A comparative study of micromorphic gradient-extensions for anisotropic damage at finite strains

TL;DR

This paper compares different gradient-extensions for regularizing anisotropic damage models at finite strains, demonstrating that reduced regularizations can achieve similar accuracy to full models, improving computational efficiency.

Contribution

It introduces and compares three gradient-extensions for anisotropic damage models, showing that a reduced regularization performs comparably to the full version.

Findings

Excellent agreement between full and reduced regularizations.

Reduced regularization uses fewer nonlocal degrees of freedom.

Enhanced computational efficiency without loss of accuracy.

Abstract

Modern inelastic material model formulations rely on the use of tensor-valued internal variables. When inelastic phenomena include softening, simulations of the former are prone to localization. Thus, an accurate regularization of the tensor-valued internal variables is essential to obtain physically correct results. Here, we focus on the regularization of anisotropic damage at finite strains. Thus, a flexible anisotropic damage model with isotropic, kinematic, and distortional hardening is equipped with three gradient-extensions using a full and two reduced regularizations of the damage tensor. Theoretical and numerical comparisons of the three gradient-extensions yield excellent agreement between the full and the reduced regularization based on a volumetric-deviatoric regularization using only two nonlocal degrees of freedom.