FEM gmsh Mesh cannot makes volume

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qwqwhs
Posts: 1
Joined: Mon May 11, 2020 6:29 pm

FEM gmsh Mesh cannot makes volume

Post by qwqwhs »

Hello, I designed a tiny heat sink and I'd like to test it with FEM.
The problem is the FreeCad gmsh cannot make the volume mesh of my model.
Isome forum said, "set Max size of element appropriately" but I cannot test it because when I set the max size as 0.5mm then it stops.

Could you help me?

Image

The file size is big so an attached the drive link

https://drive.google.com/file/d/1xhIE19 ... sp=sharing

OS: Windows 10
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.18.4 (GitTag)
Build type: Release
Branch: releases/FreeCAD-0-18
Hash: 980bf9060e28555fecd9e3462f68ca74007b70f8
Python version: 3.6.6
Qt version: 5.6.2
Coin version: 4.0.0a
OCC version: 7.3.0
Locale: Korean/SouthKorea (ko_KR)
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chrisb
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Posts: 53919
Joined: Tue Mar 17, 2015 9:14 am

Re: FEM gmsh Mesh cannot makes volume

Post by chrisb »

Moved to FEM forum.
A Sketcher Lecture with in-depth information is available in English, auf Deutsch, en français, en español.
Jee-Bee
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Posts: 2566
Joined: Tue Jun 16, 2015 10:32 am
Location: Netherlands

Re: FEM gmsh Mesh cannot makes volume

Post by Jee-Bee »

When i check the model in part (part >> check geometry: https://wiki.freecadweb.org/Part_CheckGeometry)

Code: Select all

HeatSink.refine:
  VERTEX    : 618
  EDGE      : 914
  WIRE      : 317
  FACE      : 301
  SHELL     : 1
  SOLID     : 1
  COMPSOLID : 0
  COMPOUND  : 1
  SHAPE     : 2153
it looks like it is a solid.

When i set the bop check on i got a bunch of errors. could be possible that the reason of your problem.
domad
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Posts: 2051
Joined: Mon Jun 22, 2020 12:16 pm

Re: FEM gmsh Mesh cannot makes volume

Post by domad »

Hello!
Tip: when performing Boolean operations it is preferable that the contact surfaces are not coplanar but interpenetrating by a few tenths of mm.
This is the error report from FEM Mesh Gmsh:
“Error : Invalid boundary mesh (overlapping facets) on surface 251 surface 253 Error : No elements in volume 1 Warning : Surface mesh: worst distortion = -2594.44 (avg = -0.393704, 99 elements with jac.”
A further investigation was not possible because your file is not complete with all the parametric construction phases.

However I think this can be very useful to you: https://forum.freecadweb.org/viewtopic.php?t=34912

Hi Good job!
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