Uniaxial compression performance of multicellular fractal bionic carbon fiber thin-walled tubes

Abstract Inspired by the multicellular fractal architecture of plant stems, this study proposes a novel biomimetic plant stem multi-cellular carbon fiber thin-walled tube (BPSMT). The structure integrates concentric nested carbon fiber tubes filled with polyurethane foam to mimic matrix-bound cellular hierarchies. Quasi-static axial compression tests reveal the progressive crushing failure modes and synergistic energy absorption exceeding the linear superposition of individual components. The arrangement of small tubes influences performance, which configurations with relative distribution outperform those with adjacent distribution in energy absorption. Increasing the small tube count enhances peak crushing force, with the 8-tube adjacent-distribution achieving the highest peak crushing force of 93.68 kN. The optimal relative distribution with 8 tubes demonstrates specific energy absorption of 59.61 kJ/kg, exceeding single tubes by 17%. The error of the crushing force prediction model is less than 6%. Compared to traditional foam-filled single tubes, BPSMTs have a 5.7% reduction in density and a 17% increase in specific energy absorption, confirming their superior lightweight and energy absorption capabilities.