An improved nonlinear energy sink with electromagnetic damping and energy harvesting

A nonlinear energy sink can achieve vibration reduction without changing the resonant frequency of the system. In this work, an improved nonlinear energy sink is proposed by integrating with an electromagnetic system. The vibration reduction performance is further enhanced and an energy harvesting function is achieved at the same time. The dynamic equations of the primary system with the improved nonlinear energy sink are established, and the electromagnetic analysis is performed. The steady-state response of the system is solved with the harmonic balance method and verified by numerical simulations. The integration of the electromagnetic system provides additional damping to the nonlinear energy sink, and the vibration reduction performances under the harmonic and the impulsive excitations are enhanced. At the same time, the vibrational energy is effectively harvested by the electromagnetic system. The integration of the electromagnetic system does not change the resonant frequency of the system and retains the targeted energy transfer characteristic. The proposed system is applicable to the nonlinear energy sink with originally insufficient damping, and the electromagnetic coupling coefficient is a key parameter affecting both the vibration reduction and the energy harvesting performances. This integrated system is expected to provide a new strategy for multifunctional devices.