Advanced hyper mesh

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<p>HyperMesh Advanced Training</p> <p>For technical support, contact us at: PHONE (248) 614-2400. Mon Thurs: 8:00 AM to 7:00 PM (EST). Fri: 8:00 AM to 5:00 PM (EST). Ask for HyperMesh Support (248) 614-2410 hmsupport@altair.com www.altair.com</p> <p>FAX EMAIL WEB</p> <p>FTP Site: ADDRESS LOGIN PASSWORD ftp.altair.com or ftp2.altair.com ftp </p> <p>Copyright 2001 Altair Engineering, Inc., All rights reserved. Altair HyperMesh Advanced Training</p> <p>Trademark Acknowledgments: Altair HyperMesh is a registered trademark of Altair Engineering, Inc. All other trademarks and registered trademarks are the property of their respective owners.</p> <p>Comments concerning the training material may be made to documentation@altair.com.hmadvtrain_v40.doc</p> <p>Table of ContentsPreface................................................................................................................... 1</p> <p>Section 1: Advanced Geometry Clean-up and Meshing Techniques............ 3Element Quality Criteria ................................................................................................... 3 Exercise 1: Suppressing features adversely affecting element quality ................ 5 Exercise 2: Adjusting fixed points to correct surface edge definitions.................. 9 Exercise 3: Meshing around a troublesome feature ........................................... 14 Working with Defeaturing and Geometry Cleanup Tools ........................................... 23 Exercise 4: Preparing the bracket....................................................................... 25 Exercise 5: Preparing the base component........................................................ 32 Exercise 6: Meshing the parts ............................................................................ 36</p> <p>Section 2: HyperMesh Macros ....................................................................... 41Overview .......................................................................................................................... 41 What is a HyperMesh Macro .......................................................................................... 42 The Macro Menu.............................................................................................................. 42 Page..................................................................................................................... 43 Display ................................................................................................................. 43 Shortcuts.............................................................................................................. 44 Tool ...................................................................................................................... 44 Files Associated with HyperMesh Macros ................................................................... 46</p> <p>Altair Engineering</p> <p>Advanced HyperMesh</p> <p>i</p> <p>HyperMesh options Panel .............................................................................................. 47 HyperMesh Macro Commands ...................................................................................... 47 Exercise 1: Creating a button ............................................................................. 49 Process for Creating Basic HyperMesh Macros.......................................................... 52 Exercise 2: A macro to save the model .............................................................. 53 Exercise 3: A macro to create a reverse video JPEG ........................................ 57 Creating HyperMesh Macros Using Tcl ........................................................................ 61 Syntax of Macros vs Tcl/Tk.................................................................................. 62 Creating Macros using Tcl/Tk .............................................................................. 62 Tcl/Tk Help....................................................................................................................... 63 Exercise 4: Create a macro to invoke a Tcl script .............................................. 64 Exercise 5: Create a macro to save a file to a user-specified directory and filename ............................................................................................................... 65 Exercise 6: A macro that checks the model for elements having a Jacobian below a user specified value................................................................................ 68</p> <p>Appendix A: HyperMesh Macro Menu Commands ...................................... 73Macro File Example ............................................................................................. 73 Command List ................................................................................................................. 75 *appendmark() ..................................................................................................... 75 *beginmacro() ...................................................................................................... 76 *callmacro().......................................................................................................... 77 *createbutton() ..................................................................................................... 78 *createbuttongroup() ............................................................................................ 80 *createlistpanel() .................................................................................................. 82 *createmarklast().................................................................................................. 83 *createmarkpanel() .............................................................................................. 84 *createtext() ......................................................................................................... 85 *endmacro() ......................................................................................................... 86 *enterpanel() ........................................................................................................ 87 *includemacrofile() ............................................................................................... 89 *nextmacrofile().................................................................................................... 90 *prevmacrofile().................................................................................................... 91 *pushmacrofile()................................................................................................... 92 *setactivegroup().................................................................................................. 93 *setactivepage() ................................................................................................... 94</p> <p>ii</p> <p>Advanced HyperMesh</p> <p>Altair Engineering</p> <p>*setbuttongroupactivecolor()................................................................................ 95</p> <p>Appendix B: HyperMesh Tcl/Tk Interface...................................................... 97Overview .......................................................................................................................... 97 Executing Tcl/Tk Scripts ................................................................................................ 97 GUI Development ............................................................................................................ 