Effect of geometric structure and fiber orientation on crashworthiness of honeycomb-inspired composite thin-walled tubes

This study investigates the crashworthiness of biomimetic composite thin-walled tubes under quasi-static axial crushing, focusing on the effects of geometric structure and fiber orientation. The thin-walled tubes, inspired by honeycomb structures, were manufactured using carbon fiber composites through multi-cavity preform mold method. Quasi-static crushing tests and CT scanning observation were conducted to characterize the mechanical response, crashworthiness mechanisms and energy absorption capacity of the thin-walled tubes. Results demonstrated excellent energy absorption capacities across all configurations, with the C-0/45 configuration achieving the highest specific energy absorption at 115.03 kJ/kg. The optimal crushing energy absorption process for thin-walled tubes involves achieving high peak loads and maintaining high load levels. Sustaining high loads requires progressive and stable damage without the formation of extensive intermediate cracks between different plies (indicative of strong interlaminar shear strength). The structural integrity of the uncrushed sections must remain intact without significant damage during the crushing process. Fiber orientation parallel to the loading direction enhances peak load levels and interlaminar shear strength between plies, but may compromise circumferential stiffness and structural stability. The influence of geometric configuration is primarily manifested in the progressive and stable crushing phase, where the tube requires sufficient space to accumulate its own debris without causing damage to the uncrushed thin-walled structure.Highlights Structures and fiber orientation boost crashworthiness in biomimetic composite tubes. Biomimetic structures were produced using a multi-cavity preform mold method. CT scans were conducted to characterize the energy absorption mechanisms. Composite tubes demonstrated excellent energy absorption capacity of 115 kJ/kg. The typical crushing process of thin-walled tubes with Structure A under various fiber orientations at different compression displacements. image