FEM MESH HAS NO VOLUME ELEMENTS

About the development of the FEM module/workbench.

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cti2019
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Joined: Fri Feb 08, 2019 4:14 pm

FEM MESH HAS NO VOLUME ELEMENTS

Postby cti2019 » Fri Feb 08, 2019 4:24 pm

Hi,

I just registered on the forum and immediately apologize for my English.
I have a problem with the FEM module.
The mechanical design, by corporate choice, is made with Creo Elements.
For this reason, to import my model into FreeCAD I use the STEP file.
I import the model, I combine all the details with the Boolean operation of union, I create the FEM analysis, I assign the material, I assign the constraints, I assign the forces, I create the MESH "N" and I have no problem.
When I launch the simulation, I get the following error message:

FEM mesh has no volume elements, either define a shell thicknesses or provide a FEM mesh with volume elements.

Anyone can tell me where I'm wrong and how can I do to go on ??

Thanks in advance.
Have a nice weekend.
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bernd
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Re: FEM MESH HAS NO VOLUME ELEMENTS

Postby bernd » Fri Feb 08, 2019 5:19 pm

yes, your mesh has no volume elements. This mostly happens when your geometry does not contain solid geometry or has problems. Would you post your geometry? May be have a look her too ... https://forum.freecadweb.org/viewtopic. ... 10#p285383
cti2019
Posts: 12
Joined: Fri Feb 08, 2019 4:14 pm

Re: FEM MESH HAS NO VOLUME ELEMENTS

Postby cti2019 » Mon Feb 11, 2019 7:46 am

Good morning and good start of the week to everyone.

I attach some images to clarify the situation.
It is a simple structure in 50x3 square tubes with some worked plates.

Thank you in advance.
Attachments
Cattura3.JPG
Mesh results
Cattura3.JPG (103.82 KiB) Viewed 555 times
Cattura2.JPG
Structure
Cattura2.JPG (77.08 KiB) Viewed 555 times
Cattura1.JPG
Error Message
Cattura1.JPG (243.47 KiB) Viewed 555 times
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bernd
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Re: FEM MESH HAS NO VOLUME ELEMENTS

Postby bernd » Mon Feb 11, 2019 8:12 am

might be easy for you to create but for sure not for the mesher to mesh with volume elements.

Have you checked your geometry? See https://forum.freecadweb.org/viewtopic. ... 10#p285492
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bernd
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Re: FEM MESH HAS NO VOLUME ELEMENTS

Postby bernd » Mon Feb 11, 2019 8:14 am

I assume your mesh has no volumes. You can check this by right click on the mesh and print mesh infromations. If you would like to make a analysis with volume elements you should provide a mesh with volume elements. Example from FEM 3D example ...


screen.jpg
screen.jpg (206.1 KiB) Viewed 547 times
cti2019
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Re: FEM MESH HAS NO VOLUME ELEMENTS

Postby cti2019 » Mon Feb 11, 2019 8:51 am

I attach mesh info..
Attachments
Cattura.JPG
Mesh Info
Cattura.JPG (102.71 KiB) Viewed 544 times
cti2019
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Re: FEM MESH HAS NO VOLUME ELEMENTS

Postby cti2019 » Mon Feb 11, 2019 9:35 am

how can I do a FEM 3D analysis ??
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bernd
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Re: FEM MESH HAS NO VOLUME ELEMENTS

Postby bernd » Mon Feb 11, 2019 9:48 am

as you can see there is no volume element in your mesh, thus you can not make a volume element analysis. For a volume element analysis you need to provide a mesh with volume elements.

I would recomend to play with 3D FEM example and 2D FEM example from StartWB for half an hour to understand the difference ...

Would you provide your Geometry as FreeCAD file?
cti2019
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Re: FEM MESH HAS NO VOLUME ELEMENTS

Postby cti2019 » Mon Feb 11, 2019 10:59 am

the freecad file is 117 mb, perhaps because of the mesh.
I attach the step file from which I start.
Attachments
SOLO_TEL.stp
(663.83 KiB) Downloaded 10 times
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bernd
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Re: FEM MESH HAS NO VOLUME ELEMENTS

Postby bernd » Mon Feb 11, 2019 11:27 am

cti2019 wrote:
Mon Feb 11, 2019 10:59 am
the freecad file is 117 mb, perhaps because of the mesh.
I attach the step file from which I start.
select the mesh in tree view, clear mesh will delete the mesh data and keep the mesh obj properties