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Constructing Complex 3D geometry / Importing CAD geometry

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Hi,

I am trying to create a geometry in COMSOL for solving a magnetic problem using an FEA solver.
I was working with a few other softwares before and was able to import this geometry from a CAD file (.sat). However the import option in COMSOL seems to support limited file extensions among which ‘.sat’ is not one. I tried converting my model from ‘.sat’ to a few file formats that I see in COMSOL (like .dxf) but still could not import it.

Finally I gave up trying to import and started constructing it using COMSOL. Now, I am stuck up at a point where I had to split my object at specific sections. Please find attached a figure of the geometry that I am trying to build.

Any insight on how I can create this geometry or any other possible ways to import from my CAD file?
I appreciate your help.

Thanks,
DheeraJ.


13 Replies Last Post Jun 15, 2012, 9:29 p.m. EDT
Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)

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Posted: 1 decade ago Jul 22, 2010, 4:48 p.m. EDT
Hi

COMSOL accepts several CAD formats (but I do not remeber if .sat is on the list, probably not if you didnt succed) solidworks, parasolid, Pro-e etc, dxf for 2D but some are linked to the live-link or CAD interface module. For your type of 3D you should try parasolid (in my opinion), but you can also generate it with COMSOL, V4 has further enhancements w.r.t v3.5

--
Good luck
Ivar
Hi COMSOL accepts several CAD formats (but I do not remeber if .sat is on the list, probably not if you didnt succed) solidworks, parasolid, Pro-e etc, dxf for 2D but some are linked to the live-link or CAD interface module. For your type of 3D you should try parasolid (in my opinion), but you can also generate it with COMSOL, V4 has further enhancements w.r.t v3.5 -- Good luck Ivar

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Posted: 1 decade ago Jul 22, 2010, 6:00 p.m. EDT
Hi Ivar,

Thank you for your response.

The only CAD formats that COMSOL appears to support are .dxf , .gds & .asc.. and as per my knowledge all three are for 2D. I have tried Solidworks but it doesn't generate any file format that is listed with COMSOL. Parasolid is something new and I shall try looking into the availability of that.
We just got a glimpse at V4, but there are some upgrade issues that are yet to be resolved before I get to work on V4.
Meanwhile, can you suggest any methods or any specific commands that I might be missing to create this geometry in COMSOL 3.5

I had a 2D model made as shown in the attached figure 1, and extruded it to obtain the horizontal splits (as in figure 2). If there is some way to create sectional cuts on this , I would be very close to my desired geometry. Your expertise would be of great help with this.

Thanks again!
DheeraJ
Hi Ivar, Thank you for your response. The only CAD formats that COMSOL appears to support are .dxf , .gds & .asc.. and as per my knowledge all three are for 2D. I have tried Solidworks but it doesn't generate any file format that is listed with COMSOL. Parasolid is something new and I shall try looking into the availability of that. We just got a glimpse at V4, but there are some upgrade issues that are yet to be resolved before I get to work on V4. Meanwhile, can you suggest any methods or any specific commands that I might be missing to create this geometry in COMSOL 3.5 I had a 2D model made as shown in the attached figure 1, and extruded it to obtain the horizontal splits (as in figure 2). If there is some way to create sectional cuts on this , I would be very close to my desired geometry. Your expertise would be of great help with this. Thanks again! DheeraJ


Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)

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Posted: 1 decade ago Jul 23, 2010, 3:47 a.m. EDT
Hi

Then you do not have the CAD interface toolbox, because COMSOL can read far more 3D formats, as I have CAD and SolidWorks for V3.5 and V4 I can also link directly with SolidWorks, very handy.

Now for your gemoetry my approache would be to generate it as two circles and a diagonal vertical line that I would duplicate and rotate (CNTRL+C CNTRL+V then CR (no displacements) Rotate around 0,0 angle X°). This in 2D, then I would Coerce it to one solid (as I expect you have done from your image, extrude it N times and keep the items you want. All in COMSOL

--
Good luck
Ivar
Hi Then you do not have the CAD interface toolbox, because COMSOL can read far more 3D formats, as I have CAD and SolidWorks for V3.5 and V4 I can also link directly with SolidWorks, very handy. Now for your gemoetry my approache would be to generate it as two circles and a diagonal vertical line that I would duplicate and rotate (CNTRL+C CNTRL+V then CR (no displacements) Rotate around 0,0 angle X°). This in 2D, then I would Coerce it to one solid (as I expect you have done from your image, extrude it N times and keep the items you want. All in COMSOL -- Good luck Ivar

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Posted: 1 decade ago Jul 23, 2010, 12:48 p.m. EDT
WoW! Thanks Ivar!!

