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Sheldon's ANSYS Tips (56 entries)
 
MUFFLER
  Sheldon Imaoka (ANSYS, Inc.)
  This memo provides basic instruction on performing acoustic analyses in Workbench Mechanical 14.0. An example of calculation of transmission loss in a muffler is demonstrated.
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SIYSDCAP
  Sheldon Imaoka (ANSYS, Inc.)
  Tip on visualizing the Drucker-Prager Cap model yield surface.
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Average Rating: 8.4 (16 votes)  
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User-Defined Failure Criteria with USERFC [ZIP]
  Sheldon Imaoka (ANSYS, Inc.)
  "The FC command provides users with the ability to predict first-ply failure using maximum strain, maximum stress, or Tsai-wu failure criteria. In ANSYS 12.0.1, users can also take advantage of the userfc subroutine to define up to nine different criteria.
This memo reviews the userfc subroutine, and a sample implementation of the Hashin criterion is included."

(Week 54, week of 10/11/09)
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PSD Postprocessing of Relative Displacement [ZIP]
  Sheldon Imaoka (ANSYS, Inc.)
  "PSD users may wish to determine the relative 1-sigma results between two points. This memo covers three methods to perform this operation, in hopes that it will give users more familiarity with PSD postprocessing in ANSYS."
(Week 53, week of 03/07/09)
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Contact Analysis Tips [PDF]
  Sheldon Imaoka (ANSYS, Inc.)
  "Generally speaking, nonlinear analyses involving contact can be quite challenging to solve when the contacting area changes during the load history. However, ANSYS Workbench Simulation has very robust contact technology, along with diagnostic tools that can help the user obtain converged, accurate solutions. This memo hopes to discuss some tips related to contact analyses in hopes of aiding the user who encounters difficulties when solving contact analyses."
(Week 52, week of 02/22/09)
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Average Rating: 9.7 (29 votes)  
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Compiling UPFs and Creating Customized ANSYS Executables [PDF]
  Sheldon Imaoka (ANSYS, Inc.)
  "ANSYS User Programmable Features (UPFs) are quite powerful means of customizing ANSYS beyond the scripting capabilities of the ANSYS Parametric Design Language (APDL). Writing one’s own constitutive models or complex loading functions or even creating a user-defined element are possible with UPFs.
Because some users may find it challenging to get started using UPFs, this memo hopes to discuss general issues related to compiling and linking a customized version of ANSYS for Windows and Linux environments."

