A novel 3D composite auxetic sandwich panel for energy absorption improvement

In recent years, great research value has been attributed to sandwich structures as energy-absorbing components in structural protection due to their lightweight advantages. However, research on improving the energy absorption of sandwich structures by studying 3D sandwich cores is rare. Therefore, this work proposes a 3D re-entrant four-pointed star sandwich panel (RFSP) to enhance energy absorption. Grille sandwich panels (GSP) and re-entrant sandwich panels (RSP) serve as the control groups. The results show that the 3D RFSP has higher load-bearing capacity and stable deformation. Moreover, its cores compact later, which improves energy absorption. The EA of the RFSP is 1.49 times that of the GSP and 2.96 times that of the RSP. The SEA of the RFSP is 1.17 times that of the GSP and 2.33 times that of the RSP. The structure proposed in this manuscript can be applied to automotive crash beams and components of soft robots, among other applications. Furthermore, the design of 3D sandwich structures is also beneficial for the design of prefabricated sandwich panels.