Dynamic response of aluminum-foam-based sandwich panels under hailstone impact

In this work, by inserting an additional sheet, called the middle sheet, between the upper and lower sheets of a traditional single-layer foam core sandwich panel consisting of a core with bonded with two sheets on either side, we fabricated sandwich panels with five structures that have the same dimensions and weights by changing the position of the middle sheet. The ratios of the upper core thickness to the total core thickness are 0: 30, 10: 30, 15: 30, 20: 30 and 30: 30, respectively. On the basis of dimensional analysis, we conducted numerical analysis of the sandwich panels subjected to hailstone impact using the nonlinear finite element program LS-DYNA, and investigated the influence of the middle sheet's position on the energy absorption, energy dissipation and dynamic response of the sandwich panel. The numerical results show that the middle sheet provides an effective protection for the lower core, and the anti-impact performance of the sandwich panel exhibited a tendency to change from strong to weak and then from weak to strong as the middle sheet moved along the direction of the hailstone impact. The results of the numerical simulation offer a reference for the optimization design of the sandwich structures under hailstone impact.