Mechanical properties of lotus petiole bio-inspired structures under quasi-static radial load

The lotus petiole in nature is characterized by its porous structure and high bending resistance. Inspired by this, in this paper, random sampling of lotus petiole was carried out to clarify the porous distribution pattern of lotus petiole in cross section. On this basis, the original structures with 12 and 13 wells (Os-12w, Os-13w) were constructed, and equal mass hollow circular tube (Emhct) was also designed for comparison. Based on the experimentally verified finite element models, Os-12w, Os-13w and Emhct were comparatively analyzed. In addition, comparisons were made with five other bionic circular structures Compared to the rest of the structures, Os-13w performs better in all comprehensive properties. The bending and traction in the core region of the bionic structure caused the surrounding structures to join in the buckling earlier, creating a global crushing trend. More interestingly, further bending and traction in the core region creates a negative Poisson's ratio phenomenon. In addition, the results of the parametric study show that the optimum loading angle of Os-12w is between 60° and 90°, and the proper adjustment of its core cross-section characteristics can improve the mechanical properties of the structure. This study provides some reference for the development of thin-walled porous structures under radial loading conditions.