring/Damper Property to define if the elements referencing this Property are CBUSH elements or a combination of CROD and/or CVISC elements when exporting to Nastran.

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Added support for NEi Nastran Failure Theories, Max Stress (STRESS), NASA LaRC (LAERC02), Puck PCP (PUCK), and Multicontinium (MCT), on Laminate Property.

Aeroelasticity - New for 10.3!

10.3-19

Aeroelasticity - New for 10.3! The commands under the Model, Aeroelasticity menu are used to create entities required to perform Static Aeroelastic analysis (SOL 144) and Aerodynamic Flutter analysis (SOL 145) with Nastran solvers. An underlying finite element model is also needed to properly run an aeroelastic analysis. Typically, this underlaying “structural model” consists of only beam and/or shell elements. There are 4 different types of aeroelastic entities supported for Nastran: •

Aero Panel/Body

•

Aero Property

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Aero Splines

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Aero Control Surfaces

The various “Aero entities” interact with one another in several ways. Every Aero Panel/Body is required to have an appropriate Aero Property assigned. Several Aero Panels/Bodies may reference the same Aero Property. Next, each Aero Spline must reference an Aero Panel/Body and a group of “structural” nodes in the model. The Aero Spline entities connect the “aeroelastic model” to the underlying “structural model”. Any number of “aerodynamic boxes” (Aero Mesh) may be selected from the referenced Aero Panel/Body. Finally, each Aero Control Surface needs to reference at least one “aerodynamic box” (Aero Mesh) on an Aero Panel/Body set to “Aero Panel”. Once all the Aero entities have been defined, additional options for Static Aeroelasticity and Aerodynamic Flutter will need to be set using the Analysis Set Manager.

Model, Aeroelasticity, Panel/Body... ...creates an Aero Panel or Aero Body (Slender Body and/or Interference Body). The dialog box changes depending on what is specified for Aero Body Type. When Aero Body Type is set to “0..Aero Panel (CAERO1)”, then FEMAP is making an “Aero Panel”, which will be written to Nastran as a CAERO1 entry. When Aero Body Type is set to “1..Aero Body (CAERO2)”, then FEMAP is making a “Slender/Interference Body”, which will be written to Nastran as a CAERO2 entry. Each Aero Body Type contains different inputs, will be discussed in greater detail later. The ID, Title, Color, Layer, and Property fields are common to both Aero Body Types, as well as the Orientation CSys and IGID fields in the Options section. Note: The ID value for Aero Panel will increment by 1000 automatically. This is due to to the fact that each Aero Panel/Body has a Mesh Control section which defines the “Aero Mesh” (Number Chord * Number Span for an “Aero Panel”, Number of Body Elements for “Aero Slender Body”) and each “Aero Element” must have a unique ID. FEMAP numbers the “Aero Mesh” using the Aero Panel/ Body ID as a prefix. For example, an “Aero Panel” with ID of 2000 has Number Chord set to 10 and Number Span set to 5 for a total of 50 “Aero Elements”. They are numbered 2000 to 2049 for this Aero Panel. Select an existing Aero Property from the Property drop-down. The Type on the Areo Property must correspond to the Aero Body Type on Aero Panel/Body (i.e., Type must be “Aero Body (PAERO2)” on the Aero Property used by an Aero Panel/Body with Aero Body Type set to “1..Aero Body (CAERO2)”). If an Aero Property does not currently exist, click the Create Aero Property icon button to create one “on-the fly”. Orientation CSys is used to orient the locations of Point 1 and Point 4 (Aero Panel Only) and is written to the CP field of the CAEROi entry, while IGID designates the “Interference Group ID” and writes out the IGID field to CAEROi entry (aerodynamic elements with different IGIDs are uncoupled). Note: To change the IGID value on multiple Aero Panel/Body entities all at once, use the Modify, Update Other, Aero Interference Group command.

10.3-20

Finite Element Modeling

Aero Body Type = “0..Aero Panel (CAERO1)” This Aero Body Type will create an “Aero Panel”. The values represent two “leading edge” locations and the length of two “side chords”. The number of divisions for “chord” and “span” are also entered to define the “Aero Mesh”. Typically, the panel will have 4 corners, but can have 3 by setting the length of one “side chord ” to 0.0.

Surface Point 1 - XYZ values of the first “leading edge” location in the Orientation CSys. Enter values directly as text, click in X, Y, or Z field and select a location from the graphics window, or use the Specify Location icon button. Writes values to the X1, Y1, and Z1 fields on the CAERO1 entry. Point 4 - XYZ values of the other “leading edge” location in the Orientation CSys. Same options as Point 1, except writes values to the X4, Y4, and Z4 fields on the CAERO1 entry. Edge Chord 1-2 - Specifies the “side chord length” from “Point 1” to “Point 2” in the X-direction of the Orientation CSys. Writes value to X12 field of CAERO1 entry. Edge Chord 4-3 - Specifies the “side chord length” from “Point 4” to “Point 3” in the X-direction of the Orientation CSys. Writes value to X43 field of CAERO1 entry. Mesh Control Number Chord - Specifies the number of evenly spaced divisions used to represent the “Aero Mesh” (Aero Boxes) from “Point 1” to “Point 2” (“Point 4” to “Point 3”) on the Aero Panel. Writes value to NCHORD field on the CAERO1 entry. Number Span - Specifies the number of evenly spaced divisions used to represent the “Aero Mesh” (Aero Boxes) from “Point 1” to “Point 4” (“Point 2” to “Point 3”) on the Aero Panel. Writes value to NSPAN field on the CAERO1 entry. Custom option - Alternatively, to specify a custom set of “division points” for the “Chord” or “Span”, turn on the Custom option, then click the (0) Defined button to open the Create Panel Divisions dialog box.

Model, Aeroelasticity, Panel/Body...

10.3-21

When Division Spacing is set to “Custom”, enter text values directly into the Location field or click the Specify Location icon button to select from the graphics window. Values MUST be between 0.0 and 1.0 and the list MUST include 0.0 and 1.0 to create a valid aero mesh. Click the Add button to add the current value in Location to the list of values. Once a value is in the list, it can ben highlighted and the location will be shown in the graphics window. Click Update button to change a highlighted value to the value currently in the Location field or click Delete button to remove the value from the list. The Reset button can be used to clear all values from the list. The Copy button can be used to copy the “custom” panel division list from another Aero Panel/Body in the current model. The Copy to Clipboard and Paste from Clipboard icon buttons can be used to copy/paste the current list of values to/ from the clipboard. Copy to Clipboard

Paste from Clipboard

The Apply button will show the current divisions on the Aero Panel in the graphics window.

When Division Spacing is set to “Bias”, enter a Number, choose a type of Bias (“Bias Equal”, “Bias at Start”, “Bias at End”, “Bias at Center”, or “Bias at Both Ends”) and a enter a Bias Factor (if needed). Once these parameters have been specified, click the Add button in the listing section to add values.

When “Custom” is used for Number Chord, an AEFACT entry will be written to Nastran and the ID of the AEFACT will be referenced by the LCHORD field on the CAERO1. When “Custom” is used for Number Span, the AEFACT is referenced by the LSPAN field of the CAERO1.

10.3-22

Finite Element Modeling

Some example Aero Panels - Point 1 at (0.0, 0.0, 0.0), Point 4 at (2.0, 10.0, 0.0), Edge Chord 1-2 = 5, Edge Chord 4-3 = 3, Orientation CSys = Basic Rectangular:

Number Chord = 4, Number Span = 8

Number Chord (Custom) = 4, Bias at Start, BF = 4 Number Span (Custom) = 8, Bias at Both Ends, BF = 2

Aero Body Type = “1..Aero Body (CAERO2)” This Aero Body Type will create an “Aero Slender/Interference Body”. The values required are a location for the start of the body and the length of the body. The number of divisions for “Slender Body” is also entered to define the “Aero Mesh”. Additionally, a value for the number “Interference Body” divisions needs to be entered.

Only the divisions along the length of the “Slender/Interference Body” are specified using this dialog box. The values for the “Slender Body Radius”, “Interference Body Radius”, and the “Theta Arrays” are defined using the Aero Property with Type set to “Aero Body (PAERO2)”. Surface Point 1 - XYZ values of the first start of the Slender/Interference Body in the Orientation CSys. Enter values directly as text, click in X, Y, or Z field and select a location from the graphics window, or use the Specify Location icon button. Writes values to the X1, Y1, and Z1 fields on the CAERO2 entry. Edge Chord 1-2 - Specifies the “side chord length” from “Point 1” to “Point 2” in the X-direction of the Orientation CSys. Writes value to X12 field of CAERO2 entry. Mesh Control Number Body Elements - Specifies the number of evenly spaced divisions used to represent the “Aero Mesh” (Aero Boxes) on the “Slender Body” from “Point 1” to “Point 2” on the “Slender Body”. Writes value to NSB field on the CAERO2 entry. Number Interference Elements - Specifies the number of evenly spaced divisions used to represent the “Interference Body” from “Point 1” to “Point 2”. Writes value to NINT field on the CAERO2 entry. Custom option - Alternatively, to specify a custom set of “division points” along the length of the “Slender Body” or “Interference Body”, turn on the Custom option, then click the (0) Defined button to open the Create Panel Divi-

Model, Aeroelasticity, Property...

10.3-23

sions dialog box. For more information on using the Create Panel Divisions dialog box, see the “Custom option” portion of the Aero Body Type = “0..Aero Panel (CAERO1)” section above. When “Custom” is used for Number Body Elements, an AEFACT entry will be written to Nastran and the ID of the AEFACT will be referenced by the LSB field on the CAERO2. When “Custom” is used for Number Interference Elements, the AEFACT is referenced by the LINT field of the CAERO2.

Number of Body Elements = 6 Number of Interference Elements = 6 Reference Radius on Aero Property = 2.5 Shown in Wireframe Display Mode

Number of Body Elements = 8 Number of Interference Elements = 8 Reference Radius on Aero Property = 2.5 Slender Body Division Radius list on Aero Property 0, 1.111, 1.778, 2, 2, 2, 2.5, 2.5, 2.5

Model, Aeroelasticity, Property... ...creates an Aero Property for an Aero Panel or an Aero Body (Slender Body and/or Interference Body). The dialog box changes depending on what is specified for Type. When Type is set to “Aero Panel (PAERO1)”, then FEMAP is making a “Aero Panel” property, which will be written to Nastran as a PAERO1 entry. Other than ID, Title, Color, and Layer, there is nothing else to enter for an “Aero Panel” property.

When Type is set to “Aero Body (PAERO2)”, then FEMAP is making a “Slender/Interference Body” property, which will be written to Nastran as a PAERO2 entry. Along with the ID, Title, Color, and Layer fields, there are several other values which many be entered and effect the display and behavior of all Aero Body entities which reference a particular Aero Property. These additional options are described in greater detail below. Common Reference Radius - Is the reference half-width of “Slender Body” and the half-width of the constant width “Interference Tube. Writes the WIDTH entry to the PAERO2 entry. Aspect Ratio (h/w) - Aspect Ratio of interference tube (height/width). Writes the AR field to the PAERO2 entry.

10.3-24

Finite Element Modeling

Slender Body Properties Orientation - Specifies the type of motion allowed for bodies. The selected direction (Z, Y, or ZY) is in the specified “aerodynamic coordinate system” for the analysis. Writes “Z”. “Y”, or “ZY” to the ORIENT field of the PAERO2 entry. Note: In FEMAP, the “aerodynamic coordinate system” is defined using the Analysis Set Manager (“Model, Analysis” command). When Analysis Type is set to “25..Static Aeroelasticity”, the aerodynamic coordinate system is specified by the Aerodynamic CSys drop-down in the NASTRAN Aerodynamic Data (AEROS) dialog box. When Analysis Type is set to “26..Aerodynamic Flutter”, it is specified by the Aerodynamic CSys drop-down in the NASTRAN Aerodynamic Data (AEROx, MKAEROx) dialog box. Slender Body Division Radius - When on, allows you to enter a list of slender body half-widths at the “end points” of the slender body “Aero Elements”. When off, the half-width of the entire slender body is specified by the Reference Radius value in the Common section. Click the Custom List... button to enter values in the Create Custom Cross Section dialog box. See Create Custom Cross Section dialog box section below for more details. Note: The number of Radius values entered for the Aero Property MUST correspond to the number of divisions specified Number Body Elements (constant or custom) on the Aero Body. Therefore, if there are 8 constant divisions, you need to enter 9 Radius values (1 value for the “start” of the aero body, 7 for each “division location”, and 1 value for the “end”). Interference Body Division Radius - When on, allows you to enter a list of slender body half-widths at the “end points” of the interference body “Aero Elements”. Click the Custom List... button to enter values in the Create Custom Cross Section dialog box. See Create Custom Cross Section dialog box section below for more details. Note: The number of Radius values entered for the Aero Property MUST correspond to the number of divisions specified Number Interference Elements (constant or custom) on the Aero Body. Therefore, if there are 8 constant divisions, you need to enter 9 Radius values (1 value for the “start” of the aero body, 7 for each “division location”, and 1 value for the “end”).

Model, Aeroelasticity, Spline...

