Design of antisymmetric hybrid laminates for maximum buckling load: II. Optimal layer thickness

Abstract Antisymmetric, angle-ply laminates under biaxial compression are optimized with respect to layer thicknesses. The laminates are constructed with inner layers of a low-stiffness fibre composite material and outer layers of a high-stiffness fibre composite material. The optimal design problem consists of determining the ratio of inner layer thickness to the total laminate thickness so as to maximize the buckling load subject to a mass or thickness constraint. Numerical results are given for laminates of equal total thickness and equal mass made of boron, kevlar and glass fibre reinforced plastics. The optimal laminate configuration is found to be consisting of layers of high-stiffness or low-stiffness material or a combination of both depending on the ply angles and the materials. The optimal layer thickness is observed to have jump discontinuities with respect to fibre orientation.