Interface crack between isotropic Kirchhoff plates

In this work Kirchhoff plate theory is used to calculate the energy release rate function in delaminated isotropic plates. The approximation is based on the consideration of the equilibrium equations and the displacement continuity between the interface plane of a double-plate model. It is shown that the interface shear stresses are governed by a fourth order partial differential equation system. As an example, a simply supported delaminated plate subjected to a point force is analyzed adopting Lévy plate formulation and the mode-II and mode-III energy release rate distributions along the crack front were calculated by the J-integral. To confirm the analytical results the 3D finite element model of the delaminated plate was created, the energy release rates were calculated by the virtual crack-closure technique and the J-integral. The results indicate a good agreement between analysis and numerical computation.