10.3-25

Create Custom Cross Section dialog box Used to enter list of custom Radius (half-width) values for the slender body and interference body. When Divisions is set to “Custom”, enter text values directly into the Radius field. Values must be above 0.0. Click the Add button to add the current value in Radius to the list of values. To add a value to a specific place in the list, highlight a value, enter the new value, then click Add and the value will be added above the highlighted line. Once a value is in the list, it can ben highlighted. Click Update button to change a highlighted value to the value currently in the Radius field or click Delete button to remove the value from the list. The Reset button can be used to clear all values from the list. The Copy button can be used to copy the “custom” divisions from another Aero Property in the current model. The Copy to Clipboard and Paste from Clipboard icon buttons can be used to copy/paste the current list of values to/ from the clipboard. The Apply button will show the current radius values at each division on the “Aero Body” in the graphics window. Copy to Clipboard

Paste from Clipboard

When Divisions is set to “Bias”, enter a Number, choose a type of Bias (“Bias Equal”, “Bias at Start”, “Bias at End”, “Bias at Center”, or “Bias at Both Ends”) and a enter a Bias Factor (if needed). Once these parameters have been specified, enter a Radius value, then click the Add button in the listing section to add values from 0.0 to the Radius value based on the type of bias selected. Interference Body Theta Array 1 and Interference Body Theta Array 2 Divisions - use the Define Div... button to open the Create Body Theta Locations dialog box, where you can then enter a list of “theta divisions” for the interference body. The Create Body Theta Locations dialog box is very similar to the Create Custom Cross Section dialog box described above. The only difference is that you are entering Angle values instead of Radius values. The Angle values must be between 0 and 360 degrees. The Divisions set in the Interference Body Theta Array 1 will be written to an AEFACT entry in Nastran which is referenced by the LTH1 field of the PAERO2 entry. The Divisions set in the Interference Body Theta Array 2 will be written to an AEFACT entry in which is referenced by the LTH2 field of the PAERO2 entry. The portion of the Interference Body Theta Array 1 section where you can enter 3 different Interference Element 1 and Interference Element 2 “ranges of aero body elements” is used to define THIi (first aero element) and THNi (last aero element) entries on the PAERO2 entry. Up to 3 ranges can be specified. All aero body elements specified in these ranges will use the Divisions of Interference Body Theta Array 1, while all other aero body elements referencing this Aero Property will use the Divisions of Interference Body Theta Array 2. See figures in Aero Body Type = “1..Aero Body (CAERO2)” portion of Section 4.5.1, “Model, Aeroelasticity, Panel/Body...” for examples of various Slender Body and Interference Body options specified on the Aero Property.

Model, Aeroelasticity, Spline... ...creates an Aero Spline, which “connects” an Aero Panel/Body entity to nodes on the underlying “structural model”. This is done by interpolating motion (displacement) and/or forces from the aeroelastic analysis. There are two “spline types”, Surface Spline and Beam Spline. Regardless of Spline Type, each Aero Spline must reference an existing Aero Panel/Body and must reference a FEMAP Group containing nodes on the structural

10.3-26

Finite Element Modeling

model. Also, at least 2 “aerodynamic points” (aero elements/aero boxes) from the referenced Aero Panel/Body must be selected.

The ID, Title, Color, and Layer fields are common to both Spline Types. Type Spline Type - choose between “0..Surface Spline” and “1..Beam Spline”. When using “0..Surface Spline” the Aero Spline will be written as a SPLINE1 entry to Nastran and additional entries for the SPLINE1 may be specified in the Surface Spline section. A “1..Beam Spline” will be written as SPLINE2 and additional entries for SPLINE2 may be specified in the Beam Spline section. Spline CAERO ID - used to enter the ID of an existing Aero Panel/Body entity. The ID may be entered in manually or an Aero Panel/Body may be chosen from the graphics window. The Show When Selected icon button will highlight the specified Aero Panel/Body in the graphics window, while the Select Aero Panel icon button will allow you to choose an Aero Panel/Body from a list. This value will be written to the CAERO field on the SPLINEi entry. Structural Grid Group ID - used to specify the ID of a Group in FEMAP containing nodes on the structural model. The Show When Selected icon button will highlight nodes in the group in the graphics window. The Quick Group icon button will open the Quick Group dialog box, which can be used to create a new Group or edit an existing one. In the Quick Group dialog box, click New Group to create a new group. Highlight the new group or an existing one, then click Edit Group to Add, Remove, or Exclude nodes to/from the group. Since these groups only need to contain nodes, the only thing which can be selected using this dialog box is nodes. You can rename any group by highlighting it in the list, then clicking Rename. To “Show” the highlighted group in the graphics window, click Show. When done looking at the Group, press Hide. Click Done to exit the Quick Group dialog box.

Model, Aeroelasticity, Spline...

10.3-27

The selected group will be written to as a SET1 entry to Nastran which is referenced by the SETG field of the SPLINEi entry. Aerodynamic Points Box1 - enter the ID or select an aero element (aero box) from the screen to be the first aero element in a “range of aero elements” where motions (displacements) will be interpolated. Click the Select Aero Mesh for Aero Spline icon button to bring up a dialog box which may make graphical selection of the aero element easier. This value will be written to the BOX1 field on the SPLINE1 and to the ID1 field of the SPLINE2 entry. Box2 - similar to Box1, but is last aero element in a “range of aero elements” where motions (displacements) will be interpolated. This value will be written to the BOX2 field on the SPLINE1 entry and to the ID2 field of the SPLINE2 entry . All Boxes button - when chosen, places the aero element with the lowest ID on the referenced Aero Panel/Body into the Box1 field and the one with the highest ID in the Box2 field. Usage Determines if the Aero Spline applies to Force transformation, Displacement transformation, or Both. Writes FORCE, DISP, or BOTH to the USAGE field for the SPLINEi entry. Surface Spline These options are only used for Aero Spline entities with Spline Type set to “0..Surface Spline” and will be written to the appropriate field on the SPLINE1 entry. Attachment Flexibility - specifies the linear attachment flexibility. Value written to the DZ field on SPLINE1 Nelem- number of structural elements along the local spline x-axis if using “2..FPS” option for Spline Fit Method. Value written to NELEM field on SPLINE1 Melem - number of structural elements along the local spline y-axis if using “2..FPS” option for Spline Fit Method. Value written to MELEM field on SPLINE1 Spline Fit Method - designates which spline fit method to use for the Aero Spline. Choose between 0..IPS (HarderDesmarais Infinite Plate Spline), 1..TPS (Thin Plate Spline), or 2..FPS (Finite Plate Spline). Writes IPS, TPS, or FPS to METH field on SPLINE1 Beam Spline These options are only used for Aero Spline entities with Spline Type set to “1..Beam Spline” and will be written to the appropriate field on the SPLINE2 entry. Attachment Flexibility - specifies the linear attachment flexibility. Value written to the DZ field on SPLINE2 Torsional Flexibility - specifies the torsional flexibility ratio (EI/GJ). Value written to DTOR field on SPLINE2. Use 1.0 for “aero bodies”. X Rot Flex - specifies the rotational attachment flexibility about the spline’s x-axis (in-plane bending rotations) is specified in Y CSys. Not used for “aero bodies”, only “aero panels”. Value written to DTHX field on SPLINE2. Y Rot Flex - specifies the rotational attachment flexibility about the spline’s y-axis (torsion) is specified in Y CSys. May be used for “slope” of “aero bodies”. Value written to DTHY field on SPLINE2. Note: The values for Attachment Flexibility, X Rot Flex, and Y Rot Flex are used for smoothing. Flexibility values of 0.0 in these fields imply rigid attachment (i.e., no smoothing). Negative values for X Rot Flex and Y Rot Flex imply infinity, therefore, no attachment. Y Csys - Rectangular coordinate system where the y-axis defines the axis of the spline. Not used for “aero bodies”, only “aero panels”. Only rectangular coordinate systems will be available for selection. Value written to DCID field on SPLINE2. For display purposes, each Aero Spline will be drawn “on top” of the selected “aero mesh” of the referenced Aero Panel/Body. In addition, straight “connection lines” will be drawn from each node in the referenced Structural Grid Group to the centroid of the referenced Aero Panel/Body.

10.3-28

Finite Element Modeling

For example, an “aero panel” and an “aero body” are shown on the left. The corresponding Aero Splines for these Aero Panel/Body entities are shown on the right.

1 “aero panel” and 1 “aero body”

Same “aero panel” and “aero body” shown with corresponding aero splines

Model, Aeroelasticity, Control Surface... ...creates an Aero Control Surface, which is used to specify an aerodynamic control surface. Each Aero Control Surface uses ranges of aero elements on “aero panels” (not “aero bodies”) to represent the aerodynamic control surface. Two ranges of aero elements may be specified on each Aero Control Surface, with each “control surface” range able to use a different “hinge orientation coordinate system”.

The ID, Title, Color, and Layer fields work as the do for other entities. Usage These options allow you to create an easy to recognize label which will be written to the Nastran input file and effect how each Aero Control Surface is used in the aeroelastic analysis. Label - specifies the name of the control surface. Limited to 7 characters. Text written to the LABEL field on AESURF.

Model, Aeroelasticity, Control Surface...

10.3-29

Linear Downwash/No Linear Downwash - specifies if “Linear DownWash” is computed as part of the database (Linear Downwash) or if the effects of the control surface must be entered by the user directly (No Linear Downwash). Writes LDW or NOLDW to the LDW field on AESURF. Effectiveness - specifies the control surface effectiveness, which cause forces to be modified by this value (i.e., to achieve 40% reduction of effectiveness, specify this value as 0.6). Value written to EFF field on AESURF entry. Ref Chord Length - specifies the reference chord length of the control surface. Value written to CREFC field on AESURF entry. Ref Surface Area - specifies the reference surface area of the control surface. Value written to CREFS field on AESURF entry. Deflection Limits Specifies the Lower and Upper deflection limits for the control surface in radians. Values written to PLLIM and PULIM fields on AESURF entry. Hinge Moment Limits Specifies the Lower and Upper hinge moment limits for the control surface in force-length units. Values written to HMLLIM and HMULIM fields on AESURF entry. Deflection Limits vs Pressure Allows you to choose functions to specify Lower and Upper deflection limits for the control surface as a function of dynamic pressure. Functions written as TABLED1 entries to Nastran then referenced by TQLLIM and TQULIM fields on AESURF entry. Control Surface 1 and Control Surface 2 Specify a rectangular coordinate system as the Hinge Orientation CSys (writes CIDi to AESURF entry), then click the Aero Mesh... button to choose “aero panel elements” using a typical Entity Selection dialog box. The selected “aero mesh” in each section will be written as an AELIST to Nastran, then referenced by the corresponding ALIDi field(s) on the AESURF entry Aero Control Surfaces are displayed “on top” of the “aero panel elements”. A “complete” Aero model shown below with Aero Control Surfaces: RUDDER (single control surface on Aero Control Surface entity)

AILERON (both defined on same Aero Control Surface entity)

10.3-30

Finite Element Modeling

Static Aeroelasticity Analysis NX and MSC/MD Nastran have the ability to perform Static Aeroelasticity analysis using Solution Sequence 144 (SOL 144). Specific Solution 144 dialog boxes will appear in the Analysis Set Manager when the Analysis Type has been set to 25..Static Aeroelasticity. The NASTRAN Aerodynamic Data (AEROS) dialog box allows you to enter basic parameters for static aeroelasticity and an optional conversion factor PARAM used for all subcases. On the other hand, the NASTRAN Aeroelastic Trim Parameters dialog box contains a number of “Trim Parameters”, which may be specified in the “Master Requests and Conditions” for an analysis with no subcases or specified individually for each subcase. AEROF and APRES will be written to case control to request results from static aeroelastic analysis. NASTRAN Aerodynamic Data (AEROS)

Aerodynamic Physical Data Aerodynamic CSys - specifies the aerodynamic coordinate system. Must be a rectangular coordinate system. Flow is in the +X direction. Value written to the ACSID field of the AEROS entry. Ref CSys - specifies the reference coordinate system. Must be a rectangular coordinate system. All AESTAT degrees-of-freedom defining trim variables will be defined in this coordinate system. Value written to the RCSID field of the AEROS entry. Chord Length - specifies reference chord length. Value written to the REFC field of the AEROS entry. Span - specifies reference span. Value written to the REFB field of the AEROS entry. Wing Area - specifies reference wing area. Value written to the REFS field of the AEROS entry. PARAM, AUNITS - writes PARAM, AUNITS to the Nastran input file with the specified value. This parameter is used to convert accelerations specified in units of gravity on the TRIM entries to units of distance per time squared.

Symmetry XZ - specifies the symmetry “key” for the x-z plane of the Aerodynamic CSys. Based on option selected for XZ, writes an integer to the SYMXZ (Symmetry = +1, No Symmetry = 0, Anti-Symmetry = -1). XY - specifies the symmetry “key” for the x-y plane of the Aerodynamic CSys, which can be used to simulate “ground effects”. Based on option selected for XY, writes an integer to the SYMXY (Symmetry = -1, No Symmetry = 0, Anti-Symmetry = +1). NASTRAN Aeroelastic Trim Parameters The Enable Trim check box may be used to toggle the options set in the NASTRAN Aeroelastic Trim Parameters dialog on/off in the Master case and for each subcase. The Trim Parameters in the upper portion of the dialog box are used to define values on the TRIM bulk data entry. Mach Number - specifies the mach number. Value written to the MACH field of the TRIM entry. Dynamic Pressure - specifies a value for dynamic pressure. Value written to the Q field of the TRIM entry. Rigid Trim Analysis - specifies if trim analysis is rigid. When “on” a value of 0.0 is written to the AEQR field of the TRIM entry. When “off”, a value of 1.0 is written to the AEQR field of the TRIM entry.

Aerodynamic Flutter Analysis

10.3-31

The Trim Parameters in the lower portion of the dialog box write AESTAT and/or TRIM entries using values entered for various “Trim Variables” in the list. When set to Rigid Body Motion: a. Select from the list of "Standard Labels Defining Rigid Body Motions" on the AESTAT (ANGLEA, SIDES, ROLL, PITCH, YAW, URDD1, URDD2, URDD3, URDD4, URDD5, and URDD6) b. Select a Usage (1..Free or 2..Fixed). If 2..Fixed, enter a magnitude as well (UXi value on TRIM entry). c. Click Add to add the “Trim Variable” to the list in the lower portion of the dialog box. When set to Control Surfaces: a. Select from the list of Aero Control Surfaces in your model, then follow steps b and c above. To update a “Trim Variable”, highlight one in the list, set the appropriate values, then click Update. The Delete button is used to delete a single highlighted “Trim Variable” from the list, while Reset will delete all “Trim Variables” from the list.

Aerodynamic Flutter Analysis NX and MSC/MD Nastran have the ability to perform Aerodynamic Flutter analysis using Solution Sequence 145 (SOL 145). Specific Solution 145 dialog boxes will appear in the Analysis Set Manager when the Analysis Type has been set to 26..Aerodynamic Flutter. The NASTRAN Aerodynamic Data (AEROx, MKAEROx) dialog box allows you to enter basic parameters for unsteady aerodynamics, a table of Mach numbers vs. Reduced frequencies, and some additional dynamic analysis information. On the other hand, the NASTRAN Flutter Parameters dialog box contains a number of “Flutter Parameters”, which may be specified in the “Master Requests and Conditions” for an analysis with no subcases or specified individually for each subcase. The standard NASTRAN Modal Analysis dialog box is also used to setup a Flutter analysis. See Section 8.7.1.9, “Modal Analysis” for more information about the options available in this dialog box. When using the PK method, results from the Flutter Summery Table will be imported into FEMAP as functions.

