'lack of memory' problem in mesh module

Hi everyone!

I've been using SALOME-MECA for last few weeks, and found most problems with meshing.

I've been meshing few different models imported from STEP files, with some succeed going up to 1 700 000 elements, and sometimes I cannot even mesh model to have usable mesh. I'm trying different algoithms (those that can generate tetrahedron mesh) and different hypothesis, and could not find any reason that sometimes computation ends succesfully and sometimes getting 'lack of memory', even on simple geometry.
My question is: is there any way to deal with this problem? Some repairing geometry? Some combination of algorithms and hypothesis? Maybe 64-bit version will be solution?

Hello,

If you are able to post your STEP file here, maybe I can try to help. I have encountered meshing problems myself and tried some techniques posted in these forums and have been successful at times. At other times modification of the manner in which the underlying geometry was created causes problems and has to be re-constructed. There is no set of rules that have always worked. Much of it is trial an error as you might have already learnt or tried.

Regards
JMB

I'm working from STEP files as well, output from Catia. Here are some things I have learned that may save you some work:

-Catia V4 models often don't convert well to V5 that outputs to .stp files. Solidworks has a 'heal' process that helps, so go V4->Solidworks/heal->V5->.stp

-V5 native seems to work best to .stp output.

-Ensure the solid modeler you're getting your model from has a tight geometry - they need to reduce the tolerance of the geometry - so the edges of a box are sealed and not open at 0.0000001mm for example. 'Catia' etc will show a sealed box but after translating the box turns into six unconnected sheets. You may have to experiment with simple boxes to determine what you need.

-import .stp file into Salome-Geometry, run 'repair' option and leave default categories but increase two tolerance inputs to 1e-9 or or 0.1 (you may need to test for your model). Then Explode and go to Mesh.

-I start with Netgen 3-2-1 as it's quick, de-select Optimize and start with Coarse. If too many errors pop up, the go to Tet/Mefisto-ID/Wire and ratio similar to 1000/100/10 or 25/12/6 depending on your problem and RAM. The '1D' parameter creates the most change in the number of elements, the model size, and RAM required.

-If problems you may need to get a model that has radii/fillets turned off from your Catia modeler.<br /><br />Post edited by: J S, at: 2009/06/27 16:48