A multi-bionic design strategy for modular energy absorption system based on interlocking suture integrated with Bouligand-like arranged perforations

Thin-walled tubes are widely used in the field of cushioning energy absorption as an ideal structural unit. However, the performance of the thin-walled tube system is greatly limited by the presence of redundant connection structures. To address these issues, a multi-bionic design strategy for high-performance modular system was developed in this work, which innovatively combines the robust joint structure of the interlocking suture with the efficient deformation mode of the Bouligand structures. In the design process, the suture-inspired system was studied separately, and its mechanical behaviors were investigated by FEM simulations and experiments. The results showed that the modular system has good structural scalability and tunable deformation mode, and can be adjusted on demand to accommodate different loads and geometric features. Furthermore, in order to reduce the weight and improve the deformation degree of the system, an optimization strategy inspired by the efficient deformation mode of the Bouligand structure was proposed by perforating a sequence of helix-arranged guide holes in the sidewalls of the tubes. The results showed that the double-helix perforated system can reduce the weight by 10% while increasing the specific energy absorption by 58% compared with the unperforated system. In addition, the specific energy absorption and energy absorption efficiency of the system are as high as 48.25 J/g and 56.17%, which is comparable to traditional honeycomb sandwich panels while retaining structural stability and adjustable performance. Therefore, this multi-bionic strategy can integrate the advantages of various natural structures and provide new insights for the design of high-performance protective systems.