Stiffness and strength optimization of laminated composite materials

In this study, the stiffness and strength of laminated composite plates are optimized by using the genetic algorithm. Therefore, in the optimization problem, classical composite plates equations and equations with lamination parameters are used and the results are compared.The simply supported composite plate used for stiffness optimization is made of graphite-epoxy. Studies are performed for a plate with 24 or 48 plies. The composite plate used for strength optimization is made of glass-epoxy and is exposed to different in-plane loads and has 48 plies. Ply angles are considered as design variables. In these problems, there are many equal global maxima and it is difficult to find all configurations by using classical methods. The optimal configurations for the stiffness and the strength of the composite plate are found by using genetic algorithm method economically. Furthermore, the results by the use of classical composite plate equations and by the equations with lamination parameters are compared, and for their effectiveness. The optimization studies that is performed by the use of lamination parameters find the results effectively.