Delamination crack originating from transverse cracking in cross-ply laminates under various loadings

Abstract

Delamination cracks originating from transverse cracking in two types of cross-ply laminates [90/0]s and [0/90]s are analysed for three types of loadings: plane strain extension, plane strain bending and antiplane shear. The asymptotic solution for stress and displacement field is constructed based upon the Stroh formalism for anisotropic elasticity and the method of eigenfunction expansion. Its structure is determined from appropriate near-field conditions leading to the eigenvalue equation, and then the singular hybrid finite element method in conjunction with a quadratic programming procedure for treating the partial contact of crack faces is employed to complete the field solution. The stress intensity factor properly defined for anisotropic interfacial cracks and the energy release rate are computed from the complete solution. The stability of crack growth and the effect of the relative ply thickness upon the crack growth stability are examined in terms of the energy release rate and the phase angle.