The Axial Compression Energy Absorption Characteristics of Bionic Variable Cross-Section Tubes

To design an energy-absorbing structure that combines low peak crushing force (PCF) with high-energy absorption efficiency, this study draws inspiration from the cross-sectional shape of bamboo joints to propose a bionic tube with variable cross-sections. Tests and numerical simulations show that it performs better than traditional tubes under quasi-static loads. The research indicates that under the influence of the variable cross-section design, stress is guided along the curved walls to concentrate in the stronger central area, leading to a stable, segmented deformation that effectively avoids the high PCF associated with global buckling. Specifically, by adjusting the angle of the variable cross-section design and the number of sides of the cross-section, the energy absorption efficiency of the structure can be significantly enhanced. As the number of sides increases, both the PCF and specific energy absorption (SEA) of the structure rise. Meanwhile, increasing the angle notably mitigates the issue of rising PCF in the bionic tube. Notably, the BCT-60 model stands out, reducing the PCF by 44.76% and significantly increasing the SEA by 95.92% compared to traditional circular tubes. This offers a fresh perspective for designing energy-absorbing structures that achieve low PCF and high energy absorption efficiency.