The Effects of Moisture Induced Swelling Upon the Shapes of Anti-Symmetric Cross-Ply Laminates

Abstract

This paper presents an investigation of the effects of moisture-induced swelling upon the out-of-plane warping of general anti-symmetric cross-ply composite laminates. The analy sis assumes linear elastic material behavior and includes non-linear geometric effects. Ap proximate solutions are obtained by assuming kinematically admissible expressions for the mid-plane displacements in terms of several generalized coordinates which are subse quently found by requiring a minimal value for the total potential energy of the laminate. It is shown that any specific anti-symmetric cross-ply lay-up will assume either a unique "saddle" shape or one of two possible approximately cylindrical shapes depending upon the in-plane dimensions of the laminate and the amount and distribution of moisture within the laminate.