Buckling of cross-ply laminates subject to linearly varying compressive loads and in-plane boundary restraints

Abstract

In-plane prebuckling stresses arise under axial edge loading as a result of a plate boundary being restrained from deformation in the plane of the plate. These stresses exhibit a uniform distribution only under a special set of boundary conditions and in general such uniform in-plane stress distributions do not exist under most boundary conditions encountered in practice. In the present study, in-plane prebuckling stresses are investigated for various in-plane boundary constraints and the stress contour lines are given for rectangular cross-ply laminated plates under linearly varying edge loads. The second part of the article involves the computation of the optimal layer thickness to maximize the buckling load under various combinations of in-plane boundary restraints. The numerical solutions are obtained by finite elements based on first-order shear deformable plate theory which include the in-plane deformations as nodal degrees of freedom. Numerical results show that the exclusion of the in-plane restraints may lead to errors in stability calculations and consequently in the design of laminated plates.