10.3-32

Finite Element Modeling

NASTRAN Aerodynamic Data (AEROx, MKAEROx)

Aerodynamic Physical Data Aerodynamic CSys - specifies the aerodynamic coordinate system. Must be a rectangular coordinate system. Flow is in the +X direction. Value written to the ACSID field of the AERO entry. Velocity - specifies the velocity for aerodynamic force data recovery and to calculate the BOV parameter. Value written to the VELOCITY field of the AERO entry. Ref Length - specifies reference length for reduced frequency. Value written to the REFC field of the AERO entry. Ref Density - specifies reference density. Value written to the RHOREF field of the AERO entry.

Symmetry XZ - specifies the symmetry “key” for the x-z plane of the Aerodynamic CSys. Based on option selected for XZ, writes an integer to the SYMXZ (Symmetry = +1, No Symmetry = 0, Anti-Symmetry = -1). XY - specifies the symmetry “key” for the x-y plane of the Aerodynamic CSys, which can be used to simulate “ground effects”. Based on option selected for XY, writes an integer to the SYMXY (Symmetry = -1, No Symmetry = 0, Anti-Symmetry = +1).

Mach Number - Frequency Table Select a function to specify a list of Mach Numbers vs. Reduced Frequencies (Type of function MUST be “34..Mach Number vs. Freq”). To create a new function “on-the-fly”, click the New Function icon button. Writes as many MKAERO2 entries as needed for all XY data pairs in the function (4 data pairs per MKAERO2).

Dynamics Options These options allow you to limit the modes used to analyze the response of the structure by allowing you to set a subset of the frequency range specified in the NASTRAN Modal Analysis dialog box or simply enter a fewer number of modes to use. This can be useful if restarting from a Modal Analysis which had a larger frequency range or more modes than are needed to run an accurate Modal Transient analysis. Number of Modes will write the PARAM,LMODES entry, Lowest Freq (Hz) will write PARAM,LFREQ and Highest Freq (Hz) will write PARAM,HFREQ. Specify Rigid Body Zero Modes (FZERO) to have modes with values under specified value be considered “0”. When checked, the As Structural check box will write out PARAM,KDAMP,-1, which causes the viscous modal damping, specified by the Modal Damping Table in the NASTRAN Flutter Parameters, to be entered into the complex stiffness matrix as structural damping.

Aerodynamic Flutter Analysis

10.3-33

NASTRAN Flutter Parameters The Model Damping Table can be specified here (function Type must be “6..Structural Damping vs. Freq”, “7..Critical Damping vs. Freq”, or “8..Q Damping vs. Frequency”) and writes a TABDMP1 entry..

The Enable Flutter check box may be used to toggle the options set in the NASTRAN Flutter Parameters dialog on/ off in the Master case and for each subcase. A FMETHOD= # case control entry will be written to each subcase, specifying which FLUTTER entry to use for each subcase.

Flutter Parameters Flutter Method - specifies the flutter analysis method. There are four methods available: 0..K-Method (K written to METHOD field on FLUTTER entry) 1..PK-Method (PK written to METHOD filed on FLUTTER entry). Is the default method. 2..PKNL-Method (PKNL written to METHOD on FLUTTER entry). Is PK-Method with no looping. 3..KE-Method (KE written to METHOD on FLUTTER entry). Is K-Method restricted for efficiency. Density Ratios - select a function to specify the density ratio vs. aerodynamic factor. Type of function must be “35..vs.Aerodynamic Factor”. Function values written to FLFACT entry which is then referenced by the DENS field of the FLUTTER entry. Mach Numbers - select a function to specify the mach numbers vs. aerodynamic factor. Type of function must be “35..vs.Aerodynamic Factor”. Function values written to FLFACT entry which is then referenced by the MACH field of the FLUTTER entry. Velocity/Reduced Freq - select a function to specify the velocity (PK and PKNL methods) or reduced frequencies (K and KE methods) vs. aerodynamic factor. Type of function must be “35..vs.Aerodynamic Factor”. Function values written to FLFACT entry which is then referenced by the RFREQ field of the FLUTTER entry. Interpolation Method (K and KE methods only) - specify an interpolation method for aerodynamic matrix interpolation. Choose between Linear (writes L to IMETH field on FLUTTER entry. Default) or Surface (writes S to IMETH field on FLUTTER entry). Number Eigenvalues (PK and PKNL methods only) - specify the number of eigenvalues. Value written to NVALUE field on the FLUTTER entry. Convergence (PK and PKNL methods only) - specify a convergence value for k, which a value used to accept eigenvalues. Value written to EPS field on the FLUTTER entry.

10.3-34

Finite Element Modeling

Loads and Constraints •

Updated Model, Load, From Freebody command to allow selection of a Freebody entity currently in the model.

•

Added Map Tolerance field for Model, Load, Map Output from Model command and in Data Surface editor

Map Tolerance - When a “Target” location is projected onto the “Source” data surface and the distance to a discrete data point is less than the tolerance, the “Source” value of the "coincident" location is directly mapped to the “Target” without interpolation. If multiple nodes fall within this tolerance, then the first one encountered numerically will be directly mapped. Default value is the "Merge Tolerance" of the "Target” model. •

Enhanced Model, Constraint, Expand command.

Connections (Connection Region, Properties, and Connectors) •

Added Activation Distance section to Penetration section on the NEiNastran tab. Allows you to specify a value (real or AUTO) for MAXAD or specify values for MAXNAD and/or MAXRAD)

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Added Friction section to LS-DYNA tab to restore ability to set these values for LS-Dyna contact.

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Updated Fluid Regions to not use the PLANE1, PLANE2, RMAX, FMEXACT inputs when NEi Nastran is default solver.

Groups and Layers •

Added on Group, Coord Sys, On Property to add coordinate systems on a Property to a group and Group, Coord Sys, on CSys to add coordinate systems referenced by selected coordinate systems to a group.

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Enhanced Group, Operations, Add Related Entities to now add Coordinate Systems referenced on Properties and coordinate systems referenced by other coordinate systems to a group.

Views •

Added on View, Align by, Surface to align the view normal to a selected surface and View, Align by, Normal to Plane to align view normal to a specified plane.

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Added Aero Panel, Aero Mesh, Aero Interference, Aero Splines, and Aero Control Surfaces to Labels, Entities and Color Category of View, Options.

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Added Preview option to Tools and View Style Category of View, Options. Controls the size of the “marker” shown in the graphics window when using the Preview button to preview the location of a coordinate.

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Added Freebody, Freebody Node Markers, Freebody Vectors, Freebody Total Force, Freebody Total Moment, Freebody Nodal Force, and Freebody Nodal Moment to PostProcessing Category of View, Options.

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Added Max Only and Min Only options to the Label Mode of the Contour/Criteria Style option in the PostProcessing Category of View, Options.

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Only tabs of entity types which currently exist in the model will be displayed in the View, Visibility dialog box.

Output and Post-Processing •

Freebody display has been enhanced and is now managed via the Freeboy tool in the PostProcessing Toolbox.

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Added “Select By Vector” options for Nodal and Elemental output in Model, Output, Forced Response. This allows you to limit the amount of output created by this command.

Geometry Interfaces The following FEMAP interfaces have been updated to support newer geometry formats: FEMAP Interface Parasolid Solid Edge NX

Latest Supported Version Parasolid 24.0 Solid Edge with Synchronous Technology 4 NX 8.0

Analysis Program Interfaces

FEMAP Interface Catia Pro/Engineer ACIS SolidWorks •

10.3-35

Latest Supported Version CATIA V5 R20 Wildfire 5.0 ACIS 21, SP3 SolidWorks 2010

Updated stereolithography export to export both solid and plate elements at the same time if they are both selected. If some plates are coincident with

For details, see “Geometry Interfaces” in the FEMAP User Guide.

Analysis Program Interfaces Several of the analysis program interfaces have been improved. These changes include: •

Analysis Set Manager Enhancements

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FEMAP Neutral File Interface

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NX Nastran Interface

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Nastran Interfaces (NX and MSC/MD)

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MSC/MD Nastran Interface

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NEi Nastran Interface

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ANSYS Interface

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ABAQUS Interface

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DYNA Interface

For details, see “Analysis Program Interfaces” in the FEMAP User Guide.

Analysis Set Manager Enhancements •

Updated Preview Analysis Input File dialog box to show 80 characters per line by default.

FEMAP Neutral File Interface •

Updated Neutral Read and Write for v10.3 changes

NX Nastran Interface •

Added support for BGRESULTS Glue Output results.

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Added support for PLOADE1 entry.

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Added support for “Mean Dilatational Formulation” on the PPLANE entry.

•

Added support MATVE and TABVE entries. GFUNC and KFUNC are defined using dimensionless FEMAP functions where x = decay factor and y = bulk or shear modulus. MOD0 is defined by adding decay time = 0 and MOD0 first term.

10.3-36

Finite Element Modeling

•

Added support for MATHEV and MATHEM to the MATHE material definition for SOL 601/701.

•

Added support for PARAM,CNTSET

A number of bugs were corrected For details, see “Analysis Program Interfaces” in the FEMAP User Guide.

Nastran Interfaces (NX and MSC/MD) •

Added Preference to write continuation cards as “+” only.

•

Added support for the Automatic Householder Method (AHOU) for modal analysis.

•

Added support for multicase SUPORT1 definition.

•

Added support for SOL AESTAT (SOL 144), SOL SEFLUTTER (SOL 145), CAERO1, CAERO2, PAERO1, PAERO2, SPLINE1, SPLINE2, AESURF, AEFACT, AEROS, SET1, TRIM, AERO, FLUTTER, FLFACT, FMETHOD, MKAERO1, and MKAERO2 to support Static Aeroelasticity and Aerodynamic Flutter.

•

Added support for PARAM,AUNITS to support Static Aeroelasticity.

A number of bugs were corrected For details, see “Analysis Program Interfaces” in the FEMAP User Guide.

MSC/MD Nastran Interface •

Added support for nonlinear results on solid elements from versions above 2008. Results from versions 2008 and before are also still supported.

A number of bugs were corrected. For details, see “Analysis Program Interfaces” in the FEMAP User Guide.

NEi Nastran Interface •

Added support for Laminate Failure Theories: Max Stress (STRESS), NASA LaRC (LAERC02), Puck PCP (PUCK), and Multicontinium (MCT). Specified on Laminate Property.

•

Added support for PARAM, RIGIDELEM2ELAS, ON and PARAM, RIGIDELEMTYPE, BAR to support thermal expansion of Rigid elements.

•

Added support for EXTRACTMETHOD (options = LANCZOS, AUTO, or SUBSPACE) for Modal Analysis.

•

Added support for PARAM,INREL,AUTO.

•

Added support for NITINOL material type. Found in dialog box when Type = Other Types.

•

Added support for MAXAD and MAXNAD/MAXRAD for contact.

A number of bugs were corrected. For details, see “Analysis Program Interfaces” in the FEMAP User Guide.

ANSYS Interface •

Added support for ANSYS 13.0

A number of bugs were corrected. For details, see “Analysis Program Interfaces” in the FEMAP User Guide.

ABAQUS Interface A number of bugs were corrected. For details, see “Analysis Program Interfaces” in the FEMAP User Guide.

DYNA Interface •

Added support for ABCD Contact entries.

Tools

10.3-37

A number of bugs were corrected. For details, see “Analysis Program Interfaces” in the FEMAP User Guide.

Tools •

Added Color, Next ID, and Inc values for Aero Panel, Aero Property, Aero Spline, and Aero Surface to Tools, Parameters.

•

Added ability to determined surface area of “combined surfaces” to Tools, Measure, Surface Area.

•

Added “Skew” element quality check to Tools, Check, Element Quality command.

Skew measures internal angular deviation of a face using the edge bisector method. This check matches results reported by NX Nastran. Only this command will return Skew results for faces of supported solid elements. For Triangular elements and element faces, Skew measures internal angle and reports minimum for all angles of 2D (a1, a2 & a3 in figure below) and all angles of all faces of supported 3-D type elements. For Quadrilateral elements and element faces, Skew test for quadrilateral faces reports minimum angle between face edge bisectors ( a1 & a2 in figure below ). Minimum for all faces is reported for supported 3-D elements.

OLE/COM API New API Objects and Attributes • Added Element Quality (feElementQuality) object to the API. Also added AspectRatioOn, TaperOn, AlternateTaperOn, InternalAngleOn, SkewOn, WarpingOn, NastranWarpingOn, TetCollapseOn, JacobianOn, CombinedOn, ExplicitTimeStepOn, AspectRatioLimit, TaperLimit, AlternateTaperLimit, InternalAngleLimit, SkewLimit, WarpingLimit, NastranWarpingLimit, TetCollapseLimit, JacobianLimit, CombinedLimit, and ExplicitTimeStepLimit to Element Quality Object. •

Added Aero Panel/Body (feAeroPanel) object to the API. Also added color, layer, title, propID, defCSys, nSpan, nChord, iIgid, Pt1, Pt4, dChord12, dChord43, nLspanID, nLchordID, and type attributes to the Aero Panel/Body object.

•

Added Aero Property (feAeroProp) object to the API. Also added color, layer, title, pdval, pnval, ap_d_width, ap_d_ar, ap_i_orient, ap_i_lrsb, ap_i_lrib, ap_i_lth1, ap_i_lth2, ap_i_thi1, ap_i_thi2, ap_i_thi3, ap_i_thn1, ap_i_thn2, ap_i_thn3, and type attributes to the Aero Property object.

•

Added Aero Spline (feAeroSpline) object to the API. Also added color, layer, title, type, icaero, ibox1, ibox2, isetg, dz, meth, nelem, melem, usage, dtor, cid, dthx, and dthy attributes to the Aero Spline object.

