In subroutine ``uhardening.f'', the user can insert his own isotropic and/or kinematic hardening laws for (visco)plastic behavior governed by the keyword sequence *PLASTIC,HARDENING=USER. The header and variable description is as follows:
subroutine uhardening(amat,iel,iint,t1l,epini,ep,dtime,fiso,dfiso, & fkin,dfkin) ! ! INPUT: ! ! amat: material name (maximum 80 characters) ! iel: element number ! iint: integration point number ! t1l: temperature at the end of the increment ! epini: equivalent irreversible strain at the start ! of the increment ! ep: present equivalent irreversible strain ! dtime: time increment ! ! OUTPUT: ! ! fiso: present isotropic hardening Von Mises stress ! dfiso: present isotropic hardening tangent (derivative ! of the Von Mises stress with respect to the ! equivalent irreversible strain) ! fkin: present kinematic hardening Von Mises stress ! dfkin: present kinematic hardening tangent (derivative ! of the Von Mises stress with respect to the ! equivalent irreversible strain) !