Free vibration optimization of a sandwich structure with a hybrid composite grid core

Abstract This study presents the multi‐objective optimization of weight and cost concerning the vibration behavior of a sandwich structure. In this regard, the maximization of frequency against the minimization of the structure's weight or cost is considered the objective functions in the optimization algorithm. For this purpose, a sandwich structure with two composite skins and an orthotropic grid core is designed. The design variables including the core geometrical variables, and the type of the applied composite materials for each group of stiffeners of the core. The first‐order shear deformation theory and the Ritz method have been used to obtain the natural frequencies of the plates. Eventually, optimization has been performed using the genetic algorithm.