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Prestressed modal analysis

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Hi,

Dose anybody have idea that the prestressed modal analysis is based on the deformed configuration or just work on the initial configuration?

Thanks

7 Replies Last Post 23 apr 2012, 05:28 GMT-4
Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)

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Posted: 1 decade ago 9 apr 2012, 04:13 GMT-4
Hi

I cannot really tell, like that, but, what disturbsme with your question is on the other hand: can you have a prestressed beam without any deformation ?

One way to check is (perhaps) to try a manual 1D compression stress (in 2D) and see if it affects, with and without change in length

--
Good luck
Ivar
Hi I cannot really tell, like that, but, what disturbsme with your question is on the other hand: can you have a prestressed beam without any deformation ? One way to check is (perhaps) to try a manual 1D compression stress (in 2D) and see if it affects, with and without change in length -- Good luck Ivar

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Posted: 1 decade ago 9 apr 2012, 12:47 GMT-4
Thanks Ivar.

To make clear, my question is the prestressed analysis mode in COMSOL consider the deformation of structure or not? Or COMSOL just performs prestressed analysis on initial configuration.

Thanks
Thanks Ivar. To make clear, my question is the prestressed analysis mode in COMSOL consider the deformation of structure or not? Or COMSOL just performs prestressed analysis on initial configuration. Thanks

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

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Posted: 1 decade ago 9 apr 2012, 13:09 GMT-4
Hi

an eigenfrequency analysis based on a stressed (or at rest) starting point, is a linearised analysis based on the intial values,

--
Good luck
Ivar
Hi an eigenfrequency analysis based on a stressed (or at rest) starting point, is a linearised analysis based on the intial values, -- Good luck Ivar

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Posted: 1 decade ago 9 apr 2012, 14:12 GMT-4
Thanks a lot.

So, if I want to do prestressed modal analysis based on deformed configuration by COMSOL, I should use deformed mesh mode of COMSOL.

Does it make sense?

Thank you!
Thanks a lot. So, if I want to do prestressed modal analysis based on deformed configuration by COMSOL, I should use deformed mesh mode of COMSOL. Does it make sense? Thank you!

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

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Posted: 1 decade ago 10 apr 2012, 06:04 GMT-4
Hi

No
use a standard solid + stationary to apply your initial stress, then add an eigenfequency using the stationry as linearization and initial values (both in the same study.

Check the model library linear buckling example its based on the same two solver process principle.
There is a lso a few prestressed eigenvalue cases in the model libnrary (be sure you have updated it) and I'm talking about the 4.2a one, as I do not have the earlier versions anymore

--
Good luck
Ivar
Hi No use a standard solid + stationary to apply your initial stress, then add an eigenfequency using the stationry as linearization and initial values (both in the same study. Check the model library linear buckling example its based on the same two solver process principle. There is a lso a few prestressed eigenvalue cases in the model libnrary (be sure you have updated it) and I'm talking about the 4.2a one, as I do not have the earlier versions anymore -- Good luck Ivar

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Posted: 1 decade ago 10 apr 2012, 14:25 GMT-4
Thanks a lot!

I tried the prestressed eigenvalue cases. But I think in these cases, the deformation of structure is not taken into account in the following eigenvalue analysis.

I try to find the method to do prestressed modal analysis based on the deformed configuration rather than initial configuration.


Thanks a lot! I tried the prestressed eigenvalue cases. But I think in these cases, the deformation of structure is not taken into account in the following eigenvalue analysis. I try to find the method to do prestressed modal analysis based on the deformed configuration rather than initial configuration.

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Posted: 1 decade ago 23 apr 2012, 05:28 GMT-4
did you have any success?
did you have any success?

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