•

Added Aero Control Surface (feAeroSurf) object to the API. Also added color, layer, title, csys, csys1, aeid, aeid1, eff, ldw, crefc, crefs, pllim, pulim, hmllim, hmulim, tqllim, tqulim, and label attributes to the Aero Control Surface object.

•

Added Freebody (feFreebody) object to the API. Also added title, DisplayMode, Group, CSys, NodeMarkerColor, TotalVectorMode, ShowTotalVec, SumComponents, TotalVecColor, x, y, z, NodalVectorMode, ShowNodalVec, NodalVecColor, and SumContributions attributes to the Freebody object.

•

Added Geometry Preparation and Meshing (feMesher) object to the API. This object has been partially added and is for “Future Use” and should not be used.

10.3-38

Finite Element Modeling

•

Added NasAeroOn, NasAeroCsID, NasAeroRefCsID, NasAeroRefLength, NasAeroRefSpan, NasAeroRefArea, NasAeroSymXY, NasAeroSymxz, NasAeroAeunit, NasAeroAeunitVal, NasAeroVelo, NasAeroRefDens, NasAeroMkFuID, vNasAeroFreqKeep, NasAeroModesKeep, NasAerobPARAMfzero, NasAerodPARAMfzero, and NasAeroDampMethod attributes to Analysis Manager (AnalysisMgr)object for Static Aeroelasticity and Aerodynamic Flutter. Also, added NasBulkCntAset for Bulk Data.

•

Added NasCaeOn, NasCaeMachNumber, NasCaeDynPressure, NasCaeRigidTrim, NasCaeWrtieTrim, NasCflOn, NasCflMethod, NasCflDenID, NasCflMachFactID, NasCflRfreqFactID, NasCflFliMethod, NasCflEig, NasCflEps, NasCflWriteFlutter, NasCflSdamp attributes to Analysis Case (AnalysisCase) object for Static Aeroelasticity and Aerodynamic Flutter.

New API Methods • Added NextExistingInSet to Entity API objects •

Added Clear, SetModelDefaults, GetModelDefaults, CheckQuality, GetAspectRatio, AspectRatio, GetTaper, Taper, GetAlternateTaper, AlternateTaper, GetInternalAngle, InternalAngle, GetSkew, Skew, GetWarping, Warping, GetNastranWarping, NastranWarping, GetTetCollapse, TetCollapse, GetJacobian, Jacobian, Get Combined, Combined, GetExplicitTimeStep, and ExplicitTimeStep to Element Quality object.

•

Added GetDivisionList, PutDivisionList, SlenderBodyCount, InterferenceBodyCount, PanelSpanCount, PanalChordCount, and GetBoxSet to Aero Panel/Body object

•

Added GetThetaList, PutThetaList, GetRadiList, PutRadiList, ClearSbList, ClearIbList, ClearTheta1List, and ClearTheta2List to Aero Property object

•

Added GetNodeSet and GetBoxSet to Aero Spline object

•

Added PutSurfaceSet1, PutSurfaceSet2, GetSurfaceSet1, GetSurfaceSet2, ClearSurfaceSet1, and ClearSurfaceSet2 to Aero Control Surface object

•

Added GetElements, SetElements, ClearElements, GetNodes, SetNodes, ClearNodes, CalculateNodalCenter, and CalculateSummation to Freebody object.

•

Added Axis and TwoAxis to CSys object

•

Added ClearMeshLoc and PointsAsSet to Curve object

•

Added FindMappedMeshingCorners, AddMeshPoint, CountMeshPoint, and PointLoops to Surface object

•

Added CountCommon, CountNotCommon, HasNotCommon, and NextAfter to Set object

•

Added SetMultiGroupListFromSets to View object

•

Added IsEmpty to SortSet object

•

Added ElementsAsSet2 to Solid object

•

Added MapFromModelToSet2 to MapOutput object.

•

Added DeleteAnalysisCase to Analysis Case object.

•

Added GetList to Group object

New Global Variables • Added Pref_JTFileVersion, Pref_GIFOptimized, and Pref_2DTensorPlotOverride •

Added Pref_RenderXORPicking, Pref_RenderMultiModelMem, Pref_RenderDebugElapsedTime, Pref_DebugAllTime, Pref_DebugOGLErrors, Pref_RenderBlockSize, and Pref_DialogRefresh

•

Added Pref_PickMethod, Pref_ConfirmDelete, Pref_ShowMode, Pref_ShowLables, Pref_ShowNormals, and Pref_ShowColor.

•

Added Pref_PreserveNextID, Pref_DBOpenSaveWindowsIO, and Pref_DBOpenSaveUnblockedIO

•

Added Pref_Prev10TetMesh, Pref_Prev10SurfaceMesh, Pref_ElemQualAspectRatio, Pref_ElemQualTaper, Pref_ElemQualAltTaper, Pref_ElemQualIntAngles, Pref_ElemQualSkew, Pref_ElemQualWarping, Pref_ElemQualNastranWarping, Pref_ElemQualTetCollapse, Pref_ElemQualJacobian, Pref_ElemQualCombined, Pref_ElemQualExplicitTime, Pref_ElemQualAspectRatioVal, Pref_ElemQualTaperVal, Pref_ElemQualAltTaperVal, Pref_ElemQualIntAnglesVal, Pref_ElemQualSkewVal,

Preferences

10.3-39

Pref_ElemQualWarpingVal, Pref_ElemQualNastranWarpingVal, Pref_ElemQualTetCollapseVal, Pref_ElemQualJacobianVal, Pref_ElemQualCombinedVal, and Pref_ElemQualExplicitTimeVal. Also, added Pref_OrientSolidIsoOuput, Pref_OrientSolidAnisoOutput, Pref_OrientSolidHyperOutput, Pref_Tria3StressOutput, PrefTria3StrainOutput, PrefTria3ForceOutput, Pref_Tria6StressOutput, PrefTria6StrainOutput, PrefTria6ForceOutput, Pref_Quad4StressOutput, PrefQuad4StrainOutput, PrefQuad4ForceOutput, Pref_Quad8StressOutput, PrefQuad8StrainOutput, PrefQuad8ForceOutput •

Added Pref_NastranScratchLocation, Pref_NasAlternateContinue and Pref_NasDballScratch

•

Added Pref_LibLayup

•

Added vPref_SpaceballFactors, Pref_SpaceballFactors, Pref_SpaceballSensitivity, and Pref_SpaceballDebug

•

Added slots 18-21 for Aero Panel, Aero Prop, Aero Spline, and Aero Control Surface to Pref_EntityColor

•

Updated Pref_LengthBasedMeshSize from BOOL to INT4

The following functions have been added: • feFileIsModified •

feGroupBoolean2

•

feSurfaceExtend

•

feOutputForceBalance2

•

feLoadFromFreebody

•

feVectorNormalizedDotProduct

•

feSurfaceMidAttrib

•

feCoordCenterOfPoints

Preferences Views • Added JT File Version drop-down Sets the default value displayed for “JT File Version” in the JT Options dialog box when saving a picture as a JT file (see Section 2.5.4.7, “File, Picture, Save JT...”). Determining the proper “JT File Version” for software packages which support JT files is up to the user. Available file versions are 8.0, 8.1, 8.2, 9.0, 9.1, 9.2, 9.3, 9.4, and 9.5. •

Added Optimized check box to the Color Optimization section of GIF Options.

The Optimized option will remove infrequently used colors in the picture first when reducing to 256 colors. •

Both the actual and log values will be included as text when the Include Text for XY Plots option is on.

Render • Added the All, Elapsed Time, and OpenGL Errors check boxes under Print Debug Messages in the Advanced/ Debug options section. If you turn this option on, FEMAP will write print debug messages to the Messages window. FEMAP Support may request this information to help you resolve a graphics display problem. The “Elapsed Time” option reports “elapsed times” of various operations related to FEMAP graphics. Turning on the “All” option will report quite a bit more information, but will also be slower. “OpenGL Errors” will report any errors specifically related to OpenGL. If there are no OpenGL errors, then nothing different will be reported. This option is off by default as it takes additional time to query FEMAP for these types of errors. User Interface • Added Pick Method drop-down to Graphical Selection section to allow selection of a default “Pick Method”. This option controls the default Pick Method for Entity Selection dialog boxes. Choices are “Pick Normal”, “Pick Query”, and “Pick Front”. See Section 4.3.1, "Entity Selection" for more information about the Pick Methods. Database • Added “16K test” to Read/Write Test for determining optimal Open/Save Method.

10.3-40

Finite Element Modeling

Geometry/Model • Added “Skew” to enter default value in the Element Quality Preferences dialog box. •

Changed Use Length Based Mesh Sizing option to Mesh Sizing drop-down to allow choice of the new default option, “2..Parametric/Equal Length”.

Interfaces • Added Write Alternate Line Continuation option to the Nastran Solver Write Options section When this option is on, FEMAP will write all Nastran line continuation markers to “+” only. The only exception is for the “Basic Cylindrical” and “Basic Spherical” coordinate systems written out to every Nastran file by default. Previous versions of FEMAP would write “descriptive” continuation markers, which can be turned on again by turning off this option •

Added Include Database Files in Scratch option to the Nastran Solver Write Options section

When on, this option will make sure the Nastran files (i.e., *.DBALL, *.MASTER, *.OBJSCR, *.SCR300, *.SCRATCH, etc.) are also written to the specified Scratch Directory for Nastran. This is accomplished by using the “dbs” Nastran command line option when running the analysis. •

Check References on Open and Create Geometry References in File Reference Options section are now “Off” by default.

Color • Added options to set the default color for Aero Panel, Aero Prop, Aero Spline, and Aero Control Surface.

3.

Analyzing Buckling for a Bracket

In this first example, you will explore the buckling load of a simple bracket subject to a concentrated cantilevered load. The bracket, although solid, will be idealized as a thin shell finite element model, fixed at the base and loaded at the tip.

You will work through the entire FEMAP analysis process, which includes: •

importing the geometry of the bracket

•

meshing the model

•

applying constraints and loads

•

analyzing the model using the NX Nastran solver

•

post-processing the results

Importing the Geometry What Import a FEMAP neutral file containing the geometry of the bracket.

How Step

UI

Command/Display

1.

File, New Menu

2.

File, Import, FEMAP Neutral Menu

3-2 Step

UI

Analyzing Buckling for a Bracket

Command/Display

3.

Read Model from FEMAP Neutral dialog box: Go to the Examples directory in your FEMAP installation.

4.

File name: Bracket.NEU Open Neutral File Read Options dialog box: OK

V1

ZX Y

Meshing the Model The first step for the meshing process will be to define the property and material for the elements. Next, you will mesh the surfaces.

Defining the Property and Material The shell property represents the thickness of the material making up the two regions of the part.

What Define the shell element property.

How Step

UI

Command/Display

1.

Model, Property Menu

2.

Define Property - PLATE Element Type dialog box: Elem/Property Type

3.

Element/Property Type dialog box: Plane Elements: Plate OK

Meshing the Model

Step 4.

UI

3-3

Command/Display Define Property - PLATE Element Type dialog box: Title: Shell Notice: Titles can be up to 79 characters long

5.

Property Values: Thicknesses: 0.1

6.

OK Yes (to create material) Notice: You have created the property, but you also need to define the associated material. In steps below, you will choose a standard material from the FEMAP material library.

7.

Define Material - ISOTROPIC dialog box: Load

8.

Select from Library dialog box: AISI 4340 Steel (select)

9.

OK, then... In Define Material - ISOTROPIC dialog box: OK, then... In Define Property - PLATE Element Type dialog box: OK, then Cancel Tip: Once you defined the first property, FEMAP automatically prompted you to enter another property. To end the command, press Cancel. Generally, you will need to press Cancel to exit from any entity creation command.

Meshing the Model The geometry that you imported is simply a wireframe representation of the part’s midsurfaces. To create finite elements in FEMAP, you need to specify the regions, or “boundaries” where you need to mesh. You also need to specify how many elements that you want along the edges of a region. By default, all geometry is assigned a mesh spacing of 1.0. If you mesh this part without specifying a tighter mesh size, your mesh will be too coarse to give meaningful answers. By default, you have been viewing the model in the regular wireframe mode. Once you have created the mesh, you will change to the Free Edge model style to ensure that the part is meshed continuously. Since it isn’t, you’ll use the Coincident Nodes check to merge duplicate nodes at the split between the two regions.

What Create boundary surfaces for both regions of the model.

3-4

Analyzing Buckling for a Bracket

How Step

UI

Command/Display

1.

Geometry, Boundary Surface, From Curves Menu

2.

Entity Selection dialog box: Select the four curves that make up one of the regions (see figure below). OK

3.

Select the four curves that make up the part’s other region. OK Cancel (to end the command)

Notice: You should now have two new boundary surfaces.

V1

ZX Y What Specify the mesh size for the surfaces.

Meshing the Model

3-5

How Step

UI

Command/Display

1.

Mesh, Mesh Control, Size on Surface Menu

2.

Entity Selection dialog box: Select All OK

3.

Automatic Mesh Sizing dialog box: Element Size: 0.3 OK Cancel

What Mesh the surfaces.

How Step

UI

Command/Display

1.

Mesh, Geometry, Surface Menu

2.

Entity Selection dialog box: ID: 1 OK

3.

Automesh Surfaces dialog box: Click More Options button

4.

Property: Shell

5.

In the Node Options portion of the Automesh Surfaces dialog box: UNCHECK Connect Edge Nodes option Notice: Usually, Connect Edge Nodes is a good option to use. It is being turned off in this example simply as a way to create a mesh which is not fully connected. This allows you to see how a “free edge” plot is displayed in FEMAP and also use the “Tools, Check, Coincident Nodes” command later in the exercise.

3-6 Step

UI

Analyzing Buckling for a Bracket

Command/Display

6.

OK

7.

Mesh, Geometry, Surface Menu

8.

Entity Selection dialog box: ID: 2 OK

9.

Automesh Surfaces dialog box: OK

What Display the model using the Free Edge style.

How Step

UI

Command/Display

1.

F5 key

View Select Tip: You can also press the View Select icon (on the toolbar) or View, Select command to open the dialog box.

2.

