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Large Deformation and Hyperelasticity of Shell Elements
Posted May 29, 2015, 1:13 p.m. EDT Structural Mechanics 2 Replies
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Hi,
I am currently working on modeling shell elements in COMSOL, and my material will undergo large deformations. Thus, there is a good chance that a hyperelastic material model will be required. Under the shell physics, I only found a linear material model, so I was wondering if there is a way to use nonlinear models as well (whether the shell elements could be modified or other models could be imported into the module).
Additionally, I am having problems with the material's large deformations when it is modeled as a shell. When using plates or beams, I check the "include geometric nonlinearity" checkbox in study1r>step1:stationary and use segregated step as demonstrated in one of the COMSOL examples titled "large deformation analysis of a beam." However, this same procedure does not produce the large deformation for a shell element. It is still bending for a case of small deformation (no bending/curling is occurring, just vertical tip displacement). Are there extra steps that need to be taken for a shell element?
Additional information about the model: the material is subject to an internal distributed moment (body load) and an internal axial stress. The paragraph above is for just the distributed moment case. I later plan on using this model in the multibody dynamics module.
Thanks,
Anil Erol
The Pennsylvania State University
I am currently working on modeling shell elements in COMSOL, and my material will undergo large deformations. Thus, there is a good chance that a hyperelastic material model will be required. Under the shell physics, I only found a linear material model, so I was wondering if there is a way to use nonlinear models as well (whether the shell elements could be modified or other models could be imported into the module).
Additionally, I am having problems with the material's large deformations when it is modeled as a shell. When using plates or beams, I check the "include geometric nonlinearity" checkbox in study1r>step1:stationary and use segregated step as demonstrated in one of the COMSOL examples titled "large deformation analysis of a beam." However, this same procedure does not produce the large deformation for a shell element. It is still bending for a case of small deformation (no bending/curling is occurring, just vertical tip displacement). Are there extra steps that need to be taken for a shell element?
Additional information about the model: the material is subject to an internal distributed moment (body load) and an internal axial stress. The paragraph above is for just the distributed moment case. I later plan on using this model in the multibody dynamics module.
Thanks,
Anil Erol
The Pennsylvania State University
2 Replies Last Post Jun 4, 2015, 12:14 p.m. EDT
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Posted:
9 years ago
Hi,
I think it is enough to enable the large deformation by checking the "include geometric nonlinearity". You can check the variable dx/dX to see if it is large deformation. And, it seems that you cannot check the "force linear strain" in the solid mechanics, because it will force the structure as a small deformation.
Best,
Rong
I think it is enough to enable the large deformation by checking the "include geometric nonlinearity". You can check the variable dx/dX to see if it is large deformation. And, it seems that you cannot check the "force linear strain" in the solid mechanics, because it will force the structure as a small deformation.
Best,
Rong
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Posted:
9 years ago
Hi Rong,
I have the large deformation working now for shells. However, I am still not sure if there is a way to implement hyperelastic material models to shell elements.
Thank you,
Anil
I have the large deformation working now for shells. However, I am still not sure if there is a way to implement hyperelastic material models to shell elements.
Thank you,
Anil