100% failed tetra collapse

Nathan Champion_20606

Hi,

I have a question about "Tetra mesh" process of my 2D mesh surfaces.

More precisely, I want to understand why, when I click on "fix 3d elements", almost 100% of my elems are "Tetra collapse" (see attachment). It is change only when I modify my "thresold" from 0.1 to 0.

I already seen explanations about this on support.altair, but usually when this is appearing people cannot launch an Optistruct analysis contrary to me.

Can you enlight me about the actual signification of this, potentials impacts on my analysis and results, and tips to avoid this phenomena (if its penalizing).

Best Regards,

 

100% failed.png

Community-Pasted-Attachment-1614689261399.png

Adriano Koga_20259

0.10 is already the bare minimum for Tet Collapse for OptiStruct, and it means that below that, your results are probably very compromised, and lacking accuracy.

 

You should review better how are you generating your Tetra mesh, and maybe even go SimLab for generating a good tetra mesh easily.

In HM, my suggestion would be:

- import geometry

- use autoclean-up to remove evident geometry failures

- create a 2D mesh first

- check element quality for 2D mesh, and look after small elements, aspect ratios too high, ...

- after checking, correct local bad elements

- after having your 2d mesh corrected, generate your 3D tetra mesh, using your good 2d mesh as the source.