Finite element analysis of the indentation-induced delamination of Bi-layer structures

Contact deformation can cause local damage of mechanical structures and lead to structural failure of mechanical devices. In this work, we use the finite element method to analyze the indentationinduced delamination of a film-substrate structure and the critical tensile stress as the criterion to determine local delamination on the interface between the film and the substrate. The simulation results show that both the size of the delamination zone and the maximum separation increase with increasing the indentation depth and with decreasing the film thickness. The delamination also depends on the interfacial friction for the sliding on the interface. The largest delamination occurs at the friction coefficient of 0.5 for the film-substrate structure used in this work. For friction coefficient larger than 0.5, the size of the delamination zone decreases with increasing the friction coefficient.