Part-o-magic and gmsh-meshing in FEM

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HoWil
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Part-o-magic and gmsh-meshing in FEM

Post by HoWil »

Hello,
I posted this here and not in FEM so hopefully DeepSIOC and Bernd can join the discussion (
DeepSOIC wrote:Discussion appreciated
bernd wrote:Discussion appreciated
).
I played a bit with Part-o-magic regarding using it to create multibody mesh in FC and do really like the idea (maybe have to play a little more :D ).

The nicest thing is that all elements inside a Module are seen as one solid. See...
Screenshot from 2017-03-13 13-18-58.png
Screenshot from 2017-03-13 13-18-58.png (129.26 KiB) Viewed 893 times
That's good regarding meshing in FEM-wb, because if several solids are given to gmsh the mesh-points at the interface do not coincide.
Problem:
When I now try to mesh such an Module only the 'Tip'-element of the Module gets meshed!

I think Bernd usually uses "Compound filter" from Lattice2 to create multibodies but this does not work for intersecting bodies like the one in the example above. At least not if one wants to have one single resulting solid (keyword: Filtertype=bypass).

BTW: how are elements such as the depicted treated to get one solid.... is it a compound?? Could it also be a Boolean-Fragments?

BR,
HoWil
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Screenshot from 2017-03-13 13-26-51.png
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DeepSOIC
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Re: Part-o-magic and gmsh-meshing in FEM

Post by DeepSOIC »

Part Fuse your solids, inside of Module!
EDIT: and leave the module before creating the mesh (either deactivate it by double-clicking, or use PoM Leave command). The way you did it, if the mesh were linked to the body, it would cause a dependency loop.
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DeepSOIC
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Re: Part-o-magic and gmsh-meshing in FEM

Post by DeepSOIC »

And I have plans for extending ShapeGroup to support a compsolid mode, stay tuned...
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DeepSOIC
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Re: Part-o-magic and gmsh-meshing in FEM

Post by DeepSOIC »

OK, I think I missed the most important part, that FEM wants a solid directly, not a solid in compound. Module just copies the result of Fusion, so it becomes solid-in-compound.

May I ask you, why is FEM so intolerant to getting a solid in compound? So that you have to go to all the trouble of integrating compoundfilter into master?
HoWil
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Re: Part-o-magic and gmsh-meshing in FEM

Post by HoWil »

DeepSOIC wrote:OK, I think I missed the most important part, that FEM wants a solid directly, not a solid in compound. Module just copies the result of Fusion, so it becomes solid-in-compound.

May I ask you, why is FEM so intolerant to getting a solid in compound? So that you have to go to all the trouble of integrating compoundfilter into master?
Please see for instance https://forum.freecadweb.org/viewtopic. ... nd#p164086 .
As long as Boolean-Fragments is run before everything should be fine with meshing. It should result in no intersecting solids and whatever. I usually use Boolean-Fragments but would like to extent/simplify my work-flow.... see https://forum.freecadweb.org/viewtopic. ... 92#p165112 .
Thats where I thought Part-o-magic could help, fusing/compounding/boolean-fragmenting solids.

BR,
HoWil
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