View Select dialog box: Model Style: Free Edge OK

Meshing the Model

Step

UI

3-7

Command/Display

Notice: The model is displayed with only the free edges showing. As expected, there are free edges around the outside of the part. There are also free edges where the part needs to be connected, at the split line between the two regions. This indicates that there are duplicate nodes at these locations, each connected to shell elements on one side of the edge. Tip: If you had selected all the surfaces and meshed them together, the meshes on the two surfaces would have been connected.

What Check for coincident nodes, and merge them.

How Step

UI

Command/Display

1.

Tools, Check, Coincident Nodes Menu

2.

Entity Selection dialog box: Select All OK

3.

Check/Merge Coincident dialog box: Action: Merge Keep ID: Automatic Move To: Current Location

4.

OK

Notice: You will notice on the Check/Merge Coincident dialog box that a “Preview” button exists. When this button is clicked, FEMAP will enter a mode which allows you to highlight the nodes which will be “Kept”, “Merged”, or “Both” in your model. Clicking “Done” will bring you back to the Check/Merge Coincident dialog box. Click OK to complete the merge operation with the selected options.

3-8 Step

Analyzing Buckling for a Bracket

UI

Command/Display

5.

Window, Regenerate Menu

6.

F5 key

7.

View Select View Select dialog box: Model Style: Draw Model OK

Applying Constraints and Loads Next, you will apply constraints and loads to the model. Since most parts and systems of parts can be held and loaded in any number of ways, FEMAP uses sets to manage constraints and loads. First, you will create a constraint set, then you will fix all of the nodes at the base of the model. Next, you will create a load set, then apply a 100 pound load to the tip of the bracket. In a buckling analysis, the actual loading of the part is applied, and the solver returns a buckling eigenvalue. The eigenvalue is multiplied by the applied load to give the critical buckling load.

Applying Constraints What Create the constraint set.

Applying Constraints

How Step

UI

Command/Display

1.

Model, Constraint, Create/Manage Set Menu

2.

Constraint Set Manager dialog box: Click New Constraint Set, then...

3.

New Constraint Set dialog box: Title: (enter a title)

4.

Click OK, then... Constraint Set Manager dialog box: Click Done

What Create the constraints to fix the nodes at the base of the model.

How Step

UI

Command/Display

1.

Model, Constraint, Nodal Menu

2.

Entity Selection dialog box: Pick the nodes at the edge of the model. OK

3.

Create Nodal Constraints/DOF dialog box: Fixed OK Cancel

3-9

3-10 Step

4.

UI

Analyzing Buckling for a Bracket

Command/Display

Click View Visibility icon (on View Toolbar) OR Press Crtl+Q

5.

Choose Labels radio button

6.

Click All Off button, then... Click Done Notice: You can use the Entity Display Toolbar to quickly toggle Labels on and off. If the Entity Display Toolbar is not visible, you can turn it on using the Tools, Toolbars, Entity Display command to make visible (shown “undocked”).

The third icon allows you to toggle Labels on and off.

Applying Loads

Applying Loads Apply the 100-pound load to the model.

What Create the load set.

How Step

UI

Command/Display

1.

Model, Load, Create/Manage Set Menu

2.

Load Set Manager dialog box: Click New Load Set, then...

3.

New Load Set dialog box: Title: (enter a title)

4.

Click OK, then... Load Set Manager dialog box: Click Done

What Create the load in the negative Y direction.

How Step

UI

Command/Display

1.

Model, Load, Nodal Menu

2.

Entity Selection dialog box: Pick node at the tip of arrow (see following figure). OK

3-11

3-12 Step

UI

Analyzing Buckling for a Bracket

Command/Display

V1 C1

A

ZX Y 3.

Create Loads on Nodes dialog box: FY: Value: 100

4.

Click OK, then... Click Cancel

Analyzing the Model The FEMAP analysis manager stores the options for creating an input file for a solver (an analysis set). It can launch the NX NASTRAN solver or another solver that has been set up to run on the same PC. The analysis manager, together with VisQ, can also set up and run analyses with solvers on other PCs. The analysis sets are stored with the FEMAP model file, and can also be stored in a FEMAP library that can be accessed from different model files.

What Create the analysis set and solve the model.

How Step

UI

Command/Display

1.

Model, Analysis Menu

Post-processing the Results

Step

UI

3-13

Command/Display

2.

Analysis Set Manager dialog box: New

3.

Analysis Set dialog box: Title: Buckling

4.

Analysis Program: 36..NX Nastran Analysis Type: 7..Buckling

5.

Click OK

Notice: The analysis set manager displays all analysis sets defined in the model, and the sections that make up the input file for the solver. Clicking on a plus sign will expand the tree and display individual options that can be edited by double-clicking on an option. For this analysis, you’ll use the default values for these options. 6.

Analyze

Notice: The NX Nastran Analysis Monitor will display the status of the solve. You’ll know that the solve is done when the Messages dockable pane tells you that cleanup of the output set is complete.

Post-processing the Results For this example, you will display the buckling shape and buckling factor.

What Display the deformed model (buckled shape) and the critical buckling factor.

How Step

UI

Command/Display

1.

View, Select Menu

2.

View Select dialog box: Deformed Style: Deform

3.

Deformed and Contour Data

3-14 Step 4.

UI

Analyzing Buckling for a Bracket

Command/Display Select PostProcessing Data dialog box: Output Set: 2..Eigenvalue 1 33.06344 OK (all dialog boxes)

Notice: The set value is the eigenvalue and critical buckling factor for a buckling analysis. In this case, the part would buckle at a load 33.03 times higher than the applied load. This is the end of the example. You don’t need to save the model file.

4.

Analyzing a Beam Model

In this example, you’ll use rod and L beam elements to represent a truss structure.

You will work through the entire FEMAP analysis process, which includes: •

importing the geometry of the truss

•

defining the material and property

•

meshing the model using beams and rods

•

applying constraints and loads

•

analyzing the model using NX Nastran

•

post-processing the results

Importing the Geometry What Open a new model file and import the geometry of the truss. These curves will be meshed with rod and beam elements.

How Step

UI

Command/Display

1.

File, Import, FEMAP Neutral Menu

2.

Read Model from FEMAP Neutral dialog box: Go to the Examples directory in your FEMAP installation. Truss.NEU Open OK

4-2 Step

UI

Analyzing a Beam Model

Command/Display

Y

X Z

Defining the Material and Property The first step for the meshing process will be to define the material and property for the beam and rod elements.

Defining the Material What Define the material by selecting a standard material from the FEMAP material library.

How Step

UI

Command/Display

1.

Model, Material Menu

Tip: You can also create a new Material using the New command on the “context sensitive menu” located on the Materials branch in the Model Info tree (simply click to highlight the top level of the Materials branch or any existing Material, then right mouse click to see the context sensitive menu). 2.

Define Material - ISOTROPIC dialog box: Load

3.

Select from Library dialog box: AISI 4340 Steel OK OK, then... Cancel

Defining the Beam Property FEMAP has a library of general cross sections for you to choose from, but you may not always want to use them. You can define an arbitrary cross section by creating a surface in FEMAP, or by importing external geometry. FEMAP will then calculate the section properties from that surface.

Defining the Beam Property

4-3

The neutral file that you imported has a boundary surface on a different layer that is not currently shown. You will now display it.

What First, hide the default layer. Next, display the boundary surface on a hidden layer.

How Step

UI

Command/Display

1.

Click View Visibility icon (on View Toolbar) OR Press Crtl+Q. Visibility dialog box: Choose the Layer tab.

2.

CHECK “2..Beam Section” UNCHECK “1..Default Layer”

3.

4.

Click Done

Ctrl - A

Autoscale Notice: The boundary section and curves are displayed.

Y

X Z

What Define a property for the beam elements. You’ll first create a general beam cross section, then define a vector to define the section’s Y axis. Next, you’ll define the beam property with the cross section and the AISI 4340 material that you’ve created.

How Step

UI

Command/Display

1.

Model, Property Menu

4-4 Step

UI

Analyzing a Beam Model

Command/Display Tip: You can also create a new Property using the New command on the “context sensitive menu” located on the Properties branch in the Model Info tree (simply click to highlight the top level of the Properties branch or any existing Property, then right mouse click to see the context sensitive menu).

2.

Define Property dialog box: Elem/Property Type

3.

Element Property Type dialog box: Line Elements: Beam OK

4.

Define Property - BEAM Element Type dialog box: Shape

5.

Cross Section Definition dialog box: Shape: General Section

6.

Surface

7.

Select Surface to Check dialog box: Click on the surface. OK

8.

Vector Locate - Define Section Y Axis dialog box: Base: 0, 0, 0 (make sure these are the X,Y,Z values for the base) Tip: 0, 1, 0 (enter these X,Y,Z values for the tip) OK Notice: This vector defines the Y axis for the section.

9.

Cross Section Definition dialog box: OK

10.

Define Property dialog box: Title: General Beam Section Notice: The calculated section properties are now displayed in this dialog box.

11.

Material: AISI 4340 Steel OK, then... Cancel

Meshing the Model

Step

UI

4-5

Command/Display

Meshing the Model This model will be meshed with two types of elements: beam elements on the longitudinal curves, and rod elements on the curves that connect the beams. Once you’ve created the elements, you’ll merge the coincident nodes.

Creating the Beam Mesh First, mesh the longitudinal curves with beams whose properties were defined in the previous section.

What Hide the beam section and show the default layer.

How Step

UI

1.

Command/Display Click View Visibility icon (on View Toolbar) OR Press Crtl+Q.

2.

CHECK “1..Default Layer” UNCHECK “2..Beam Section”

3.

Click Done

Tip: You can “hide and show” layers very easily using the Model Info tree. You can simply check or uncheck layers one at a time. You can also select any number of layers using the Ctrl or Shift keys and the mouse. Once the layers are selected, right mouse on the “visibility check boxes” and choose the Show Selected, Show Selected Only, or the Hide Selected command. You can also choose to View All Layers or View Visible Layers Only by selecting those commands from the “context sensitive menu” for Layers 4.

Ctrl - A

Autoscale

4-6 Step

UI

Analyzing a Beam Model

Command/Display V1

Y

X Z

What Rotate the model to get a trimetric view for meshing.

How Step

UI

Command/Display

1.

View, Rotate, Model Menu

Tip: You can press the F8 key instead of using the command above. 2.

View Rotate dialog box: Trimetric OK

What Mesh the longitudinal curves with beams. You’ll use the general beam cross section to define the beam. After you select the cross section, you’ll enter a vector to define the beam element orientation. It’s important that this vector be identical to the one used to define the cross section properties; otherwise, your analysis results may be incorrect.

How Step

UI

Command/Display

1.

Mesh, Geometry, Curve Menu

2.

Entity Selection dialog box: Pick the curves highlighted in the following figure (Curve IDs 7, 8, 9, 11, 12, 13, 14, 15, 24, 25, 26, 28, 29, 30, 31, and 32). OK

Creating the Beam Mesh

Step

UI

3.

Command/Display

Geometry Mesh Options dialog box: Property: General Beam Section OK

4.

Vector Locate dialog box: Base: 0, 0, 0 (make sure these are the X, Y, Z values for the base) Tip: 0, 1, 0 (enter these X, Y, Z values for the tip) OK V1

Y X Z

What Display the beam elements with their cross sections visible.

How Step

UI

Command/Display

1.

F6 key

View Options

2.

View Options dialog box: Category: Labels, Entities, and Color Option: Element Orientation/Shape (select) Element Shape: Show Cross Section (select) OK

4-7

4-8 Step

UI

Analyzing a Beam Model

Command/Display

Tip: You can also “toggle” the cross-sections of line elements on/off using the “Thickness/ Cross Section” command from the View Style menu located on the View Toolbar.

What Rotate and zoom the model to get a better look at the cross section. Your cross section may have an incorrect orientation that you need to modify.

How Step

UI

Command/Display

1.

Rotate the model slightly to the see the cross sections better.

2.

Zoom (on View Toolbar)

Notice: Compare your beams with the following diagram. Note that the “notch” on each cross section faces the inside of the part. If some of your beams are oriented differently, you will need to modify them. The following steps show you how to reverse the normals when they are facing in the wrong direction. It is normal for you to need to modify the normal direction of some of your beams to make it look like the figure below.

Creating the Rod Mesh

Step

UI

4-9

Command/Display

3.

Modify, Update Elements, Line Element Reverse Direction Menu

4.

Entity Selection dialog box: Pick the elements to modify. (Pick only the elements with cross sections facing in the wrong direction.) OK

5.

In Update Element Direction dialog box: Reverse Direction OK

6.

Ctrl - A

Autoscale

Creating the Rod Mesh You will now mesh the remaining curves with rod elements to connect the beams.

What Mesh the curves. You’ll also need to create a new property to define the rods.

How Step

UI

Command/Display

1.

Mesh, Geometry, Curve Menu

4-10 Step 2.

UI

Analyzing a Beam Model

Command/Display Entity Selection dialog box: Pick all of the unmeshed curves: the cross braces and the connection between the two rows of beams. OK

3.

Geometry Mesh Options dialog box: Property “icon button” Notice: You only have the General Beam Section property in your model. You’ll need to create a rod property.

4.

Define Property dialog box: Elem/Property Type

5.

Line Elements: Rod OK

6.

Define Property - ROD Element Type dialog box: Title: 2 inch Diameter Rod Area: 3.14

7.

Material: AISI 4340 Steel OK

8.

Geometry Mesh Options dialog box: OK Notice: The property you created is selected for the element’s property. Notice: The curves are meshed with rod elements.

What Reduce the amount of information displayed by turning off the display of geometry and labels.

Merging Coincident Nodes

4-11

How Step 1.

UI

Command/Display Click View Visibility icon (on View Toolbar) OR Press Crtl+Q

2.

Visibility dialog box: Choose the Entity/Label tab UNCHECK Geometry.... header (unchecks all geometric entities)

3.

Choose Labels radio button

4.

Click All Off button, then... Click Done Notice: You can use the Entity Display Toolbar to quickly toggle Geometry and Labels on and off. If the Entity Display Toolbar is not visible, you can turn it on using the Tools, Toolbars, Entity Display command to make visible (shown “undocked”).

You have the option to toggle ALL Geometry on and off using the first icon or you can turn them on and off individually by clicking the icon for each geometric entity one at a time. The third icon allows you to toggle Labels on and off.

