Hello,
I have the following problem:
I want to implement a hyperelastic material model with a damage function (like the pseudo-elasticity of Ogden) by using a UMAT in Abaqus/Standard.
For this, in the first step I try to implement the damage of Ogden, which already exist in Abaqus/Standard.
But I don't know in which way I build the tangent stiffness matrix for this case (nonlinear and dependent of the history)
Do anywhere know a good literature in order to read and understand this issue?
Ideally anywhere have a such numerical formulation what I can take over.
Thank you in advance
Ahmetoglu