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Error, No eigenvalues found

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Hi All,

I have a 3D geometry and am trying to obtain eigenfrequencies. It is very simple geometry, I obtained eigenfrequencies for 2D, but I cannot obtain for 3D. Comsol gives me an error, saying that "no eigenvalues found" . This is the first time I've been working on 3D geometries, maybe I am missing something?

Is there anyone who come across this problem before, or has any idea why I get this error?

Thanks in advance,
Elif


4 Replies Last Post 8 déc. 2010, 08:42 UTC−5
Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)

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Posted: 1 decade ago 4 déc. 2010, 07:39 UTC−5
Hi

that can happen if you have a missing boundary condition, i.e. no fixed or restrained dof (or not sufficient restained dof) often this gives also 1-6 eigenfrequencies around 0Hz depending on the number of restrained Dof

--
Good luck
Ivar
Hi that can happen if you have a missing boundary condition, i.e. no fixed or restrained dof (or not sufficient restained dof) often this gives also 1-6 eigenfrequencies around 0Hz depending on the number of restrained Dof -- Good luck Ivar

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Posted: 1 decade ago 4 déc. 2010, 07:54 UTC−5
Ivar,
I guess this wouldn't lead to the error message. Elif might forget to add a 3-D application (physics) after he'd added his 3-D geometry.

Elif,
may you attach your file. That may help.

Good luck,
Stephan
Ivar, I guess this wouldn't lead to the error message. Elif might forget to add a 3-D application (physics) after he'd added his 3-D geometry. Elif, may you attach your file. That may help. Good luck, Stephan

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

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Posted: 1 decade ago 5 déc. 2010, 03:05 UTC−5
Hi

I agree that there are probably seveal reasons for this error, and that a clean "free-free" 3D body eigenvalue simulation so far has always given me a result with 1-6 frequencies at or around 0Hz. There are so many possible combinations

--
Good luck
Ivar
Hi I agree that there are probably seveal reasons for this error, and that a clean "free-free" 3D body eigenvalue simulation so far has always given me a result with 1-6 frequencies at or around 0Hz. There are so many possible combinations -- Good luck Ivar

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Posted: 1 decade ago 8 déc. 2010, 08:42 UTC−5
Thanks very much for the answers. I guess it was boundary related problem, I have changed the boundaries and some other things, now it works.
Thanks very much for the answers. I guess it was boundary related problem, I have changed the boundaries and some other things, now it works.

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