Mechanical Responses and Performance Evaluation of Bioinspired Helical and Staggered Thin‐Walled Energy‐Absorbing Structures

Inspired by the helical structures of grapevines, the staggered architectures of nacre, and the porous structures of pomelo peels, this study designs and fabricates three helical structures, three helical‐staggered composite structures, and polyurethane‐foam‐filled structures for lightweight energy absorption. Quasistatic compression tests and drop‐weight impact tests are conducted to compare crushing modes, energy absorption, and dynamic impact responses. A comprehensive evaluation model based on the CRITIC‐entropy weighting method is further established to assess the mechanical performance of the proposed structures. The results show that the 30° helical structure exhibits the best performance among the helical configurations, with a crush force efficiency of 74.56% and a stable, symmetric double‐Y‐shaped collapse mode. Based on this configuration, the 30° curved stepped staggered structure shows uniform progressive deformation without obvious local stress concentration, achieving an energy absorption of 375.24 J while maintaining high specific energy absorption and crushing efficiency. After polyurethane foam filling, the crush force efficiency increases to 86.18%, although the specific energy absorption decreases because of the additional mass. Overall, the proposed bioinspired thin‐walled tube achieves a specific energy absorption above 14 500 J/kg and a crush force efficiency above 80%.