Is it possible to combine gmsh ?

About the development of the FEM module/workbench.

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jcerro
Posts: 3
Joined: Thu Feb 07, 2019 10:24 am

Is it possible to combine gmsh ?

Postby jcerro » Thu Feb 07, 2019 10:45 am

Hi everyone,

Thank you for the great job you made on Freecad, it's amazing to see how much can be done when you have passion.

I'm trying to do some simple FEM analysis on a camera support arm, like gravity effect or side push. It is aimed to carry a small webcam over a soccer-table to perform ball tracking. I've designed the arm using multiple single parts, and then assemble them using Assembly2 workbench.

The problem I'm now facing is that it seems impossible to select multiple parts of an assembly to create one mesh using gmsh, neither to combine multiple already created gmsh from the parts in assembly.

The only solution I found by now is to create a muxed assembly, but I can't create 3D elements, neither with netgen of gmsh, and I'm afraided it might create some link between parts that have DoF one to another.

I hope I explained my issu clearly enough.

Thank you all !

OS: Windows 10
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.17.13541 (Git)
Build type: Release
Branch: releases/FreeCAD-0-17
Hash: 9948ee4f1570df9216862a79705afb367b2c6ffb
Python version: 2.7.14
Qt version: 4.8.7
Coin version: 4.0.0a
OCC version: 7.2.0
Locale: French/France (fr_FR)
chrisb
Posts: 18003
Joined: Tue Mar 17, 2015 9:14 am

Re: Is it possible to combine gmsh ?

Postby chrisb » Thu Feb 07, 2019 12:00 pm

Moved to FEM forum.
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bernd
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Location: Zürich, Switzerland

Re: Is it possible to combine gmsh ?

Postby bernd » Thu Feb 07, 2019 12:23 pm

would you post a simple example file from your problem? This makes it much more easier to talk about your problem.

bernd
jcerro
Posts: 3
Joined: Thu Feb 07, 2019 10:24 am

Re: Is it possible to combine gmsh ?

Postby jcerro » Thu Feb 07, 2019 12:38 pm

No problem,

Please find attached an archive with all the files of the assembly, and the so-called assembly, here called calc.FCStd.

Thank you !
Attachments
calc.zip
(424.28 KiB) Downloaded 7 times
jcerro
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Re: Is it possible to combine gmsh ?

Postby jcerro » Fri Feb 08, 2019 8:50 am

Hi,

I was wondering if the multiple mesh analysis will be supported ? The pop-up window says that it is not supported YET ? Have you intels about thats ?

Thank you !
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bernd
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Re: Is it possible to combine gmsh ?

Postby bernd » Fri Feb 08, 2019 9:50 am

jcerro wrote:
Fri Feb 08, 2019 8:50 am
I was wondering if the multiple mesh analysis will be supported ? The pop-up window says that it is not supported YET ? Have you intels about thats ?
No multiple meshes are not supported at all ATM. But you can do one mesh from multiple bodies :) without any problems.

BTW file and screen of the nice arm attached for others to try too. In FEM we love screens :mrgreen: It woll not easy to make a mesh out of this detailed geometry. It might be much more easier to simplify the geometry for an analysis. Might be even simpler by pen and paper because it is just a cantilever and only make a analysis for the several parts.

But I will give it a try to mesh anyway ...

calc.FCStd
(173.65 KiB) Downloaded 8 times

screen.jpg
screen.jpg (78.23 KiB) Viewed 187 times
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bernd
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Location: Zürich, Switzerland

Re: Is it possible to combine gmsh ?

Postby bernd » Fri Feb 08, 2019 9:57 am

Another possibility would be to use some development branch, which exactly trys to solve this problem ... https://forum.freecadweb.org/viewtopic. ... 00#p261413 and the branch to test would be https://github.com/berndhahnebach/FreeC ... utocontact