Novel low frequency bionic vibration isolation structure

Inspired by the hind limbs of goats, a bio-inspired polygon vibration isolation structure with nonlinear stiffness and damping is proposed. The bionic mechanism consists of four bionic legs with different rods (as skeleton), 12 inclined tension springs (as muscle or tendon), a bearing platform, a base, and so on. A theoretical model is developed to characterize its stiffness nonlinearity through geometrical and mechanical analysis. Theoretical analysis shows that the bionic structure has nonlinear positive stiffness and large working range. The dynamic model of the structure is established based on the Lagrange principle, and the influence of various structural parameters on the vibration isolation performance of the structure was analyzed combined with ADAMS. Thanks to the unique bionic design, the device allows the stiffness and damping characteristics of the system to be adjusted by varying the structural parameters, resulting in excellent stability, high static and low dynamic stiffness, excellent vibration isolation performance, and good load carrying capacity without active control.