Buckling of Anisotropic Composite Plates under Stress Gradient

Abstract

In composite structures characterized by lightweight, thin‐walled members, the linear buckling load is one of the most important design considerations. Plate structures (bridge decks and ship hulls) are often subjected to differential compression due to nonuniform bending during their service life. This paper presents a general formulation for the buckling of rectangular, anisotropic, symmetric, angle‐ply composite laminates under linearly varying, uniaxial compressive force using the energy method in conjunction with orthogonal polynomial sequences, generated by a Gram‐Schmidt process. Orthogonal polynomials provide a simpler and efficient tool for handling complex combinations of simple and clamped boundaries. The present study highlights the unusual insensitivity of the buckling load of anisotropic laminates to fiber orientation under in‐plane tension‐compression‐type loading. Such behavior is not known to exist under idealized loading of constant, uniaxial compression, and orthotropic material behavior. The paper introduces an effective approximation technique of differential quadrature as an alternative to energy methods and discusses its credibility for solving complex plate stability problems against benchmark solutions provided by the Ritz method.