Sean Harvey
Ansys Employee

Hello Sarvesh,

Thank you for sharing.  So the material curves you provided. Do they make physical sense to you?  For example, a uniaxial tensile test that has a negative slope means that if I push to material into compression, it will stretch.  In other words, negative stress, gives a positive strain.

It seems this material is a type of silicone right?  Would you expect this behavior?  Did the paper you get this from have the stress-strain curves to verify against?  Also, there are some hyperleastic material models that even though are the same name, the implementation is a bit different.  For example, in Ansys and Abaqus, there can be a difference in the implementation even though the coefficients seem to be the same symbols. 

Can you share your material reference, or elaborate?  Thank you.