Strain Energy Release Rate in Finite Graphite/Epoxy Plate with a Crack Under Mixed Mode Deformation

Abstract

We investigate the mixed mode problem numerically and experimentally for the finite orthotropic plate where an inclined crack parallel to the fiber direction is centrally placed. The mixed mode correction factors of strain energy release rate are calculated by using the modified mapping colocation method and those of graphite/epoxy plates are presented as functions of the crack length for various aspect ratios, crack angles and boundary conditions. To confirm the validity of these results, the mixed mode fracture test for graphite/epoxy specimens is performed for selected combinations of crack length and angle. Mixed mode strain energy release rates for various crack angles and crack lengths are obtained