Gmsh unknown error

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PeterII
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Joined: Sat Aug 14, 2021 8:53 am

Re: Gmesh unknown error

Post by PeterII »

Hi,
I now made the wire model, and I fused it. Then I created cross section, and I meshed it. Assigned material and tried to compute it. However to no avail. I always get the same error: *ERROR in gen3dfrom1d: element 1 is a linear beam element with circular cross section
Please use quadratic elements for beams with circular cross section
.

Does someone know what am I doing wrong?
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Sticks_mesh.FCStd
(120.2 KiB) Downloaded 23 times
Kind regards,
Peter
Jee-Bee
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Re: Gmesh unknown error

Post by Jee-Bee »

Sorry I want to try it but somhow GMSH is not part of the default FC anymore...

What i would do now is export the brep and check if you are able to create a mesh inside GMSH self. And if it workout well you can import that one. or compare what the differences are in settings.

To be honest i don't like the GMSH functions inside FC. For everything you need an separated function and most of the time Netgen is create a better mesh(at least for 3D)...
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NewJoker
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Re: Gmesh unknown error

Post by NewJoker »

Jee-Bee wrote: Tue Aug 02, 2022 8:06 am Sorry I want to try it but somhow GMSH is not part of the default FC anymore...
Which version of FreeCAD do you use ? Gmsh should still be included.

Jee-Bee wrote: Tue Aug 02, 2022 8:06 am To be honest i don't like the GMSH functions inside FC. For everything you need an separated function and most of the time Netgen is create a better mesh(at least for 3D)...
Yeah, most meshing issues in FreeCAD happen with Gmsh. However, it's good to have two meshers to choose from and Netgen has some limitations. Most importantly, it doesn't support beam and shell elements in FreeCAD - it can only generate tetrahedrons and Gmsh is needed for other types of elements.
PeterII
Posts: 21
Joined: Sat Aug 14, 2021 8:53 am

Re: Gmesh unknown error

Post by PeterII »

Hi,
I am using:
OS: Windows 10 Version 2009
Word size of FreeCAD: 64-bit
Version: 0.20.27422 (Git)
Build type: Release
Branch: master
Hash: d938733eaf2c2ce7cb18d1cbb56147185c473530
Python version: 3.8.6+
Qt version: 5.15.2
Coin version: 4.0.1
OCC version: 7.5.3
Locale: Slovenian/Slovenia (sl_SI)

So Jee-Bee you think issue is with mesh? Why is that since I get mesh is done correctly status?
Do you think it is possible to do the mesh in meshlab, and then import it?
Kind regards,
Peter
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NewJoker
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Re: Gmesh unknown error

Post by NewJoker »

PeterII wrote: Tue Aug 02, 2022 5:33 am Please use quadratic elements for beams with circular cross section.
Try doing what the error message says - change the element order to 2nd. You may get other errors then but at least this one will be gone.
PeterII
Posts: 21
Joined: Sat Aug 14, 2021 8:53 am

Re: Gmesh unknown error

Post by PeterII »

Hi,
it helped =)
now the error says: *ERROR in gen3delem: first thickness. Any ideas?
Kind regards,
Peter
Jee-Bee
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Re: Gmesh unknown error

Post by Jee-Bee »

NewJoker wrote: Tue Aug 02, 2022 8:36 am Which version of FreeCAD do you use ? Gmsh should still be included.

Code: Select all

OS: macOS 10.15
Word size of FreeCAD: 64-bit
Version: 0.20.29177 (Git)
Build type: Release
Branch: (HEAD detached at 0.20)
Hash: 68e337670e227889217652ddac593c93b5e8dc94
Python 3.9.13, Qt 5.12.9, Coin 4.0.0, Vtk 9.1.0, OCC 7.5.3
Locale: C/Default (C)
Installed mods: 
  * A2plus 0.4.56
  * fasteners 0.3.41
  * Assembly4 0.11.12
PeterII wrote: Tue Aug 02, 2022 9:20 am So Jee-Bee you think issue is with mesh? Why is that since I get mesh is done correctly status?
Do you think it is possible to do the mesh in meshlab, and then import it?
No i didn't say that. I sayed that if i don't get it to work i try in GMSH self. If it able to mesh there i should be able to do it too in FC.
I don't know meshlab so can't help with that
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bernd
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Re: Gmsh unknown error

Post by bernd »

I edited the title since the name is Gmsh
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NewJoker
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Re: Gmesh unknown error

Post by NewJoker »

PeterII wrote: Tue Aug 02, 2022 9:20 am Do you think it is possible to do the mesh in meshlab, and then import it?
MeshLab is not meant for finite element mesh generation but for operations on triangle meshes, like those contained in the STL files: https://en.wikipedia.org/wiki/Triangle_mesh

FreeCAD's Mesh Design module serves a similar purpose.
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bernd
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Re: Gmsh unknown error

Post by bernd »

Jee-Bee wrote: Tue Aug 02, 2022 8:06 am Sorry I want to try it but somhow GMSH is not part of the default FC anymore...
Netgen is included if FreeCAD is compiled with Netgen. Gmsh binary is a separate programm. On Windows FreeCAD this binary is included. Genarally on OSX and Linux this binary has to be installed separately and the path might be set in FEM prefs.
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