Dynamic characteristics analysis of magnetorheological semi-active vibration isolator with high-static-low-dynamic stiffness

Abstract

High static and low dynamic stiffness vibration isolators have the advantages of high load-bearing capacity and small static displacement, but their negative stiffness components will cause a jump phenomenon at the resonance frequency. A semi-active vibration isolator with high-static-low-dynamic stiffness based on magnetorheological (MR) damper is proposed. The equivalent dynamic model of the MR semi-active vibration isolator is established, and the main resonance steady solution and stability conditions of the vibration isolation system are obtained using the average method. The influences of the basic excitation amplitude, excitation frequency, coulomb force, viscous damping coefficient, load-bearing mass, nonlinear elastic force coefficient and linear elastic force coefficient on the stability and performance of vibration isolation systems are analyzed. The results will provide a certain theoretical basis for the design of semi-active control strategies.