Discrete element modeling of effect of interfacial roughness and pre-crack on crack propagation in thermal barrier coatings

Particle erosion is a major failure mechanism in thermal barrier coatings. In this work, a discrete element model is developed to simulate the crack propagation due to particle erosion. The effects of the interface bond layer roughness and pre-crack are focused. The results show that with the increasing roughness of the bonding layer, the extension length of the delamination cracks is reduced. The delamination cracks are suppressed when the roughness increases. The initial vertical TC defects can effectively inhibit the nucleation and extension of the new cracks. This study provides a theoretical foundation for understanding the crack failure mechanism in thermal barrier coatings.