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 sub- sequent evolution of the debonding process. The study clarifies the essential differences in behavior between joints with flat and curved substrates during debonding. The new ana- lytical 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 pre- diction of the load–displacement behavior during the entire debonding process. The rela- tionship between the predictions of the CZ and LEFM models regarding the load at initiation of debonding is also established.