A combined vibration isolation system with quasi-zero stiffness and dynamic vibration absorber

The vibration control performance of a combined vibration isolation (CVI) system consists of a quasi-zero stiffness (QZS) system and a linear dynamic vibration absorber (DVA) is investigated. Firstly, the dynamic equation is established and the amplitude-frequency response of the CVI system is deduced by the harmonic balance method, and the analytical result is verified by numerical simulation. Secondly, the mechanism of CVI system is revealed from the perspectives of vibration amplitude, energy, and force transmission: The vibration isolation performance of the QZS system can be improved by reducing the vibration amplitude. Thirdly, the control performance of the CVI system is analyzed in terms of the effects of the stiffness, damping, mass ratio of DVA, and the damping of the primary system, as well as the robustness of the system. The findings lead to the development of an explicit tuning rule for the DVA attached to the QZS system. Lastly, a comparison of control performance with other three models is conducted. The results demonstrate that the CVI system can effectively suppress the vibration amplitude and broaden the isolation frequency band. The mechanism and tuning rule for the CVI system presented in this paper provides a useful reference for improving the control performance of the QZS system.