Experimental and numerical methodology to characterize 5083-aluminium behavior considering non-associated plasticity model coupled with isotropic ductile damage

Abstract

In the present work, an elastoplastic-damage model fully coupled with the constitutive equations of the non-associated plasticity is developed, to enrich the existing research results on the non-associated plasticity finite element models. The yield function and the plastic potential are represented independently by two different (Hill, 1948) quadratic functions to describe the anisotropic behavior of 5083-aluminium alloy. The current model develops a first attempt to establish a general formulation with two ductile degradation functions, one for elasticity and the other for plasticity, with variable degradation coefficients. Further, the elastoplastic behavior of 5083-aluminium alloy is determined through uniaxial tensile tests, so that the anisotropic, the isotropic hardening and the damage parameters are acquired. Experimental-numerical confrontation proves the reliability of the current formulation to describe the behavior of 5083-aluminium alloy with good accuracy. Furthermore, a novel numerical optimization procedure is firstly used to analytically identify Lemaître damage parameters in order to limit the non-unicity of these parameters. The adopted optimization procedure offers a compromise between good accuracy and low computational time to determine the damage parameters.