High velocity impact mitigation with gradient cellular solids

The dynamic behavior of gradient cellular solids subjected to high velocity impact is investigated, with shock theory and rigid-perfectly-plastic-locking idealization. The impact is induced by the fragments of a cased charge explosion in near field, sufficiently high to progressively crush the cellular solids from the loading part, regardless of the density variation of the cellular solids. The dynamic response and energy absorption are examined for different gradient cellular solid layers with the same mass and thickness, but different density variation. The cellular solids with larger density gradient lead to smaller crushed distance and higher energy absorption compared to those with smaller density gradients, when subjected to the same impact, provided that the cellular solid is not fully densified. However, when the cellular layer is fully crushed, the effect of density variation on energy absorption vanishes.