Quasi-static and dynamic crushing behavior of Kirigami folded circular tubes

This study proposes a kirigami-inspired Folded Circular Tube (KFC) as a novel thin-walled sacrificial energy-absorbing component for enhancing the impact resistance of load-bearing building columns. The KFC was designed to achieve high energy absorption capacity and improved impact resistance, and was evaluated against a conventional circular tube and a hierarchical configuration (HC) counterpart of identical wall thickness and mass. Quasi-static axial compression tests were conducted to investigate the collapse behavior and energy absorption characteristics, while validated finite element models were employed to quantify key crashworthiness indicators, including the specific energy absorption (SEA) and crushing force efficiency (CFE). Results indicate that the KFC exhibits superior structural stiffness and energy absorption performance, with a 7 % higher SEA and a 1.63-folds of CFE than the HC structure. Under quasi-static loading, foam filling effectively stabilized the deformation of the KFC-A configuration and enhanced the energy absorption of KFC-C by 9 %. Low-velocity impact tests further confirmed that the KFC structures achieved a significantly lower initial peak crushing force (only 26 % of that of the HC), a smoother plateau response, and minimal IPCF amplification under dynamic effects. Overall, the KFC demonstrates clear advantages over the HC design, highlighting the critical role of geometric tailoring in improving crashworthiness. These results demonstrate the potential of KFC structures as lightweight, high-performance energy-absorbing components for applications requiring impact-resistant building elements.