Weight minimization of composite laminated plates with multiple constraints

A multi-constraint optimization methodology for the design of composite laminated plates manufactured by Resin Transfer Molding (RTM) process is presented. As design constraints, both the manufacturing process requirement and the structural requirement were considered. The stacking sequence of layers and the thickness of the structure were optimized for a preassigned geometry of the structure, constituent materials and loading condition. As a structural requirement, either the stiffness constraint or strength constraint was selected. Such constraint was used as basis in the enhancement for the specific mechanical performance of composite structures. Maximum allowable mold filling time was assigned as a process requirement in the effort to increase productivity. The objective function was newly defined without introduction of any auxiliary parameters, such as scaling parameters, weighting coefficients and penalty parameters which are usually involved in multi-constraint or multi-objective optimization problems. As an optimization method, the genetic algorithm was used. The results for a sample problem show the validity of the proposed optimization methodology.