Analysis of fracture mechanics on delamination in composite laminate

The fracture mechanics feature of elliptical delamination in a composite laminate is studied. Using the method of normal slices, the relationship between the stress intensity factor and the energy release rate along the front of the elliptical delamination area was established, based on the stress field and the displacement field in the vicinity of the delamination-tip of the plane shear delamination and anti-plane shear delamination in the composite laminate. The distribution expression of the energy release rate and the stress intensity factor along the front of the elliptical delamination area was obtained, combining with the total potential energy determined by the additional displacements. Computational results show that the distribution of energy release rate and the stress intensity factor are in close relationship with the shape of delamination, the load and the thickness ratio of the laminate.