Low-Frequency Vibration Isolation Performance of Floating Slab Track System

Author(s):  
Jun Yuan ◽  
Lin Song ◽  
Min-Zhe Wu ◽  
Zhao-Bo Meng
Author(s):  
Shengyang Zhu ◽  
Jizhong Yang ◽  
Chengbiao Cai ◽  
Zili Pan ◽  
Wanming Zhai

This paper aims to develop a low-frequency vibration isolation track based on passive vibration isolation theory and vehicle–track interaction analysis. First, a preliminary low-frequency vibration isolation track is proposed by attaching multiple dynamic vibration absorbers to a discontinuous floating slab track, and the optimal design parameters of the multidynamic vibration absorber are determined by searching the minimum values of two assessment functions. Further, a three-dimensional coupled dynamic model of a metro vehicle and the low-frequency vibration isolation track is established by using Ansys Parametric Design Language, where the equations of motion of the vehicle subsystem and the wheel–rail contact calculations are incorporated in the software Ansys using the Ansys Parametric Design Language, and the low-frequency vibration isolation track subsystem is directly created by using common elements in Ansys. The vibration isolation performance of the preliminary low-frequency vibration isolation track with multidynamic vibration absorber is investigated under harmonic load and vehicle dynamic load, respectively. Results show that the slab acceleration and supporting force are significantly reduced at low frequencies of 10–20 Hz compared with those of the traditional floating slab tracks. Finally, an improved low-frequency vibration isolation track is developed for actual manufacturing and practical application, and simulations show that the improved low-frequency vibration isolation track exhibits a more robust vibration isolation performance even if optimal design parameters have variations due to manufacturing errors or material deterioration.


Author(s):  
Xuancheng Yuan ◽  
Shengyang Zhu ◽  
Lei Xu ◽  
Wanming Zhai ◽  
Huailong Li

Floating slab track is an effective countermeasure to mitigate undesirable vibrations caused by metro trains. In this work, a stochastic fractional derivative model is proposed for simulating the dynamic behavior of rubber bearings in floating slab tracks. The stochastic fractional derivative model is based on the Grünwald representation of fractional calculus, the number theoretical method, and the probability density evolution method (PDEM). It considers the viscoelastic characteristics of the rubber bearings, as well as randomness in mechanical behavior due to manufacturing tolerances, aging, and fatigue. The stochastic fractional derivative model is then implemented into a vehicle–floating slab track coupled dynamics model to investigate the vibration isolation performance of the floating slab track with rubber bearings. The characteristics and advantages of the stochastic fractional derivative model with deterministic parameters are illustrated by comparing the results with the conventional Kelvin model. Finally, stochastic analyses of the dynamic response and the vibration isolation performance of the floating slab track are carried out using the coupled vehicle–floating slab track system dynamics model. Results show that the stochastic simulation of the vehicle–floating slab track system using PDEM is efficient and reliable compared with the Monte Carlo method. Thus, the proposed model is effective and useful for evaluating the vibration levels in floating slab tracks with uncertain parameters, and for predicting the reliability of the vibration isolation performance.


2017 ◽  
Vol 21 (3) ◽  
pp. 1119-1132 ◽  
Author(s):  
Gui-Lan Yu ◽  
Hong-Wei Miao

The vibration isolation performance of a PC sandwich plate with periodic hollow tube core is investigated experimentally and numerically. The experiment results reveal that there exist vibration attenuation zones in acceleration frequency responses which can be improved by increasing the number of periods or tuning some structure parameters. The presence of soft fillers shifts the attenuation zone to lower frequencies and enhances the capability of vibration isolation to some extent. Dispersion relations and acceleration frequency responses are calculated by finite element method using COMSOL MULTIPHYSICS. The attenuation zones obtained by experiments fit well with that by simulations, and both are consistent with the band gap in dispersion relations. The numerical and experimental studies in the present paper show that this PC sandwich plate exhibits a good performance on vibration isolation in low frequency ranges, which will provide some useful references for relevant research and potential applications in vibration propagation manipulations.


2012 ◽  
Vol 131 (4) ◽  
pp. 3344-3344
Author(s):  
Wilson Ho ◽  
Banting Wong ◽  
Isaac Chu ◽  
Calvin Kong ◽  
Richard Kwan

2017 ◽  
Vol 139 (3) ◽  
Author(s):  
Jiaxi Zhou ◽  
Kai Wang ◽  
Daolin Xu ◽  
Huajiang Ouyang ◽  
Yingli Li

A platform supported by a hexapod of quasi-zero-stiffness (QZS) struts is proposed to provide a solution for low-frequency vibration isolation in six degrees-of-freedom (6DOFs). The QZS strut is developed by combining a pair of mutually repelling permanent magnets in parallel connection with a coil spring. Dynamic analysis of the 6DOFs QZS platform is carried out to obtain dynamic responses by using the harmonic balance method, and the vibration isolation performance in each DOF is evaluated in terms of force/moment transmissibility, which indicates that the QZS platform perform a good function of low-frequency vibration isolation within broad bandwidth, and has notable advantages over its linear counterpart in all 6DOFs.


2009 ◽  
Vol 131 (6) ◽  
Author(s):  
Qiao Sun ◽  
Robert A. Wolkow ◽  
Mark Salomons

The extreme sensitivity of a scanning probe microscope demands an exceptional noise cancellation device that could effectively cut off a wide range of vibration noise. Existing commercial devices, although excellent in canceling high frequency noise, commonly leave low frequency vibration unattenuated. We design an add-on active stage that can function together with a standalone existing active stage. The objective is to provide a higher level of noise cancellation by lowering the overall system cut-off frequency. This study is concerned with the theoretical aspects of the coupling characteristics involved in stacking independently designed stages together to form a two-stage isolator. Whether an add-on stage would pose a stability threat to the existing stage needs to be addressed. In addition, we explore the use of coupling effects to optimize the performance of the overall system.


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