Remerciez-le!

Remerciez @Admin pour avoir partagé cet document gratuitement, de la manière la plus simple, en partageant sur les réseaux sociaux.

Basic Analysis Guide ANSYS Release 11.0 January 2007 ANSYS, Inc. and ANSYS Euro

Basic Analysis Guide ANSYS Release 11.0 January 2007 ANSYS, Inc. and ANSYS Europe, Ltd. are UL registered ISO 9001:2000 Companies. ANSYS, Inc. Southpointe 275 Technology Drive Canonsburg, PA 15317 ansysinfo@ansys.com http://www.ansys.com (T) 724-746-3304 (F) 724-514-9494 Copyright and Trademark Information © 2007 SAS IP, Inc. All rights reserved. Unauthorized use, distribution or duplication is prohibited. ANSYS, ANSYS Workbench, AUTODYN, CFX, FLUENT and any and all ANSYS, Inc. brand, product, service and feature names, logos and slogans are registered trademarks or trademarks of ANSYS, Inc. or its subsidiaries located in the United States or other countries. ICEM CFD is a trademark used by ANSYS, Inc. under license. All other brand, product, service and feature names or trademarks are the property of their respective owners. Disclaimer Notice THIS ANSYS SOFTWARE PRODUCT AND PROGRAM DOCUMENTATION INCLUDE TRADE SECRETS AND ARE CONFIDENTIAL AND PROPRIETARY PRODUCTS OF ANSYS, INC., ITS SUBSIDIARIES, OR LICENSORS.The software products and documentation are furnished by ANSYS, Inc., its subsidiaries, or affiliates under a software license agreement that contains provisions concerning non-disclosure, copying, length and nature of use, compliance with exporting laws, warranties, disclaimers, limitations of liability, and remedies, and other provisions.The software products and documentation may be used, disclosed, transferred, or copied only in accordance with the terms and conditions of that software license agreement. ANSYS, Inc. and ANSYS Europe, Ltd. are UL registered ISO 9001:2000 Companies. U.S. Government Rights For U.S. Government users, except as specifically granted by the ANSYS, Inc. software license agreement, the use, duplication, or disclosure by the United States Government is subject to restrictions stated in the ANSYS, Inc. software license agreement and FAR 12.212 (for non DOD licenses). Third-Party Software See the online documentation in the product help files for the complete Legal Notice for ANSYS proprietary software and third-party software.The ANSYS third-party software information is also available via download from the Customer Portal on the ANSYS web page. If you are unable to access the third- party legal notices, please contact ANSYS, Inc. Published in the U.S.A. Table of Contents 1. Getting Started with ANSYS ................................................................................................................... 1 1.1. Building the Model ........................................................................................................................... 1 1.1.1. Specifying a Jobname and Analysis Title ................................................................................... 1 1.1.1.1. Defining the Jobname ..................................................................................................... 1 1.1.1.2. Defining an Analysis Title ................................................................................................. 1 1.1.1.3. Defining Units ................................................................................................................. 2 1.1.2. Defining Element Types ............................................................................................................ 2 1.1.3. Defining Element Real Constants .............................................................................................. 3 1.1.3.1. Creating Cross Sections ................................................................................................... 4 1.1.4. Defining Material Properties ..................................................................................................... 4 1.1.4.1. Linear Material Properties ................................................................................................ 4 1.1.4.2. Nonlinear Material Properties .......................................................................................... 6 1.1.4.3. Anisotropic Elastic Material Properties ............................................................................. 7 1.1.4.4. Material Model Interface .................................................................................................. 7 1.1.4.4.1. Accessing the Interface ........................................................................................... 7 1.1.4.4.2. Choosing Material Behavior .................................................................................... 8 1.1.4.4.3. Entering Material Data ............................................................................................ 9 1.1.4.4.4. Logging/Editing Material Data .............................................................................. 11 1.1.4.4.5. Example: Defining a Single Material Model ............................................................ 12 1.1.4.4.6. Example: Editing Data in a Material Model ............................................................. 13 1.1.4.4.7. Example: Defining a Material Model Combination .................................................. 13 1.1.4.4.8. Material Model Interface - Miscellaneous Items ...................................................... 14 1.1.4.5. Using Material Library Files ............................................................................................ 14 1.1.4.6. Format of Material Library Files ...................................................................................... 15 1.1.4.7. Specifying a Default Read/Write Path for Material Library Files ........................................ 15 1.1.4.8. Creating (Writing) a Material Library File ......................................................................... 15 1.1.4.9. Reading a Material Library File ....................................................................................... 16 1.1.5. Creating the Model Geometry ................................................................................................ 16 1.2. Applying Loads and Obtaining the Solution .................................................................................... 17 1.2.1. Defining the Analysis Type and Analysis Options ..................................................................... 17 1.2.2. Applying Loads ...................................................................................................................... 18 1.2.3. Specifying Load Step Options ................................................................................................. 18 1.2.4. Initiating the Solution ............................................................................................................. 19 1.3. Reviewing the Results ..................................................................................................................... 19 2. Loading ................................................................................................................................................. 21 2.1.What Are Loads? ............................................................................................................................. 21 2.2. Load Steps, Substeps, and Equilibrium Iterations .............................................................................. 22 2.3.The Role of Time in Tracking ............................................................................................................ 