(Week 51, week of 02/08/09)
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Hill's Potential [ZIP]
  Sheldon Imaoka (ANSYS, Inc.)
  "Anisotropic plasticity using Hill’s yield criterion was introduced in ANSYS 5.7, and the extensions to anisotropic creep and viscoplasticity were added in ANSYS 6.0. While Hill’s stress potential is most commonly used for rolled sheets, it can be used for other situations where three orthogonal planes of symmetry are preserved. This memo will introduce details of the usage of Hill’s potential in ANSYS."
(Week 50, week of 08/31/08)
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Viscoelasticity [ZIP]
  Sheldon Imaoka (ANSYS, Inc.)
  "Viscoelastic constitutive models allow users to analyze the time-dependent relaxation or creep behavior of materials, including glass, polymers, solid rocket propellants, to name a few. One may view viscoelastic materials as containing an elastic and viscous component, similar to a spring and dashpot in series. This memo will introduce viscoelastic input in ANSYS and as well as cover curve-fitting procedures."
(Week 49, week of 06/08/08)
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Average Rating: 9.8 (21 votes)  
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User-Defined Output with USEROUT.F [ZIP]
  Sheldon Imaoka (ANSYS, Inc.)
  "There are various situations where a user may wish to define specific type of output to postprocess — this can range from simple evaluation of safety factors to more involved damage calculations. While APDL, the ANSYS command language, allows users to manipulate results in any manner one sees fit, user-programmable features (UPFs) also provide a means for users to calculate specific output results efficiently at the solution level."
Example of calculating fatigue and Cap (Extended Drucker-Prager) output.
(Week 48, week of 06/01/08)
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Chaboche Nonlinear Kinematic Hardening Model [PDF]
  Sheldon Imaoka (ANSYS, Inc.)
  "The Chaboche nonlinear kinematic hardening model was added in ANSYS 5.6 to complement the existing isotropic and kinematic hardening rules that users relied on. Despite its availability for nearly ten years as of the time of this writing, the Chaboche model has enjoyed limited popularity, in part because of the perceived complexity of calibrating the material parameters. This memo hopes to introduce the basics related to the Chaboche nonlinear kinematic model."
(Week 47, week of 05/04/08)
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Average Rating: 9.6 (14 votes)  
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Basics on Structural Damping (Addendum) [ZIP]
  Sheldon Imaoka (ANSYS, Inc.)
  "Since ANSYS 5.6, there have been numerous enhancements as well as facets of the software program that have changed, including treatment of damping. This article is meant to serve as an addendum to Section 6 of the author’s "Structural Damping" memo, which was written in October, 2000."
(Week 46, week of 04/27/08)
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Introduction to the Residual Vector Method [ZIP]
  Sheldon Imaoka (ANSYS, Inc.)
  "The residual vector method can improve the accuracy of mode-superposition harmonic response or transient analyses, especially when the high-frequency content of the structure is excited. This memo provides details on how users can take advantage of this analysis technique introduced in ANSYS 11.0."
(Week 45, week of 04/20/08)
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Drucker-Prager Models [PDF]
  Sheldon Imaoka (ANSYS, Inc.)
  "The Drucker-Prager material model is used for pressure-dependent inelastic behavior of materials such as soils, rock, concrete, and powder. Because ANSYS offers three different Drucker-Prager constitutive models, this memo hopes to provide a comparison of the available options."
(Week 44, week of 03/16/08)
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Average Rating: 9.8 (24 votes)  
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Meshing in Workbench [PDF]
  Sheldon Imaoka (ANSYS, Inc.)
  "Mechanical users have long enjoyed access to a variety of powerful meshing tools inside of ANSYS to generate high-quality shell, tetrahedral, and swept meshes. During the past several years, meshing in ANSYS Workbench Simulation has not only grown to encompass traditional meshing algorithms in ANSYS but has also developed many features requested by ANSYS users as well as integrated meshing technologies from ANSYS CFX and ANSYS ICEM CFD."
(Week 43, week of 03/02/08)
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Average Rating: 9.2 (24 votes)  
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Acoustic Postprocessing [ZIP]
  Sheldon Imaoka (ANSYS, Inc.)
  "Acoustic analyses in ANSYS provides insight to the propagation of sound, and both visual and aural postprocessing can aid in this objective. This memo hopes to cover postprocessing methods for acoustic problems other than standard contour and XY plots."
(Week 42, week of 11/18/07)
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Buckling in Workbench Simulation [PDF]
  Sheldon Imaoka (ANSYS, Inc.)
  "Buckling may be a concern for some situations, where a user may need to modify the design to prevent buckling within a given load range. Conversely, failure analysis may need to be performed when a structure has collapsed.
ANSYS and Workbench Simulation have many tools to aid users in solving geometric instability problems, ranging from linear (eigenvalue) buckling to nonlinear, post-buckling analyses."

(Week 41, week of 10/14/07)
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User-Defined Creep Laws with USERCREEP [ZIP]
  Sheldon Imaoka (ANSYS, Inc.)
  "ANSYS provides 13 creep equations for use with implicit creep – these range from the simple Norton law to the hyperbolic sine form to the Blackburn model to a rational polynomial expression, to name a few – that can be used to model a range of creep behavior for metals. The TBFT command provides curve-fitting functionality for the user wishing to evaluate creep material parameters from test data. Also, the user can model anisotropic creep as well as combine implicit creep with rate-independent plasticity to model a wide range of complex material response.
Despite this wealth of features, however, one may wish to incorporate one’s own creep law into ANSYS. For example, a company may have their own creep equation with material parameters already defined and validated through testing. The built-in creep laws in ANSYS assume creep used in design rather than failure analysis, so the available creep laws are meant to model primary and secondary creep – consequently, another need to incorporate a user-defined creep law would arise when a user wants to include tertiary creep and/or to evaluate creep damage.
This memo will hope to address some aspects of writing one’s own user-defined creep law with the USERCREEP.F subroutine to address this issue."

