Metamodel based multi-objective design optimization of laminated composite plates

In this paper, a multi-objective multiparameter optimization procedure is developed by combining rigorously developed metamodels with an evolutionary search algorithm-Genetic Algorithm (GA). Response surface methodology (RSM) is used for developing the metamodels to replace the tedious finite element analyses. A nine-node isoparametric plate bending element is used for conducting the finite element simulations. Highly accurate numerical data from an author compiled FORTRAN finite element program is first used by the RSM to develop second-order mathematical relations. Four material parameters- E-1/E-2, G(12)/E-2, G(23)/E-2 and u(12) are considered as the independent variables while simultaneously maximizing fundamental frequency, lambda(1) and frequency separation between the 1st two natural modes, lambda(21). The optimal material combination for maximizing lambda(1) and lambda(21) is predicted by using a multi-objective GA. A general sensitivity analysis is conducted to understand the effect of each parameter on the desired response parameters.