Characteristic analysis of bionic-induced structures with negative stiffness inspired by the growth and deformation differences of branches

Negative stiffness (NS) structures with curved beams easily experience beam fracture in small-scale designs, limiting their repeatability and energy absorption. The induced energy absorption structure (IEAS), which achieves negative stiffness by altering load transfer paths, is designed inspired by the growth and deformation of tree branches. By means of the variation method of geometric parameters, a unique asymmetric buckling deformation mode is realized in IEAS. The NS and energy absorption characteristics in IEAS are analyzed based on load distribution and major principal strain theory. Compression results demonstrate that the asymmetric buckling mode exhibits higher energy absorption and specific energy absorption compared to symmetric linear buckling, effectively improving structural toughness. Through gradient analysis of geometric parameters and comprehensive analysis of induced structure layouts, the asymmetric buckling mode is successfully implemented in multi-layer IEAS. The multi-layer IESA exhibits excellent ability of energy absorption and toughness, making it have potential applications in areas that require small-sized designs with high energy absorption capabilities.