Q) I am trying to apply a cylindrical load (in the hoop direction) on a part in WBE Design Simulation by using a cylindrical coordinate system, but the resultant distorted shape does not look correct. What is going wrong?
A) In the initial release of this feature in WBE 9.0, there is an error in the transformation matrix when the part is not located at the Global Origin. i.e. if you have translated the part away from the global origin, then created a cylindrical coordinate system to apply a load in the "hoop" direction, the transformation may not be correct. (Ref. Defect #29648)
The only way to check, is to transfer the model to Classic Ansys, and verify the orientation of the pressures on the SURF154 elements. As a workaround, you can pick other Local Coordinate Directions until you get the orientation that you desire. |
Q) I am trying to apply a cylindrical load (in the hoop direction) on a part in WBE Design Simulation by using a cylindrical coordinate system, but the resultant distorted shape does not look... |
Q) Can you use the EKILL command within a modal analysis?
A) No. The EKILL command may be used in static and nonlinear transient analyses where the Newton-Raphson solver option is set to full explicitly in the first load step. In Ansys, modal analyses are linear by definition. |
Q) Can you use the EKILL command within a modal analysis?<br><br>A) No. The EKILL command may be used in static and nonlinear transient analyses where the Newton-Raphson solver... |
At Simulation 9.0 my Pre and Postprocessing command branches have no effect on my solution. The commands funtioned properly at 8.1 but now do not show up in my solver output and don't affect my solution. What's wrong? |
At Simulation 9.0 the Pre and Postprocessing command branches were inadvertently disabled. With the 9.0 release command objects were introduced as a replacement for Pre and Post command branches.... |
Is it possible to disable contact calculations in WORKBENCH? |
In Release 9.0, it is possible to disable all contact calculations (including FSUM) by turning off "Calculate Contact" in the details view of the answer set. This capability is a... |
After executing an ISFILE command, ANSYS gives the following message below. However, there is no element 2884. What is wrong?
*** ERROR *** CP = 17.266 TIME= 15:43:49
Stresses file does not contain a stress records for
element number 2885. You may unselect this element or
provid an element record for it in the Stress File.
The ISFILE command is ignored.
************* |
It is likely the format of the "jobname.ist" file. Make sure that this file is comma delimited AND without TABS.<br>The 10.0 documentation will be further clarified to include the TABS... |
Q. What is the status of SHELLs and Beams with regards to cast iron material models?
A. Development had determined at 8.1 that the cast iron model has very bad convergence patterns for shells and beams and is not a suitable material model for these elements. Unfortunately, the 9.0 documentation is not consistent since these elements were not completely removed from the TB,CAST and TB,UNIAXIL command documentation. This inconsistency will be corrected for 10.0 (Ref Documentation Defect 29867). |
Q. What is the status of SHELLs and Beams with regards to cast iron material models?<br><br>A. Development had determined at 8.1 that the cast iron model has very bad convergence... |
QUESTION:
Is it possible to perform an acoustic analysis and impose complex impedance as a boundary condition? The impedance is set with material property MU, however ANSYS only allows a real value for this property. Does ANSYS have any plans to extend the functionality to allow complex impedance? Alternatively, is there a workaround for achieving the same result?
--------------------------------------------------------------
ANSWER:
One method of applying complex impedance is to use SURF153/154 on the boundary. Since impedance (SF,,IMPD) is "damping at the surface," the user could put SURF153/154 with appropriate values for added mass per unit area (real constant 6) and viscosity (MP,VISC) for the real and imaginary portions of impedance:
VISC = Re[impedance]
ADMSUA = Im[impedance]/w (for z > 0)
EFS = -w*Im[impedance] (for z < 0)
If the imaginary part of impedance is negative, elastic foundation stiffness EFS (real constant 4) can be used instead of added mass per unit area ADMSUA, as ANSYS will not accept "negative" mass or stiffness.
