Vibration attenuation using a nonlinear dynamic vibration absorber with negative stiffness

To suppress resonance and broaden the bandwidth for vibration absorption, a nonlinear dynamic vibration absorber (NDVA) with negative stiffness is developed in this paper. The magnetic negative stiffness spring (MNSS), the generation mechanism of negative stiffness, is composed of three magnet rings arranged in attraction, and employed to connect with mechanical spring in parallel. The magnetic force and its corresponding stiffness of the MNSS are investigated firstly. Attaching the NDVA to main mass, the dynamic equations of the coupled system is established, and the averaging method is also applied to the dynamic responses. With the aim of excellent vibration absorption performance of the NDVA, an iterative algorithm is proposed to perform the parameter optimization with the purpose of avoiding time consumption. Finally, the results show that the optimization algorithm can significantly improve the efficiency of parameter selection for the NDVA, resulting in the remarkable vibration attenuation for primary system and a larger bandwidth for vibration absorption.