Mesh not showing up

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pbhspace
Posts: 4
Joined: 21 Aug 2016, 02:32
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Mesh not showing up

Post by pbhspace »

I used FreeCAD to generate a STEP file, which I imported into the Elmer GUI. The model shows up, but the mesh does not. I have tried using the View menus to show everything, but still cannot get the mesh.

Note: My STEP file was generated in FreeCAD with the different components making up the part. I do not know if this matters. Here is my part:
Q1_Structure.png
(25.97 KiB) Not downloaded yet
I was following a YouTube tutorial from calculix, and the part with the mesh is where I am getting hung up.

Suggestions?
mzenker
Posts: 1999
Joined: 07 Dec 2009, 11:49
Location: Germany

Re: Mesh not showing up

Post by mzenker »

Hi,

you need to generate a mesh in order to see it...
Generally a tool like gmsh, Salomé or netgen is used for that. I don't know FreeCAD (yet), but I have heard that it contains the same SMESH module as Salomé. If this is so, you might be able to generate the mesh in FreCAD directly.

HTH,

Matthias
pbhspace
Posts: 4
Joined: 21 Aug 2016, 02:32
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Re: Mesh not showing up

Post by pbhspace »

Thanks Matthias -

I made some changes to my CAD model and re-exported it as a STEP file. Elmer loaded it and tried to mesh it, but Visual C++ Runtime crashed. When I was installing Elmer, it told me that it could not install VC++RT because I already had a newer version installed. Now I will look around for a solution to the VC++RT issue...

Thanks, again.
mzenker
Posts: 1999
Joined: 07 Dec 2009, 11:49
Location: Germany

Re: Mesh not showing up

Post by mzenker »

Hi,

perhaps I was not clear - I would not use Elmer (and especially not ElmerGUI) to generate a mesh. I would advise to rather use gmsh, Salomé or the meshing module of FreeCAD for that purpose.

HTH,

Matthias
pbhspace
Posts: 4
Joined: 21 Aug 2016, 02:32
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Re: Mesh not showing up

Post by pbhspace »

I went ahead and generated a mesh using the FEM workbench in FreeCAD. I then exported the mesh as an STL file. When I load that STL file into Elmer, I end up with the same situation of the mesh not showing up. The mesh summary does not have a lot of information in it, so I am wondering if a mesh is being generated properly - either by FreeCAD and the export, or by what I am trying to do with Elmer.
mzenker
Posts: 1999
Joined: 07 Dec 2009, 11:49
Location: Germany

Re: Mesh not showing up

Post by mzenker »

Hi,

I have tried to check the export formats of the meshing workbench of FreeCAD, and it seems that none can contain a mesh suitable for 3D FEM (STL does just represent the outer surface, right?). So I am afraid you need to use gmsh or Salomé...

HTH,

Matthias
Wil
Posts: 72
Joined: 10 Jan 2014, 13:26
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Location: Austria

Re: Mesh not showing up

Post by Wil »

Dear pbhspace,
I tried to create your geometry since I also use FreeCAD to build my models.
I was able to import my created model as .brep or .step as you see in the attached image.
Screenshot from 2016-10-22 21-00-58.png
(242.34 KiB) Not downloaded yet
The main difference between our designs is that your bar-elements are much more thinner. I tested the import also with much thinner walls and found, that ElmerGUI crashes when importing the desing.
So, simply try to increase the wall thickness and import it into ElmerGUI with File->Open.
Alternatively you should also consider to use salome (or GMSH) for meshing.
BR,
Wil
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