Finite Element Analysis with ANSYS ®:
Information and Tips

Peter Budgell

© 1998 by Peter C. Budgell -- You are welcome to print and photocopy these pages.
These tips and comments are intended for user education purposes only. They are to be used at your own risk. The contents were originally based on my experience with ANSYS 5.3 -- more recent versions may change things. I am currently (2003) beginning to update the page. The contents do not attempt to discuss all the concepts of the finite element method that are required to obtain successful solutions. It is your responsibility to determine if you have sufficient knowledge and understanding of finite element theory to apply the software appropriately. I have attempted to give accurate information, but cannot accept liability for any consequences or damages which may result from errors in this discussion. Accordingly, I disclaim any liability for any damages including, but not limited to, injury to person or property, lost profit, data recovery charges, attorney's fees, or any other costs or expenses.

ANSYS ® ASD in Toronto, Ontario, Canada ↔ ROI Engineering Inc

Finite Element Model Detail  
8-Node Curved Shell Elements  
An FEA Model Detail

CONTENTS:

  Introductory comments:
 
About This Web Site
 
The Author
 
Links to Other FEA Information

  Author's Comments

  Detailed Information Pages:
 
FEA and Optimization Introduction Page
 
FEA Modeling Issues Page My discussion of FEA modeling issues
 
ANSYS Tips Page  My collection of ANSYS tips
 

About This Web Site

These pages are intended to serve several purposes. They introduce Finite Element Analysis (FEA), which I use regularly. They include my experiences using FEA with ANSYS®. These web pages record and share insights into ANSYS and finite element techniques that I acquire from work on various kinds of models. A page of ANSYS Tips and a page of FEA Modeling Issues give in-depth discussion. ANSYS terminology is used in these documents. I am publishing these web pages independently, and have included no proprietary insights or information. I update these pages from time to time, adding information and new items, clarifying, and correcting the way I explain things, so return here occasionally if the information is of interest to you.

My comments are restricted to FEA as it is used in analyzing mechanical engineering structures. FEA is used in many other disciplines -- for civil engineering, and to examine such things as electric and magnetic fields, acoustic fields, fluid flow, heat transfer, and their interaction with structures. Stepwise approximation with iteration to convergence makes FEA applicable to systems in which there is some nonlinearity in material properties or amplitude of displacement.

Disclaimer: When I first developed these pages, I was not affiliated with ANSYS, Inc. I now work for an ANSYS Support Distributor" (ASD). I have used ANSYS for more than 10 years in three industries. As a user, I have been happy with the software and with the support that I have received. The FEA user should understand the reason why any modeling detail is used, and whether it is acceptable. My comments in these pages are intended to communicate my own understanding of some modeling methods. There has been no independent review of the contents; there may be erroneous information here, and relevant information may be missing. Use any of the contents at your own risk. The FEA user should always show that the results of a Finite Element Analysis are valid, on the basis of other methods of analysis, previous practice, various typical checks, and experience. Many structural problems will only be highlighted in FEA if the model is intentionally designed to look for them, if a range of types of analysis are covered (e.g. static, modal, transient, buckling, fracture, thermal deformation, and nonlinear analysis) and if appropriate postprocessing is pursued in a thorough manner. A structure should reflect the contents of various codes that impose statutory regulation, as well as advise on good practice.

If you want to try ANSYS, start with a look at The ANSYS® Home Page and look for the distributor in your region. If you want to use ANSYS on a personal budget for self-teaching, consider ANSYS/ED. The ANSYS/ED program is relatively inexpensive and will let you explore the wide multiphysics range of abilities of ANSYS, on models of limited size. The 7.0 version of ANSYS/ED includes computational fluid dynamics and explicit dynamics with LS-Dyna capabilities. Because ANSYS/ED ships with the ANSYS documentation manuals on the disk, substantial self-teaching is possible.

I invite your feedback on and corrections to the contents of these pages. My email address (manually fix it – I am trying to avoid spam) is below.

Go Up to Contents

Information on the Author:

Peter C. Budgell, P.Eng.

Burlington, Ontario, Canada

I develop and analyze mechanical engineering structures. The analysis includes manual calculations, as well as modeling in the computer. Some simpler structures can be analyzed using manual calculations in a spreadsheet, such as MS Excel. This can permit optimization of a design using optimization tools that are included in the spreadsheet software. A package like MathCad makes "manual" calculations re-usable and very presentable. In ANSYS, the *VWRITE command can write data in a format that MathCad can import, and do calculations based on the results of an ANSYS model. Computer-based Finite Element Analysis can give detailed information about the stresses and deflections in a proposed design. I have worked in the automotive, railway, power generation, and CAE software consulting/sales/support/training industries.

Experience:

Finite Element Analysis:

·  Complex 3-D FEA model development with solid, axisymmetric, shell, beam, pipe, link, gap, contact, and combination elements. Complex ANSYS macro and input file development (individual files running to thousands of lines of code).