Merging Coincident Nodes Because the curves were meshed with two meshing operations, there will be nodes at the ends of both the beam and rod elements. You will merge these coincident nodes to effectively “sew” the model together.

What Merge the coincident nodes.

4-12

Analyzing a Beam Model

How Step

UI

Command/Display

1.

Tools, Check, Coincident Nodes Menu

2.

Entity Selection dialog box: Select All OK

3.

Check/Merge Coincident dialog box: Action: Merge Keep ID: Automatic Move To: Current Location

4.

OK

Notice: Look in the Messages dockable pane to see how many coincident nodes have been merged. All rod and beam elements are now connected together.

Applying Constraints and Loads You will create a constraint set to model symmetry and fix the end. The symmetry of the truss will be used to reduce the model to half the size. You will also apply a load to this model to simulate something hanging from the truss.

Modeling Symmetry and a Fixed End To simulate the symmetry of this part, you will constrain the four nodes that are at the halfway point of the structure. You are defining symmetry across the X-plane through these four points. By imposing this type of constraint condition, you are actually introducing a stiffness exactly equal to the structure modeled, just mirrored above the X-plane.

What Create the constraints to model symmetry and fix the end. You’ll also constrain the rest of the model in all DOF except the X and Y translations.

How Step

UI

Command/Display

1.

View, Rotate, Model Menu

Tip: You can press the F8 key instead of using the command above.

Modeling Symmetry and a Fixed End

Step

UI

4-13

Command/Display

2.

View Rotate dialog box: Isometric OK

3.

Model, Constraint, Nodal Menu

Notice: First, you’ll apply constraints at these nodes to model symmetry. 4.

New Constraint Set dialog box: Title: (enter a title) OK

5.

Entity Selection dialog box: Pick nodes A, B, C, and D (see the following figure). OK

A D B C 6.

Create Nodal Constraints/DOF dialog box: X Symmetry OK Notice: The TX, RY, and RZ DOF are selected. Because you are applying nodal constraints, you could control the constraint of each degree of freedom individually in the dialog box, or you can use the quick keys to apply common constraint conditions.

7.

Entity Selection dialog box: Pick nodes E and F (see the following figure). OK Notice: You are now fixing the nodes on the opposite end.

4-14 Step

UI

Analyzing a Beam Model

Command/Display F E

8.

Create Nodal Constraints/DOF dialog box: Fixed OK Notice: All DOF are selected.

9.

Entity Selection dialog box: Select All OK Notice: Finally, you’ll restrain the DOF for all nodes in the Z translation and all rotations.

10.

Create Nodal Constraints dialog box: DOF: TZ, RX, RY, RZ (check) OK

11.

No (to combine the constraints) Entity Selection dialog box: Cancel

What Turn off element cross sections to better see the constraints.

How Step

UI

Command/Display

1.

F6 key

View Options

Applying a Load to the Model

Step

UI

4-15

Command/Display

2.

View Options dialog box: Options: Element Orientation/Shape (select) Element Shape: Line/Plane Only (select) OK

Tip: If you turn the constraint labels back on, you’ll see the degree of freedom numbers displayed for each constraint. (To do this, pick F6. Pick Options, Constraint. Under Label Mode, pick Degree of Freedom.)

Applying a Load to the Model You will now apply a load in the negative Y direction to simulate something hanging from this truss. Like constraints, loads are grouped in sets. Before creating any loads, you must create a set to hold them.

What Create the load in the negative Y direction.

How Step

UI

Command/Display

1.

Model, Load, Nodal Menu

2.

New Load Set dialog box: Title: (enter a title) OK

3.

Entity Selection dialog box: Pick nodes A and B. OK

4-16 Step

UI

Analyzing a Beam Model

Command/Display

B A

4.

Create Loads on Nodes dialog box: FY: Value: -200 OK, then... Cancel Notice: The default load type is force.

Analyzing the Model Analyze the model using the NX Nastran solver.

What Create the analysis set and solve the model.

How Step

UI

Command/Display

1.

Model, Analysis Menu

Post-Processing the Results

Step

UI

2.

4-17

Command/Display Analysis Set Manager dialog box: New

3.

Analysis Set dialog box: Title: (enter a title for the solve)

4.

Analysis Program: 36..NX Nastran Analysis Type: 1..Static OK

5.

Analyze

Post-Processing the Results For this example, you will display three types of results: criteria plots, beam diagrams, and stresses on beam cross sections.

Displaying Criteria Diagrams As an alternative to contours, you can use a basic criteria display that shows the output value of each element. The primary purpose of a criteria display, however, is to limit the display based on a selected criteria.

What Display a basic criteria view of the results.

How Step

UI

Command/Display

1.

F5 key

View Select

2.

View Select dialog box: Deformed Style: Deform

3.

Contour Style: Criteria

4.

Deformed and Contour Data

5.

Select PostProcessing Data dialog box: Output Vectors: Deformation: Total Translation Contour: 3022..Beam EndA Axial Force OK (all dialog boxes)

4-18 Step

UI

Analyzing a Beam Model

Command/Display

6.

View, Rotate, Model Menu

Tip: You can press the F8 key instead of using the command above. 7.

View Rotate dialog box: Trimetric OK

What To reduce clutter, turn off display of undeformed elements.

How Step

UI

Command/Display

1.

F6 key

View Options

2.

View Options dialog box: Category: PostProcessing

3.

Options: Undeformed Model

Displaying Criteria Diagrams

Step

UI

4.

4-19

Command/Display UNCHECK Draw Entity OK

What Modify the criteria for the elements to be displayed. Display the elements above the maximum limit of 350.

How Step

UI

Command/Display

1.

F6 key

View Options

2.

View Options dialog box: Notice: The PostProcessing category is already selected.

3.

Options: Criteria Limits

4.

Minimum: 0 Maximum: 350

5.

Limits Mode: Above Maximum OK

4-20 Step

UI

Analyzing a Beam Model

Command/Display Notice: Only the elements with axial force values above 350 are displayed as shaded beams; the other elements don’t have color.

Displaying Beam Diagrams To conclude the example, you’ll generate beam diagrams of the axial stress. Beam diagrams display results along the length of line elements. You can set options to control the direction of beam diagrams.

What Generate a beam diagram of beam end axial stress.

How Step

UI

Command/Display

1.

View Select (On View Toolbar)

2.

View Select dialog box: Deformed Style: None - Model Only Contour Style: Beam Diagram

3.

Deformed and Contour Data

Displaying Beam Diagrams

Step

UI

4.

4-21

Command/Display Select PostProcessing Data dialog box: Contour: 3139..Beam EndA Pt1 Comb Stress OK (all dialog boxes)

What You can change the plane where the beam diagram will be drawn. FEMAP always draws the diagram in the plane that you choose, even if the output is actually based on forces/stresses in a different plane.

How Step

UI

Command/Display

1.

F6 key

View Options

2.

View Options dialog box: Options: Beam Diagram Default Direction: Element Z OK Notice: The beam diagrams are now drawn on the element Z plane.

4-22 Step

UI

Analyzing a Beam Model

Command/Display

What Interactively view calculated stresses on the cross-section of beam elements.

How Step

UI

Command/Display

1.

View Select (On View Toolbar)

2.

View Select dialog box: Contour Style: None - Model Only

3.

OK

4.

View, Advanced Post, Beam Cross Section Menu

5.

In Beam Cross Section Stress Control dialog box: Select Single in Elements section

6.

Click in text field next to Single, then... Pick Element 2 (Top row, towards back of model, middle element).

Displaying Beam Diagrams

Step 7.

UI

4-23

Command/Display In Location section: Position: 85

8.

Select Screen Space radio button

A plot of the Axial Stress on the cross section of the beam should now appear while the dialog box is still displayed.

9.

In Location section: Select Model Space radio button Shown zoomed in for clarity

10.

In Location section: Move the slider bar between End A and End B. This will dynamically change the results for a single element when set to Screen Space or Model Space.

4-24 Step

UI

Analyzing a Beam Model

Command/Display

11.

Position: 50

12.

Select Screen Space radio button

13.

In Show Stress section: Select Combined Shear from drop-down

14.

CHECK Vector Plot option

15.

Click Advanced button

16.

In Advanced Options dialog box: In Vector Plot Options section: UNCHECK Solid Vector option CHECK Section Outline

17.

Vector Length: 80

18.

OK (All dialog boxes)

Notice: Once the view is Redrawn or Regenerated, the graphics window will revert back to showing the model with no Beam Cross Section stresses displayed. To display the stresses again using the same options, simply choose the View, Advanced Post, Beam Cross Section command again. This is the end of this example. You don’t need to save the model file.

5.

Analyzing a Midsurface Model of an Electrical Box In this example, you will learn to work with FEMAP’s semi-automatic midsurface extraction capabilities to build an idealized model of an electrical box. To work through this example, you must have a licensed copy of NX Nastran for FEMAP. You will not be able to complete this example with the 300-node demo version.

The example includes the following steps: •

importing the geometry using the STEP interface

•

creating the midsurface model

•

meshing the model

•

applying loads and constraints

•

analyzing the model using NX Nastran

•

post-processing the results

Importing the Geometry To begin the example, you will import the geometry.

What Start FEMAP and open a new model file. Import the STEP file.

How Step

UI

Command/Display

1.

File, Import, Geometry Menu

Go to the Examples directory in your FEMAP installation. Import the mp.STP file. 2.

STEP Read Options dialog box: OK

5-2 Step

UI

Analyzing a Midsurface Model of an Electrical Box

Command/Display

3.

View, Rotate, Model Menu

Tip: You can press the F8 key instead of using the command above. 4.

View Rotate dialog box: Dimetric OK

5.

View Style Menu (on View Toolbar) Choose Wireframe

Creating the Midsurface Model Create the midsurface model, then delete the original solid. Once the midsurface has been generated, you will need to so some additional cleanup work on the geometry before you can mesh it.

Creating the Midsurface What Use the automatic midsurfacing capability to create a midsurface model.

How Step 1.

UI

Command/Display Zoom and rotate the part to get a better view of the points we will be picking to designate the “Target Distance” for midsurfacing.

Creating the Midsurface

Step

UI

5-3

Command/Display

2.

Geometry, Midsurface, Automatic Menu

3.

Entity Selection dialog box: Select All OK

4.

In the Mid-Surface Tolerance dialog box: OR Ctrl-D

Click the Measure Distance icon button or press Ctrl-D on the keyboard. Doing either will open FEMAP’s distance measuring tool. Notice: The Measure Distance icon button or Ctrl-D command lets you determine distance for the target thickness. The software uses this value to determine which surfaces to place a midsurface between. The target thickness should be slightly larger than the largest distance between the planes on the solids that you want midsurfaced. If the target thickness is too low, the midsurfaces will not be created. If the target thickness is too high, some midsurfaces will be created between the wrong surfaces.

5.

Locate dialog box: Methods

6.

On Point

7.

On Point dialog box: Pick point A (see following figure). OK

5-4 Step

Analyzing a Midsurface Model of an Electrical Box

UI

Command/Display

V1

A B

ZY X 8.

Pick point B. OK

9.

Midsurface Tolerance dialog box: OK (accept the value calculated by the Measure Distance command) Notice: The target thickness value should be approximately 4.93.

V1

Z Y X

Deleting the Solid What Delete the original solid.

Cleaning Up the Geometry

How Step

UI

Command/Display

1.

Delete, Geometry, Solid Menu

2.

Entity Selection dialog box: ID: 1 OK OK

3.

View Style Menu (on View Toolbar) Choose Solid

Back

Front

Cleaning Up the Geometry To create a more accurate midsurface model, you must trim each rib, then delete the top portion.

What Trim the surface of each rib.

5-5

5-6

Analyzing a Midsurface Model of an Electrical Box

How Step

UI

Command/Display

1.

Geometry, Midsurface, Trim with Curve Menu

2.

Select Surface/Solid to Trim dialog box: Pick one of the eight ribs. OK

C

3.

Entity Selection dialog box: Pick the curve on the lower portion (see C above). OK Notice: The curve now cuts through the surface.

4.

Repeat the process to trim the other seven ribs. Tip: When you are performing any command in Render mode, you can rotate the model by holding down the middle mouse button and moving the mouse.

Cleaning Up the Geometry

5-7

What Delete the top portion of each rib. How Step

UI

Command/Display

1.

Delete, Geometry, Surface Menu

2.

Entity Selection dialog box: Pick the new surfaces that have been created on the top of each rib (see D in the following figure). OK OK

D

Notice: The top of each rib has been deleted.

What .Intersect the new ribs with the walls of the electric box.

5-8

Analyzing a Midsurface Model of an Electrical Box

How Step

UI

Command/Display

1.

Geometry, Midsurface, Intersect Menu

2.

Entity Selection dialog box: Select All OK

Meshing the Model The first step in meshing the model is to assign mesh attributes for the different surfaces. If the correct attributes are not assigned, the results won’t be correct. Next, set the size for the mesh. Finally, mesh the midsurface.

Assigning Mesh Attributes What Assign the mesh attributes to the surfaces.

How Step

UI

Command/Display

1.

Geometry, Midsurface, Assign Mesh Attributes Menu

2.

Entity Selection dialog box: Select All OK

3.

Define Material - ISOTROPIC dialog box: Load

4.

In Select from Library dialog box: AISI 4340 Steel OK (Twice)

5.

“OK to Consolidate Properties by Thickness?” question box: No

Meshing the Model

Step

UI

5-9

Command/Display Notice: Each surface now has a Plate property and a material assigned to it. Clicking Yes would have minimized the number of new properties created based on similar thickness. Tip: If midsurfaces are created manually using commands such as Geometry, Surface, Offset or Geometry, Surface, Extrude, the surfaces do not have mesh attributes. You must manually assign mesh attributes by creating or assigning existing properties using the correct thickness.

Meshing the Model What Set the mesh size to the default value, then mesh the model.

How Step

UI

Command/Display

1.

Mesh, Mesh Control, Size on Surface Menu

2.

Entity Selection dialog box: Select All OK, then... Automatic Mesh Sizing dialog box: OK, then... Cancel

3.

Mesh, Geometry, Surface Menu

4.

Entity Selection dialog box: Select All OK, then... Automesh Surfaces dialog box: OK

5.

