Three-Dimensional Analysis of Laminates With Cross Cracks

Abstract

An approximate 3-dimensional analysis to study the effects of a system of transverse and longitudinal matrix cracks in cross-ply laminates is given. The method considers a repeating unit cell containing three subcells in every one of which the displacement vector is expanded to second order. The equilibrium equations, in conjunction with continuity conditions of displacements and tractions, together with the appropriate loading and boundary conditions, provide a system of equations for the elastic field variables. The dependence of the effective axial stiffness and Poisson’s ratio of the laminate on the cross-cracks density is given. The Poisson’s ratio appears to be a good indicator for the state of damage of the laminate. The distribution of the axial displacement and stress in the cracked laminate is shown.