Cell‐Offset Honeycombs With Enhanced Plateau Stress and Energy Absorption Under In‐Plane Impact Loading

Honeycomb structures exhibit significant potential in the field of energy absorption. However, with the continuous expansion and deepening of engineering requirements, the energy absorption capacity of conventional honeycomb structures remains to be enhanced. In this regard, a novel cell‐offset design strategy was proposed in this work. Taking the re‐entrant hexagonal honeycomb as the subject, a novel offset honeycomb was developed by the cell‐offset design strategy. A finite element model for the in‐plane crushing behaviors of the offset honeycombs was established and then validated by the existing theoretical results. The stress–strain curves, deformation behaviors, plateau stress and energy absorption capability of the novel offset honeycombs were systematically studied. The results reveal that the impact velocity and the offset displacement have a significant effect on the deformation behaviors of the honeycombs. Interestingly, the offset honeycombs exhibit a dual‐plateau stage under low‐velocity impact and a stress enhancement phenomenon under high‐velocity impact. The plateau stress and specific energy absorption (SEA) of the offset honeycombs are higher than those of the RHH; that is, the offset honeycombs exhibit improvements of 548% and 354% in plateau stress and SEA under low‐velocity impact, 382% and 181% under medium‐velocity impact, and 120% and 28% under high‐velocity impact, respectively. Additionally, a gradient offset design, applying varying offsets across different layers, can further improve the plateau stress and SEA under low‐ and medium‐velocity impacts. As a result, the cell‐offset design strategy is highly applicable to general honeycomb structures and has significant potential for high‐energy absorption scenarios, thus providing valuable guidance for the design and development of high‐performance honeycomb structures.