Nonlinear Electromagnetic Shunt Damping for Nonlinear Vibration Isolators

This paper presents the concept of nonlinear electromagnetic shunt damping (N-EMSD) and employs it for the vibration isolation enhancement of nonlinear vibration isolators. A nonlinear electromagnetic vibration isolator (NEVI) is designed. Two configurations of the permanent magnets and coils are constructed to illustrate the damping mechanisms of linear electromagnetic shunt damping (L-EMSD) and N-EMSD, respectively. The nonlinear electromagnetic coupling coefficient of the NEVI is modeled. The theoretical models of the NEVI with L-EMSD and N-EMSD are established. Both the numerical simulation and experimental efforts are performed to verify the vibration isolation performance of the NEVI with L-EMSD and N-EMSD. The results demonstrate that the proposed N-EMSD can provide wonderful nonlinear damping to reduce vibration in the resonance region but do not affect the isolation performance in the isolation region. L-EMSD has a better vibration suppression performance than N-EMSD in the resonance region; however, the vibration isolation performance becomes worse in the isolation region. Furthermore, the effect of the isolation mass is also studied experimentally. This work opens a new opportunity to further study EMSD technique in linear and nonlinear systems.