FEM object types

[bernd]

To get fandals requirement to work, we need a different approach, where the user has to say, what he wants. The division of material and mesh-volumes into independent objects is the key to this. The user can than click on an shape-object and say it should be meshed as a volume. We give this information to the mesher (works already with gmesh) and than know what is needed to write into the input file. It allows the user to click on the same object again, asking for a shell. In this case both the volumes and the faces will be written into the input file.
Having independent objects for volume meshes and shell meshes, allows to give them a link to a material object. So the user has control over all aspects and there is no need to write complicated if-cascades for all cases of material and mesh combinations. There will be always a combination, that is not anticipated by an automatic algorithm, as we have now.

This would be the Mercedes, we create another mesh group object like the meshregion for element length we use meshregion for mesh element type. This would not need much development. But than the AbaqusWriter would need to write group data. This has been on my long term todo change the Abaquswriter to support writing defined mesh groups or write a Python inp writer supporting mesh groups. This is needed if you would like to use different element types for elements with the same node numbers. Means if you would like to use two different tria6 elements. I do not know a use case but there might be some. I myself would not need this I just need the mix of shell beam elments or shell solid element.

[ulrich1a]

But than the AbaqusWriter would need to write group data.

If we can agree on this approach, I would try to attack the AbaqusWriter. It will need some time, as I have to learn additional programming skills first.
We may put the plan posted here https://forum.freecadweb.org/viewtopic. ... 20#p169893
in a FEM-roadmap wiki and make adjustments to it as needed.

Ulrich

[bernd]

But than the AbaqusWriter would need to write group data.

If we can agree on this approach, I would try to attack the AbaqusWriter. It will need some time, as I have to learn additional programming skills first.

great

We may put the plan posted here https://forum.freecadweb.org/viewtopic. ... 20#p169893
in a FEM-roadmap wiki and make adjustments to it as needed.

I have been reading this diagram a few times but not fully understand how this would look like in classes and objects. I'm not a programmer, I miss the imagination how this looks in objects. Let's attract the group writing of writeAbaqus and go further step by step. By the time I will be ready with the element sets for mixed meshes. Since I implemented some python inp writer I can test my code without the new smart writeAbaqus.

EDIT: Feel free to put it on the roadmap. But it would be cool if you could write some words ... FEM_project is what had been used for this years ago. This page is absolutely wiped out (hoffnungslos veraltet).

[bernd]

this may help ...

Code: Select all

mesh = App.ActiveDocument.getObject("CompSolid_Mesh").FemMesh
mesh.GroupCount
mesh.Groups

for g in mesh.Groups:
    print(mesh.getGroupElementType(g))
    print(mesh.getGroupName(g))
    print(mesh.getGroupElements(g))

implemented how to retrieve the group data out of SMESH:

https://github.com/FreeCAD/FreeCAD/blob ... 1136-L1156
https://github.com/FreeCAD/FreeCAD/blob ... #L929-L990

I remember I was very proud when I got this working with my small knowledge of C++

[bernd]

Much less hacks, and in addition to mixed mesh elements, multiple shell sections and multiple beam sections ...

https://github.com/berndhahnebach/FreeC ... ixedmeshes

screen.jpg (302.21 KiB) Viewed 1602 times

the FreeCAD file

mixed_mesh_edge_face_2.fcstd

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[bernd]

solids, shells and edges in one analysis ...

static

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frequency

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[UR_]

"-"

ThatsCool.gif (13.85 KiB) Viewed 1558 times

[HoWil]

WOW
looks fantastic.
BR,
HoWil

[bernd]

adapted constraint fixed ...

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[bernd]

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