The performance of sandwich beams with expanded metal sheets as core was studied under transverse impact loading. Relationships between the force and displacement at the mid-span of the sandwich beams were obtained from the experiments. Numerical simulations were carried out using ABAQUS/EXPLICT and the results were thoroughly compared with the experimental results. Then, the influence of the core layer number, cell orientation, size of the cell, and thickness of the substrates was investigated. The results showed that the increase in the core layers up to three times increased the energy absorption ( E_a) by 33.88%. Moreover, increasing the thickness by up to three times increased the E_a by 61.33%. It was found that effects of the cell size and cell orientation on the E_a were dependent on each other, governing the low-velocity impact response of the sandwich beams with lattice cores.

The performance of sandwich structure with expanded metal sheets as the core was studied under axial crushing and transverse impact bending. Relationships between the force and displacement at the mid-span of the sandwich beams were obtained from the experiments. Numerical simulations were carried out using ABAQUS/EXPLICIT and the results were thoroughly compared with the experimental results. Then, the influence of the cell orientation and size of the cell were investigated. It was shown that the cell orientation was a critical parameter affecting the failure mode and energy absorption capability, leading to the increase in the peak load and specific energy absorption during the axial crushing tests. Specific energy absorption of the sandwich beams with lattice core under axial crushing ranges from 117 to 2934 J/kg, which is higher than that of beams under transverse bending. The results showed that the increase in cell angle up to ϴ = 90 increased the energy absorption by 624.4%. It was found that effects of the cell size and cell orientation on the energy absorption were dependent on each other governing the low-velocity impact response of the sandwich beams with lattice cores.