A CONTINUUM THERMODYNAMIC ANALYSIS OF COHESIVE ZONE MODELS

A global thermodynamic analysis of the running crack problem is presented. The crack is modeled as an evolving partially cohesive interface endowed with a thermodynamic structure distinct from that of the surrounding body. Constitutive relationships for the cohesive part of the crack surface are formulated in a general way that allows one to account for various dissipative mechanisms and to recover most of the cohesive zone models available from the literature. Particular attention is focused on some of the fundamental and necessary requirements for formulating cohesive zone models. The relationship between such requirements and the interface evolution is discussed and analysed.