Ansys elastomer's characterization

[demox13]

Hi. I'm a new member of the site.
I'm a student who is doing his thesis about an engineering application of elastomers. I'm using Ansys as modelling software. I'd like to know some information about how to insert the model's material properties. For the moment I just know that I have to choose the material between hyperelastic kinds but I don't know what kind of strain energy potentials I've to use and which costants I've to associate to them. And what about experimental data?

Thanks.

Gianluca - demox13@fastwebnet.it

Bye :P :P

[Jorgen]

Hello Gianluca,

In order to answer your questions I need more information:
:arrow: What elastomer are you working with?
:arrow: How do you plan on deforming the elastomer?
:arrow: How large strains do you expect?
:arrow: Are you interested in predicting both loading and unloading or only monotonic loading?
:arrow: Do you already have experimental data for the elastomer?

The best material model for your simulation work will depend on these issues.
Best of luck,
Jorgen

[demox13]

Thanks a lot.
Now I take the required information and I'll give you them.
Bye.

[demox13]

These are the information you have required:

For the moment I haven't a precise idea about the kind of elastomer.
What I want to do with my analysis is: deform an irregular closed thin
membrane (dimensions about 200 x 70 x 70 mm). Its thickness is about 5 mm.
I want to move some points of the membrane in order to stretch it (so I
impose displacements to points) and then remove the displacements to view
the material's response.
Therefore I'm interested in loading and unloding.
I expect large deformation: the point's displacement are about 50 mm.
I don't have any experimental data for elastomers. I have only downloaded
from your site those about natural rubber.

Thanks a lot.

[Jorgen]

Based on your information I would start with a simple hyperelastic material model, e.g. the Neo-Hookean, Eight-chain, or Yeoh models.

Either of these models are will capture the main part of the elastomer response, but they will not capture the influence of deformation rate or stress-relaxation. To capture these effects you need a more advanced model such as the Bergstrom-Boyce model.

Jorgen