Debonding analysis of thin plates from curved substrates

This paper is focused on the analytical modeling of the interface between a rigid substrate with constant curvature and a thin bonded plate. In a previous investigation, an analytical cohesive zone (CZ) model capable of predicting the interfacial behavior prior to the onset of debonding has been proposed by the authors. As a follow-up, this paper presents a new analytical model, which is able to predict both the load at onset of debonding and the subsequent evolution of the debonding process. The study clarifies the essential differences in behavior between joints with flat and curved substrates during debonding. The new analytical model is based on linear-elastic fracture mechanics (LEFM) and is developed under two distinct assumptions: a mode-independent fracture energy, and a fracture energy dependent on the mode mixity, according to a simple mixed-mode fracture criterion. The model is applied to the determination of the load at onset of debonding, and to the prediction of the load–displacement behavior during the entire debonding process. The relationship between the predictions of the CZ and LEFM models regarding the load at initiation of debonding is also established.