Out-of-plane compression and energy absorption performance of twisted auxetic honeycomb tubes

Lightweight structures with exceptional energy absorption properties are essential for the engineering demands. Auxetic honeycombs are promising candidates for dynamic impact protection and high-performance energy absorption devices. Inspired by horsetail stems and helical geometry, this study proposes a novel twisted auxetic honeycomb tube (TAHT), which combines the advantages of auxetic structures, thin-walled tubes, and twisted configurations. The energy absorption performance of the TAHT under out-of-plane compression is investigated through experiments and numerical simulations. The influence of the optimal twist angle, multi-layer configuration, and wall thickness is further analyzed. The results show that the twist angle changes the deformation mode from parallel crushing to a unique twisting-compression mode, delaying densification and significantly enhancing energy absorption. Specifically, the TAHT with an optimal twist angle increased specific energy absorption ( SEA ) by 41.9 % and crush force efficiency ( CFE ) from 72.6 % to 78.3 % compared to a non-twisted structure. Furthermore, a multilayer configuration and increased wall thickness both improved energy absorption performance. A theoretical model derived from the super folding element theory, accurately predicts the mean crushing force ( F_mean ) and validates with experimental and numerical results. These findings confirm the superior energy absorption capabilities of the TAHT, offering new design insights for lightweight and high-strength metamaterials.