Performance analysis of a quasi-zero stiffness vibration isolation system with scissor-like structures

Abstract

To isolate low-frequency vibration, a novel single-degree-of-freedom vibration isolation system with quasi-zero stiffness (QZS) and nonlinear damping using geometric nonlinearity is proposed in this study. One of the remarkable features of this system is the use of scissor-like structures (SLSs) to achieve the nonlinear stiffness and damping. The length difference between the connecting rods in SLS is considered. First, both the stiffness and damping characteristics are derived and analyzed in detail. Then, the frequency response and force transmissibility are obtained using the harmonic balance method. Finally, the effects of structural parameters on the isolation performance are investigated. Theoretical results show that the proposed QZS vibration system can not only isolate low-frequency vibration but also suppress the high-amplitude vibration in the resonant region. Besides, increasing nonlinear damping has little influence on the isolation performance in high frequencies. The proposed QZS vibration system can outperform a classical counterpart.