·  Solid model geometry development within ANSYS, and importation via IGES with subsequent cleanup

·  Elastic & plastic material property stress analysis

·  Thermal transient and thermal stress modeling

·  Vibration analysis (Modal, Pre-stressed, Steady State, Harmonic, Transient Linear and Transient Large Deflection)

·  Linear and nonlinear (Large Displacement) stress, buckling, and displacement analysis

·  Nodal coupling, nodal constraint, gap element, and surface contact element techniques

·  ANSYS load case techniques for efficiency

·  Development of ANSYS macros to automate FEA -- model development and results assessment

·  Development of parametrically defined models run from input files with APDL

·  Development and presentation of an ANSYS APDL training course

·  Teaching of the packaged ANSYS training courses

·  ANSYS Multiphysics modeling for MEMS and other applications

·  Animation of results

·  Computer Algebra -- Automated derivation of finite elements from first principles with the computer algebra program MACSYMA, including MACSYMA programming to identify redundancies in the algebraic expressions beyond capability supported by included Macsyma functionality, in order to output efficient Fortran code for finite element generation. Arrangement of the sequence of element derivation operations to minimize the complexity of the resulting stiffness matrix equations. Both analytical and numerical integration over the interior of the elements.

·  Masters in Engineering (Mechanical) in FEA from McMaster University in Hamilton, Ontario

Spreadsheets (Excel, Quattro Pro) for design, optimization and statistics

MathCad Worksheet development

Computer Aided Engineering

Optimization of Engineering Designs

Computer Programming (Visual Basic, C, Fortran)

Computer Graphics (programming and applications)

Engineering workstation administration: UNIX, Windows NT, Windows 95

Desktop Publishing (FrameMaker, MS Word, Word Perfect)

Statistical experimental design (DOE); Statistical Process Control

Dimensional Tolerancing

Design for Assembly

Taught Mechanics of Materials courses to 2nd and 3rd year engineering students

 

Current and previous industry experience includes:

·  ANSYS technical support, training, mentoring, and consulting

·  Tubular steam generator structures analysis, to ASME codes

·  Railway freight car structures analysis and design, to AAR codes

·  Automotive structural parts analysis and design

·  Automotive engine control parts product engineer

·  Nuclear pressure vessel equipment stress analysis and design, to ASME codes

Go Up to Contents
FEA and Optimization Introduction Page
FEA Modeling Issues Page My discussion of FEA modeling issues
ANSYS® Tips Page My collection of ANSYS tips
Author's Comments

© 1998 by Peter C. Budgell -- You are welcome to print and photocopy these pages (don't plagiarize or sell the contents).
Note to reader: The HTTP addresses used by the server require exact use of upper- and lower-case letters.

Last Revised: May 2003

Links to FEA and Other Information:

The ANSYS® Home Page at www.ansys.com
ANSYS® ASD in Toronto, Ontario, Canada ROI Engineering Inc
Dermot Monaghan's FEA Page Definitely worth studying, at www.dermotmonaghan.com
Computational Mechanics Moves Ahead from "Science and Technology Review", at Lawrence Livermore National Laboratory. Supercomputing developments in DYNA3D -- great pictures.
Finite Element Method Universal Resource
Internet Finite Element Resources
National Agency for Finite Element Methods and Standards (NAFEMS)
The Information Retrieval on Finite Element Books Organized references to many FEA textbooks.
Edinburgh Engineering Virtual Library An extensive repository of engineering information.
Introduction to Finite Element Method (Course Notes)
Finite Element Method/Boundary Element Method (Course notes -- PDF and PS formats)
Finite Element Analysis Lecture Notes PowerPoint format
TWI Job Knowledge for Welders Pages explaining welding practice -- a nice introduction with excellent pictures.
American Welding Society The AWS Home Page. Books they have available are listed in the BOOK STORE, such as "Fatigue Strength of Welded Structures, 2nd Edition" and "FWSH Design Handbook for Calculating Fillet Weld Sizes" and "Design of Weldments" and "Welded Joint Design, 2nd Edition", along with pricing.
World Centre for Materials Joining Technology
Links on Engineering Design
Self Designing Structures, Research on an FEA optimisation approach, includes interesting examples.
FIDO and ADOPT Research on FEA optimisation at Swansea
ANSYS Tutorials at the University of Alberta

NIST ANSYS Tutorials
Meshing Research Corner
Mechanical Engineering Magazine: reducing steel automobile weights
What can go wrong with FEA? One of a series of articles by KJ Bathe
Mechanical Engineering Magazine Online Including back issues -- FEA articles in most issues
Design News Web site for the magazine -- lots of info.
Engineer on a Disk A wide variety of Mech Eng topics are covered by H Jack.
MacTutor History of Mathematics Archive Tons of information on great mathematicians, and some physicists. There are real people behind all those terms you learn. The complexity of the interrelationships is far greater than what is usually mentioned in undergrad courses.

There are many other finite element information sources on the Internet – just go searching with your favourite search engine.

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