The user should keep in mind the following:
1) The values of ADMSUA (or EFS) need to be modified between substeps since these would otherwise be frequency-dependent
2) The unsymmetric option (FSI) needs to be used between the FLUID29/30 and SURF153/154 interface |
QUESTION:<br>Is it possible to perform an acoustic analysis and impose complex impedance as a boundary condition? The impedance is set with material property MU, however ANSYS only allows a... |
Is there a method to always set a system variable to enabled (checked)
in the Workbench Simulation (DesignSpace) - Tools > Variable Manager? |
This can be accomplished by a registry setting.<br> Attached is an example which shows how to add a variable called "TRACK RESULTS" and set it equal to 1.<br> This... |
QUESTION:
I have a problem with High-Frequency Electromagnetic Analysis when using ANSYS 8.1.
The following error messages occur and the analysis terminates:
*** FATAL *** CP= 11.850 TIME= 18:32:15
Internal memory manager error during solution (too many blocks per
tag). Please report this system error to your ASD or ANSYS, Inc.
This error occurred with the Windows XP 64-bit for Itanium2. It does not occurr in Windows XP 32-bit.
The specification of a computer is as follows:
model - HP zx6000
CPU - Itanium2,1.5GHz
memory - 16GB
OS - Windows XP 64bit Edition Version 2003
ANSWER:
This appears to be related to a bug which was corrected during 9.0 development that affected symbolic assembly and HF emag problems only (HF119 and HF120).
For the PCG memory manager, we estimate the size of each memory block based on the number of defined nodes times the number of DOF per node at the start of the SOLVE command. These two element types use only 1 DOF per node and it appears that internal nodes/DOF are created later during the solution. Thus, the memory block size estimation was too low and some HF emag models resulted in a PCG memory manager error.
Below are two suggested workarounds.
1. Define a shell63 element in the input deck. ANSYS then assumes 6 dofs per node in its memory calculations and it bypasses the problem.
2. Use the assopt,frontal command which uses frontal assembly for the matrices. This is really the recommended workaround. |
QUESTION:<br><br>I have a problem with High-Frequency Electromagnetic Analysis when using ANSYS 8.1.<br>The following error messages occur and the analysis... |
Q) I would like to apply a load for pressure stiffening effects in a PSD analysis with a pressure PSD. However, that pressure loading will be considered in the PSD analysis, so how do I separate the prestress and PSD pressure loads?
A) A prestressed modal analysis can be performed to accomplish this. First, run the static analysis with the prestress pressure and the PSTRES,ON command. Then, remove the preload pressure and apply the PSD pressure in the modal analysis (with PSTRES,ON). This will create the load vector of only the PSD pressure loading. Lastly, the PSD analysis can be run as usual.
Please note that this method includes the stress stiffening effects from the first pressure loading, so the stiffness changes, but the PSD results only include the loading effects from the PSD pressure loading.
An example model is below, where the preload is a membrane pressure loading and the PSD load is an internal pressure loading.
-------------------------------
finish
/clear
MYRADIUS=3
/view,1,1,2,3
/triad,off
/auto
/prep7
et,1,181
keyopt,1,3,2
r,1,0.1
mp,ex ,1,10e6
mp,nuxy,1,.3
mp,dens,1,0.1/386.1
cylind,MYRADIUS,,0,5,0,90
vdele,all
csys,1
asel,s,loc,x,MYRADIUS
asel,inve
adele,all,,,1
csys,0
allsel,all
mshape,0
mshkey,1
esize,MYRADIUS*2*acos(-1)/80
amesh,all
lsel,s,loc,z,0
nsll,s,1
d,all,rotx
d,all,roty
d,all,uz
lsel,s,loc,x,0
