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Dynamic stiffness of rubber bushing with static pre-load

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Hello,
I am interested to model a rubber bushing and to calculate its dynamic stiffness (frequency analysis). The bushing is pre-loaded, which means it could have large deformations. Any good advice on which approach and module to use?
Thank you in advance for your time.
Regards

3 Replies Last Post 18 mars 2014, 22:37 UTC−4
Nagi Elabbasi Facebook Reality Labs

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Posted: 1 decade ago 17 mars 2014, 22:38 UTC−4
HI,

You should set up a Prestressed Analysis – Frequency Domain . That probably requires the Structural Mechanics Module. One challenge in this type of problems is to select a material model that has a dynamic stiffness (storage and loss moduli) that closely represents that of your rubber material.
HI, You should set up a Prestressed Analysis – Frequency Domain . That probably requires the Structural Mechanics Module. One challenge in this type of problems is to select a material model that has a dynamic stiffness (storage and loss moduli) that closely represents that of your rubber material.

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Posted: 1 decade ago 18 mars 2014, 14:55 UTC−4
Hello,
Thanks for your answer. I guess that one of the issue is to, firstly, make the pre-stress, using some hyperelastic material (Mooney-Rivlin), and secondly calculate the frequency response using a viscoelastic material (Boltzmann's relaxation model). But what is the procedure to model a material in 2 steps (stationary and then frequency) and have a different material model for each step?

Regards

HI,

You should set up a Prestressed Analysis – Frequency Domain . That probably requires the Structural Mechanics Module. One challenge in this type of problems is to select a material model that has a dynamic stiffness (storage and loss moduli) that closely represents that of your rubber material.


Hello, Thanks for your answer. I guess that one of the issue is to, firstly, make the pre-stress, using some hyperelastic material (Mooney-Rivlin), and secondly calculate the frequency response using a viscoelastic material (Boltzmann's relaxation model). But what is the procedure to model a material in 2 steps (stationary and then frequency) and have a different material model for each step? Regards [QUOTE] HI, You should set up a Prestressed Analysis – Frequency Domain . That probably requires the Structural Mechanics Module. One challenge in this type of problems is to select a material model that has a dynamic stiffness (storage and loss moduli) that closely represents that of your rubber material. [/QUOTE]

Nagi Elabbasi Facebook Reality Labs

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Posted: 1 decade ago 18 mars 2014, 22:37 UTC−4
There is a pre-defined analysis type for this in COMSOL called “Prestressed Analysis – Frequency Domain”. Regarding switching materials between the two studies/steps it is possible and in some cases it is the most suitable way. However, you lose the benefits of the pre-stress analysis since the new material is no longer in equilibrium at the start of the frequency response step.

Nagi Elabbasi
Veryst Engineering
There is a pre-defined analysis type for this in COMSOL called “Prestressed Analysis – Frequency Domain”. Regarding switching materials between the two studies/steps it is possible and in some cases it is the most suitable way. However, you lose the benefits of the pre-stress analysis since the new material is no longer in equilibrium at the start of the frequency response step. Nagi Elabbasi Veryst Engineering

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