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interaction between 2 membranes with incompressible solid in between

Thongchai Asavaparjukul

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Hi,
I would like to simulate the model which has 2 membrane on both side of the solid. If the solid is incompressible, when the force acts on 1 membrane it should press the solid down. The transferring of mass should interact with another membrane which is on another side of solid. All of this should happen if the solid is incompressible but in my simulation, there has no interaction to another membrane. Please give me some suggestion.
Thank you very much.


2 Replies Last Post 17 mai 2012, 10:01 UTC−4
Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)

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Posted: 1 decade ago 16 mai 2012, 13:45 UTC−4
Hi

Have you checked your values carefully ?
You are pressing with 5[TPa] and holding that on a 1um thick side edge of a membrane, and your mebrane has only 1 mesh element in the thickness, your shear stress is about at the level of INF at least numerically, no wonder the solver has problems to come to something reasonable.

But the main reason for no motion is that you have fixed the interiour boundary under your tip thin membrane. Often its better to work in "wireframe" view to select items with such aspect ratios. (remove boundary "9" from your fixed BC list)

I would also suggest to use a sweep mesh in the thickness, to get 3-5 elements in the membrane thickness, while you do not really need much more than 5-10 in the total bulk thickness

--
Good luck
Ivar
Hi Have you checked your values carefully ? You are pressing with 5[TPa] and holding that on a 1um thick side edge of a membrane, and your mebrane has only 1 mesh element in the thickness, your shear stress is about at the level of INF at least numerically, no wonder the solver has problems to come to something reasonable. But the main reason for no motion is that you have fixed the interiour boundary under your tip thin membrane. Often its better to work in "wireframe" view to select items with such aspect ratios. (remove boundary "9" from your fixed BC list) I would also suggest to use a sweep mesh in the thickness, to get 3-5 elements in the membrane thickness, while you do not really need much more than 5-10 in the total bulk thickness -- Good luck Ivar

Thongchai Asavaparjukul

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Posted: 1 decade ago 17 mai 2012, 10:01 UTC−4
Thank you very much Dr.Ivar. Now the problem was solved :)
Thank you very much Dr.Ivar. Now the problem was solved :)

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