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Meshing Error due to too many edges
Posted 5 giu 2012, 11:24 GMT-4 Mesh Version 4.3 6 Replies
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I was trying to build a 3D model but the mesh keeps giving me errors.
I imported a dxf 2D geometry file and extrude it into 3D. The problem is that the shape has many unnecessary edges. So when I try to mesh it, it gives errors "edge is much shorter than the specified minimum element size" and "face is (or has a narrow region that is much smaller than the specified minimum element size. I tried to change the default relative repair tolerance to a smaller value, but it still doesn't work.
So I'm wondering whether there are effective ways to reduce or delete some of the small edges.
Thank you in advance!
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inded DXF is often not very robust as CAD source, but on the other hand those "errors" I believe are mostly warnings, telling you that the mesher has skipped a few small lines and made some short-cuts. This does not necesarily mean that the mesh is not good enough. To get less of these warnings you need to reduce the mesh size even perhaps beyond the extremely fine, or use a fluid physics instead of general physics settings. But then you need much more RAm and the model solves much slower with a very fine mesh.
Perhaps you can regenerate the CAD model in COMSOl by sketching over the DXF file and then disregard it and keep your new COMSOL geoemtry ?
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Good luck
Ivar
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Is there a simpler way to sketch in comsol besides creating a polygon?
Thanks in advance!
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in 2D you have the polyline and bezier curves, you need to learn to play with the ticks for the udnerlaying grid, and how to edit the resulting lines or bezier curves if you want rounded number at the positions, and I do not know if there are new features in V4.3, my CD has not yet arrived, but it should be somewhere in the post, these things take time, one tend to forget that, by hes days of super-connections ;)
The best is to check the doc, and to do the exercives, and the model library examples
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Good luck
Ivar
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I am working on RF MEMS switch ( Capacitive switch) . I got a problem while meshing the structure . After computing , I am getting the following errors.
ERROR 1 : No mesh on domains 4 5 18 19 in geometry 1, mesh case 0.
ERROR 2 : Failed to evaluate operator
operator : mean
geometry : 1
boundary : 32,33,34,36,38,41,55,69,70,71
Even when i mesh all the domains, same error message is displayed . I am pretty new to comsol . I am using 4.2 version.
Is there any particular way of finding a suitable mesh for a particular structure? can we use the same mesh for any type of structure? where can i find some material on meshing ?
My aim is to find the effect of Residual stress on the switch and to find how it affects pull down voltage.
Thanks in advance.
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the Error 2 is due to Error 1, you have not meshed all domains here, solve "1" and "2" should disappear
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Good luck
Ivar