Research On Mechanical Behavior Characteristics Of Double Magnetic Ring Negative Stiffness Mechanism And Vibration Isolation Performance Of Quasi-Zero System

With the development of China’s economy and the progress of industry,the operating environment of engineering vehicles is also put forward higher requirements.Engineering vehicles travel and operation speed is low,load is large,drivers and occupants are often exposed to low frequency vibration,resulting in low operating efficiency,and even lead to serious vibration occupational diseases.In the field of low frequency vibration isolation research,the proposal of quasizero stiffness has provided a new solution,and in recent years,the nonlinear passive distr amplitude element formed by paralleling the positive stiffness element with the negative stiffness element has been proved to be an excellent way to extend the bandwidth to suppress low frequency vibration.This paper summarizes and looks forward to the future development trend of quasi-zero stiffness shock absorbers.The quasi-zero stiffness vibration isolation system has high static-low kinetic stiffness characteristics and can effectively filter low frequency vibration energy.Contact negative stiffness mechanism can bring frictional loss and other problems,resulting in the instability of the mechanics form of the negative stiffness mechanism.A quasi-zero stiffness isolation system based on non-contact multimagnetic ring negative stiffness mechanism and PAM positive stiffness mechanism parallel is developed.In order to detect the rigidity behavior mechanism of the system,the negative stiffness analysis model was established based on Bio-Safar’s law and ampere’s law,and the stiffness behavior characteristics of the negative stiffness mechanism under different parameters(magnetic filling strength,geometric parameters and magnetic field strength)were analyzed,and verification experiments were carried out.The results show that the axial charge ratio radial charge can obtain significant negative stiffness characteristics,increase the outer diameter,increase the outer diameter thickness,increase the outer diameter magnetic field strength of the magnetic ring.That all can make the carrying performance greate of the negative stiffness performance,but do not change its negative stiffness interval,increase the upper and lower magnetic ring spacing can expand the negative stiffness interval,but not change its carrying performance,and compare the math model with the experimental results,the model sees the accuracy needs.It provides a theoretical basis for the modeling,parameter optimization,It provides a theoretical basis for engineering used in NCNS QZS vibration isolator.These isolators typically have a high static-low dynamic stiffness,where high static stiffness is used to support payloads and low dynamic stiffness to improve the performance of low-frequency isolation.In order to isolate low frequency vibration,a non-contact negative stiffness diffuser with high static-low dynamic stiffness(HSLDS)characteristics is developed,which is composed of combining magnetic negative stiffness spring(NCNS)with positive stiffness spring.The positive stiffness spring(PAM)is parallel.NCNS consists of three magnetic rings,which are configured as attractive and are used to reduce the resonant frequency of the isolator.Then the magnetic negative stiffness k1 of NCNS is derived according to the current model,and the approximation of keq is further sought.The effect of parameters on keq is analyzed by Maxwell method.The vibration model of the isolator is established,the calculation results are obtained by the harmonic balance method(HBM),and the transmission rate curve is drawn by the Newton Rafson method.From the transmission rate curve,it can be seen that the magnetic spring element of non-contact dual magnetic ring is introduced on the basis of the linear vibration isolation system,which,while reducing the inherent frequency of the system,widens the frequency band of the whole vibration isolation system,and at the same time greatly improves the damping characteristics of the vibration isolation system and effectively reduces the resonance peak.Also get the transfer rate comparison curve of different damping parameters,and get the influence law and optimal parameter selection.Finally,a prototype of a quasi-zero system experimental entity is developed.The experimental scheme is designed,and the quasi-zero system test experiment can be carried out by using a variety of test equipment to explore the problem of low frequency vibration isolation.