Parameter identification for anisotropic Yld2000-2d stress function under non-associated flow rule

摘要

In the present paper, widely used orthotropic Yld2000-2d stress function under non-associated flow rule is applied to the aluminum alloy 5754-H22 sheet. Non-associated formulation based on Yld2000-2d stress function contains sixteen anisotropy parameters that can be determined using selected experimental data by an error minimization technique. Such formulation, with parameters calculated by standard approach, might result in excellent predictions of uniaxial plastic material behavior, but in unacceptable predictions of some complex sheet metal forming processes. Motivated by these observations, in this paper, weight parameters and additional artificial assumptions are introduced into the parameter identification procedure for the considered formulation applied to AA5754-H22 sheet. It has been revealed that predictions of uniaxial plastic material properties and yield function/plastic potential contours obtained for the tested material by analyzed non-associated formulations significantly depend on additional constrains introduced in the parameter identification procedure.