Dynamic analysis and performance evaluation of nonlinear inerter-based vibration isolators

Abstract

This paper investigates a nonlinear inertance mechanism (NIM) for vibration mitigation and evaluates the performance of nonlinear vibration isolators employing such mechanism. The NIM comprises a pair of oblique inerters with one common hinged terminal and the other terminals fixed. The addition of the NIM to a linear spring-damper isolator and to nonlinear quasizero-stiffness (QZS) isolators is considered. The harmonic balance method is used to derive the steadystate frequency-response relationship and force transmissibility of the isolators subject to harmonic force excitations. Different performance indices associated with the dynamic displacement response and force transmissibility are employed to evaluate the performance of the resulting isolators. It is found that the frequency response curve of the inerter-based nonlinear isolation system with the NIM and a linear stiffness bend towards the low-frequency range, similar to the characteristics of the Duffing oscillator with softening stiffness. It is shown that the addition of NIM to a QZS isolator enhances vibration isolation performance by providing a wider frequency band of low amplitude response and force transmissibility. These findings provide a better understanding of the functionality of the NIM and assist in better designs of nonlinear passive vibration mitigation systems with inerters.

Design and Tests of a Controllable Inerter With Fluid-Air Mixture Condition

“…The fluid inerter has superior application potential because of its simpler design and high impact resistance. As a common hydraulic drive system, the nonlinearity factors of fluid inerter cannot be ignored [21][22]. In [23], Akkaya proposed that in the analysis and design of the hydraulic transmission control system, the oil bulk modulus should be considered as a variable parameter.…”

Suppression of Vibration Transmission Between Oscillators Coupled With an Inerter-Based Joint

“…Since the introduction of the inerter concept, it has been applied to aircraft landing gear shimmy suppression [8], vehicle suspension systems [9] and building vibration control system [10]. Some studies have also been reported on the performance of inerter-based single degree-of-freedom (DOF) vibration isolators [11], dual-stage isolator [12] and nonlinear inerter-based isolator [13].…”

Dynamic performance analysis of a mixed‐connected inerter‐based quasi‐zero stiffness vibration isolator

“…Due to its mechanical property, the inerter has been observed as an efficient vibration attenuation device whose benefits are shown in many structures, for instance, vehicle suspensions, [13][14][15] train suspensions, 16 tuned mass dampers, [17][18][19][20] building vibration control systems, [21][22][23][24][25] landing gears, 26 nonlinear energy sinks, 27,28 and vibration isolators. [29][30][31][32][33][34][35] Here, the inerter applied in the vibration isolators is especially concerned. Hu et al 29 analyzed the dynamic performance for five kinds of vibration isolator using inerter, indicated that it could have a smaller transmissibility than the common linear one consists of damper and spring.…”

“…Wang et al 34 further analyzed the isolation performance of this vibration isolator and found that the force transmissibility is smaller, and the isolation frequency band is wider than those of the linear one. Yang et al 35 proposed a nonlinear inertance mechanism, applied it in the linear and nonlinear vibration isolators, and found that it could have an advantageous effect for vibration attenuation.…”

“…In the above researches, the inerter utilized in the linear vibration isolator has been investigated in detail; by designing different structural layouts of inerter, damper, and spring [29][30][31][32] or using geometrically nonlinear inerter, [33][34][35] a better isolation performance could be obtained. So far, the inerter applied in the nonlinear vibration isolator has been rarely discussed; thus, in this paper, the authors combine the nonlinear stiffness characteristic of the QZS vibration isolator and the mass magnification effect of the inerter, considering their corresponding benefits, and propose the inerter-based quasi-zero stiffness (IQZS) vibration isolator.…”