Q. Is there any guidance on how to determine the parameters for a Chaboche material model?
A. You need to start by generating cyclic test data of your material application and from the test data, determine what effects (i.e. shakedown, ratcheting) need to be modeled. From there, you can use some of the guidelines found in Chapter 5 of the Advanced Structural Nonlinear Course notes for choosing the right combination of hardening models in Chaboche to start your curve fitting. ANSYS does not currently offer tools or training expertise in the area of curve fitting for this material model.
The material model involves two physics associated with kinematic hardening and isotropic hardening. They are in turn described by two sets of parameters. A correct procedure would be to carefully set up experiments to separate the two behaviors, such that curve fitting can be performed with each one. We can't use a uniaxial tensile test to get the parameters out of it such as we do for hyperelasticity, since it is the mixed behavior from the two hardenings. Also, kinematic hardening itself has several variations, so it is hard to establish a unique experimental set up. It will depend on what the test lab can do. Hence, user needs to consult with a reputable test lab (Datapoint Labs or Axel Products).
Refer also to Mechanics of Solid Materials by Lemaitre & Chaboche, English Translation by Cambridge University Press, 1990. |
Q. Is there any guidance on how to determine the parameters for a Chaboche material model?<br><br>A. You need to start by generating cyclic test data of your material application and... |
Currently in WB11, avi animations are created and saved one at a time. How can I create and save a batch of avi animations, one for each result in the Solution branch? |
Please try the attached script (JScript). To run it, choose "Tools" > "Run Macro".<br><br>It should run through each result item in the tree, and... |
When attempting to read an ACIS (.sat) or CatiaV5 (.CATPart, .CATProduct) CAD file into standard ANSYS 11.0SP1, the ANSYS Connection fails to read the CAD file, then produces messages similar to the following in the Output log window:
--------------------------------------------------
C:user1>"C:Program FilesANSYS Incv110CommonFilesCATIAV5intel_acodebin
ac4catia5.exe" "C:/testCUBE3.CATPart" "CUBE3.anf" SOLIDS ANF
The system cannot execute the specified program.
*** WARNING *** CP = 2.625 TIME= 15:23:59
File CUBE3.anf does not exist.
The /INPUT command is ignored.
--------------------------------------------------
The user may also report that the Workbench readers for ACIS and CATIAv5 work correctly, or that the problem seems to occur on some computers, but not others.
ANSYS 11.0 SP1
ANSYS Connection for Catia V5
ANSYS Connection for SAT |
The problem is that the Visual C++ 2005 Redistributable Package libraries included with the ANSYS 11.0SP1 portal download are "Visual C++ 2005", whereas the ANSYS Connection for... |
After I solve a large model in Workbench Simulation (ANSYS result file is several GB), "Evaluate All Results" takes a long time. What is a possible reason for this? |
When using "Evaluate All Results," open up the Windows Task Manager, under "Performance" tab, to see "Physical Memory" information. If the System Cache... |
I have installed CFX 11 SP1 on my Windows PC. I have the Intel Fortran compiler 10.0.027 installed.
I have used the header files cfd_constants.h and stacK_point.h in my User Fortran file spring_input.f, giving:
=========================
SUBROUTINE SPRING (
& NLOC, NRET, NARG, RET, ARGS, CRESLT, CZ,DZ,IZ,LZ,RZ )
CC
CC
#include "cfd_constants.h"
#include "stacK_point.h"
CC --------------------
CC Input
CC --------------------
CC
CC NLOC - size of current locale
CC NRET - number of components in result
CC NARG - number of arguments in call
CC ARGS() - (NLOC,NARG) argument values
...
...
==========================
However when I try to compiler the User Fortran file using
cfx5mkext spring_user.f
I get the following:
=======================
C:Program FilesIntelCompilerFortran10.0.027Ia32Binifort -iface:cvf -MD -object:winntspring_input.o -c spring_input.f
Intel (R) Visual Fortran Compiler for applications running on IA-32, Version 10.0
Build 20070809 Package ID: W_FC_C_10.0.027
Copyright (C) 1985-2007 Intel Corporation. All rights reserved.
