A quasi-zero-stiffness isolator with a shear-thinning viscous damper

Abstract

Quasi-zero-stiffness (QZS) vibration isolators have been widely studied, because they show excellent high static and low dynamic stiffnesses and can effectively solve low-frequency and ultralow-frequency vibration. However, traditional QZS (T-QZS) vibration isolators usually adopt linear damping, owing to which achieving good isolation performance at both low and high frequencies is difficult. T-QZS isolators exhibit hardening stiffness characteristics, and their vibration isolation performance is even worse than that of linear vibration isolators under a large excitation amplitude. Therefore, this study proposes a QZS isolator with a shear-thinning viscous damper (SVD) to improve the vibration isolation performance of the T-QZS isolators. The force-velocity relation of the SVD is obtained, and a dynamic model is established for the isolator. The dynamic responses of the system are solved using the harmonic balance method (HBM) and the Runge-Kutta method. The vibration isolation performance of the system is evaluated using force transmissibility, and the isolator parameters are analyzed. The results show that compared with the T-QZS isolators, the proposed QZS-SVD isolator achieves the lower initial vibration isolation frequency and peak value, and exhibits better vibration isolation performance at medium and high frequencies. Moreover, the proposed isolator can withstand a large excitation amplitude in the effective vibration isolation range.

Research on a Novel CRSM for a Type of QZS Vibration Isolator

“…For cutting down the load static deflection, two sets of diagonal mechanical springs are introduced to the vibration isolator [5]. In order to upgrade the attenuation performance when the amplitude of excitation is large, a shear-thinning viscous damper is adopted in QZS vibration isolator [6]. Static bearing capacity and vibration isolation performance are often difficult to achieve simultaneously, but both are equally important.…”

Parameter optimization of vibration control system for adjacent building structures based on negative stiffness inerter damper

“…The addition of linear viscous damping to a conventional QZS system decreases the vibration isolation performance, and the use of dry friction element can maximize the vibration isolation performance of the system with smallest possible viscous damping 5 . The vibration isolator consisting of QZS system and shear-thinning viscous dampers solves the problem that the conventional QZS system is unable to withstand large external excitations, and thus exhibits better vibration isolation performance at medium and high frequencies 6 . A nonlinear inertance mechanism can broaden the effective isolation bandwidth of QZS and has better force transmissibility under high frequency excitation 7 .…”

Accurate nonlinear dynamic characteristics analysis of quasi-zero-stiffness vibration isolator via a modified incremental harmonic balance method

“…It is clarified that the displacement transmissibility is unbounded when the damping is less than a specific value [7]. In fact, the three-spring model is one of the most widely used QZS vibration isolation structures [8][9][10]. Xu [11] and Zhou [12] have done systematic research on the design, modeling and experimental research of the model in the aspect of QZS vibration isolation.…”