  A coupled cohesive zone model based on an analogy between fracture and
contact mechanics is proposed to investigate debonding phenomena at imperfect
interfaces due to thermomechanical loading and thermal fields in bodies with
cohesive cracks. Traction-displacement and heat flux-temperature relations are
theoretically derived and numerically implemented in the finite element method.
In the proposed formulation, the interface conductivity is a function of the
normal gap, generalizing the Kapitza constant resistance model to partial
decohesion effects. The case of a centered interface in a bimaterial component
subjected to thermal loads is used as a test problem. The analysis focuses on
the time evolution of the displacement and temperature fields during the
transient regime before debonding, an issue not yet investigated in the
literature. The solution of the nonlinear numerical problem is gained via an
implicit scheme both in space and in time. The proposed model is finally
applied to a case study in photovoltaics where the evolution of the
thermoelastic fields inside a defective solar cell is predicted.