Click View Visibility icon (on View Toolbar) OR Press Crtl+Q

5-10 Step 6.

UI

Analyzing a Midsurface Model of an Electrical Box

Command/Display Visibility dialog box: Choose the Entity/Label tab Choose Draw Entity radio button

7.

UNCHECK Node box located in the Mesh section,

UNCHECK the “top-level” box for Geometry

then... 8.

Click Done

Applying Loads and Constraints To load the model, you will apply a pressure to the surface at the back of the part. You will also constrain the holes at the base.

What Create a load set, the apply a pressure to the back of the part.

Applying Loads and Constraints

5-11

How Step

UI

Command/Display

1.

Model, Load, On Surface Menu

2.

Because no load sets exist in the model, FEMAP will prompt you to create one New Load Set dialog box: Title: (enter a title)

3.

Click OK

4.

Entity Selection dialog box: ID: 129 OK Notice: Surface 129 is the middle surface at the back of the part.

5.

Create Loads on Surfaces dialog box: Pressure

6.

Pressure: Value: -1 OK, then... Cancel

5-12

Analyzing a Midsurface Model of an Electrical Box

What Constrain the holes at the bottom of the part.

How Step

UI

Command/Display

1.

Model, Constraint, On Curve Menu

2.

Because no constraint sets exist in the model, FEMAP will prompt you to create one New Constraint Set dialog box: Title: (enter a title)

3.

Click OK

4.

Entity Selection dialog box: Pick the eight curves around the holes at the base. OK Tip: You may want to rotate the model and zoom in on the corners of the model to make selection of these curves easier. While in a command you can use the middle mouse button to rotate the model as well as the Zoom and Previous Zoom icons on the View Toolbar.

5.

Create Constraints on Geometry dialog box: Pinned - No Translation OK, then... Cancel

V1 L1 C1 TT TT Y ZX Tip: To see the nodes on which the loads and constraints are applied, use the Model, Load, Expand and Model, Constraint, Expand commands.

Analyzing the Model

Analyzing the Model Solve the model using the NX Nastran solver.

What Create the analysis set and solve the model.

How Step

UI

Command/Display

1.

Model, Analysis Menu

Create an analysis set.

2

Analysis Program: 36..NX Nastran Analysis Type: 1..Static OK

3.

Analyze

Post-processing the Results For this analysis, you will display deformation and stress contours.

What Display and deformed/contour plot of translation and stress.

How Step

UI

Command/Display

1.

F5 key

View Select

2.

View Select dialog box: Deformed Style: Deform Contour Style: Contour

3.

Deformed and Contour Data

4.

Select PostProcessing Data dialog box: Output Vectors: Deformation: 1..Total Translation Output Vectors: Contour: 7026..Plate Top MajorPrn Stress OK (all dialog boxes)

5-13

5-14 Step

7.

UI

Analyzing a Midsurface Model of an Electrical Box

Command/Display

Rotate the model so that you can see the back.

Notice: You can see the plate top stress contour on both faces of the plate elements.

Post-processing the Results

5-15

What Change the contour options to display double-sided planar contours. If you select a standard top or bottom plate vector for contouring, as you did above, FEMAP can automatically contour both top and bottom stresses on the same plot. How Step

UI

Command/Display

1.

F5 key

View Select

2.

View Select dialog box: Deformed and Contour Data Select PostProcessing Data dialog box: Contour Options

3.

Select Contour Options dialog box: Contour Type: Elemental

4.

Data Conversion: Average

5.

Data Conversion: Use Corner Data

6.

Other Options: Double-Sided Planar Contours OK (all dialog boxes) Notice: The display has changed. The contour now shows plate top major principle stress on the top face of the plate elements and plate bottom major principle stress on the bottom face of the plate elements.

5-16 Step

7.

UI

Analyzing a Midsurface Model of an Electrical Box

Command/Display

Rotate the model to look at the back.

Notice: The contour on the back of the part shows plate top major stress.

What To more easily see double-sided results, change the view to show the element thicknesses.

Post-processing the Results

5-17

How Step

UI

Command/Display

1.

F6 key

View Options

2.

View Options dialog box: Category: Labels, Entities and Color

3.

Options: Element - Orientation/Shape, then... Element Shape: 1..Show Fiber Thickness

4.

Category: Tools and View Style

5.

Options: Filled Edges

6.

UNCHECK Draw Entity OK Tip: You can also toggle the “Filled Edges” and the “Thickness/Cross Section” on and off very easily using the View Style menu located on the View Toolbar. Simply select Filled Edges or Thickness/Cross Section from the View Style menu to turn them off, then select the command again to turn them back on at any time. .

Notice: The contour on the back of the part shows plate top major stress This is the end of the example. You don’t need to save your model file.

5-18

Analyzing a Midsurface Model of an Electrical Box

6.

Analysis of a Simple Assembly

In this example, you will create a model of a simple assembly using contact conditions automatically generated by FEMAP, then solve the model two times using NX Nastran, once using “Glued Contact” and once using “Linear Contact”. Also, this example makes extensive use of the Model Info tree and Select Toolbar.

You will work through the entire FEMAP analysis process, which includes: •

importing the geometry of the assembly

•

creating connections between different parts of the assembly

•

meshing the model

•

applying constraints and loads

•

analyzing the model using the NX Nastran solver (Glued and Linear)

•

post-processing the results

Importing the Geometry What Import a FEMAP geometry file containing the geometry of the assembly.

How Step

UI

Command/Display

1.

File, Import, Geometry Menu

Go to the Examples directory in your FEMAP installation. Import the Assembly.x_t file.

6-2 Step

UI

Analysis of a Simple Assembly

Command/Display

2.

Solid Model Read Options dialog box: OK

3.

View, Rotate, Model Menu

Tip: You can press the F8 key instead of using the command above. 4.

View Rotate dialog box: Click Trimetric, then... Click OK

Creating Connections You will be creating connections between the different parts of the assembly. In this example, the connections will be contact conditions which NX Nastran will use during the solving process to have the parts interact with one another. In general, there are three separate entities needed to create a connection in FEMAP: Connection Property - A specific property used to set-up contact conditions for a specific solver or analysis type. We will be using the “NX Linear” tab and the Defaults button for this example. Connection Regions - Regions designated in the model which can be placed into contact with any number of other regions. Regions can be created using different types of entities such as surfaces, elements, and properties. In this example, you will create contact between the different solid parts using the surfaces of those solids. Connectors - Connectors create “contact pairs” between Connection Regions (using a Master/Slave relationship) and the contact between those regions is governed by the values set in the specified Connection Property for each Connector. Each of these entities can be created individually using the Connect menu, but FEMAP offers a few methods for creating them in a more streamlined manner. One method is to use the Connect, Surfaces command which simply allows you to choose a surface (or set of surfaces) to “connect” to another surface (or set of surfaces). The surfaces in each set will be used to create the Connection Regions, a Connection Property can be chosen (or created from inside this command), and then a single Connector will be created between the selected surfaces.

Automatic Connection Creation

6-3

In this example, we will be using the Connect, Automatic command. This creates connections automatically based on the proximity of geometric entities selected in your model using a number of parameters. These parameters include specific values for Tolerance (distance between bodies) and Angle Tolerance, as well as choice of a “Detection Strategy” (Minimal to Aggressive) and options for the way multiple Connection Regions will be combined on the same solid.

Automatic Connection Creation What Create connections automatically between the parts of the assembly.

How Step

UI

Command/Display

1.

Connect, Automatic... Menu

2.

Entity Selection - Select Solid(s) to Detect Connections dialog box: Click Select All, then... Click OK Auto Detection Options for Connections dialog box: The following values should be selected:

If it does not, make sure all of the above options are chosen. Then...

6-4 Step 3.

UI

Analysis of a Simple Assembly

Command/Display Click OK Entity Selection - Select Solid(s) to Detect Connections dialog box: Click Cancel Tip: Creating connections automatically can also be accomplished by using the “context sensitive menu” for the Geometry branch in the Model Info tree. Simply highlight the top-level Geometry branch in the tree (or individual solids), then click the right mouse button and choose Automatic Connection from the menu. This will bring up the Connect, Automatic command

You will notice the there are new Connection Regions which are visible where the parts come together.

You can take a closer look at each Connection Property, Connection Region, and Connector created using the Connections branch of the Model Info tree.

Examining Created Connections

6-5

Examining Created Connections Using a few “context sensitive menu” commands from the Connections branch of the Model Info tree, you can graphically see the different Connection Regions and Connectors which were created by the Connect, Automatic command. If it is not open, you will need to have the Model Info tree open for this step.

What Use the Model Info tree to examine the connections in the model.

How Step

UI

Command/Display

1. Menu

If the Model Info tree is NOT already open, you can bring it up using the Tools, Model Info command to make it visible.

Tip: If you are not familiar with the Model Info tree or the other “dockable panes” in FEMAP, you can find more information about them using the Help, Dockable Panes... menu. The “dockable panes” contain a tremendous amount of features. It is highly recommended to take a look at the documentation for these very helpful tools. 2.

Model Info tree: Expand the Connections branch (click on the “+” sign to the right of the title) to see the different Connection entities

You will notice that Connection Properties, Connection Regions, and Connectors are all available in the Model Info tree.

6-6 Step 3.

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Analysis of a Simple Assembly

Command/Display Expand the Connectors branch to view the Connectors in the model

You will notice that two Connectors were created in the model by the automatic contact detection. They are listed in the following format: #(number of Connector)..Region “#-#” (“Master/Target” Connection Region - “Slave/ Source” Connection Region). Highlight “1..Region 1-2” by clicking on it. 4

Click the right mouse button on the highlighted Connector. When the “context sensitive” menu appears, choose the Show Master (Target) command.

Examining Created Connections

Step

UI

6-7

Command/Display You will notice that the “Master/Target” Connection Region of Connector “1” has been highlighted in Yellow and labeled and the rest of the parts have been made transparent in the model. If your display does not look like the one below, please see the “notice” below this cell.

The model will remain in this display state until Windows, Regenerate (Ctrl+G) has been used or a command which includes a “Regenerate” (such as an entity creation command) has been performed. Notice: The Show Master (Target) and Show Slave (Source) commands follow the current settings in the Windows, Show Entities command. By default, nothing is set in FEMAP and you will get the figure above when using the Show Master (Target) and Show Slave (Source) commands. If you have changed any of the settings in the Windows, Show Entities command itself or the Show When Selected commands in the Model Info tree or Data Table, then the Show Master (Target) and Show Slave (Source) commands will use those settings. 5

Click the right mouse button on the highlighted Connector. When the “context sensitive” menu appears, choose the Show Slave (Source) command.

6-8 Step

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Analysis of a Simple Assembly

Command/Display Tip: Although it does not matter for this model, in some cases you may want to “swap” the “Master/Target” and “Slave/Source” Connection Regions. This can be accomplished by using the Reverse command in the Connectors “context sensitive” menu

Tip: It is also possible to “Enable” and “Disable” Connectors in FEMAP. This allows you to choose which Connectors will be exported out of FEMAP for analysis. With this capability, you do not have to delete and recreate Connectors when determining which parts should be coming into contact in certain scenarios.

Applying Loads and Constraints For loads, create a load on front surface of the “Plunger”, normal to the surface. Next, create a “pinned” boundary condition using the surfaces of the rear holes of the “Baselink”.

What Create a load set, then apply a force “normal” to the front surface of the “Plunger”.

How Step

UI

Command/Display

1.

Model, Load, Create/Manage Set Menu

2.

Load Set Manager dialog box: Click New Load Set, then...

Applying Loads and Constraints

Step

UI

6-9

Command/Display

3.

New Load Set dialog box: Title: “Normal Force”

4.

Click OK, then... Load Set Manager dialog box: Click Done For the selection of the surface to load, use the Select Toolbar (Shown Undocked)

If the Select Toolbar is not visible, you can make it visible using the Tools, Toolbars, Select command or by right-mouse clicking in any area where a toolbar can be “docked” and choosing Select from menu. For more information on where a toolbar can be “docked”, please use the Help, Toolbars, Using the Toolbars command to view the documentation. All of the icons on the Select Toolbar are actually menus which allow you to modify the way the Select Toolbar will be used. For more information on the Select Toolbar, please view the documentation specifically created for it using the Help, Toolbars, Select command. 5. Menu

Using the Selector Entity menu on the Select Toolbar (first icon), select Surface. You will notice that the icon on the Select Toolbar has changed to the Select Surface icon.

This will make Surfaces “Active” in the Selector. Having an “Active” entity in the Selector allows you to choose Surfaces in the model before selecting any commands. In this case you will only be selecting one surface at a time, but there are options for selecting multiple surfaces, then choosing commands. This also will give you access to the “context sensitive menu” for the “Active” Entity Type in the graphics window. 6.

With Surface “Active” in the Select Toolbar: Pick the front round surface of the “Plunger” (surface 36). If you turn on the Entity Info dockable pane, you will be able to see which surfaces you are choosing as you pick them. Use the Tools, Entity Info command to open up this pane.

6-10 Step

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Analysis of a Simple Assembly

Command/Display

Note: The surface will NOT change color (This has been done for this example to show which surface to select), but the small “Selected Marker” (circle in above figure) will appear in FEMAP to let you know the surface has been selected. 7.

Click the right mouse button on the highlighted Surface or anywhere in the graphics window. When the “context sensitive menu” appears, choose the Load command. This will bring up the Create Loads on Surfaces dialog box. Tip: When the Select Toolbar has an “Active” entity type, a right mouse click in the graphics window will always bring up the “context sensitive menu” for the “Active” Entity Type. Because of this, you will not be able to use the “normal right-mouse menu” simply by clicking the right-mouse button. Instead you have to hold down the Alt key, then click the rightmouse button to get to the “normal right-mouse menu”. When there is no longer an “Active” Entity Type in the Select Toolbar, holding down Alt is not required. Tip: You can also use icons from various toolbars to perform commands on the entities in the currently in the Selector. In this case, you could have used the Create Load on Surface icon on the Loads Toolbar. Create Load on Surface icon

8.

Create Loads on Surfaces dialog box: Highlight Force from the selection list

9.

Select Normal to Surface in the Direction section

10.

Enter “100” in Magnitude field of the Load section

11.

