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Problems with Simulation 2009 SP1.0

Question asked by Derek Bishop on Dec 7, 2008
Latest reply on Dec 11, 2008 by Derek Bishop
The following notes were sent through to our VAR. The model comprised an assembly with parts of a vehicle mounted crane. The model was contructed for Simulation as a surface for the beams and solids for brackets and bearing plates. An attempt was made to do this two way - one way was to import the whole model into simulation and then exclude the relevant solids. There were problems hiding and showing the excluded bodies. The other way was to delete the solids from the model in the feature tree.

FEA was done on the attached assembly using SW Simulation 2009-1. The model was meshed as a combination of shells and solids. Problems encountered were as follows:

It takes a long time to carry out analysis of the model. Over an hour and a half was spent by the program just trying to solve contacts. Running this model as a complete solid was much quicker but there were concerns about the validity of the results with plates represented with one element across its thickness.

What is the minimum recommended number of elements across the plate thickness to give sensible results? In the Cosmos courses we were advised to ensure there was a minimum of two elements across the plate thickness. This normally creates a solid mesh so small that it becomes unfeasible.

The program was unable to hide a solid body after the body was excluded from the analysis. This can lead to confusion and error. In 2008 solids were hidden automatically when a component was defined with a shell mesh. This was preferred.

There were problems trying to redefine surfaces that were previously defined for mesh control after a part was excluded from the analysis or suppressed. Please investigate and advise if there is a problem here.

When trying to define shell thicknesses the program failed to correctly identify shell faces of a part that was previously excluded or suppressed. Please investigate and advise if there is a problem here.

Provide recommendations on the best way to mesh this model?

When a part in an assembly is suppressed, how does the program handle the previously specified mesh control surfaces and contacts for that part. What needs to be done by the software user when this happens to the mesh controls and contacts previously defined?

Hardware details are as follows: 8 GB of ram, Machine HP xw6400, graphics card Nvidia FX 1700, processor Core 2 Duo Intel E6850.