Example using Anand's model.
(Week 40, week of 10/07/07)
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User-Defined Hyperelasticity with USERHYPER [ZIP]
  Sheldon Imaoka (ANSYS, Inc.)
  "User-Programmable Features (UPFs) are an extremely useful feature for analysts that need additional advanced functionality, especially in the area of constitutive modeling.
TB,HYPER allows users to include many incompressible and compressible hyperelastic material behavior – Ogden, Arruda-Boyce, Gent, Yeoh, Blatz-Ko are but some of the available models. However, for those wishing to use a customized strain energy function, the USERHYPER.F subroutine is available."

(Week 39, week of 09/30/07.)
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Spatially-Varying Pressure Loading in Workbench Simulation [ZIP]
  Sheldon Imaoka (ANSYS, Inc.)
  "Workbench Simulation 11.0 allows users not only to apply constant pressure loads or force vectors per unit area but also to utilize hydrostatic pressure loads and line pressure loads (force per unit length), and these can be defined as a function of time. Moreover, fluid pressures can be mapped from a steady-state or transient ANSYS CFX solution.
Despite these options, there may be situations where a user may want to import a predefined, spatially-varying pressure field from an external text file. This can be accomplished through the use of a “Commands” object and APDL tables, which this memo will introduce."

(Week 38, week of 07/01/07.)
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Using CMS in Workbench Simulation [ZIP]
  Sheldon Imaoka (ANSYS, Inc.)
  "At Workbench 11.0, the ANSYS Rigid Dynamics add-on module enables users to model complex kinematic assemblies, whereby system-level performance as well as accurate force loading on components can be obtained.
Although the parts in the assembly may initially be considered rigid, an interesting, related method is the use of component mode synthesis (CMS) to account for the flexibility of parts. This memo will attempt to cover a way in which users can incorporate CMS in their multibody analyses in Workbench Simulation."

[For version 12.0, use supplied "cms_use_v12.mac" instead of "cms_use.mac" - courtesy of D. Creech.]
(Week 37, week of 05/27/07.)
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Modeling Viscous Behavior [ZIP]
  Sheldon Imaoka (ANSYS, Inc.)
  "Amorphous solids or solids at elevated temperatures may exhibit viscous behavior. It may be difficult for some users to determine how best to model such behavior. This memo hopes to describe some available options in ANSYS and to differentiate between viscoelastic and viscoplastic constitutive models."
(Week 36, week of 12/03/06.)
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Using the Radiosity Solver in Workbench Simulation [PDF]
  Sheldon Imaoka (ANSYS, Inc.)
  Please note that in Workbench Mechanical 12.1, surface-to-surface radiation (using the Radiosity Solution Method) has been introduced in the GUI, so this memo is obsolete if you use version 12.1 and higher.
"Radiation can play an important role in heat transfer analyses. In Workbench Simulation 10.0, a “Radiation” load has been added to allow users to account for losses to the surroundings, although this does not include radiation exchange between surfaces.
For users wishing to utilize the ANSYS surface-to-surface radiation capabilities, this memo hopes to introduce an easy method to include these effects within Workbench Simulation via Named Selections and Command objects.
This type of methodology can be extended to include any other advanced solution feature of ANSYS which the user may wish to incorporate inside of Workbench Simulation."

(Week 35, week of 11/05/06.)
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22x Coupled-Field Elements [PDF]
  Sheldon Imaoka (ANSYS, Inc.)
  "The 22x direct coupled-field elements (PLANE223, SOLID226-227) provide a wide array of material behavior for multiphysics applications - these include piezoelectricity, piezoresistivity, thermoelasticity, and thermoelectricity. This memo hopes to introduce some of the pertinent features of these elements."
(Week 34, week of 06/11/06.)
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Using the WB Simulation Remote Solution Manager [PDF]
  Sheldon Imaoka (ANSYS, Inc.)
  "Workbench Simulation has the ability to allow the user to solve multiple jobs locally or remotely. These capabilities are defined within the “Solution” branch of WB Simulation as well as in the WB Remote Solution Manager.
"This memo hopes to introduce this capability, especially with regards to solving multiple jobs locally on a Windows machine."