Extrude N times did work! I didn't realize that extrude function could do a piecewise linear extrusion.
WoW! Thanks Ivar!! Extrude N times did work! I didn't realize that extrude function could do a piecewise linear extrusion.

Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)

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Posted: 1 decade ago Jul 24, 2010, 3:07 a.m. EDT
Hi

You know with COMSOL one can do almost everything, the only issue is that you must THINK, at least think PHYSICS, (and search/investigate a little) not that a bad thing, but one has almost forgotten to think these days with the usual clickable engineering tools all around.

It took me some time to get back "thinking" again but now I'm really having fun ;)

--
Good luck
Ivar
Hi You know with COMSOL one can do almost everything, the only issue is that you must THINK, at least think PHYSICS, (and search/investigate a little) not that a bad thing, but one has almost forgotten to think these days with the usual clickable engineering tools all around. It took me some time to get back "thinking" again but now I'm really having fun ;) -- Good luck Ivar

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Posted: 1 decade ago Jan 18, 2011, 6:20 p.m. EST
Hi, I am fresh man with COMSOL. Currently, I want to generate 3D geometry. Could you tell me how to do it in COMSOL? By the way, what the V4? Thanks for your help.
Hi, I am fresh man with COMSOL. Currently, I want to generate 3D geometry. Could you tell me how to do it in COMSOL? By the way, what the V4? Thanks for your help.

Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)

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Posted: 1 decade ago Jan 18, 2011, 6:45 p.m. EST
Hi
V4 is the new version 4 approach of COMSOL, much smoother, but somewhat different from the old 3.5, in methodology. see the main veb site of COMSOL.

Check the doc, there are amny 2D and 3D commands for geometry inside COMSOL

--
Good luck
Ivar
Hi V4 is the new version 4 approach of COMSOL, much smoother, but somewhat different from the old 3.5, in methodology. see the main veb site of COMSOL. Check the doc, there are amny 2D and 3D commands for geometry inside COMSOL -- Good luck Ivar

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Posted: 1 decade ago Jan 18, 2011, 10:58 p.m. EST
Hi, Ivar
Thanks for your reply. My tricky thing and also my classmate also have difficulty in building 3D geometry using 3D data(format: x, y, z), not just a simple geometry. So, could you tell me the convinient way to do so? Thank you.

Best regards,
Lichun
Hi, Ivar Thanks for your reply. My tricky thing and also my classmate also have difficulty in building 3D geometry using 3D data(format: x, y, z), not just a simple geometry. So, could you tell me the convinient way to do so? Thank you. Best regards, Lichun

Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)

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Posted: 1 decade ago Jan 19, 2011, 1:45 a.m. EST
Hi

if it is scanned images in mesh geometry, I can only suggest a) to write a program in Matlab, but its a rather tough issue, certainly interesting. Or, for an engineer, and not students, buy one of the third party software or service to get the data translated, see the main web site

--
Good luck
Ivar
Hi if it is scanned images in mesh geometry, I can only suggest a) to write a program in Matlab, but its a rather tough issue, certainly interesting. Or, for an engineer, and not students, buy one of the third party software or service to get the data translated, see the main web site -- Good luck Ivar

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Posted: 1 decade ago Jan 19, 2011, 5:16 a.m. EST
Hi Wang,

There is a free meshing toolbox for MATLAB that can mesh a given point cloud data like yours. It can make triangular surface meshes or solid tetrahedral meshes.

It is bit simple to use, but importing into comsol should be done through a matlab +comsol transfer. I warn you that it may not always be successful all the time.

kodanda
Hi Wang, There is a free meshing toolbox for MATLAB that can mesh a given point cloud data like yours. It can make triangular surface meshes or solid tetrahedral meshes. It is bit simple to use, but importing into comsol should be done through a matlab +comsol transfer. I warn you that it may not always be successful all the time. kodanda

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Posted: 1 decade ago Mar 20, 2012, 8:33 a.m. EDT
Hi. Just wonder can I import 3D geometry from AutoCAD?
Hi. Just wonder can I import 3D geometry from AutoCAD?

Jeff Hiller COMSOL Employee

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Posted: 1 decade ago Mar 20, 2012, 8:38 a.m. EDT
Check out COMSOL's LiveLink for AutoCAD: www.comsol.com/products/livelink-autocad/
Check out COMSOL's LiveLink for AutoCAD: http://www.comsol.com/products/livelink-autocad/

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Posted: 1 decade ago Jun 15, 2012, 9:29 p.m. EDT
I use livelink for Autocad but when importing some triangular surface from cad it only works for limited number of elements and when increasing the elements numbers it does not import and disconnects synchronizing.

has version 4.3 solved this problem?
I use livelink for Autocad but when importing some triangular surface from cad it only works for limited number of elements and when increasing the elements numbers it does not import and disconnects synchronizing. has version 4.3 solved this problem?

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