nsll,s,1
d,all,ux
d,all,roty
d,all,rotz
lsel,s,loc,y,0
nsll,s,1
d,all,rotx
d,all,uy
d,all,rotz
lsel,s,loc,z,5
nsll,s,1
sf,all,pres,-1e3
allsel,all
eplot
finish
/solu
antype,static
pstres,on
ematwr,yes
solve
finish
/solu
antype,modal
modopt,lanb,10
mxpand,10
pstres,on
sfedele,all,all,pres
sfe,all,1,pres,,1e3
allsel,all
solve
finish
/solu
antype,spectr
spopt,psd
psdunit,1,pres
psdfrq,1,,1,5e3
psdval,1,1e6,1e6
lvscale,1
dmprat,0.05
pfact,1,node
psdres,disp,rel
psdcom
solve
finish
/post26
numvar,20
store,psd,5
nsol,2,node(MYRADIUS,0,5),u,x
nsol,4,node(MYRADIUS,0,5),u,z
rpsd,12,2,,,,UX_NOPRESTRESS
rpsd,14,4 |
Q) I would like to apply a load for pressure stiffening effects in a PSD analysis with a pressure PSD. However, that pressure loading will be considered in the PSD analysis, so how do I separate... |
What does a complex eigenvector output from QRDAMP mean, and can you provide an example? |
At 9.0, the complex eigenvector can be requested with MODOPT,QRDAMP,,,,,ON using the QR Damped eigenvalue extraction method. This type of output was already available in the past with DAMP or... |
The CFX5 NOx model is drastically overpredicting NOx. How can I fix this? |
It is possible that your NOx model might be tuned to a different fuel. Often, this is done through the adiabatic flame temperature. CFX5 allows the adiabatic flame temperature used by the NOx... |
In section 5.1.4.1 of the 9.0 Contact Guide, TCC is defined as the thermal contact conductance coefficient, having units of HEAT/(TIME * TEMPERATURE * AREA) for force-based node-to-surface contact, or units of HEAT/(TIME * TEMPERATURE) for the traction-based model. This seems to be inconsistant with the definition of force based and traction based. |
The units are backwards.<br><br>It should read: "...having units of HEAT/(TIME * TEMPERATURE ) for force-based node-to-surface contact, or units of HEAT/(TIME * TEMPERATURE*... |
I am having problems with a PVM parallel setup problem on Windows XP.
When I to run a parallel job the information below shows up in a command window.
hoster() 1 to start, wait id 262158
0. t80000 FINITE-5 so=""
pl_startup() trying FINITE-5
phase1() trying rsh to FINITE-5
av[0]="C:WINDOWSsystem32rsh" av[1]="FINITE-5" av[2]="-l" av[3]="CFX" av[4]="$
PVM_ROOT/lib/pvmd -s -d0x0 -nFINITE-5 1 c0a80004:11e3 4080 2 c0a80005:0000"
Bound to port 1023
EADDRINUSE on connect, trying again ...
Bound to port 1022
EADDRINUSE on connect, trying again ...
Bound to port 1021
EADDRINUSE on connect, trying again ...
Bound to port 1020
EADDRINUSE on connect, trying again ...
Bound to port 1019
EADDRINUSE on connect, trying again ...
Bound to port 1018
EADDRINUSE on connect, trying again ...
Bound toport 1017
EADDRINUSE on connect, trying again ...
Bound to port 1016
EADDRINUSE on connect, trying again ...
Bound to port 1015
Bound to port 1014
socket closed (?) after reading from :
The system cannot find the file specified.
socket closed (?) after reading from FINITE-5:
Error doing $PVM_ROOT/lib/pvmd -s -d0x0 -nFINITE-5 1 c0a80004:11e3 4080 2 c0a800
05:0000 on FINITE-5
phase1() rsh failed for host FINITE-5 |
The message `The system cannot find the file specified.¿ refers to a problem when running in distributed parallel, which is documented in the release notes of... |
How to define an interior mesh surface in ICEM CFD for later post-processing use in CFX-Post? |
<br><br>1. ICEM CFD Tetra: Mesh --> Global Mesh Size --> Define Thin Cut<br>2. ICEM CFD Hexa, 2 alternatives<br> a. Create two volume parts:<br> ... |
******** NOTICE *********
The workbench.pdf file provided on the Release 9.0 CDs (or downloads) for ANSYS Workbench Environment
and ANSYS DesignSpace is incorrect. (It is the 8.1 version of the file - ref. defect 29733).
