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Problem with the eigenfrequency solver using matlab
Posted 9 févr. 2011, 06:09 UTC−5 MEMS & Nanotechnology, MEMS & Piezoelectric Devices, LiveLink for MATLAB, Studies & Solvers 1 Reply
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Hi,
I use Comsol Versoin 3.5. I'm searching for eigenfrequencies of a vibrating membrane under stress.
After I solved the eigenfrequency problem, I saved the m-file and reopened it with Comsol. Unfortunately, it now calculates eigenvalues instead of eigenfequencies.
To reproduce the problem, create a new file (MEMS Module -> Structural Mechanics -> Solid, Stress-Strain -> Eigenfrequency analysis), define a random block, initialize mesh and solve the problem. Go to Plot Parameters -> General -> Solution to use, and note, that it shows some eigenfrequencies there. Then go to File-> Save as.... and save it as a Model M-file. Reopen the just saved m-file and again, go to Plot Parameters and there you will see, that it calculated eigenvalues instead of eigenfrequencies.
Checking the solver parameters after loading the m-file, I noticed that Comsol is no longer able to auto select the solver. It also doesn't show the eigenfrequency solver, just the eigenvalue solver.
Is there a way to calculate eigenfrequencies using matlab?
Thanks a lot
I use Comsol Versoin 3.5. I'm searching for eigenfrequencies of a vibrating membrane under stress.
After I solved the eigenfrequency problem, I saved the m-file and reopened it with Comsol. Unfortunately, it now calculates eigenvalues instead of eigenfequencies.
To reproduce the problem, create a new file (MEMS Module -> Structural Mechanics -> Solid, Stress-Strain -> Eigenfrequency analysis), define a random block, initialize mesh and solve the problem. Go to Plot Parameters -> General -> Solution to use, and note, that it shows some eigenfrequencies there. Then go to File-> Save as.... and save it as a Model M-file. Reopen the just saved m-file and again, go to Plot Parameters and there you will see, that it calculated eigenvalues instead of eigenfrequencies.
Checking the solver parameters after loading the m-file, I noticed that Comsol is no longer able to auto select the solver. It also doesn't show the eigenfrequency solver, just the eigenvalue solver.
Is there a way to calculate eigenfrequencies using matlab?
Thanks a lot
1 Reply Last Post 10 févr. 2011, 05:06 UTC−5
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Posted:
1 decade ago
Hey there,
the problem is kind of solved. Matlab can't give out the eigenfrequencies, but the eigenvalue is just the same multiplied by 2*pi*i. I still don't understand, why I cant change the solver in Comsol after opening a m.file. But as long as I get my eigenfrequencies, I'm happy... ;-)
the problem is kind of solved. Matlab can't give out the eigenfrequencies, but the eigenvalue is just the same multiplied by 2*pi*i. I still don't understand, why I cant change the solver in Comsol after opening a m.file. But as long as I get my eigenfrequencies, I'm happy... ;-)