Energy-absorbing characteristics of hollow-cylindrical hierarchical honeycomb composite tubes under conditions of dynamic crushing

This paper presents an experimental and numerical study on the energy-absorbing characteristics of Biomimetic Multi-Cell Tubes (BMCTs), these being hollow-cylindrical-joint hierarchical honeycomb composite tubes inspired by the microstructural features of a beetle's forewing and geometrical features found in a spider's web. The BMCTs were fabricated using carbon fiber composites in optimized multi-tiered configurations. Low velocity crushing tests were conducted to characterize the load-displacement response, crashworthiness mechanisms, and energy absorption capacity of the BMCTs based on specific layer stacking sequences (LS). Additionally, the dynamic response of the BMCTs was modeled using the finite element analysis techniques. The predicted load-displacement relationships and failure modes show good agreement with the experimental results. Dynamic effects in the energy absorption characteristics of the tubes were evaluated. It is shown that the dynamic energy-absorbing capability of the BMCT-LS2 structure (Wall [±45/±30/±15]s Cylinder [±45/±30/±15/06]) is 6.5% higher than its quasi-static counterpart. In contrast, the SEA of BMCT-LS1 (Wall [+453/-453]s Cylinder [+453/-453/06]) is almost the same under both loading regimes. Finally, the quasi-static SEA of the plain circular tube is 13.8% lower than its dynamic counterpart. However, the SEA values of both BMCT-LS1 and BMCT-LS2 structures are 65% and 173% higher than the plain circular tubes, respectively.