Effects of substrate compliance on circular buckle delamination of thin films

The present work analyzes circular delamination buckling in a film/substrate system based on the Von Karman nonlinear plate theory with the consideration of elastic deformation of the substrate. Due to the axisymmetry of circular buckling, the substrate deformation is modeled by coupled springs and the spring compliances are determined from the dimension analysis and finite element calculations. The numerical shooting method is used to solve the nonlinear post-buckling problem. The stress intensity factors, the energy release rate, and the phase angle are given here for a variety of the elastic mismatch between the film and the substrate. The results show that in some cases, the energy release rate can be several times larger than that derived from the widely used clamped edge condition.