Numerical analysis of sandwich panels under high-velocity impact

Composites are gaining importance in aircraft structures, due to their high specific strength, stiffness, and low weight. There are different types of composites used in aircraft structures out of which carbon fiber reinforced polymer (CFRP) serves best in the aircraft industry. Half of the weight of the Boeing 787 is made of CFRP and other composites that reduced the weight of the aircraft by 20% as compared to the conventional design with aluminum alloy. Similar to CFRP the recent trend focused on the usage of sandwich structures in aircraft design. Sandwich structure is a composite material made of the lightweight thick core placed between the thin face sheets made of CFRP or Glass fiber reinforced polymer. During service, aircraft panels are subjected to severe structural, aerodynamics loads, and impact loads. These loads cause severe damage to the structure that affects the residual strength. The impact is the more susceptible damage in composite panels. In this paper, a numerical impact analysis of the sandwich panel is carried out. There are different parameters that influence the impact strength of sandwich panels are face sheet material, core material, and thickness of the core. In this paper, finite element-based parametric analysis is carried out by varying face sheet materials such as CFRP, GFRP, Al alloy, Ti alloy, and core materials (such as honeycomb structure and PVC foam). Further, in this work, the combined MADM method using TOPSIS and AHP is applied to find out the optimal face sheet material for the sandwich panel. The attribute data for applying the MADM method is obtained from finite element analysis (FEA).