Impact experiment of six-layer pyramidal lattices sandwich panels subjected to near field underwater explosion

To investigate the explosion resistance of multilayered pyramidal lattices panels subjected to near field underwater explosion (UNDEX) , the UNDEX experiment is carried out, the distortional energy of the model is simulated, which reveals the deformation mode of multilayered pyramidal lattices. The whole pyramidal lattices structure presents dynamic buckling deformation, and in particular, the thicker upper panel is seen to have integral settlement deformation, sandwich panels between buckling cores present wave wrinkle deformation, and the bottom panel absorbs energy through bending and tensile deformation. The results show that though the first and sixth sandwich cores are more severely damaged, the energy absorption of sandwich cores protects the bottom panel to a certain extent.