[solved] FreeCAD creates only surface mesh, no volume mesh

[baudri]

Hi,

I am struggling with FEM for a combination of three parts with different material. I tried to do it the same way as in https://www.youtube.com/watch?v=T-ggqH3tXHs

I created a compound via boolean fragments and compound filter.

Solids: 3
CompSolids: 1
Compounds: 0

When I try to mesh it, I get only a surface mesh (both with Netgen and gmsh). I think, once it worked, but I can not repeat ist.

I already replaced the screws by simple solids without any success. I also could not find any solution in the forum. Any hint would be highly appreciated.

The attached file has a low resolution grid for low file size.

I am using:
OS: Windows 10 Version 2009
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.19.24276 (Git)
Build type: Release
Branch: releases/FreeCAD-0-19
Hash: a88db11e0a908f6e38f92bfc5187b13ebe470438
Python version: 3.8.6+
Qt version: 5.15.1
Coin version: 4.0.1
OCC version: 7.5.0
Locale: German/Germany (de_DE)

[UR_]

... I get only a surface mesh ...

Can't confirm.

========================== Dump contents of mesh ==========================

1) Total number of nodes: 60084
2) Total number of edges: 798
3) Total number of faces: 8804
4) Total number of polygons: 0
5) Total number of volumes: 39138
6) Total number of polyhedrons: 0

7) Total number of linear edges: 0
8) Total number of linear faces: 0
9) Total number of linear volumes: 0

10) Total number of quadratic edges: 798
11) Total number of quadratic faces: 8804
11.1) Number of quadratic triangles: 8804
11.2) Number of quadratic quadrangles: 0
12) Total number of quadratic volumes: 39138
12.1) Number of quadratic hexahedrons: 0
12.2) Number of quadratic tetrahedrons: 39138
12.3) Number of quadratic prisms: 0
12.4) Number of quadratic pyramids: 0

===========================================================================

version (conda):
OS: Windows 10 (10.0)
Word size of FreeCAD: 64-bit
Version: 0.20.24720 (Git)
Build type: Release
Branch: master
Hash: 8b0c58d1b45017ad42bf0fa8f827f1cf22a398e7
Python version: 3.8.8
Qt version: 5.12.9
Coin version: 4.0.0
OCC version: 7.5.1
Locale: German/Germany (de_DE)

[RatonLaveur]

Same here, check your mesh in ParaView if you need to ve reassured.

[baudri]

Thanks. My first mesh also had volumes. Then, when I changed parameters to get a finer mesh, I never got volumes anymore.

When I look at the data of the FEM mesh, I get the following:

freeCad_mesh.PNG (38.23 KiB) Viewed 992 times

I deleted the mesh and again created it and now there are volumes. Did the same for at least three times before writing this post.I do not know what I did wrong the last time. Sorry for the confusion.