Some Issues Regarding Gmsh Meshing

PyLith
1

Dear Baagaard,

When I tried to embed a fault into the block, a problem occurred. Before the embedding, the mesh could be generated normally, and according to the visualization plugin, I could see that I had 30 surfaces.

30
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However, after I ran the embedding command, an error was produced.

gmsh.model.occ.fragment([(3, self.domain1)], [(2, self.s_kg)], removeTool=True)

Info    : Meshing 3D...
Info    : 3D Meshing 4 volumes with 1 connected component
Info    : Tetrahedrizing 19998 nodes...
Info    : Done tetrahedrizing 20006 nodes (Wall 0.231054s, CPU 0.203125s)
Info    : Reconstructing mesh...
Info    :  - Creating surface mesh
Info    : Found two exactly self-intersecting facets (dihedral angle  0.00000E+00).
Info    :   1st: [164, 163, 19365] #37
Info    :   2nd: [164, 163, 13517] #28
Error   : Invalid boundary mesh (overlapping facets) on surface 37 surface 28
Traceback (most recent call last):
  File "trace.py", line 305, in <module>
    App().main()
  File "F:\celltest\yt\gmsh_utils.py", line 110, in main
    self.generate_mesh(args.cell)
  File "trace.py", line 299, in generate_mesh
    gmsh.model.mesh.generate(3)
  File "E:\Anaconda3\envs\py37\lib\site-packages\gmsh.py", line 2164, in generate
    raise Exception(logger.getLastError())
Exception: Invalid boundary mesh (overlapping facets) on surface 37 surface 28

I checked the fault surface and found that the embedded fault intersected with the block boundary. In this case, could it be because the fault surface is not smooth enough, causing mesh distortion when fitting to the surface? How can I solve this type of problem?

fa
fa1720×982 199 KB

2

I can see the intersection of the green surface (fault?) and a yellow surface in the image, but I don’t understand the general context. Are the blue, yellow, and green surfaces three distinct surfaces or subsets of a single surface? What do they represent? What is the geometry of these surfaces relative to the domain? What are the constraints on the geometry of these surfaces? Are the discretizations of the surfaces consistent with the uncertainties in their geometry?