Optimal Design of a Composite Sandwich Panel with a Hexagonal Honeycomb Core for Aerospace Applications

Composite sandwich panels are increasingly used in aerospace applications owing to their high strength and stiffness to weight ratio. A number of these panels are continuously subjected to out-of-plane pressure during their service life. In this paper, the optimal design of a composite sandwich panel under out-of-plane pressure is performed by a Niching-Memetic particle swarm optimization (NMPSO) algorithm. The panel is made of a honeycomb core with regular hexagonal cells and two-layer composite face-sheets and is assumed to be subjected to a uniform out-of-plane pressure. A first-order shear deformation laminated plate theory is used to model the panel deformation. Minimizing the panel weight has been selected as the objective function, while the buckling and shear resistance of the core, the panel maximum deflection, and the yield of the face sheets have been included as constraints in the optimization problem. The problem has been also solved by the genetic algorithm to examine the validity of the proposed NMPSO approach. It has been observed that using a higher number of cells with smaller cross-section and increasing their height is the best way for reducing the panel deformation and buckling probability in the low-pressure regime. While the core and face sheets thickness have proven to be the most influential design parameters in higher pressures, and the cells' shear stress, deformation, and buckling probability are reduced by increasing these parameters. Variation of the objective function and the problem constraints have also been discussed in different pressure regimes and useful information has been provided for improving the design of sandwich panels.