A ductile damage model including shear stress effects

摘要

Since the early work of Gurson, ductile damage macroscopic constitutive laws based on microvoid growth have been improved, the well-known Tveggaard (2) plastic potential included some coalescence effects, Rousselier formulated relations for finite deformations of plastically dilatant materials, more recently Brunhs and Schiesse have developed a continuum model of elastic-plastic materials with anisotropic damage by oriented microvoids. Most of the existing plastiicty-damage theories consider the mean normal stress as the main parameter controlling the microvoid growth even though the deviatoric part of the stress tensor acts on the phenomena at the microscopic or mesoscopic levels.