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Does the 3D mechanical shell support large deformation?

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Hi
We need to know whether the 3D mechanical shell model supports the large deformation? We have nonlinear small speaker membrane analysis using shell model. It needs the large deformation which the solid stress strain mode support but shell mode does not to create the nonlinear stiffness behavior. Thank you for the helps and best regards.
Lei.Chen

3 Replies Last Post 30 dic 2015, 03:45 GMT-5

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Posted: 1 decade ago 20 nov 2009, 04:45 GMT-5
Hi
Is there any work around way to anlayze the speaker membrane large deformation. The thickness of the membrane is very small comparing to its size. Please help. Many thanks.
Hi Is there any work around way to anlayze the speaker membrane large deformation. The thickness of the membrane is very small comparing to its size. Please help. Many thanks.

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

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Posted: 1 decade ago 20 nov 2009, 07:19 GMT-5
Hi

You are asking an interesting question there about large deformations theory and the simplified shell models. These type of questions are typicaly what I ask support.

Normally with bulk structural mode the large deformations uses Greens stress, versus Engierring stress for small deformations, but when using shells, isn't all this predefined ?

Il you check the smeref.pdf doc, you see that large deformations is mentionned for trusses, but not explicitely for beams nor for shells !

When you open the shell and beam modes in 2D or 3D [V3.5a] there is NO option for large deformations. therefore I would conclude that the default shell items are NOTcompatible with large deformations.

I would use bulk 3D, even if correct meshing is somewhat more complex.

Good luck
Ivar
Hi You are asking an interesting question there about large deformations theory and the simplified shell models. These type of questions are typicaly what I ask support. Normally with bulk structural mode the large deformations uses Greens stress, versus Engierring stress for small deformations, but when using shells, isn't all this predefined ? Il you check the smeref.pdf doc, you see that large deformations is mentionned for trusses, but not explicitely for beams nor for shells ! When you open the shell and beam modes in 2D or 3D [V3.5a] there is NO option for large deformations. therefore I would conclude that the default shell items are NOTcompatible with large deformations. I would use bulk 3D, even if correct meshing is somewhat more complex. Good luck Ivar

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Posted: 8 years ago 30 dic 2015, 03:45 GMT-5
I have the same question.
When I calculate the force vs deformation for a ultrathin membrane, such as graphene, which model is most suitable? 3D membrane? or 2D plate is fine too?
I have the same question. When I calculate the force vs deformation for a ultrathin membrane, such as graphene, which model is most suitable? 3D membrane? or 2D plate is fine too?

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