DESIGN OF LAMINATED PLATES FOR MAXIMUM BENDING STRENGTH

Abstract

A procedure is proposed for maximizing the bending strength of symmetric, laminated, fiber-reinforced plates. Laminate strength is described by a failure criterion in strain space. Design variables include the fiber directions and/or the layer thicknesses. The Rayleigh-Ritz technique is used lo calculate plate deformations. Optimization is performed via a quasi-Newton method, with the initial point determined by a random jump technique. As an illustrative example, a graphite/epoxy laminate having equal thickness layers, resting on simple supports, and subject to a single concentrated force is considered. Application of the optimization procedure is found to result in a significant increase in failure load; in general, bending stiffness as well as strength is increased.