Discussion Closed This discussion was created more than 6 months ago and has been closed. To start a new discussion with a link back to this one, click here.
Problem with the eigenfrequency solver using matlab
Posted Feb 9, 2011, 6:09 a.m. EST MEMS & Nanotechnology, MEMS & Piezoelectric Devices, LiveLink for MATLAB, Studies & Solvers 1 Reply
Please login with a confirmed email address before reporting spam
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 Feb 10, 2011, 5:06 a.m. EST
Please login with a confirmed email address before reporting spam
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... ;-)