fortcom: Warning: Bad # preprocessor line
spring_input.f(7): warning: Bad # preprocessor line
#include "cfd_constants.h"
-^
spring_input.f(8): Warning: Bad # preprocessor line
#include "stacK_point.h"
-^
spring_input.f(90) : Error: syntax error, found END-OF-STATEMENT when expecting one of: => = . < : %
___stack_point___ pVAR
------------------------------^
spring_input.f(90) : Error: The statement is positioned incorrectly and/or has syntax errors
___stack_point___ pVAR
------------------------------^
Compilation aborted for spring_input.f (code 1)
An error has occurred in cfx5mkext:
C:program filesintelcompilerfortran10.0.027ia32Binifort exited with return code 1
============================================
I was wondering if you could suggest anything? |
When you are using header files you need to specify the name of the Fortran file witha .F extension not a .f extension (ie use capital F rather than small f). The .F extension tells the compiler... |
I am using Linux, and I want to print out my report in Simulation, but there is no print button. |
This is a known limitation. Below is a workaround:<br><br>1) Click on the "Publish" button to publish the report. It will ask for a location to save the... |
A user attempts to import Catia V5 geometry into Workbench using the CADNEXUS Capri associative reader. The CADNEXUS Capri reader is installed correctly, Catia V5 CAD program is installed and licensed, but the reader still fails. The user may also report that geometry can be imported initially, but all subsequent CAD Parameter updates fail. What could be wrong? |
The problem may be caused by a Catia V5 Service Pack. To determine if a Service Pack has been applied, the user should open Catia V5, then Help > About to determine if this is the case. The... |
I am using the Lagrangian Particle Tracking based erosion models in ANSYS CFX, but the erosion rates that I am getting seem unreasonably high.
What could be causing this behavior? |
<br><br>The Finnie and Tabakoff erosion models in CFX both contain a number of adjustable constants. Without reasonable values for the constants, the erosion rates predicted in CFX... |
SYMPTOM:
In a parallel run, the following message may be received:
"An error has occurred in cfx5solve:
A CFX-5 Partitioner executable is required for this run, but none is available."
PROBLEM:
The executable which detects the architecture of a machine does not currently support the 64-bit Xeon(tm) QuadCore and AMD Opteron(tm) family
of processors. |
WORKAROUND:<br>No workaround is available.<br><br>FIXED IN:<br>ANSYS CFX Release 12.0. A custom x86info.exe executable for ANSYS CFX Release 11.0 Service Pack 1 is available on... |
I have found that when using a Porous Domain the CFX Solver is more stable with higher Volume Porosity values. In a Porous Domain, if I increase the Volume Porosity value and leave everything else the same, will the pressure drop be the same? |
<br>For some cases, a low Volume Porosity value can cause convergence problem when the flow is parallel to the Fluid-Porous interface. Convergence can sometime be improved by using a higher... |
I am trying to test the FORTRAN routine pt_injection.F from the /examples folder of the CFX installation user routine for injecting particles into a domain using a user FORTRAN routine to set the particle location, velocity, diameter, temperature, and mass flow rate. I keep getting errors when I try to run this case and would like help getting this routine to run. |
<br><br>There are a number of things to consider if you use this routine as is.<br><br>1. Make sure that the order of the return variables listed in the CCL is the same as... |
I am doing a Lagrangian Particle tracking run and would like to compute the average residence time of particles
exiting a boundary as well as compute some statistics on the distribution of residence times for the particles.
How can I do this? |
<br><br>The easiest starting point for this analysis would be to have a file which lists all the particles exiting the boundary of<br>interest and their residence or traveling... |
User observes that his model no longer converges after he switches his units from meters to inches in Workbench. The unit conversion is done correctly. Is this a bug? |
In the example presented, the material is fully incompressible and the element has restraint in normal direction on left, right and bottom. On the top, pressure is applied, which tries to compress... |
I would like to be able to read/write to files from a User Fortan routine, how can I do this? |
<br>First, a few general rules:<br><br>- file writing should only be done from Junction Box routines. If you try to write a file from a User CEL Function you can run into... |
How does my Reference Pressure or the Pressure level in my domain affect the force calculations on a boundary? |
<br>The force on a boundary is similar to taking the integral of the solution variable "Pressure" over the boundary (although it is not calculated this way). Therefore the... |
I observe sharp changes in the pressure which correspond to partition boundaries. What causes this and how can I correct it? |
<br>In general the location of partition boundaries does not affect the solution. However, there are at least 3 cases where this is not true:<br><br>1. When a partition boundary... |
The ANS_ADMIN - CAD interface configuration for ProE does not recognize Linux 64 platforms as being valid.
