عنوان مقاله [English]
Coatings are used in different industries in order to improve the surface properties in components and instruments. In some situations, such as improving the wear resistance of an instrument, brittle coatings have been considered. Dominant failure mode in these structures is crack initiation and propagation. So, investigating the fracture behavior of these structures is in great importance. In this paper, discrete element method (DEM) is used to simulate the crack initiation and propagation in coating/substrate structures. This method has a great ability to predict damage initiation and propagation in structures. For this purpose, a DEM solver code is written by authors. Brittle elastic behavior is considered in coating and substrate and the effect of elastic mismatch in constituents of structure and the coating thickness in damage initiation and propagation were investigated. The results showed that in structures in which coating stiffness is less than substrate stiffness, in the case of low thickness of coating, damage appears as crack initiation and propagation into the substrate but, by increasing the coating thickness, crack grows into or parallel to interface. In structures in which the coating stiffness is greater than substrate stiffness, no matter to the coating thickness, crack grows to the substrate.