A traction-separation interface model for chemical bonding and damage in a thermo-mechanical context

Overview & Synopsis

A fully coupled thermo-chemo-mechanical cohesive zone model (CZM) is presented to describe chemical bonding, damage until rupture and friction of an interface between, at least, two solids subjected to thermomechanical loads. A traction-separation interface law is adopted and the model is formulated into a rigorous thermodynamic framework. One originality lies in the fact that the interface may not initialy be present in the problem and may form if specific thermal and mechanical conditions occur. An implementation in a UMAT subroutine in Abaqus is proposed and detailed. The numerical examples provided are based on the case of pellet-cladding interaction in nuclear fuel elements where the creation of chemical interface can play an important role on the thermal and mechanical balance.