(Week 33, week of 04/02/06.)
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Understanding the Response Surface Method in DesignXplorer [PDF]
  Sheldon Imaoka (ANSYS, Inc.)
  "ANSYS DesignXplorer enables the user to perform optimization studies based on multiple objectives, to account for uncertainties in product design and use, and to determine how best to improve product reliability. These tasks are accomplished through the use of response surfaces, and this memo hopes to cover some of the basics of DesignXplorer operation."
(Week 32, week of 12/18/05.)
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Manipulating FE Mesh [ZIP]
  Sheldon Imaoka (ANSYS, Inc.)
  "There are some special situations where a user may be required to generate or manipulate a database consisting mainly of finite element entities without solid model geometry. With some careful planning, dealing with mesh-only databases can prove to be relatively easy.

Typical situations that may arise include the following:
  • Import of mesh from Workbench Simulation or AI*Environment/ICEM CFD
  • Generation of repetitive geometry
This memo hopes to cover these situations in more detail."

(Week 31, week of 10/02/05.)
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Postprocessing Harmonic Results [ZIP]
  Sheldon Imaoka (ANSYS, Inc.)
  "In harmonic analyses, due to the fact that results may not be in phase, postprocessing quantities of interest can pose a challenge. Users may need to review non-sinusoidal results, such as equivalent stresses, at different locations, so accounting for phase information may be required.
This memo hopes to cover some of the more important points regarding postprocessing structural harmonic analysis results in both the General and Time-History Postprocessors."

(Week 30, week of 07/17/05.)
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QR Damped and Unsymmetric Stiffness [ZIP]
  Sheldon Imaoka (ANSYS, Inc.)
  "There have been significant enhancements to the QR Damped eigenvalue extraction method in the past several releases of ANSYS. At 8.0, the capability of including unsymmetric damping [C] matrix was introduced, along with support of damping defined via the DMPRAT and MDAMP commands.
ANSYS 8.1, the material-based constant damping ratio MP,DMPR allowed users to specify constant damping ratios per material ID in mode-superposition harmonic analyses, when used with the QRDAMP eigensolver. With the release of 9.0, QRDAMP also supports unsymmetric stiffness [K] matrix, output of complex eigenvectors, and the use of the PSOLVE command. This memo hopes to cover the use of QR Damped eigenvalue extraction method in friction problems, where an unsymmetric stiffness [K] matrix may be present. An example of this type of problem is brake squeal analyses, where the combination of ANSYS 17x contact elements and the QRDAMP eigensolver provide an easy-to-use, efficient means of determining unstable modes."

(Week 29, week of 01/09/05.)
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Acoustic Elements [ZIP]
  Sheldon Imaoka (ANSYS, Inc.)
  "For many years, ANSYS has 2D and 3D acoustic elements, including those used to model an “infinite” boundary. These elements can be used in modal, harmonic, and transient analyses, and fluid-structural interaction can also be accounted for in these simulations.

This memo hopes to review the following topics related to harmonic acoustic analyses: basic comparison of structural and acoustic elements, modeling complex impedance boundary conditions, and defining complex pressure loading. A set of input files, which analyze the case of a simple radiating sphere, is included with this memo."

(Week 28, week of 01/02/05.)
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Pressure Load Macro [ZIP]
  Sheldon Imaoka (ANSYS, Inc.)
  "In ANSYS, pressure loading via the SFx family of commands allows users to apply a force per unit area in a direction normal to the surface. Structural surface effect elements SURF153 and SURF154 extend pressure loading capabilities by allowing users to specify normal, tangential, or arbitrary distributed loading. In fact, for an arbitrary ‘distributed loading vector,’ the full or projected area may be used, with or without the tangential component of load. This type of loading can be useful in mimicking a bearing load (include tangential component) or wind loading (no tangential component), to name a couple of examples.
"Because of the fact that the vector-type of pressure loading can be based on full or projected area, with or without the tangential component, trying to determine an appropriate value for the loading can be cumbersome. The author has written a simple macro which can be used as an example in utilizing surface effects more effectively by allowing the user to specify the total force instead of pressure – the macro calculates the appropriate pressure value to be applied on the surface effect elements."

