Analysis And Design Of A Pneumatic Quasi-zero Stiffness Isolator

In the field of vibration and noise reduction,low-frequency vibration isolation has always been a theoretical and engineering problem.Low-frequency vibration isolation technology has broad prospects for industrial applications.Quasi-zerostiffness(QZS)vibration isolation technology is a low-frequency vibration isolation technology that has emerged in recent years.By combining the positive and negative stiffness elements in parallel,the QZS vibration isolation technology can achieve high static stiffness and low dynamic stiffness characteristics.The high static stiffness solves the problem of system stability,and the low dynamic stiffness solves the problem of low frequency vibration isolation.In this paper,a new type of pneumatic quasi-zero stiffness(PQZS)vibration isolator is proposed and designed.It combines the excellent vibration isolation performance of the airbag and QZS mechanism to realize low-frequency vibration isolation technology.The main content of this article is as follows:1.Based on the QZS principle,and a lateral wall QZS device composed of a disc spring with negative stiffness and an helical spring with positive stiffness was designed.At the same time,using airbag vibration isolation principle,the airbag bearing platform and air chamber were designed and connected to the QZS device of the side wall by the sealing film to realize the PQZS vibration isolation technology.The vibration isolator has the advantages of compact design,strong bearing capacity and low frequency vibration isolation,and can be applied to engineering applications.2.A theoretical analysis model of a PQZS stiffness vibration isolator is established.Firstly,the static stiffness analysis of the lateral wall QZS device was carried out.The force-displacement and stiffness-displacement relationships of the disc spring and helical spring combinations were studied.The QZS condition of the vibration isolator was obtained.The influence of the changes in the main structural parameters of the QZS device on the stiffness of the system is analyzed.3.The dynamic model of PQZS vibration isolation system was established.The Harmonic Balance method was used to solve the amplitude-frequency response characteristic function of the PQZS vibration isolation system.The force transmissibility of the vibration isolation system is further analyzed.Compared with the corresponding linear system.the numerical simulation results revealed the excellent low frequency vibration isolation performance of the PQZS vibration isolator.4.The effects of vibration isolation system parameters on the vibration isolation performance are analyzed,including the amplitude of the excitation force,damping ratio,the stiffness coefficient of the return force,etc,which affect the amplitude-frequency response characteristics and the force transmissibility The corresponding theoretical and numerical calculations provide an important reference for the optimization design of PQZS stiffness isolator.