98 Additional HyperMesh Commands .................................................................... 100 hm_answernext.................................................................................................. 100 hm_complist....................................................................................................... 101 hm_elemlist........................................................................................................ 102 hm_errormessage.............................................................................................. 103 hm_getentityvalue.............................................................................................. 104 hm_getfilename ................................................................................................. 105 hm_getfloat ........................................................................................................ 106 hm_getint ........................................................................................................... 107 hm_getmark ....................................................................................................... 108 hm_getstring ...................................................................................................... 109 hm_markclear .................................................................................................... 110 hm_nodelist........................................................................................................ 111 hm_nodevalue ................................................................................................... 112 hm_redraw ......................................................................................................... 113 hm_usermessage .............................................................................................. 114 Example ............................................................................................................. 115</p> <p>Altair Engineering</p> <p>Advanced HyperMesh iii</p> <p>iv Advanced HyperMesh</p> <p>Altair Engineering</p> <p>Preface</p> <p>PrefaceWho should attendThis course is designed for students who have attended HyperMesh Basic Training and have a working knowledge of HyperMesh. It covers two topics. The first is advanced geometry clean-up and meshing techniques. The second is macros and macro creation, a tool to improve your productivity using HyperMesh. Even if you have no experience writing any program code, by the end of this session, you will be successful at creating your own macros. Each section also includes hands-on exercises to help you become comfortable with the new techniques presented here.</p> <p>Manual notationsThis manual uses the following notations. courier for text that you type in bold italic for panel names, button names, and sub-panel names.</p> <p>Information that is of importance or warning messages will appear in a note box.</p> <p>F</p> <p>This is an example of a note box. Important information appears here.</p> <p>Macro commands may occasionally be longer than the text line of this document. In those cases, the text wraps to the next line and is slightly indented. When asked to enter such a command, type the entire command ignoring the wraparound. This will ensure the system can accurately interpret the command you entered.</p> <p>For more helpShould you desire additional help with material in this course, see the back of the title page of this manual for contact information. Comments about this manual may be directed to documentation@altair.com.</p> <p>Altair Engineering</p> <p>Advanced HyperMesh</p> <p>1</p> <p>Preface</p> <p>2</p> <p>Advanced HyperMesh</p> <p>Altair Engineering</p> <p>Altair Engineering</p> <p>Advanced Geometry Clean-Up</p> <p>Section 1: Advanced Geometry Clean-up and Meshing Techniques</p> <p>Geometry cleanup and automeshing, often cited as the most time consuming aspects of Finite Element Analysis (FEA) modeling, are the most critical aspects in generating a quality mesh that will give accurate analysis results. A methodical approach to geometry cleanup and automeshing activities can save a great deal of time in the analysis process and assist in obtaining dependable results.</p> <p>Element Quality CriteriaIn FEA modeling, element quality greatly effects the accuracy of the analysis results. Many modern FEA solvers have routines to compensate for some measure of poor element quality, but it is not a good practice to rely on these compensations. The FEA modeler must take into consideration element quality, and thereby judge whether the analysis results are meaningful. The ideal four-node (quad) plate element is a planar square. Two types of errors can result from translating a single node. If one of the nodes is translated in the plane of the remaining nodes, the interior angles change and the edge lengths vary between sides introducing skew and aspect ratio into the element. If one of the nodes is translated out of plane of the others, the result is warpage. With first order tria elements warpage is not possible, but aspect ratio and skew remain valid measures of element quality. The element checks in HyperMesh test these properties and provide feedback as to the quality of the element. Keep element quality criteria in mind while observing the geometry of the model. When trying to determine whether or not to cleanup the geometric feature, ask yourself the following questions. 1. Is this feature important to my analysis? Often designers model details that are unimportant in FEA. Tapers, fillets, steps and ridges in sheet</p> <p>Altair Engineering</p> <p>Advanced HyperMesh</p> <p>3</p> <p>Advanced Geometry Clean-Up</p> <p>Altair Engineering</p> <p>metal parts, while required for manufacturing, can often be ignored in analysis. 2. How will this feature affect my mesh and element quality? Consider the benefits and consequences of removing the feature versus meshing it. With HyperMesh, often the simplest way to answer this is to mesh with the feature, then mesh without the feature, and compare the results. Will it be easier to correct the geometry before meshing, or to correct the elements after meshing? As the geometric features become more detailed and complex, it is often easier and faster to mesh around them and correct the mesh afterwards. With the new element cleanup functionality in HyperMesh, correcting element quality becomes a simple, interactive task. Do I need to mesh the surfaces, or can this part be modeled using other techniques? Sometimes the more basic surfaceless meshing tools result in a better quality mesh faster and easier than using the surfaces presented. Tools such as spline, ruled mesh, line drag, spin, skin, and element offset can often be used to accurately represent a part without being confined to the given geometry.</p> <p>3.</p> <p>4.</p> <p>The next five example problems demonstrate how to manage these situations.</p> <p>4</p> <p>Advanced HyperMesh</p> <p>Altair Engineering</p> <p>Altair Engineering</p> <p>Advanced Geometry Clean-Up</p> <p>Exercise 1: Suppressing features adversely affecting element qualityStep 1: Retrieve the model taper.hm40In this exercise, use the automesher to create a surface mesh both before and after suppressing unnecessary feature lines. Use the cleanup sub-panel within the automesh panel to avoid extra panel navigation. 1. 2. 3. Go to the files panel from any page. Select the hm file sub-panel by clicking the corresponding radio button. Click in the text field next to file = and select taper.hm40 using...</p>

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