Dynamic analysis of quasi-zero stiffness vibration isolation system coupled with frequency adjustable dynamic vibration absorber

Based on the principle of dynamic vibration absorber (DVA), frequency adjustable DVA is coupled on the basis of single degree-of-freedom (DOF) quasi-zero-stiffness (QZS) vibration isolator. First, a mechanical model of the DVA's working principle and its theoretical analysis are presented. Secondly, through static analysis, the relationship between the parameters when the system meets the condition of zero stiffness is deduced, and the influence of these parameters on the stiffness characteristics of the system is analyzed. Then, the nonlinear dynamic equation of the coupled system is established, and the amplitude frequency response is analyzed by the harmonic balance method, and the expression of force transmissibility is obtained. Finally, using the numerical analysis method, the effects of different DVA damping, stiffness, mass, excitation force amplitude and effective length of spring on the dynamic response characteristics and force transmissibility characteristics of the system under the action of simple harmonic excitation force are studied and compared with the single-DOF QZS system and the two-DOF linear stiffness system. The results show that the single-DOF QZS system coupled with DVA can not only reduce the initial vibration isolation frequency of the main system, but also accelerate the attenuation rate of the system force transmissibility in local frequency band, expand the bandwidth of the effective vibration reduction frequency, reduce the amplitude of the main system at the anti-resonance frequency, improve the low-frequency vibration isolation performance of the system and realize the adaptability of the excitation frequency.Please check the edit made in the article title.Thanks a lot for the revision.