Analysis and Experimental Study on Dynamic Characteristics of an Integrated Quasi-Zero Stiffness Isolator

The dynamic performance of an integrated quasi-zero stiffness (IQZS) isolator which is constructed by a single elastic structure is investigated in this study. This prototype exhibits the characteristics of the best simplicity, high reliability, and without friction by using the minimum number of elements. For completeness, the static properties of the IQZS isolator are provided at first. And then, the dynamic behavior is analyzed and the frequency response under harmonic excitation is derived by using an equivalent mechanical model. Frequency response curves (FRCs) under force excitation condition are obtained by using the harmonic balance method (HBM). Moreover, the dynamic performance of the nonlinear isolator supporting a lumped mass is investigated, and the vibration isolation performance is evaluated by utilizing force transmissibility and comparing with an equivalent linear system with the same design parameter setting. It can be concluded that the effective isolation range of the nonlinear isolator is broader than the linear counterpart. The effects of system parameters on the transmissibility are also examined. At last, the comparison between the analytical and experimental results under force excitation shows that the analytical model of the IQZS isolator is accurate in terms of force transmissibility. The calculation results may provide a theoretical basis for designing this class of IQZS isolator in engineering practice.