Discussion Closed This discussion was created more than 6 months ago and has been closed. To start a new discussion with a link back to this one, click here.

Dynamic stiffness of rubber bushing with static pre-load

Please login with a confirmed email address before reporting spam

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 18.03.2014, 22:37 GMT-4
Nagi Elabbasi Facebook Reality Labs

Please login with a confirmed email address before reporting spam

Posted: 1 decade ago 17.03.2014, 22:38 GMT-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.

Please login with a confirmed email address before reporting spam

Posted: 1 decade ago 18.03.2014, 14:55 GMT-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

Please login with a confirmed email address before reporting spam

Posted: 1 decade ago 18.03.2014, 22:37 GMT-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

Note that while COMSOL employees may participate in the discussion forum, COMSOL® software users who are on-subscription should submit their questions via the Support Center for a more comprehensive response from the Technical Support team.