The optimal lamination arrangement of thick laminated composite plates for maximum stiffness is studied via a multi-start global optimization technique. The C0 (penalty) element in which the exact expressions for determining shear correction factors are adopted is used to perform the structural analysis of the plates subjected to transverse loads. The optimal layups for the plates with maximum stiffnesses are then designed by minimizing the strain energy of the plates via the multi-start global optimization technique. The proposed optimization algorithm has been proved to be efficient and effective in designing thick laminated composite plates. A number of examples of the design of symmetrically and antisymmetrically laminated composite plates with various aspect ratios and different number of layers are given to illustrate the application of the present method.