(Week 27, week of 07/04/04.)
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PSD Postprocessing [ZIP]
  Sheldon Imaoka (ANSYS, Inc.)
  "PSD, or random vibration, analyses present some interesting challenges in postprocessing due to the nature of the assumptions related to the analysis. This memo hopes to address some of these items, including evaluation of derived stresses and calculation of response power spectral density."
…An older doc I recently reanimated and updated…
(Week 26, week of 06/27/04.)
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Average Rating: 9.6 (13 votes)  
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PSD Calculation Efficiency [PDF]
  Sheldon Imaoka (ANSYS, Inc.)
  "A very common use of PSD analyses is to look at the response of a system under a single base excitation, such as the case with many aerospace and civil applications. The default PSD settings are very general in nature and may consequently be inefficient for such a situation. This memo hopes to outline some ways in which the user may obtain more efficient PSD solutions for the specific instance of single base excitation with relatively flat spectrum (although some techniques may be extrapolated for other cases)."
…An older doc I recently reanimated and updated…
(Week 25, week of 06/13/04.)
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Average Rating: 9.2 (13 votes)  
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APDL and Vector Operations [ZIP]
  Sheldon Imaoka (ANSYS, Inc.)
  "Vector and matrix operations in APDL are an invaluable method of manipulating array data, as they provide very fast, computationally efficient means of helping the user perform pre- or post-processing operations on the model.
There are many ways of storing data, ranging from arrays to tables to strings. Moreover, manipulation of numerical data can be in the form of vectors or matrices via the *Vxxx and *Mxxx commands, respectively. The user is referred to the APDL Programmer’s Guide in the ANSYS online help for a thorough discussion of the capabilities of APDL, but, in this memo, a basic introduction to vector operations will be covered."

(Week 24, week of 03/21/04.)
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PDS and Nonlinear Runs [ZIP]
  Sheldon Imaoka (ANSYS, Inc.)
  "The Probabilistic Design System (PDS) of ANSYS provides a very powerful tool in understanding the effect of uncertainties in one’s design. The details of PDS are covered in the online help, so this memo will discuss the specific case of setting up serial and parallel PDS runs as well as performing nonlinear analyses with PDS."
(Week 23, week of 03/14/04.)
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Manual Calculation of Strain Energy Density [ZIP]
  Sheldon Imaoka (ANSYS, Inc.)
  "Output of elastic, plastic, and creep strain energy densities (SEND) was introduced in ANSYS 6.0, although this is limited to 18x elements in nonlinear analyses. Users whose models include core elements with plasticity and creep may also wish to obtain these quantities, and this memo hopes to review this procedure."
(Week 22, week of 12/22/02.)
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Basics on Structural Damping [ZIP]
  Sheldon Imaoka (ANSYS, Inc.)
  This is an old document I wrote a while ago on damping which I sometimes use. Although written back at version 5.6, it is still applicable at version 7.0.
"Damping is required in many dynamic applications, yet because there are many ways to include it, there is often confusion regarding the implementation of damping in ANSYS. This memo hopes to provide a general summary of the representation of damping available in ANSYS."
(Week 21, week of 11/25/02.)
See also Addendum to "Basics on Structural Damping" memo.
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Using PSOLVE [ZIP]
  Sheldon Imaoka (ANSYS, Inc.)
  Although most often used for large-deflection prestressed modal analyses, PSOLVE has other applications which make it attractive to use, especially for large models.

PSOLVE can be used for the following situations:

  • Precise mass calculations
  • Detailed listing of contact pair information
  • Evaluation of tabular boundary conditions and loads

Since PSOLVE is a partial solution (namely, calculation of element matrices), it is usually much faster than performing an actual solution. Hence, the user may obtain any (or all) of the above three types of information prior to running an actual analysis, which can be a valuable way of verifying model input and settings prior to solution.

(Week 20, week of 07/14/02.)
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CERIG vs RBE3, RIGID184 [ZIP]
  Sheldon Imaoka (ANSYS, Inc.)
  "Constraint equations provide many useful features in ANSYS, such as tying together dissimilar meshes, representing parts of the system not explicitly modeled, or distributing loads. Two automated methods of generating constraint equations are the CERIG and RBE3 commands. Because there is often confusion over their use, this memo hopes to provide some information on differences between the two methods.
"Constraint equations in ANSYS are linear, so they are not valid for large-rotation analyses. RIGID184 is a beta element in version 6.1 which provides rigid link/beam capabilities, valid for large-rotation problems. The latter part of this memo will cover some details of this undocumented feature, available in 6.1."

