Structural Design And Vibration Isolation Mechanism Analysis Of Quasi-zero Stiffness Isolator Based On Compliant Mechanism

Vibration is an inevitable phenomenon when mechanical equipment is operating,violent vibrations have a bad effect on the equipment and the surrounding environment.For example,submarines,ships,airplanes and so on will produce great vibration when working,which will cause damage to the hull and airframe,and have a negative impact on the physical and psychological of the staff.Therefore,in order to ensure the safe and stable operation of the equipment,it is great significant to effectively control the harmful vibration of the mechanical system.Vibration isolation technology has been widely used in engineering.The common linear vibration isolator has simple structure and suitable for assembly,but the isolation effect is not good enough and the low-frequency vibration isolation cannot be realized.Although the traditional quasi-zero stiffness isolator can achieve low-frequency or even ultra-low frequency isolation,it has some disadvantages such as complex structure.In order to solve these problems,a quasi-zero stiffness isolator based on compliant mechanism is proposed and experiment studied.The main contents of the thesis are as follows:(1)This paper proposes and designs a quasi-zero stiffness isolator based on compliant mechanism,which is composed of trapezoidal beam and buckling beam.The trapezoidal beam has positive stiffness and the buckling beam has partial negative stiffness.The quasi-zero stiffness characteristics of the designed isolator are verified by the combination of theoretical method and finite element method.The influence factors of quasi-zero stiffness characteristics are analyzed through parameter influence.(2)The dynamic analysis of the quasi-zero stiffness isolation system is carried out,and the harmonic balance method is used as numerical solution to study the amplitude-frequency characteristics of the isolation system.The effect of stiffness,damping and excitation amplitude on system jump frequency is considered.(3)On the basis of the above simulation analysis,the stiffness characteristics experimental bench is built for experiment study,and compared with the simulation results for verification.The dynamics test bench was built to carry out the acceleration transfer rate experiment of the vibration isolation system.By comparing the experimental results of quasi-zero stiffness system and linear system to verify the superiority of the isolator.(4)The isolator designed above only applies to the case where the vibration isolation mass remains unchanged,and the scope of application is narrow.In this section,a semi-active control quasi-zero stiffness vibration isolator is designed,which applies upward or downward force on the buckling beam through piezoelectric ceramics to adapt to the change of vibration isolation mass,and the feasibility of the isolator is verified through experiments.