A study of a nonlinear magnetic vibration isolator with quasi-zero-stiffness

Abstract

A novel quasi-zero stiffness nonlinear magnetic isolator is designed by using magnetic springs in parallel with linear positive stiffness spring. Through the static analysis, the mathematical expressions of force-displacement-current and stiffness-displacement-current of the system are established, and the necessary conditions for the normal function and geometric parameters of the system are obtained. The nonlinear dynamic equations of the system under external excitation force are established. The amplitude and frequency characteristics of the system are deduced by harmonic balance method. The influence of system parameters and external excitation amplitude on the dynamic characteristics of the system is analyzed. Results showed that the vibration of the system can be controlled by controlling the electromagnet current or increasing the damping coefficient while the external excitation amplitude is kept in a certain of range. The researches provided a theoretical guidance for the design and application of the new quasi-zero stiffness nonlinear magnetic isolation system.