(Week 19, week of 07/08/02.)
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Undocumented Hyperelastic Material Models at 5.7-6.1 [ZIP]
  Sheldon Imaoka (ANSYS, Inc.)
  "From 5.7, the 18x series of elements support a variety of hyperelastic constitutive models, namely general polynomial, Mooney-Rivlin, Neo-Hookean, Arruda-Boyce, and Ogden. Four other models have been included in 5.7 onwards, although these are undocumented options for TB,HYPER. These four models consist of the Yeoh and Gent models for incompressible behavior and the Hyperfoam and Blatz-Ko options for compressible rubbers. This memo hopes to provide a summary of these material models and of the required input."
(Week 18, week of 03/11/02.)
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APDL Coding Standards [PDF]
  Sheldon Imaoka (ANSYS, Inc.)
  "Because of the flexibility and automation APDL (ANSYS Parametric Design Language) provides, many users tend to write input files and macros in addition to using the GUI.
There are currently no recognized ‘standards’ of writing APDL macros or input files, although there may exist standards within companies on APDL coding. The lack of APDL coding standards may make inheriting someone else’s input files or macros more difficult. Also, parameter or component conflicts may also arise when using multiple macros.
This memo hopes to provide some ideas for groups or individuals wishing to develop APDL standards in writing macros or input files."

(Week 17, week of 02/18/02.)
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Long Parameter and Component Names at 6.0 [ZIP]
  Sheldon Imaoka (ANSYS, Inc.)
  "Starting from version 5.7, strings have been introduced to replace character arrays. Strings allow for up to 128 characters for APDL purposes, instead of the 8-letter limit of character parameters. The /INQUIRE command as well as string manipulation functions (see *GET online help) extend the usefulness of strings to retrieve and manipulate data. *VWRITE has also been enhanced to support C-format statements, useful in writing out long strings."
"At 6.0, the 8-character limitation on parameters, components, and /POST26 variables has been removed. Users can now specify up to 32 character for these items, allowing for much more descriptive names. In /POST26, variables can also be referred to by name when plotting or listing."

(Week 16, week of 01/28/02.)
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Review of Anisotropy, Yield Criteria, Failure Criteria [PDF]
  Sheldon Imaoka (ANSYS, Inc.)
  "This memo hopes to serve as a review of the basics of anisotropy, yield criteria, failure criteria, and the ANSYS procedure related to these topics."
(Week 15, week of 01/21/02.)
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Average Rating: 8.8 (20 votes)  
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Nonlinear Submodeling [ZIP]
  Sheldon Imaoka (ANSYS, Inc.)
  "Submodeling is often used to efficiently obtain solutions at local areas. Although submodeling may be commonly thought of as being applicable to linear static structural solutions, it can also be applied to nonlinear and transient analyses, as well as other disciplines. This memo hopes to cover the specific case of nonlinear static structural submodeling."
(Week 14, week of 01/14/02.)
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Average Rating: 9.7 (19 votes)  
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Beta Electrical Contact Features at 6.0 [ZIP]
  Sheldon Imaoka (ANSYS, Inc.)
  "This issue describes a beta feature at 6.0, which is electrical contact capability of 17x surface-to-surface contact elements. This new capability allows contact in thermal-electric and structural-thermal-electric problems."
(Week 13, week of 01/07/02.)
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Average Rating: 7.9 (28 votes)  
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Modal Cyclic Symmetry Enhancements at 6.0 [PDF]
  Sheldon Imaoka (ANSYS, Inc.)
  "At ANSYS 6.0, the modal cyclic symmetry procedure has been significantly improved. New commands, CYCLIC and CYCOPT, replace the older CYCGEN and CYCSOL macros and provide more flexibility and ease-of-use."
(Week 12, week of 12/31/01.)
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Plasticity Hardening Rules [ZIP]
  Sheldon Imaoka (ANSYS, Inc.)
  "ANSYS has a wide range of constitutive models and element technology available to the user. In this memo, the basics of isotropic and kinematic hardening for plasticity will be discussed, specifically related to proportional/non-proportional, monotonic/cyclic loading, and finite strain applications."
(Week 11, week of 12/17/01.)
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Average Rating: 9.3 (23 votes)  
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Flotran Enhancements at 6.0 [PDF]
  Sheldon Imaoka (ANSYS, Inc.)
  "There have been several enhancements to Flotran at 6.0. These changes include more robust default settings, an additional advection scheme, a new coupling algorithm, and improvements to the ALE mesh morpher."
(Week 10, week of 12/10/01.)
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Tabular Boundary Conditions and Function Editor at 6.0 [PDF]
  Sheldon Imaoka (ANSYS, Inc.)
  "This tips and tricks is an introductory memo on the use of tabular and function boundary conditions. The use of the Function Editor is also discussed."
(Week 9, week of 12/03/01.)
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Average Rating: 8.9 (28 votes)  
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Improvements to Time-History Postprocessing at 6.0 [PDF]
  Sheldon Imaoka (ANSYS, Inc.)
  "This tips and tricks focuses on improvements at 6.0 on the Time-History postprocessor. (After I did this, I realized that a lot of this was already covered in the 6.0 Update seminar, but, oh well...)"
(Week 8, week of 11/12/01.)
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Understanding Lagrange Multipliers [PDF]
  Sheldon Imaoka (ANSYS, Inc.)
  "Lagrange multipliers are a general term used in different areas of ANSYS, specifically contact and element formulation. This memo hopes to provide the user with a simplified introduction to the most important concepts in using elements with Lagrange multipliers, in hopes that some of the element options and solver selection can be better understood.
Currently, at ANSYS 6.0, the node-to-node gap element CONTA178 and the Mixed U-P formulation of the 18x elements (i.e., KEYOPT(6)>0) utilize Lagrange multipliers, so the discussion will focus on these elements."

