Hello

I need a basic understanding from your side regarding UMAT code for Single crystals

I was following a paper on the same and it says that ABAQUS provides for each integration point, the values of total deformation gradient, F at the

current time t, the deformation gradient from the current natural conﬁ,guration, Fe at current time t, current value of the Cauchy stress, T and the state variables such as s(strain path length) and G(Plastic Deformation) at the current time step. It also sends an estimate of the total deformation gradient at the next time step (t + ∆,t).

The UMAT supplies the values of the state variables such as s, Fe and G and Cauchy stress at time step t + ∆,t and return it back to the ABAQUS. This process continues until a converged solution is obtained

Thus I would like to know how can we provide G, Fe and T at time step t + ∆,t. I know how to get s from the constitutive equations.

Any help would be appreciated

Thanx