Finite Element formulation of a general asymmetrical yield function for pressure sensitive metals

Finite Element formulation is developed for a recently proposed asymmetrical yield function [7] with the dependence on the stress invariants for pressure sensitive metals. The asymmetric yield function [7] is implemented into ABAQUS User Material Interface. Numerical simulations are performed for AZ31B magnesium sheet alloy for the verification purpose. Simulations are conducted under uniaxial tension and uniaxial compression in different orientations. In order to capture the r-values, non-associated flow rule is incorporated in the implementation. The simulations shows that the yield function provides reasonable predictions for strength differential effect and also anisotropic behavior in both tension and compression.