Error occurred while adjusting topology to create cohesive cells

Dear everyone,

I am sorry if I am back again with the topology error. My previous problem Unable to find final slip is gone but then it is back to the topology error.
I have tried to simulate both step02 and step03 3D subduction. ( json file for both attached below ).
json file.tar.gz (26.4 KB)

I have different geometry (smaller than current geometry) and they worked well. I extended the geometry and starting to have this topology problem again. Previously, I can fix the problem by changing the suitable mesh size (for previous geometry was 5km. Higher than 5km, it didn’t work). I have tried also to remove the fault edge for the slab as suggested in the previous topic Values in UniformDB not specified - #10 by willic3 and changed the mesh size (smaller to coarser size). But it doesn’t work as well. ( I also attached the mesh below).
mesh_tet_alvina.exo.tar.gz - Google Drive

It seems that the problem appears each time it reads the boundary at z negative without the slab. Then the topology error at slab_top shows up. I have checked the boundary condition during the mesh generation but there is no problem with that.

Is there any way to fix this?

Thank you in advance.
Alvina KK

Your mesh has some local regions with very fine discretization. I suspect that this is causing the topology problem. Start with a relatively uniform resolution mesh. If you want higher resolution near the fault, then slowly add that in after the uniform resolution mesh works.

Dear Brad,

Thank you for your reply. I have defined the size for the surface only with a uniform size. But coreform(trelis) seems to create finer mesh at several areas.

I tried to use the uniform mesh size for all the volume larger than 10km and had the same topology issue. I have tried also using a uniform mesh size ~5km but Pylith stops working and closes the session by itself. It seems due to the big size of the memory. That is why I try to vary the mesh size.

Alvina KK

Dear Brad,

I did a smoothing for the topography before creating the surface in Coreform and the topology issue has gone.
It seems that the finer detail of the topography/bathymetry resulting the topology issue.

Thank you in advance.
Alvina KK