Study on the energy dissipation mechanism of the pyramidal lattice sandwich panel subjected to underwater explosion

Abstract

The energy dissipation mechanism of a pyramidal lattice sandwich panel subjected to underwater explosion (UNDEX) is studied. Firstly, a three-layer pyramidal lattice sandwich panel with a dimension of 500 mm × 500 mm × 120 mm was fabricated by welding. The deformation mode of the pyramidal lattice sandwich panel subjected to UNDEX is revealed through an experiment. Furthermore, the deformation process of the front and back plates, interlayer sheets, and pyramidal lattices is demonstrated by simulation. The energy absorbed by every component is attained according to simulation results. Finally, the theoretical solution of the dynamic response of the experiment model in the stage of fluid-solid coupling, lattice collapse, and whole deformation is presented. Simulation and theoretical results are consistent with experimental results. Theoretical analysis shows that the advantage of the pyramidal lattice sandwich panel in the resistance to UNDEX is that the fluid-structure coupling effect could be controlled by strength design of the pyramidal lattice. The impulse transmitted to the experiment model could be considerably attenuated to 54.97% of the incident impulse, which is more efficient than the reported literature. This research could support the protection of ship structures subjected to UNDEX.