(Week 7, week of 11/05/01.)
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Average Rating: 8.4 (16 votes)  
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Customizing GUI Behavior [PDF]
  Sheldon Imaoka (ANSYS, Inc.)
  "The /UIS and /MSTART commands provide the user with control over much of the GUI behavior. At 5.7 and 6.0, this has been extended to include control over the multilegend feature, background color, and mouse button assignment for dynamic rotations. Used in conjunction with the startxx.ans file, this allows the user to change GUI behavior in each ANSYS session."
(Week 6, week of 10/29/01.)
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Average Rating: 8.5 (10 votes)  
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Contact Wizard Enhancements at 6.0 [PDF]
  Sheldon Imaoka (ANSYS, Inc.)
  Describes some of the enhancements made to the Contact Wizard at ANSYS 6.0, including support of 17x contact elements' thermal features and ability to edit contact pair options through same interface.
(Week 5, week of 10/22/01.)
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Average Rating: 9.3 (23 votes)  
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Sparse Solver Improvements [PDF]
  Sheldon Imaoka (ANSYS, Inc.)
  "There have been various sparse solver improvements in each release of ANSYS. This memo hopes to cover some general information on the solvers available in ANSYS as well as performance improvements between ANSYS 5.6 and 6.0 related to linear static analyses."
(Week 4, week of 10/15/01.)
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Average Rating: 10.0 (1 vote)  
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Using Abbreviations to Customize the Toolbar [PDF]
  Sheldon Imaoka (ANSYS, Inc.)
  "The ANSYS Toolbar provides a useful means of accessing commonly-used functions, especially for users who use the GUI rather than typing in commands."
"This memo hopes to provide a brief introduction to the ANSYS Toolbar and, more importantly, how to assign macros or specific dialog boxes to the Toolbar buttons, including Fnc_ UIDL granules or ~eui Tcl/Tk dialog boxes."

(Week 3, week of 10/08/01.)
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Average Rating: 9.6 (12 votes)  
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Preventing Rigid-Body Motion in Contact Problems [ZIP]
  Sheldon Imaoka (ANSYS, Inc.)
  "In contact problems run in a static manner, controlling rigid-body motion may sometimes be an issue under the following circumstances: (a) force-controlled systems or (b) multiple bodies with some parts unconstrained."
"This memo hopes to address some ways of controlling rigid-body motion in contact problems through the use of options available with the surface-to-surface contact elements."

(Week 2, week of 10/03/01.)
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Average Rating: 9.7 (18 votes)  
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Creating Custom Animations [ZIP]
  Sheldon Imaoka (ANSYS, Inc.)
  "Animations are quite useful, both in presenting results of an analysis to others as well as obtaining better insight into the complex response of a system. While ANSYS has many built-in animation capabilities, sometimes, it may be necessary to create a macro for a customized animation. This memo covers one method of generating such animations."
(Week 1, week of 09/24/01.)
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Average Rating: 9.4 (31 votes)  
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