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Problem when importing CAD file into COMSOL
Posted 28.07.2012, 20:50 GMT-4 RF & Microwave Engineering, Geometry, Modeling Tools & Definitions, Parameters, Variables, & Functions Version 3.5a, Version 4.0a 5 Replies
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Using COMSOL, I have imported a geometry (step file “.stp”) into COMSOL and converted it into COMSOL object.
Afterwards, the following error message keeps popping up: “Unsupported degree on Bezier representation”
Another error message that keeps popping up is: “Error in Geometry Decomposition”
What does each error message mean and how to solve these two errors ?
Thanks
Nayef
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have you checked what you can do with the geometry repair functions ?
Sometimes its better to convert to COMSOL CAD specifically, others time not ...
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Good luck
Ivar
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If you mean importing the step file into COMSOL and trying the defeaturing and repair functions (before converting the design to COMSOL object) then the answer is yes.
I have tried to use these two functions but I keep getting the same errors.
What does theses errors indicate by the way ?
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probably a very high order Bezier curve that is not supported by COMSOL, so you are missing some lines, hence some surfaces are not well closed etc. The geometry is not complet.
It can also come from small "silver faces" or other features, but normally you can detect these with the repair functionality of COMSOL.
Bezier curves often comes from free-hand surfaces, but some translators trasform even simple circles, cylinders or sheres to higher order Bezier curves.
Which CAD soft do you use ? I'm using Solid works, and have seldom such issues neither with direct read-in, nor with STEP trnslations.
By the way sometimes you have optons when writing the STEP file, perhaps you have some tick maks there to use or not higher order Beziers, take a look, but this omes from your CAD programme and not from COMSOL
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Good luck
Ivar
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The CAD programme used is CATIA.
In order to make sure that each part is error free I have imported each part of the design individually into COMSOL;
then converted it into COMSOL object. When I find any errors in any part I fix them in CATIA before importing it into COMSOL again. I repeated this procedure until all parts became error free in COMSOL.
I am now confident that all individual parts of the design are error free and don’t need repair or defeaturing.
Then in CATIA, I formed the whole structure from these individual parts (connected all these parts together to form the desired design) then imported it into COMSOL.
Unfortunately I still have the error messages: “Unsupported degree on Bezier representation” and “Internal Error in Geometry Decomposition”.
Any help ?
Many thanks
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check your options in CATIA for STEP format, there are generally a few options about which version to use. See if you find an entry for the bezier level, and ty to use a low polynomial development. Personally I have never used CATIA so I do not know which options are proposed.
Another way is to read the catia file, or use "parasolid" as format, if you have the CATIA and or COSMOL modules for this
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Good luck
Ivar