Discrete element modeling of delamination behavior in thermal barrier coating

Delamination is a common failure mode in thermal barrier coatings (TBCs). In this work, we present an improved discrete element (DE) model to simulate the coating delamination behaviors during micro-indentation tests to better understand the failure mechanisms. In the DE model, the linear parallel bond model is first calibrated with the experimental properties from the literature. Then, both the 2D Vickers and Rockwell micro-indentation tests were simulated with layered coating microstructures. The model results reveal that the coating interface delimitation has two distinctive stages, i.e., crack initiation and propagation. Additionally, TBC systems with a thicker top are more susceptible to delamination due to less strain compliance.