Buckle-driven delamination of thermal barrier coatings on a polynomial curved substrate

In this paper, buckle-driven delamination between thermal barrier coatings (TBCs) and a polynomial curved substrate is theoretically analyzed under thermal loading. First, based on the one-dimensional flat blister mode, a theoretical model for buckle-driven delamination of a polynomial curved coating blister is established. Second, a finite element model of the TBCs with an interface initial crack on different polynomial curved substrates is built to investigate the influence of temperature and the initial substrate morphology on the energy release rate and mode mixity, which agrees well with the results from the theoretical prediction. Finally, the influence of crack length, coating thickness and substrate morphology on the buckle-driven mechanism is analyzed and discussed. The results will provide important guidance for characterizing and designing curved TBCs of thermal protection structures. (paper)