Experimental and numerical study on ballistic resistance of aluminum foam sandwich panel considering porosity and dimensional effect

Sandwich panels have been widely used in various industries due to their high strength and energy absorption capacity. In this study, the ballistic behavior of a sandwich panel comprised of two aluminum face-sheets and an aluminum foam as the sandwich core is studied. The panels are constructed and subjected to the blunt-nosed projectile. The experimental test consists of a sandwich panel with three different ranges of foam densities and two thicknesses for the panels beside hardened steel projectiles. Then, numerical simulations of the projectile perforation in the panels are conducted that are in good agreement with the experiments. The failure mechanism of the sandwich panels is investigated and the role of foam core is discussed. Failure mechanism and the amount of plug depends on foam density and projectile velocity, such that different failure mechanisms such as plugging, petaling, and dishing occurred for the face-sheets. After that, the ballistic limit velocity (VBL) of sandwich panels was calculated via experiments and finite element simulations. The experiments and simulations showed that increasing the density and thickness of the foam core generally leads to an increase in VBL. Finally, we study the panels with the constant mass and (or) constant height with different foam densities and the effect of foam density is investigated in these cases.