User's that have installed 9.0 should be able to access the correct workbench.pdf
(date stamp of 11/3/2004) in the C:Program FilesAnsys Incv90CommonFilesHELPen-us
directory. The correct file can also be obtained from the ANSYS Customer Portal under Product Information > Product
Documentation > "ANSYS Workbench 9.0 Help (.pdf)" link. |
******** NOTICE *********<br><br><br>The workbench.pdf file provided on the Release 9.0 CDs (or downloads) for ANSYS Workbench Environment<br>and ANSYS DesignSpace is... |
Is there a list of Certified Linux Operating Systems for the AMD Opteron? |
Yes, the following is the list of Certified Operating Systems:<br><br>64 Opteron SuseEnterprise Server 8 kernel 2.4.21<br>64 Opteron ... |
User receives the error below when runnuing ANSYS 9.0 on HP zx6000 with dual HP Itanium and Linux AWE 3.0:
system error(22): __kmp_create_monitor: pthread_create: Invalid argument
OMP abort: fatal system error detected.
/apps/ansys_inc/v90/ansys/bin/ansys90: line 1: 3757 Aborted
/apps/ansys_inc/v90/ansys/bin/linia64/ansys.e90 -g -p ANSYS -dir /data -j "file" -s
read -l en-us -t -d X11
Details:
Solver works with CONFIG, NPROC, 1
Solver fails with /CONFIG, NPROC, 2 regardless of whether in batch or interactive mode.
What is causing this error? |
There is an environment variable that has to be set on Linux64 Altix systems that are RH 3.0.<br>It's commented out in our ansys90 script in many cases. That is because we did the 9.0... |
The monitor plots are not being updated, when restarting a run from the Solver Manager (SM). Based on the output file, the run is proceeding well. |
There are some issues that can cause monitor plots not to update:<br><br>- If the monitor data is corrupted for some reason, the residual plots will not update.<br><br>-... |
If I have a geometry that has been generated in DM (DesignModeler) or imported from another CAD package, how can I generate the negative (i.e. fluid volume) if I only have the solid parts? |
One of the easy methods to accomplish this task is to :<br>1. freeze the imported geometry;<br>2. create an enclosure solid;<br>3. use Body Opt/Slice Material to slice... |
I have a mass and a beam defined, why do I get the warning message that a real constant is referenced by 2 element types? |
The model includes BEAM189 elements defined using sections and MASS21 elements defined using real constants. By default, the first section and the real constant number is 1. ANSYS sees that the... |
Q. I get an error message when I run the AFSURF macro for a case which involves a serpentine passage. ANSYS tells me that the EN command cannot store an element because one or more nodes is not defined. What circumstance may cause this? I am running ANSYS 9.0.
A. The macro is known to fail if the distance between the serpentine passages is spanned by only one element. The work around is to refine the 3D mesh before running the AFSURF macro. Make sure there are at least two elements between them so that each 3D element is associated with no more than one surface element. |
Q. I get an error message when I run the AFSURF macro for a case which involves a serpentine passage. ANSYS tells me that the EN command cannot store an element because one or more nodes is not... |
User tries to import any Catia v5 model and nothing happens.
They don't hang per-se, just nothing happens. There were no error messages in the output.
This happens with all models and on multiple machines.
What is causing this? |
The 5 environment variables below are known to cause this. The customer will have to remove the environment variables in order for the Catia v5 connection to... |
Q. I am using the CFX-Post method to transfer heat fluxes to an ANSYS model. I have verified that the geometries match up correctly, but I am unable to see the ANSYS cdb surface after I import it. I get the following message:
"Warning - More than one patch with valid element types are defined in this file. Only the first valid patch will be used...Type,88, SURF152."
What has gone wrong?
A. CFX Post is expecting that the CDB file will contain one valid ET,#,152 command. WHen the CDB file is created, however, it will write all the ET commands that are in the ANSYS database. So you have most likely defined several sets of 152 elements, and perhaps have included only one of them in the CDB. You need to make sure that the element type of the elements actually in the CDB file corresponds to the first ET command in the CDB file.
It would be best if there were only one ET,#,152 command in the CDB file, and all the elements should be that element type number. |
Q. I am using the CFX-Post method to transfer heat fluxes to an ANSYS model. I have verified that the geometries match up correctly, but I am unable to see the ANSYS cdb surface after I import... |
I have a model with MPC184 as a revolute joint. The displacements at the two coincident nodes do not seem to be the same, however. Also, can I reuse the joint section definition? |
Usually, if the MPC184 joint is not behaving as expected, this may be due to the section definition. The local CS should be located right where the node is, so one cannot reuse a section... |