Triangulate Surface Mesh to GiD volumetric Mesh

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simonz
Posts: 33
Joined: Tue Oct 13, 2015 2:44 am

Re: Triangulate Surface Mesh to GiD volumetric Mesh

Postby simonz » Tue Nov 17, 2015 2:56 am

Hi escolano:
Thank you again for helping out, and those are really helpful.
I just wondering if you know after the converting, how to generate those tetrahedral meshes into 10-node tetra? Since from the process you mentioned i can only generate 4-node tetras.

Best regards.
Siyang
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escolano
Posts: 1627
Joined: Thu Sep 18, 2014 3:31 pm

Re: Triangulate Surface Mesh to GiD volumetric Mesh

Postby escolano » Tue Nov 17, 2015 11:58 am

Unfortunately we don't have a command to elevate the degree of the mesh from linear to quadratic or vice-versa to decrease the degree.
The command doesn't exits because direct edition of mesh is not the normal workflow of GiD. The normal way is to edit the geometry and then generate the mesh in a single step.

Elevate the degree with new nodes located in the mid-egde is a relativelly operation simple, maybe you could do it internally in your solver or writting some Tcl macro do do it in GiD. A detail that must be taken into account is to try to preserve, as better as possible, the attached data (conditions, materials, groups, layers)

We will think to add this feature to new GiD versions.
simonz
Posts: 33
Joined: Tue Oct 13, 2015 2:44 am

Re: Triangulate Surface Mesh to GiD volumetric Mesh

Postby simonz » Thu Feb 11, 2016 10:48 pm

Hi escolano:
I got some problems when using the command "Mescape Meshing MeshFromBoundary" for generating the tet mesh from triangulated meshes that i have.
First one is showing that there is a mesh error as shown in the attached picture as "first error" (for mesh 0001r-10000.obj), and if it requires the mesh to be moved to another specific point to be meshed?
The second one is about "Bad selection, exists 1 gaps..." (as shown in the attached picture as the second error) which I don't quite understand about how to fix this problem?(for mesh 0002r-10000).

Thank you for your time on helping me about this.

Simon
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simonz
Posts: 33
Joined: Tue Oct 13, 2015 2:44 am

Re: Triangulate Surface Mesh to GiD volumetric Mesh

Postby simonz » Tue Apr 19, 2016 9:49 pm

Hi escolano:
First, i really appreciate your continuous help to my concerns, and they are really helpful.
I was using the command code as you mentioned in this post, which is the "Mescape Meshing MeshFromBoundary" for converting my surface meshes to tet mesh, and it is pretty useful until few minutes ago. The GiD just suddenly stopped working every time after i enter the code and selected the mesh. I even reinstalled the program, while the same problem was popped out as the program stopped running after selecting the mesh.
Any idea about what'sss going on with the program?
Thanks a lot!!!!

Simon
simonz
Posts: 33
Joined: Tue Oct 13, 2015 2:44 am

Re: Triangulate Surface Mesh to GiD volumetric Mesh

Postby simonz » Sun Apr 24, 2016 5:13 am

Hi escolano:
Since i had some problem with using the code "Mescape Meshing MeshFromBoundary" for converting some of my particles to tetra, so i'm trying to use the second way as you mentioned as:
"This is not the normal flow of use of GiD, it is more natural to have a geometric volume, apply boundary conditions/materials and then generate the mesh.
As trick, you can create a gometrical surface for each triangle
CODE: SELECT ALL
Mescape Geometry Create Reconstruct OneSurfForEachElement

and select the triangles to create surfaces from them
then you can create a geometric volume, assign boundary conditions to geometric entities and generate a mesh
(as trick to create a triangle by surface assign a structured number of divisions=1 to all lines. Menu:Mesh->Structured->Lines->Assign number of cells)


To create thin prisms from triangles you can do a similar think, and use the copy tool with an operation of 'offset', and extruding volumes.
You can do it in mesh or geometry (it is better to do it in geometry, to allo use more edition tool, allow re-mesing, and handle assign calculation conditions."

Can you explain a bit more about some part of it? After applying the code to the particle, the surfaces are created, and as you said i did Menu:Mesh->Structured->Lines->Assign number of cells and in the window that shows "enter number of cells to assign to lines" i entered "1".
After this i am not clear about what you said, and in the "offset" operation, what type of entities should i choose? and how to decide the "Factor'? And i'm really confused about the last sentence about "do it in mesh or geometry....."

Thank you so much if you can provide me a more detailed explanation.

Sincerely,
Simon

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