Vibration isolation performance analysis of a bilateral supported bio-inspired anti-vibration control system

Abstract

To achieve better anti-vibration performance in a low frequency region and expand the range of vibration isolation, a bilateral supported bio-inspired anti-vibration (BBAV) structure composed of purely linear elements is proposed, inspired by the motion form of bird legs and the nonlinear extension and compression of muscles and tendons. The kinematic relations and nonlinear dynamic model considering vertical and rotational vibrations are established. The loading capacity and equivalent stiffness are investigated with key parameters. The amplitude-frequency characteristics and force transmissibility are used to evaluate the stability and anti-vibration performance with the effects of the excitation amplitude, rod length, installation angle, and spring stiffness. The results show that the loading requirements and resonant characteristics of the BBAV structure are adjustable, and superior vibration isolation performance can be achieved readily by tuning the parameters. The X-shaped vibration structure is sensitive to the spring stiffness, which exhibits a wider vibration isolation bandwidth with smaller spring stiffness. Besides, depending on the parameters, the nonlinear behavior of the BBAV system can be interconverted between the softening type and the hardening type. The theoretical analysis in this study demonstrates the advantages and effectiveness of the vibration isolation structure.