23 2.4. Stepped Versus Ramped Loads ........................................................................................................ 24 2.5. How to Apply Loads ........................................................................................................................ 25 2.5.1. Solid-Model Loads: Advantages and Disadvantages ................................................................ 25 2.5.2. Finite-Element Loads: Advantages and Disadvantages ............................................................. 25 2.5.3. DOF Constraints ..................................................................................................................... 26 2.5.4. Applying Symmetry or Antisymmetry Boundary Conditions .................................................... 27 2.5.5.Transferring Constraints .......................................................................................................... 28 2.5.5.1. Resetting Constraints ..................................................................................................... 28 2.5.5.2. Scaling Constraint Values ............................................................................................... 29 2.5.5.3. Resolution of Conflicting Constraint Specifications ......................................................... 29 2.5.6. Forces (Concentrated Loads) ................................................................................................... 30 2.5.6.1. Repeating a Force .......................................................................................................... 31 v Basic Analysis Guide .ANSYS Release 11.0 . © SAS IP, Inc. All rights reserved. Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates. 2.5.6.2. Scaling Force Values ....................................................................................................... 31 2.5.6.3. Transferring Forces ........................................................................................................ 32 2.5.7. Surface Loads ......................................................................................................................... 32 2.5.7.1. Applying Pressure Loads on Beams ................................................................................ 33 2.5.7.2. Specifying Node Number Versus Surface Load ................................................................ 34 2.5.7.3. Specifying a Gradient Slope ........................................................................................... 34 2.5.7.4. Repeating a Surface Load .............................................................................................. 37 2.5.7.5.Transferring Surface Loads ............................................................................................. 37 2.5.7.6. Using Surface Effect Elements to Apply Loads ................................................................ 37 2.5.8. Body Loads ............................................................................................................................ 38 2.5.8.1. Specifying Body Loads for Elements ............................................................................... 39 2.5.8.2. Specifying Body Loads for Keypoints .............................................................................. 40 2.5.8.3. Specifying Body Loads on Lines, Areas and Volumes ....................................................... 41 2.5.8.4. Specifying a Uniform Body Load .................................................................................... 41 2.5.8.5. Repeating a Body Load Specification .............................................................................. 41 2.5.8.6.Transferring Body Loads ................................................................................................. 42 2.5.8.7. Scaling Body Load Values ............................................................................................... 42 2.5.8.8. Resolution of Conflicting Body Load Specifications ......................................................... 42 2.5.9. Inertia Loads .......................................................................................................................... 43 2.5.10. Coupled-Field Loads ............................................................................................................. 45 2.5.11. Axisymmetric Loads and Reactions ....................................................................................... 45 2.5.11.1. Further Hints and Restrictions ...................................................................................... 46 2.5.12. Loads to Which the DOF Offers No Resistance ....................................................................... 46 2.5.13. Initial State Loading .............................................................................................................. 46 2.5.13.1. Examples of Initial Stress Application ........................................................................... 47 2.5.13.2. Initial Stress File Format ............................................................................................... 47 2.5.13.3. Using Coordinate Systems With Initial Stress ................................................................. 48 2.5.13.4. A Sample Initial Stress Problem Using the IST File ......................................................... 48 2.5.13.5. A Sample Initial Stress Problem Using INISTATE ............................................................. 49 2.5.13.6. A Sample Output Using the WRITE Option .................................................................... 50 2.5.14. Applying Loads Using TABLE Type Array Parameters .............................................................. 50 2.5.14.1. Defining Primary Variables ........................................................................................... 51 2.5.14.2. Defining Independent Variables ................................................................................... 53 2.5.14.3. Operating on Table Parameters .................................................................................... 53 2.5.14.4.Verifying Boundary Conditions ..................................................................................... 53 2.5.14.5. Example Analysis Using 1-D Table Array ........................................................................ 54 2.5.14.6. Example Analysis Using 5-D Table Array ........................................................................ 54 2.5.15. Applying Loads Using Function Boundary Conditions ........................................................... 56 2.5.15.1. Using the Function Editor ............................................................................................ 57 2.5.15.2. Using the Function Loader ........................................................................................... 59 2.5.15.3. Example ...................................................................................................................... 60 2.5.15.4. Graphing or Listing the Boundary Condition Functions ................................................. 64 2.5.15.4.1. Graphing BC Functions ........................................................................................ 65 2.5.15.4.2. Listing BC Functions ............................................................................................ 65 2.6. How to Specify Load Step Options ................................................................................................... 66 2.6.1. General Options ..................................................................................................................... 