Mixed mode failure curve for an interface crack between single crystal silicon and silicone rubber

An interface crack between single crystal silicon (SC-Si) and silicone rubber was examined. Mixed mode fracture tests were performed on Arcan-type specimens at different mode mixities. It was observed during the tests that silicone rubber underwent large deformations before crack propagation. Nonlinear finite element analyses (FEAs) of the fracture tests were carried out in Abaqus. A cubic (anisotropic), linear elastic material model was used for SC-Si, while a Mooney–Rivlin (hyperelastic) model was used for the silicone rubber. The virtual crack closure technique (VCCT) which has been adopted for large deformations was employed to determine the energy release rates from the FEAs. A mixed mode failure criterion was obtained from the energy release rate data.