How can I suppress the common mesh at connections of multi-body parts? In a large ship structure, for example, I want a common mesh as is produced for a multi-body part at most of the shell intersections; however, for some of the connections, I want to suppress the creation of the common mesh. Can you think of any way to accomplish this? |
The solution is to use the Joint Feature. To use this feature, first create the multi-body part and set the Shared Topology type for the part to Edge Joints. Then, create a Joint feature between... |
Why can I not see my very-small model in Simulation at 11.0? I imported a 3D geometry that has an edge size less than 1um. The model cannot be displayed. |
This is just a graphics bug (defect 70253). If you mesh the model you will see the mesh. It is due to a 1e-6 tolerance in a graphics routine. It is fixed in 12.0. |
Does the directed pressure symbol for SURF156 reflect the pressure direction? |
No, this is a graphics bug (defect 60493). The pressure is being applied in the correct direction. This is fixed in ANSYS 12.0. |
Why does a circuit element cause a harmonic piezoelectric analysis to give bad results? If the resistor element is removed, the results are as expected. |
Certain circuit elements can produce ill-conditioning, and the presence of any circuit element in ANSYS 11.0 activated a solver setting that may be inappropriate for your model. Solver... |
What does the GET function ARNODE return for a 2D planar model? I have created a 1x1 planar element, and when all nodes are selected, I get an ARNODE value of 1 for each node. I was expecting to get 0.25. |
I can see how ARNODE is not giving you what you might want, but it is documented to return the edge area for 2-D planar elements. In this case, that was 1.0. If you had selected the nodes on one... |
How can I obtain a plot of the reaction force in Workbench Simulation? |
Please see the attached example in which a 5-MPa pressure is applied on an area of 100 mm^2. A Commands Object is inserted into the tree with the PRRSOL command to obtain a listing of the reaction... |
Why am I getting the error message below with PLANE223? The same model with PLANE13 doesn't produce this error. |
PLANE223 is different because it has two way thermal-structural coupling. You may be getting the negative Cv message because your value of Cp is too small. From the numerical values in your input,... |
Why are previous 2- and 3-sigma results changing when new results are inserted? |
This is defect 62032 and has been fixed in 12.0. If there are multiple 2- or 3-sigma stress requests in the solution branch and they are not evaluated simultaneously from a clean base, the... |
How can I use FEModeler to transfer a multibody TAS model to Workbench Simulation? When I do, FEModeler treats the multiple body part as a single part and I can assign different material properties to the different bodies. |
It is possible when the procedure in the attached powerpoint is followed (see slide 7). |
Why is PLANE223 giving wrong reaction forces? After the solution, the model gives reaction forces in the range of 1e8 (PRRFOR), which are not to reasonable. The same model with PLANE13 (or PLANE223 with weak coupling) gives reaction forces on the order of 1e-8. |
This is defect 63207 which is fixed in 12.0. The error is related to the element direct assembly. To calculate the reaction forces, the stiffness matrix has to be requested in the element output... |
Why will ANSYS not mesh this cyclic volume? I am not receiving any errors, and other volumes of the same model can be meshed. |
This is defect 74384 and has been fixed in 12.0. To address the problem of no error message being displayed, the following was created for this case:<br><br>*** ERROR *** ... |
How to obtain a smooth restart for small mesh changes but identical mesh topology? |
<br>There are 2 ways for performing a restart on a case with a modified mesh:<br><br>1. The standard approach is to use the interpolator<br> a. If the meshes have a... |
Why does a large NRES value (/CONFIG,NRES) affect ANSYS performance? |
The effect of a large NRES is mainly due to the fact that the results file stores the load step, time, and cumulative-iteration numbers in an array dimensioned to the NRES value. As each solution... |
Why are the NMISC = {14,34,54,74} results for a plastic elbow (PIPE60) and elastic elbow (PIPE18) pipe so drastically different? The stresses are far below yield so they should match. |
Defect 72433 was filed, and it is clear that PIPE60 is producing some very odd results, partly due to the geometry of the elbow and some ASME Code formulas; for example, the PIPE60 does not... |
What could cause the message that a contact pair has no elements? The contact was generated automatically in Simulation 11.0. |
The following are two common reasons for this:<br><br>(1) mesh-based defeaturing of very small geometry and<br><br>(2) auto-rejection of contact with too-large of a... |
Is a negative slope permitted in a plastic MISO curve (TB,MISO)? It seems to be allowed in ANSYS 11.0. |
This was unintended. A negative slope is error trapped in 12.0 (defect 72633).<br><br>The documentation below clearly states that it isn't supported.<br><br> ... |
Can a model be rotated after creating constraint equations? |
In general, no, as the coefficients are based on the geometry; for example, rotating a model by 180 degrees after connecting some remote masses with RBE3s could cause the coefficients of many of... |
UILIST returns the wrong value in the first address when used with *VMASK in a *DO loop. A simple example is supplied below. Is this a bug? |
Yes, this is a code defect (66209) that has been corrected in CommandField.F at 12.0. The problem occurs when the first value in the mask vector is false.<br><br>The problem occurs... |
I am monitoring the pilot node reactions at several time steps with the MONITOR command. The information in the MNTR file reported a zero reaction at the pilot; however, when post processing in /POST1 or /POST26, it is obvious that zeros in the MNTR file are not true. Is this a bug? |
Yes, this is defect 67413 and has been corrected at 12.0. The problem occur when LNSR,ON. The fix was made not to overwrite reaction solution for element convergence check. |
How do I do substructuring in Workbench Simulation? |
Please see the attached example which uses a Commands Object to define master degrees of freedom, then to generate, use, and expand the superelement for the linear portion of bar. |
Why is RAPPND causing ANSYS 11.0 to hang? I am using it in a Simulation Commands Object to do a response-spectrum analysis. |
This may be due to the workspace specifications that Simulation uses for your model; for example, the memory settings may be "-m 395 -db 345". If you specify the normal default... |
In ANSYS Release 11, what Poisson's ratio factor does KCALC use for plane stress? |
The KPLAN field on the KCALC command specifies whether a plane-stress or plane-strain stress intensity factor is calculated. The plane stress Poisson's ratio factor is (3-nu)/(1+nu). The... |
I notice that the solid-shell element (SOLSH190) gives me a weak buckling behaviour compared to solid and shell elements in some cases. In some specific cases, the buckling mode is unrealistic. Is this a bug? |
The SOLSH190 used a fully-coupled 3-D stress stiffness in linear buckling and pre-stressed modal analyses; however, this method does not work well if the mesh is dominated with triangles or... |
In ANSYS Release 11.0, how does AVPRIN affect stress calculations in a Random-Vibration Analysis (PSD)? |
If AVPRIN is not issued, by default, the Segalman-Reese method is used to calculate the equivalent stress (Seqv). The Segalman-Reese method calculates Seqv without calculating the principal... |
In ANSYS Release 11.0, how can results at the mid-side nodes be obtained? |
ANSYS calculates element results at the Gauss points. The results are then extrapolated to the corner nodes. Thus, results data are available only for the corner nodes (see Section 2.2 in the... |