66 2.6.1.1. Solution Controls Dialog Box ......................................................................................... 66 2.6.1.2.The Time Option ............................................................................................................ 66 2.6.1.3. Number of Substeps and Time Step Size ......................................................................... 67 2.6.1.4. Automatic Time Stepping .............................................................................................. 67 2.6.1.5. Stepping or Ramping Loads ........................................................................................... 67 2.6.1.6. Other General Options ................................................................................................... 69 Basic Analysis Guide .ANSYS Release 11.0 . © SAS IP, Inc. All rights reserved. Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates. vi Basic Analysis Guide 2.6.2. Dynamics Options .................................................................................................................. 70 2.6.3. Nonlinear Options .................................................................................................................. 71 2.6.4. Output Controls ..................................................................................................................... 72 2.6.5. Biot-Savart Options ................................................................................................................ 73 2.6.6. Spectrum Options .................................................................................................................. 73 2.7. Creating Multiple Load Step Files .................................................................................................... 73 2.8. Defining Pretension in a Joint Fastener ............................................................................................ 75 2.8.1. Applying Pretension to a Fastener Meshed as a Single Piece .................................................... 75 2.8.2. Applying Pretension to a Fastener Meshed as Two Pieces ........................................................ 76 2.8.3. Example Pretension Analysis .................................................................................................. 76 2.8.4. Example Pretension Analysis (GUI Method) ............................................................................. 80 2.8.4.1. Set the Analysis Title ...................................................................................................... 80 2.8.4.2. Define the Element Type ................................................................................................ 80 2.8.4.3. Define Material Properties ............................................................................................. 81 2.8.4.4. Set Viewing Options ...................................................................................................... 81 2.8.4.5. Create Geometry ........................................................................................................... 82 2.8.4.6. Mesh Geometry ............................................................................................................. 83 2.8.4.7. Solution: Apply Pretension ............................................................................................. 84 2.8.4.8. Postprocessing: Pretension Results ................................................................................. 84 2.8.4.9. Solution: Apply Thermal Gradient ................................................................................... 84 2.8.4.10. Postprocessing: Pretension and Thermal Results ........................................................... 85 2.8.4.11. Exit ANSYS ................................................................................................................... 85 3. Solution ................................................................................................................................................. 87 3.1. Selecting a Solver ........................................................................................................................... 87 3.2.Types of Solvers .............................................................................................................................. 89 3.2.1.The Sparse Direct Solver ......................................................................................................... 89 3.2.2.The Preconditioned Conjugate Gradient (PCG) Solver .............................................................. 90 3.2.3.The Jacobi Conjugate Gradient (JCG) Solver ............................................................................ 91 3.2.4.The Incomplete Cholesky Conjugate Gradient (ICCG) Solver .................................................... 92 3.2.5.The Quasi-Minimal Residual (QMR) Solver ............................................................................... 92 3.2.6. The Frontal Solver .................................................................................................................. 92 3.2.7.The Algebraic Multigrid (AMG) Solver ..................................................................................... 92 3.2.8.The Distributed Direct (DSPARSE) Solver ................................................................................. 93 3.2.9.The Automatic Iterative (Fast) Solver Option ............................................................................ 93 3.3. Solver Memory and Performance .................................................................................................... 94 3.3.1. Running ANSYS Solvers under Shared Memory ....................................................................... 94 3.3.2. Using ANSYS' Large Memory Capabilities with the Sparse Solver ............................................. 94 3.3.3. Disk Space (I/O) and Post-Processing Performance for Large Memory Problems ....................... 95 3.3.4. Memory Usage on Windows 32-bit Systems ............................................................................ 96 3.3.5. Estimating Run Time and File Sizes ......................................................................................... 97 3.3.5.1. Estimating Run Time ...................................................................................................... 97 3.3.5.2. Estimating File Size ........................................................................................................ 98 3.3.5.3. Estimating Memory Requirements ................................................................................. 98 3.4. Using Special Solution Controls for Certain Types of Structural Analyses ........................................... 98 3.4.1. Using Abridged Solution Menus ............................................................................................. 98 3.4.2. Using the Solution Controls Dialog Box ................................................................................... 99 3.4.3. Accessing More Information ................................................................................................. 100 3.5. Using the PGR File to Store Data for Postprocessing ....................................................................... 101 3.5.1. PGR File Capability ............................................................................................................... 101 3.5.2. Selecting Information for the PGR File ................................................................................... 102 3.5.3. PGR