PrePoMax meshing issue – overlapping facets and unmeshed surfaces

General Questions
1

Hello,

I am currently using PrePoMax 2.6.2 Dev for an aircraft wing structural FEA model, and I am experiencing a problem during surface/volume meshing.

The main error I receive is:

Error: Invalid boundary mesh (overlapping facets) on surface 25 surface 25
External component has thrown an exception.

In addition, some surfaces of the model are not getting meshed, while the remaining surfaces are meshed successfully.

I have tried changing the mesh parameters, including the maximum and minimum element sizes. However, some surfaces still fail to mesh.

During meshing, I also receive messages such as:

It. 457000 - 450108 nodes created - worst tet radius 1.06207 (nodes removed 112 6780)

The mesher continues through a very large number of iterations, but some surfaces remain unmeshed.

2

Please share the .pmx file (or at least the geometry in the .step format).

3

I can’t share the file because of confidential things.

4

Even privately ? Then it will be hard to help. I assume that you can’t post screenshots either ?

1 Like
5

You mean that you see such “holes” in the mesh as in the picture? I confirm that they appear quite often.
Maybe it is a Gmesh/Netgen issue rather than a PrePoMax or Calculix issue, or is it?

Hole in the mesh
Hole in the mesh684×540 111 KB

6

Well, almost for sure if these flaws are generated by meshers (unless it’s just a visual issue). This usually comes from broken geometry (it may also have missing faces). Looks for orange warning signs.

But the issue mentioned by the OP is probably something different as the mesher reportedly fails to mesh entire geometrical surfaces. Of course, the geometry can be suspected here too and needs some checks as well as potential repairs and simplifications.

7

If you have a problematic region, you can crop it and share the file here. It will help with testing.