Vibration Reduction and Noise Suppression for Urban Railways with a Wheelset Dynamic Vibration Absorber

Author(s):  
Yongpeng Wen ◽  
Daniel Chen ◽  
Aizhong Wu ◽  
Haoming You
2020 ◽  
Vol 10 (11) ◽  
pp. 3934 ◽  
Author(s):  
Un-Chang Jeong

The present study on vibration reduction in systems wherein the excitation frequency is variable designed and fabricated a magnetorheological elastomer (MRE)-based tunable dynamic vibration absorber and evaluated its performance in an experimental manner. The design of an MRE-based adaptive tuned dynamic vibration absorber (ATDVA) involves designing two parts: stiffness and mass. Before designing the MRE-based ATDVA, this study determined the resonance frequency of a target object for vibration reduction. For the design of the ATDVA’s stiffness part, the thickness of specimens was determined by measuring the rate of variation of the MRE’s shear modulus with respect to the MRE’s thickness. The design of the mass part was optimized using sensitivity analysis and genetic algorithms after the derivation of formulas for its magnetic field and mass. Further, upon the application of an electric current to the MRE, its stiffness was measured so that the stiffness of the designed MRE-based ATDVA could be tuned accordingly. Finally, the vibration-reducing performance of the MRE-based ATDVA was evaluated to determine the applicability of the vibration absorber under the condition of variable-frequency excitation.


Author(s):  
Yongguo Zhang ◽  
Chuanbo Ren ◽  
Kehui Ma ◽  
Zhen Xu ◽  
Pengcheng Zhou ◽  
...  

The combination of dynamic vibration absorber and partial state feedback with time-delay is called delayed resonator. In order to suppress the seat vibration caused by uneven road surface and improve ride comfort, the delayed resonator is applied to the seat suspension to realize active control of the seat suspension system. The dynamic model of the half-vehicle suspension system is established, and the time-delay differential equation of the system under external excitation is solved by the precise integration method. The root mean square of the time-domain vibration response of seat displacement, seat acceleration and vehicle acceleration are selected as the objective function. Then, the optimal time-delay control parameters are obtained by particle swarm optimization algorithm. The frequency sweeping method is used to obtain the critical time-delay value and time-delay stable interval of the system. Finally, an active seat suspension model with delayed resonator is established for numerical simulation. The results show that the delayed resonator can greatly suppress the seat vibration response regardless of the road simple harmonic excitation or random excitation. Compared with dynamic vibration absorber, it has a better vibration absorption effect and a wider vibration reduction frequency band.


2019 ◽  
Vol 3 (2) ◽  
pp. 85
Author(s):  
Susastro Susastro ◽  
Novi Indah Riani

Vibration is one of the problems that must be reduced in a vehicle. There are many ways to reduce vibration in vehicles, one of them is by adding Dynamic vibration absorber (DVA). While Dual Dynamic vibration absorber (dDVA) is a DVA period that is able to move in the translational direction given to the system to reduce translation vibration and when there is resonance. Translation DVA is an additional type of time used to reduce the vibration of the translation direction. So far there is not much research related to the use of translational DVA to reduce rotational vibrations as well as translation. In this study, a study was conducted related to the use of independent double translational DVA (dDVA) to reduce translation vibrations as well as rotation of the beam. The research was conducted by modeling the system obtained into mathematical equations and simulations were carried out to determine the characteristics of vibrations that arise. In the simulation, one of the DVA periods is placed at the center of the main system period, while the other DVA period is given a change between the center period and the end of the system. The results of the study show that the maximum reduction in translational vibration is 95.51% and occurs when the absorber is placed at the center of the system, while the maximum rotation vibration reduction is 56.62% and is obtained when the system is given with an arm ratio of 1 and zero.


2021 ◽  
pp. 1-13
Author(s):  
Ji-Hou Yang ◽  
Xiao-Dong Yang ◽  
Qing-Kai Han ◽  
Jinguo Liu

Abstract To improve vibration reduction effect in low-frequency band of dynamic vibration absorber (DVA), a novel type of articulated silicone gel column (SGC) is introduced in the design of the tuned dynamic vibration absorber. The nonlinear variation of frequency of SGC with varying geometry is obtained by both finite element simulation and experiments. The most sensitive mode is located, which has wider frequency range by varying the geometry. The polynomial fitting is used to describe nonlinear relation between frequency and geometry. By tuning the geometry, the equivalent stiffness and then resonance frequencies can be manipulated to behave as an active vibration absorber. The vibration reduction experiment of SGC vibration absorbers is investigated. It is found that SGC has better vibration reduction effect in low-frequency band. The experimental results in the current design demonstrate that the vibration reduction effect can reach 94.03% when tuning SCG to the first order main resonance. The dimensions and material parameters of SGC should be altered for specific frequency range and vibration strength.


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