| The first section of this study compares different theories available for analyzing laminated composite plates. Symmetric and unsymmetric square sandwich panels subjected to sinusoidally varying transverse surface loadings were analyzed. The LZZHT model proved to be the most accurate followed by the ZZHT, HSDT, and FSDT theories, respectively. A genetic algorithm approach was applied to the optimum design of an idealized laminated sandwich composite aircraft wing using the ZZHT finite element model in conjunction with the genetic algorithm, GALOPPS v3.0. The optimum stacking sequence for the top and bottom face sheets was determined which produced the desired twisting response, minimized weight, and maximized in-plane stiffness while maintaining stress levels below the failure strength of the material in the fiber and matrix directions.; Four different GA architectures, single node, ring, injection, and hybrid structures were used and their results compared. The ring structure produced the design with highest fitness. The highest average fitness was achieved by both the ring and hybrid structures. The injection structure converged the fastest. |
