I am new to FEM, especially when it comes to hyperelastic materials, Im trying to model the compression and hydrostatic loading of a polyurethane seal using MSC Marc. Im not sure what type of material I should use.

I do not dispose of experimental data, and i only know E ~45MPa and v ~ 0.49, I can obtain converged solutions with the standard isotropic material model, but i think the model leads to too much compression of the elastomer.

I tried to compute Mooney-Rivlin coefs from E and v, but then the model no longer converges. I have no idea how to compute Ogden or Arruda-Boyce coefficients from E and v.

Any idea on what would be the best model that can be used with the available data would be great. Thank you!