Multilevel Optimization Procedure of Composite Structure

Abstract

We present a multilevel optimization procedure for minimum weight design of composite structures. The optimization process is divided into two levels: system level and component level. In system level the thicknesses of laminated composite plates represent the design variables. The well-known optimality criterion method based on the Kuhn-Tucker condition is used to modify the design variables. The detail design of laminated plates, i.e. to determine the optimal ply thicknesses, is handled in component level In component level, keeping the thickness of laminated composite plates and the nodal displacements invariant, the ply thicknesses are adjusted according to the strain energy possessed by each ply. As an illustrative example, a cantilever composite beam, which is subjected to several load conditions and multiple constraints, is studied. All the five examples given in this chapter present very satisfactory results. In general the optimal design can be obtained after 3–5 iterations.