Fracture Mode Separation for Delamination in Platelike Composite Structures

Abstract

A computationally efficient approach combining a plate crack-tip element model and a mixed-mode separation technique was developed to calculate mode mixities and stress intensity factors for delamination in platelike composite structures. The crack-tip element was based on classical plate theory, assuming the delamination surfaces to be traction free. Fracture mode separation was achieved by equating the total strain energy release rate from classical plate theory with that from the three-dimensional near-tip solution, along with two supplementary finite element analyses for special loadings. Using this approach, the separation of fracture modes under any other load combinations can easily be carried out. Numerical results showed that the present method gives good evaluations of the mixed-mode stress intensity factors.