Dynamics and Stability of Magnetic-Air Hybrid Quasi-Zero Stiffness Vibration Isolation System

Abstract

With the improvement of machining accuracy, external low frequency vibration has become one of the most important factors affecting the performance of equipment. The theory of quasi-zero stiffness vibration isolation shows favorable low frequency vibration isolation effect. However, the theory, mechanical properties and dynamics of the system still need to be studied and expanded. Based on our previous research on the structure of a magnetic-air hybrid quasi-zero stiffness vibration isolation system, the nonlinear mechanical expression of positive and negative stiffness structure has been analyzed in this paper, to improve application of the system and provide a theoretical basis for sequential studies of active control. To provide the judgment criteria and basis for the application of quasi-zero stiffness, a more accurate quasi-zero stiffness mechanical model was to be established, and the judgement criterion and stability of quasi-zero stiffness was to be discussed and analyzed. Then, the dynamical model based on external low frequency vibration was developed, to investigate the stability and natural frequency. At the same time, the influence of different feedback parameters on the amplitude frequency characteristics has been discussed, which provides a basis for the future study of active control. Finally, we carried out simulation and experimental analysis to verify the stiffness of high static and low dynamic and the low frequency vibration isolation effect of the vibration isolation system.