The Effects of Laminated Structure on Delamination Buckling and Growth

Abstract

Cylindrical postbuckling solutions are obtained for an arbitrarily structured laminate. The strains of the middle surface contain sinusoidal terms that are in-phase with the out- of plane deflection. Bendmg-stretching coupling significantly reduces the buckling load and enhances the postbuckling deformation. The effects may be characterized by introduc ing an equivalent bending rigidity. The postbuckling solutions for a laminate with clamped ends are applied first to a thin-film strip delamination in a base laminate subjected to uni form membrane loads and next to a mid-plane delamination in a symmetric laminate. The energy release rates at the crack tip are evaluated to determine the stability characteristics of delamination growth.