A comparison of micromorphic gradient‐extensions for anisotropic damage

Abstract

The modeling of inelastic phenomena with tensor‐valued internal variables requires a regularization to counteract mesh dependence. Here, we consider the regularization of anisotropic damage at finite strains and seek for an efficient formulation based on a reduced number of nonlocal degrees of freedom. We, thus, equip the brittle version of an anisotropic model with different gradient‐extensions in the micromorphic framework using a full and a reduced regularization of the damage tensor. The models are compared in the structural simulation of an asymmetrically notched specimen with a perforated shear band section. High agreement is observed between the full and the reduced regularization with two nonlocal degrees of freedom. Furthermore, we present a novel study of the evolution of the reduced micromorphic field variables.