An installation of ProE is confirmed to be installed and configured on the machine. |
The ANS_ADMIN program in 11.0 and 11.0SP1 mistakenly did not contain entries to recognize ProE as being valid on Linux 64.<br><br> Workarounds:<br> - Re-run the Ansys setup... |
In CFX-post, sometimes when loading in large cases on windows 64 bit computer, Post will complain: ERROR in LoadDat |
VERTICES. How to fix it?<br><br>A: There is an internal socket buffer size limit on windows XP 64bit, once the case exceeds this limit, Post will echo out the above error message. The... |
How can I know when a new volume mesh is created in CFX-Mesh? |
Before creating a new volume mesh - delete the messages that are currently showing. Then create a new volume mesh - and the message box will either show error messages or a final message giving... |
The Catia V5 (Spatial) reader is unable to import assemblies (.CATProduct files). Individual Parts (.CATPart) files work OK. |
This will occur on computers where the Catia V5 reader for ANSYS/ANSYS Workbench is installed along with the CATIA v5 CAD program. It is caused by a conflict when the Cache System is enabled in... |
I want to define particle injection locations as a function of time. In CFX-Pre, I tried to use a CEL expression but that does not seem to work. So, how can I get around this restriction? |
In CFX-Pre, one cannot use CEL expression for particle injection location. However, one can use the Command Editor to enter an expression. Right click Particle Injection Region in the outline tree... |
I have used particle tracking model in CFX and I specified Mass Flow Absorption Coefficient on the wall boundaries. How can I find out the amount of particles that has been collected on the walls? |
When using particle tracking, the mass flow absorption is available to allow a fraction of particles to leave the domain when they collide with a wall. For each particle tracked, the mass flow... |
Is it possible to define non-constant restitution coefficients at wall boundaries, or a varying mass flow absorption coefficient? |
A Particle User Routine is needed to define non-constant restitution coefficients. An example (Restitution.F ) is attached to this solution.<br><br>In this example, the argument is the... |
When will Workbench support SolidEdge Version 20? |
SolidEdge 20 should work for ANSYS Workbench 11.0 SP1. However, it is not certified and therefore not supported.<br>It will definitely be supported at ANSYS Workbench V12.
|
Q) Can gasket elements be defined in WB Simulation?
A) Although in the current release of WB Simulation (as of this writing, it is version 11.0) there is no direct way to add gasket elements, this can be done easily with a Commands object. Postprocessing of gasket output quantities would need to be done with an additional Commands object under the "Solution" branch or done interactively in the ANSYS General Postprocessor.
Note that gasket elements require special node numbering to define the 'bottom' and 'top' faces, as the pressure-closure relationship is essentially a 1D constitutive model defining the stiffness behavior in the through-thickness direction.
One can take advantage of the fact that WB Simulation has a sweep meshing capability for SOLSH190 in 3D, as the SOLSH190 and INTER195 numbering are identical. This allows the user to correctly define the orientation of the through-thickness direction for gasket elements, regardless of how the geometry is oriented.
Also, if higher-order gasket elements are used, note that INTER194 and INTER193 do not have midside nodes along the thickness direction, so special attention is required for those cases.
To add 3D, lower-order gasket elements (INTER195):
1) Add a "Mesh branch > Method" object for the gasket part. Ensure that "Method: Sweep" and "Src/Trg Selection: Automatic/Manual Thin Model" are set.
2) Under "Geometry branch > Part(s)" of the gasket parts, insert a "Commands" object with the following contents:
---begin
ET,matid,null
ET,matid,195
MPDELE,ALL,matid
TB,GASKET,matid <...>
TBDATA <...>
---end
The actual gasket material parameters in "<...>" need to be specified by the user.
3) Connect the gasket part to other parts via bonded contact, if they are not a multibody part.
This will allow that part to be meshed with INTER195 elements as well as have user-defined gasket properties.
As noted above, gasket postprocessing would be done interactively in ANSYS or by inserting the relevant comma |
Q) Can gasket elements be defined in WB Simulation?<br><br>A) Although in the current release of WB Simulation (as of this writing, it is version 11.0) there is no direct way to add... |