Micromechanics of rupture in combined tension and shear

A micromechanics model based on the theoretical framework of plastic localization into a band introduced by Rice [1] is developed. The model employed consists of a planar band with a square array of equally sized cells, with a spherical void located in the centre of each cell. The micromechanics model is applied to analyze the rupture mechanisms associated with mixed mode ductile fracture. The stress state is characterized by the stress triaxiality T and the Lode parameter μ, which adequately describe the stress state ahead of a crack tip under mixed mode loading of an isotropic elasto-plastic material. The main focus is the influence of μ on void growth and coalescence behavior. It is shown that the Lode parameter exerts a strong influence upon this behavior.