Amirkabir University of Technology Amirkabir Journal of Mechanical Engineering 2008-6032 52 5 2019 02 08 Discrete Element Method Simulation of Crack Propagation in Brittle Coatings Discrete Element Method Simulation of Crack Propagation in Brittle Coatings 1153 1166 3282 10.22060/mej.2019.15054.6014 FA M. A. Ghasemi Faculty of Mechanical Engineering, University of Guilan, Guilan, Rasht Seyed Reza Falahatgar Faculty of Mechanical Engineering, University of Guilan, Guilan, Rasht 0000-0003-1573-5619 Journal Article 2018 09 30 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 of great importance. In this paper, the discrete element method 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 discrete element 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 the low thickness of the coating, damage appears as crack initiation and propagation into the substrate but, by increasing the coating thickness, the crack grows into or parallel to the interface. In structures in which the coating stiffness is greater than substrate stiffness, no matter to the coating thickness, the crack grows to the substrate. 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 of great importance. In this paper, the discrete element method 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 discrete element 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 the low thickness of the coating, damage appears as crack initiation and propagation into the substrate but, by increasing the coating thickness, the crack grows into or parallel to the interface. In structures in which the coating stiffness is greater than substrate stiffness, no matter to the coating thickness, the crack grows to the substrate. https://mej.aut.ac.ir/article_3282_a495eebbfa243b79c5b9b224c482d0c2.pdf