Energy absorption performance of staggered triangular honeycombs under in-plane crushing loadings

The finite-element methodology is presented to evaluate the energy absorption performance of staggered triangular honeycombs under in-plane crushing loadings at impact velocities of 50-300 m/s. The minimum dynamic cushioning coefficient is proposed to characterize the maximum energy absorption efficiency of staggered triangular honeycombs. When all configuration parameters are constant, the energy absorption per unit volume is proportional to the square of the impact velocity; for a given impact velocity, the energy absorption per unit volume is related to the ratio of the cellwall thickness to the edge length by a power lawand to the expanding angle by complicated analytical equations. The maximum energy absorption efficiency is insensitive to the impact velocity. Only for the smaller ratio of the cell wall thickness to the edge length does themaximumenergy absorption efficiency increase with the increasing expanding angle. At a given impact velocity there is a threshold ratio of the cell wall thickness to the edge length. Themaximum energy absorption efficiency decreases abruptly when the ratio is larger than the threshold. The threshold ratio is approximately equal to 0.04.