Bamboo-inspired lightweight, mechanically-stable and vibration-damping structural members for engineering applications

Abstract

After millions of years of natural evolution, bamboo stems have formed exquisite variable cross-section hollow multi-node structures that are lightweight, tough, and stable. Bamboo is difficult to break and damage from the roots under dynamic loads, providing an important reference for te biomimetic design of lightweight components. This paper investigates the structural characteristics and variation patterns of bamboo stems and subsequently proposes an imitation bamboo stem structure design strategy for engineering structural members, namely, imitation bamboo double-jointed columns (IDJC). We establish a macro scale finite element model to predict the mechanical properties and failure modes of the IDJC under cyclic bending loads, and validate the model using experimental and analytical methods. The simulation and experimental results show that compared with traditional double-jointed columns (DJC), the weight of the IDJC is reduced by 41.7 %. Under bending load, the compressive stress of each section is approximately equal, reducing stress concentration, and increasing bending resistance. The strength to weight ratio of IDJC is 1.96 times that of DJC, indicating lightweight and high-strength characteristics. The stiffness degradation, energy dissipation, and damping and vibration reduction performance of the IDJC were also evaluated. The results showed that compared with the DJC, the stiffness degradation rate of the IDJC decreased by 6.87 times, the energy dissipation rate increased by 1.07 times, and the damping and vibration reduction performance improved by 48.40 %, reflecting a high stability and robust vibration reduction performance. The results demonstrate the potential application of biomimetic structures for the development and design of resource-rich, low-carbon, and sustainable bamboo for bamboo engineering members with excellent performance and functionality. Biomimetic structures have great potential in replacing nonrenewable structural materials in the fields of civil engineering and transportation.