Mechanical performance analysis of bamboo's microstructure layered structure in longitudinal direction

Bamboo has emerged as a highly promising building material due to its exceptional mechanical properties, economic viability, environmentally friendly nature, and energy-efficient characteristics. Its advantageous microstructure is increasingly attracting attention within the scientific community. Microstructurally, bamboo exhibits a distinctive fiber-reinforced composite architecture, primarily consisting of an intricate network of cellulose fibers embedded within a hemicellulose-lignin matrix. In order to study the failure mechanism of bamboo under longitudinal load, this research derived the theoretical calculation of the elastic modulus of bamboo fibers based on the hierarchical microstructure of bamboo, and compared it with the Cox model and the Halpin-Tsai model. On this basis, a micro-model along the thickness direction of the bamboo was established using finite element software, and the stress-strain distribution and displacement field were analyzed. The peak value of the lignin curve was approximately 60 MPa. A longitudinal compression test was also conducted, and the maximum stress reached during the experiment was 67 MPa. Therefore, it can be concluded that the experimental results are consistent with the simulation results, and thus the longitudinal mechanical behavior of bamboo can be systematically evaluated through multi-scale computational mechanics.