Click OK

Applying Loads and Constraints

Step

UI

6-11

Command/Display

What Create a constraint set, then create “pinned” constraints on the surfaces of the rear holes of the “Baselink”.

How Step

UI

Command/Display

1.

Model, Constraint, Create/Manage Set Menu

2.

Constraint Set Manager dialog box: Click New Constraint Set, then...

3.

New Constraint Set dialog box: Title: “Pinned”

4.

Click OK, then... Constraint Set Manager dialog box: Click Done

5. Menu

Surfaces should still be the “Active” entity type in the Select Toolbar. If there is no “Active” entity, use the Selector Entity menu on the Select Toolbar (first icon) to select Surface.

Tip: The Select Toolbar remembers the last entity type which was “Active” and a shortcut to make that entity “Active” again is to simply click the Selector Entity icon. Once you are done using the Select Toolbar, click the icon again and it will toggle back to the “no active entity” icon. This is very helpful when going back and forth between using the select toolbar and using FEMAP in the more “traditional” manner (i.e. selecting commands, then entities, then performing the actual command).

6-12 Step

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Analysis of a Simple Assembly

Command/Display

6.

Using the Selector Mode menu (second icon on the Select Toolbar), choose Select Multiple. Menu

This will allow you to choose multiple entities of the current “Active” entity type and create a “Selection List”. You can actually change the “Active” entity and place multiple entities of different types into the same Selection List. Tip: The Selection List can be viewed at the bottom of the Model Info tree. The entity types currently in the Selection List will be listed and the number of each entity type currently in the list will be shown in parenthesis after the entity type name

If you right-click any entity type in the Selection List, you will notice the same “context sensitive menu” will appear for each entity type, as when the entity type is active in the Select Toolbar. This can be an excellent way to get to commonly used commands when you are performing operations on different entity types.

Applying Loads and Constraints

Step 7.

UI

6-13

Command/Display With Surface “Active” in the Select Toolbar: Pick the 4 surfaces of the rear holes of the “Baselink” (surfaces 1, 2, 31, and 32).

Note: The surfaces will NOT change color (This has been done for this example to show which surfaces to select), but the small “Selected Markers” (circles in above figure) will appear in FEMAP to let you know the surfaces have been selected. 8.

Click the right mouse button on any of the highlighted Surfaces or anywhere in the graphics window. When the “context sensitive menu” appears, choose the Constraint command. This will bring up the Create Constraints on Surfaces dialog box.

9.

Create Constraints on Geometry dialog box: Pinned - No Translation

10.

Click OK

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Analysis of a Simple Assembly

Meshing the Model You will be using the Model Info tree to select the solids to mesh and then a command from the Solid “context sensitive menu” to actually mesh the assembly. This will reduce the number of commands needed to create the mesh by prompting you to create a material and automatically creating the correct type of property required for solid tetrahedral meshing.

What Mesh the solids using the Model Info tree.

How Step 1.

UI

Command/Display In the Model Info tree: Expand the Geometry branch (click on the “+” sign to the right of the title) to see the different Geometry entities (only Solids are in the tree)

Highlight all of solids by selecting the first solid in the list (1..Baselink), then holding the Shift key down and selecting the last solid in the list (3..Pin).

Meshing the Model

Step 2.

UI

6-15

Command/Display Click the right mouse button on the highlighted Solids. When the “context sensitive menu” appears, choose the Tet mesh command.

FEMAP will prompt you to make a material to be used for all of the selected Solids 3.

Define Material - ISOTROPIC dialog box: Click Load

4.

Select from Library dialog box: AISI 4340 Steel (select)

5.

Click OK, then... Define Material - ISOTROPIC dialog box: Click OK Tip: You will notice that the model has been sized for meshing. If you want to change the mesh size to anything but the default value, you can do this by clicking the Update Mesh Sizing button in the Automesh Solids dialog box. For this example, the default mesh size is fine.

6.

In the Automesh Solids dialog box: OK The model is now meshed and now is a good time to turn off the Geometry and some other entities in the graphics window.

7.

Click View Visibility icon (on View Toolbar) OR Press Crtl+Q

Step

6-16

Analysis of a Simple Assembly

UI

Command/Display

8.

Visibility dialog box: Choose the Entity/Label tab Click All Off button

9.

CHECK Element box located in the Mesh section, then...

10.

Click Done

Notice: The Loads and Constraints are still applied to the model, they are just no longer visible. For this example, we are turning them off now for Post-Processing after the model has been solved.

THE MODEL IS NOW READY TO BE ANALYZED!

Analyzing the “Glued Contact” Model The FEMAP analysis manager stores the options for creating an input file for a solver (an analysis set). It can launch the NX NASTRAN solver or another solver that has been set up to run on the same PC. The analysis manager, together with VisQ, can also set up and run analyses with solvers on other PCs. The analysis sets are stored with the FEMAP model file, and can also be stored in a FEMAP library that can be accessed from different model files.

What Create the analysis set and solve the model.

How Step

UI

Command/Display

1.

Model, Analysis Menu

Post-processing the Results of “Glued Contact” Analysis

Step

UI

6-17

Command/Display Tip: You can also create a new Analysis Set using the Manage command on the “context sensitive menu” located on the Analyses branch in the Model Info tree (simply click to highlight the top level of the Analyses branch or any existing Analysis Set, then right mouse click to see the context sensitive menu).

2.

Analysis Set Manager dialog box: New

3.

Analysis Set dialog box: Title: Glued Contact

4.

Select “36..NX Nastran” from the Analysis Program drop-down list, then…

Select “1.. Static” from the Analysis Type drop-down list 5.

Click OK

Notice: The analysis set manager displays all analysis sets defined in the model, and the sections that make up the input file for the solver. Clicking on a plus sign will expand the tree and display individual options that can be edited by double-clicking on an option. For this analysis, you’ll use the default values for these options. 6.

Analyze

Notice: The Analysis Monitor window will display the status of the solve. You’ll know that the solve is done when the Messages dockable pane tells you that cleanup of the output set is complete.

Post-processing the Results of “Glued Contact” Analysis For this example, you will display the Deformed Shape and Contour Plot of the Solid von Mises Stress.

What Display the deformed model and the Solid von Mises Stress.

How Step

UI

Command/Display

1.

View, Select Menu

6-18 Step 2.

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Analysis of a Simple Assembly

Command/Display View Select dialog box:

Choose Deform radio button in Deformed Style section

Choose Contour radio button in Contour Style section 3.

Click Deformed and Contour Data button

4.

Select PostProcessing Data dialog box: Output Set: 1..NX Nastran Case 1 In Output Vectors: Deformation: 1..Total Translation Contour: 60031..Solid Von Mises Stress

5.

OK (all dialog boxes)

You can perform some other Post-processing commands on this model, then save the model. For some interesting Post-processing options for Solid Elements, such as Dynamic Cutting Plane and Dynamic Isosurface, see Example 7: Using postProcessing. At this point, we will now modify the Connection Property and add a Constraint to run the Model again using “Linear Contact” instead of “Glued Contact”. To do this, you will again access a command via a “context sensitive menu” from the Model Info tree.

Modifying the Connection Property What Modify the Connection Property using the Model Info tree.

Modifying the Connection Property

6-19

How Step 1.

UI

Command/Display In the Model Info tree: Expand the Connections branch (click on the “+” sign to the right of the title) to see the different Connection entities

2.

Expand the Properties branch to view the Connection Properties in the model

You will notice there is only one Connection Property in the model. You are going to modify this property and then run the analysis again. 3.

Click the right mouse button on the highlighted Connection Property. When the “context sensitive” menu appears, choose the Edit command.

6-20 4.

Analysis of a Simple Assembly

Define Connection Property dialog box: Change the Connect Type from “1..Glued” to “0..Contact”

Notice: The NX Linear tab is currently active. When you change the Connect Type from “1..Glued” to “0..Contact” certain fields are made “inactive” (grayed out) and other fields become available. 5.

Click the Defaults button at the bottom of the Define Connection Property dialog box This sets the default values for “Linear Contact” in NX Nastran.

6.

In the Contact Pair (BCTSET) section, enter the following value: Friction: 0.4

7.

Select the “2..Calculated/Zero Penetrations” option from the Initial Penetration drop-down list in the Contact Property (BCTPARM) section.

8.

Click OK

Now you will return the model to a view where another constraint can be added easily.

What Display only the Geometry, Loads and Constraints in an undeformed, uncontoured plot.

How Step

UI

Command/Display

1.

View, Select Menu

2.

View Select dialog box: Deformed Style: None - Model Only Contour Style: None - Model Only

3.

Click OK

Modifying the Connection Property

Step 4.

UI

Command/Display Click View Visibility icon (on View Toolbar) OR Press Crtl+Q

5.

UNCHECK Element box located in the Mesh section, then... CHECK Geometry... header box (checks all constraint types)

CHECK Constraints... header box (checks all constraint types)

CHECK Loads... header box (checks all load types)

6.

Click Done

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Analysis of a Simple Assembly

Applying additional Constraints for stability You may need to place a few more constraints on the model to keep the “Pin” from sliding out of the holes in the “Baselink” and the “Plunger”.

What Create some “sliding along surface” constraints set on the two ends of the “Pin”

How Step

UI

Command/Display

1. Menu

Surfaces might still be the “Active” entity type in the Select Toolbar depending on what other post-processing you did on the Glued Contact model. If there is no “Active” entity, use the Selector Entity menu on the Select Toolbar (first icon) to select Surface. Tip: The Select Toolbar remembers the last entity type which was “Active” and a shortcut to make that entity “Active” again is to simply click the Selector Entity icon. Once you are done using the Select Toolbar, click the icon again and it will toggle back to the “no active entity” icon.

2.

Clear the Selector using the Selector Clear icon (4th icon from the left on Select Toolbar).

This will clear the Selection List. Tip: Along with clearing the entire Selection List, you can instead use the Clear Active Entity command on the Clear Selector Menu.

This will only remove the entities from the Selection List which are the same entity type as “Active” entity type in the Select Toolbar. This is very helpful if you are creating a large Selection List with many different entity types. 3.

With Surface “Active” in the Select Toolbar: Pick the surfaces at each end of the “Pin” (surfaces 41 and 42). If you turn on the Entity Info dockable pane, you will be able to see which surfaces you are choosing as you pick them. Use the Tools, Entity Info command to open up this pane. Tip: You may need to rotate the model to pick both of these surfaces. When the Select Toolbar has an “Active” entity type, you can rotate the model using by holding down the middle mouse button or wheel and then moving the mouse around.

Analyzing the “Linear Contact” Model

Step

UI

6-23

Command/Display

4.

Click the right mouse button on any of the highlighted Surfaces or anywhere in the graphics window. When the “context sensitive menu” appears, choose the Constraint command. This will bring up the Create Constraints on Surfaces dialog box.

5.

Create Constraints on Geometry dialog box: Select Surface, then... Select Sliding along Surface (Symmetry)

6.

Click OK

Note: The surfaces will NOT change color (This has been done for this example to show which surfaces to select), but the small “Selected Markers” (circles in above figure) will appear in FEMAP to let you know the surfaces have been selected. THE MODEL IS NOW READY TO BE ANALYZED!

Analyzing the “Linear Contact” Model What Analyzing the model via a “context sensitive menu” from the tree.

How Step

UI

Command/Display

1.

Model, Analysis Menu

2.

Analysis Set Manager dialog box: Click Analyze

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Analysis of a Simple Assembly

Command/Display Tip: You can also get to an existing Analysis Set using the Manage command on the “context sensitive menu” located on the Analyses branch in the Model Info tree (simply click to highlight the top level of the Analyses branch or any existing Analysis Set, then right mouse click to see the context sensitive menu). Also, if you already have an Analysis Set created, you can simply use the Analyze command on the Analyses branch “context sensitive menu”. If you only have one analysis set, FEMAP will run it from the top-level Analyses branch. If you have multiple Analysis Sets, select an individual Analysis Set and then use the context sensitive menu to Analyze that set. Notice: The Analysis Monitor window will display the status of the solve. You’ll know that the solve is done when the Messages dockable pane tells you that cleanup of the output set is complete.

Post-processing the Results of “Linear Contact” Analysis For this example, you will again display the Deformed Shape and Contour Plot of the Solid von Mises Stress.

What Display the deformed model and the Solid von Mises Stress.

How Step

UI

Command/Display

1.

Click View Visibility icon (on View Toolbar) OR Press Crtl+Q

2.

Visibility dialog box: Click All Off button

3.

CHECK Element box located in the Mesh section, then...

4.

Click Done

5.

View, Select Menu

6.

View Select dialog box:

Choose Deform radio button in Deformed Style section

Choose Contour radio button in Contour Style section

Post-processing the Results of “Linear Contact” Analysis

Step

UI

6-25

Command/Display

7.

Click Deformed and Contour Data button

8.

Select PostProcessing Data dialog box: Output Set: 2..NX Nastran Case 1 In Output Vectors: Deformation: 1..Total Translation Contour: 60031..Solid Von Mises Stress Notice: The displacements and stresses are quite a bit higher for the “Linear Contact”. This is because the model was allowed to move much more compared to when the model was “Glued” together.

9.

OK (all dialog boxes)

10.

Tools, Toolbars, Post (If the Post Toolbar is already visible just click the icons shown below) Menu

This will bring up the Post Toolbar.

Click the Post Options icon from the drop-down list

from the Post Toolbar and select Actual Deformation

Notice: This can also be accomplished by 1. Pressing the F6 key or using the View, Options menu 2. Selecting Postprocessing as the category 3. Highlighting Deformed Style in the Options list 4. Unchecking the “% of Model (Actual)” box 5. Clicking OK It is much easier to use the Post Options menu on the Post Toolbar for this task

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Analysis of a Simple Assembly

Command/Display Turn off the “Filled Edges” in the model using the View Style Menu on the View Toolbar.

Select Filled Edges from the View Style and the lines representing the elements will no longer be visible. This cleans up the view somewhat for creating pictures.

Again, you can perform some other Post-processing commands on this model, then save the model. For some interesting Post-processing options for Solid Elements, such as Dynamic Cutting Plane and Dynamic Isosurface, see Example 7: Using post-Processing. This is the end of the example. You don’t need to save the model file.