A computational and experimental investigation of three-dimensional micro-wedge indentation-induced interfacial delamination in a soft-film-on-hard-substrate system

A three-dimensional finite element (FEM) simulation was performed to study the mechanics of micro-wedge indentation-induced interfacial delamination of a soft film from a hard substrate. In this simulation, a traction–separation law, with two major parameters: interfacial strength and interfacial energy, was used to characterize the failure behaviors of the interface. Cracking of film and residual stresses were not included. The initiation and growth of the interfacial delamination were investigated for a wide range of interfacial properties. It was found that the interfacial strength influences the initiation of delamination more than does interfacial energy, while the interfacial energy is more effective to affect the propagation of the delamination crack. The effects of the length of wedge indenter tip and the thickness of film on the onset and growth of interfacial delamination were also analyzed. Furthermore, the interfacial delamination process by micro-wedge indentation was conducted experimentally, and the delamination crack fronts as well as the P–h curves in experiments and computations were compared thoroughly. Comparisons between the computational and experimental results yield quantitative good agreement.