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How to get a model M file
Posted Mar 15, 2011, 1:33 p.m. EDT Geometry Version 3.5a 1 Reply
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Hi,
I have a matlab file which loads the vertices and the connectivity between them in matlab, I am not able to export this geometry to COMSOL for further simulation. I went through the guide and I assume that a model M file is to be generated to make it accessible by COMSOL. Please help me in converting my m file into the model M file which can be loaded in COMSOL as geometry.
i am using comsol 3.5a
Thanks in Advance
I have a matlab file which loads the vertices and the connectivity between them in matlab, I am not able to export this geometry to COMSOL for further simulation. I went through the guide and I assume that a model M file is to be generated to make it accessible by COMSOL. Please help me in converting my m file into the model M file which can be loaded in COMSOL as geometry.
i am using comsol 3.5a
Thanks in Advance
1 Reply Last Post Mar 15, 2011, 4:07 p.m. EDT
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Posted:
1 decade ago
Hi
that is because a mesh is not really a "geometry", not in the sense of COMSOL. The mesh is the last operation done on a (Comsol) Geometry composed of Entities: Domains, Boundaries, which again are delimited by Edges & Points.
You apply Physics and Boundaries respectively to Domains and Boundaries (mainly, sometimes in other mixes).
So if you load i a mesh, you need to recompose the Domains and their Boundaries. This worked, more or less, in 3.5a, for simple geometries meshed and provided in "Nastran Neutral File" formats, but I havent checked how it works in V4.
Once I have understood this I have given up using meshes from other programmes, this means too that I cannot exchange with other FEM programmes, which gives me some serous issues with some clients requesting file exchange via certain formats => I must hore someone external to finish or repeat the job with these tools. In contrary to CAD exchange, where there are a few +/- good transfer formats, Ido not know of any standard for FEM !
On the other hand, you have sometimes scanner images that gives you meshed geoemtries. To use thes efficiently in COMSOL the best isto have the geometries reconstructed into larger shapes, a few third partyx software tools exist, see the main COMSOl site. To do it yourself is possible,but it should be considered as a project by itself, not necessarily trivial all depending on th shapes
--
Good luck
Ivar
that is because a mesh is not really a "geometry", not in the sense of COMSOL. The mesh is the last operation done on a (Comsol) Geometry composed of Entities: Domains, Boundaries, which again are delimited by Edges & Points.
You apply Physics and Boundaries respectively to Domains and Boundaries (mainly, sometimes in other mixes).
So if you load i a mesh, you need to recompose the Domains and their Boundaries. This worked, more or less, in 3.5a, for simple geometries meshed and provided in "Nastran Neutral File" formats, but I havent checked how it works in V4.
Once I have understood this I have given up using meshes from other programmes, this means too that I cannot exchange with other FEM programmes, which gives me some serous issues with some clients requesting file exchange via certain formats => I must hore someone external to finish or repeat the job with these tools. In contrary to CAD exchange, where there are a few +/- good transfer formats, Ido not know of any standard for FEM !
On the other hand, you have sometimes scanner images that gives you meshed geoemtries. To use thes efficiently in COMSOL the best isto have the geometries reconstructed into larger shapes, a few third partyx software tools exist, see the main COMSOl site. To do it yourself is possible,but it should be considered as a project by itself, not necessarily trivial all depending on th shapes
--
Good luck
Ivar