Size of nodes vs. accuracy of FEA

[dennis77]

It's been a long time, and I don't remember why, but I get different answers (13000 psi vs 21000 psi) when I change the default mesh size. In this case, the default mesh size is ~ 1/4 inch, but the analyzed part has some holes on the order of .125 inch. I have reduced the mesh to 5 times smaller to increase resolution, but do not have a good feel for accuracy at this level. Any rules of thumb for mesh size vs. part size, etc? Appreciate your help.

 

[TheTick]

1.) nodes have no size. They are points. Elements have size.

2.) You need to do multiple iterations with decreasing element size to be sure you are converging. As element size decreases, accuracy generally increases, along with calculated stress. Do successive analyses with decreasing mesh size until the differences in results is small enough to ignore.

3.) if the small holes are not in a high stress area and not used for constraining, remove them from your geometry.

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