Vibration Isolation Performance Analysis of Quasi-zero-stiffness Vibration Isolation System with Mechanical Frequency Modulated Dynamic Vibration Absorber
Abstract：Based on the working principle of dynamic vibration absorption, a two degree of freedom vibration isolation system is proposed by coupling the frequency adjustable dynamic vibration absorber with the single degree of freedom quasi-zero-stiffness vibration isolator. First, the working principle of dynamic vibration absorber is introduced, and its mechanical model is established. Second, through the analysis of static characteristics, a set of relations between the parameters of the system is derived when the system meets the condition of zero stiffness, and the influences of mechanical and structural parameters on stiffness characteristics of the system are studied. Then, the nonlinear dynamic equation of two degree of freedom vibration isolation system is established. By using the harmonic balance method, the expression of force transmissibility of the system is obtained. Last, using the numerical analysis method, the effects of different damping, stiffness, mass, excitation force amplitude and the effective length of spring on force transmissibility are numerically discussed. In addition, by comparing with the single degree of freedom quasi-zero-stiffness vibration isolation system and the two degree of freedom linear vibration isolation system, the vibration isolation performance of the system is studied. The results show that the designed two degree of freedom quasi-zero-stiffness vibration isolation system can effectively reduce the initial vibration isolation frequency of the system, and the low-frequency vibration isolation performance of the system in different excitation frequencies can be improved by adjusting the parameters of the dynamic vibration absorber. Furthermore, by selecting appropriate values of the damping, stiffness and mass of the dynamic vibration absorber, the effective vibration reduction frequency band width can be further expanded, the attenuation rate of the system force transmissibility in a specific frequency band can be obviously accelerated, and the low-frequency vibration isolation performance of the system can be dramatically improved.
2022, Vol. 43 
