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Defining boundary node sets in .mphtxt or in MATLAB fem.mesh structure
Posted 24 giu 2010, 05:44 GMT-4 Version 4.1 3 Replies
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Perhaps this question had already been asked in this forum, but I could not find it. My problem is to define a node set in the mesh file *.mphtxt to import it into comsole.
The problem at hand is to model a complicated geometry like the one attached with this message. It has been generated from tomographic anaysis and I have meshed it in MATLAB. I used the MATLAB to export the elements and coordinate to export into fem.mesh, following the commands in the documentation. But now I cannot precisely select only the top and bottom surface nodes using "box" tool; it always selects some more nodes from other planes below. So I started to wonder if I can define a group of a boundary node set (for example like in ABAQUS), then BC application will be precisely imposed on the desired nodes. However, I could not find how to define a node set in the MATLAB. I figured out how to create a new group in "fem.bnd.constrant and fem.bdn.ind". The problem remains to how to associate some nodes to this new group. The fem.mesh object is not accessible in matlab workspace so I cannot see/over ride the values.
I tried to understand the format of .mphtxt of a simple unit cube. There I found a the domain numbers of vertices. But if change the number of domains from 7 to 3 (for athe unit cube 6 faces and interior) and import it in COMSOL nothing seems to be changed- I see the same original number of groups inside COMSOL.
I would prefer a way to define the group in matlab and pass it on to COMSOL as I will be dealing with complicated geometries.
Any help is greately appreciated.
Regards,
Kodanda
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Hello kodanda
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