Antiprism folding mechanisms for enhanced energy absorption

Thin-walled structures are extensively utilized as lightweight energy absorbers in aerospace applications, including landing gear shock attenuation, fuselage crashworthy zones, and wing tip and leading-edge protection, owing to their superior energy dissipation efficiency. This study proposes a novel antiprism-patterned tube to enhance the crashworthiness of thin-walled structures under axial loading. The geometry is characterized by two parameters: the polygonal cross-section sides ( N ) and the number of axial modules ( M ). Quasi-static axial compression tests and validated finite element simulations were performed to investigate the crushing behavior and energy absorption characteristics. For benchmarking, the antiprism tubes were directly compared with square origami tubes of identical mass and wall thickness. The antiprism design introduces a distinct folding mechanism that generates multiple interacting fixed and traveling plastic hinges, leading to markedly improved energy absorption. Short antiprism tubes ( M = 1, N = 3) achieved 54% higher average specific energy absorption (SEA) and 63% greater crushing force efficiency (CFE) compared to square origami tubes. For longer tubes ( M = 2), incorporating foam fillers and bulkhead reinforcements further improved structural stability and crashworthiness, with the N = 4 configuration showing a 30% SEA increase over its origami counterpart. Microstructural examinations and repeated tests were conducted to identify printing-induced and material defects and clarify their influence on mechanical performance. From the material microstructure perspective, the enhanced SEA of the antiprism tubes is attributed to uniform plastic deformation zones and delayed local fracture initiation. Dynamic drop-weight impact tests confirmed that the antiprism design offers higher plateau force, longer force duration, and more stable progressive collapse compared with square origami tubes. These results highlight the effectiveness and tunability of the antiprism folding concept, demonstrating its strong potential for advanced energy-absorbing and crashworthy applications.