Self‐Adaptive Model for Structural Softening of Brittle Materials

Abstract

A constitutive model that is able to follow softening behavior in terms of stress and strain variables is presented. The model, when used in a finite element context, gives mesh‐insensitive results. It is based on the concept that the softening tangent modulus is not a characteristic of the material, but is governed instead by the structural behavior. This concept is employed by assuming that the fracturing phase at a single point occurs at constant external actions, i.e., as a neutral equilibrium bifurcation. The model's main purpose is to allow use of conventional strain variables, thereby avoiding the conceptual and numerical problems usually arising when dealing with softening materials in terms of local quantities.