New Developments in Elastic Degradation and Damage: Anisotropic Formulations and Evolution Laws in Lag Space

Abstract

Anisotropic damage modeling still poses a number of open challanges. One of the most important is how to formulate the evolution laws in a way that is simple and makes physical sense. The theory tells us that loading function and damage rule have to be defined in the space of conjugate forces to the primary damage variable.
Choosing the 2nd-order integrity tensor (or any of the usual related tensors) as such variable, the resulting conjugate
force lacks physical meaning and proposing evolution laws becomes a difficult task. A (2nd-order) pseudo-log rate of damage is proposed which remedies this problem and exhibits a number of additional advantages. A first simple
model is developed based on these ideas, which exhibits very promising features.