Parametric Study of Track Support Structure to Minimize the Occurrence Possibility of Rail Corrugation

Author(s):  
Xiaolu Cui ◽  
Tong Li ◽  
Bo Huang ◽  
Haohao Ding

Changing the track support structure is an effective method to suppress or eliminate rail corrugation in practical engineering. Rail corrugation on small-radius curves with booted short sleepers is the main research object in the present paper. A relevant finite element model of the wheelset-track system supported by booted short sleepers is built combined with the dynamic analysis of the vehicle-track system. The effects of various parameters of booted short sleeper structure on the wheel–rail friction-induced vibration are investigated by complex eigenvalue analysis. Considering the interaction of multiple parameters in the booted short sleeper structure, the multi-parameter fitting equation forecasting the possibility of rail corrugation is obtained using the least squares algorithm. Results show that wheel–rail friction-induced oscillation is a contributing factor in the formation of rail corrugation. Controlling wheel–rail friction-induced oscillation with a frequency of about 300 Hz is beneficial to suppress the possibility of rail corrugation in sections with booted short sleepers. Lower fastener stiffness or greater vertical fastener damping make it less likely that rail corrugation will occur. Rail corrugation is not generated when the vertical stiffness of the fastener is controlled below 20 MN/m in the booted short sleeper.

2021 ◽  
Vol 12 (1) ◽  
pp. 31-40
Author(s):  
Zhiqiang Wang ◽  
Zhenyu Lei

Abstract. In order to effectively prevent and control the generation and development of rail corrugation, according to the actual line condition of the small radius curve section, the vehicle (with flexible wheel sets)–track space coupled model was established by using the multi-body dynamic software UM (Universal Mechanism), which could consider the coupled relationship in three directions of space, and the dynamic analysis for the corrugation section was carried out by using the model. Then, based on the theory of friction self-excited vibration, the three-dimensional model of a wheel–rail system was established by using the finite-element software ABAQUS, and the complex eigenvalue analysis of influence factors of rail corrugation was conducted based on wheel–rail contact parameters obtained by dynamic calculation. Through the stability analysis of the wheel–rail system with different fastener vertical and lateral stiffnesses, friction coefficients, and superelevation states, we find that properly increasing the fastener vertical and lateral stiffnesses, controlling the wheel–rail friction coefficient below 0.4, and keeping the balanced superelevation state of the track structure can effectively reduce the occurrence possibility of unstable vibration of the wheel–rail system, thus inhibiting the generation and development of rail corrugation. The excess superelevation state of the track structure results in the unstable friction self-excited vibration of the wheel–rail system at the inner wheel–inner rail, while the deficient superelevation state results in the unstable friction self-excited vibration of the wheel–rail system at the outer wheel–outer rail, which shows that the superelevation state of the track structure directly affects the formation of rail corrugation and determines the development order of corrugation of inner and outer rails. This conclusion can well explain the cause of corrugation appearing on only one side rail.


Author(s):  
Denis J. Feld ◽  
Dana J. Fehr

Abstract A conventional finite element model of an aircraft wheel and brake is extended to include forces responsible for friction-induced noise. Responses of aircraft brake vibration modes change the normal force across the brake friction interfaces, and consequently the friction forces. The resulting friction force variations are assembled in the form of a supplemental stiffness matrix and added to the finite element model. Complex eigenvalue analysis that includes the friction force variations provides frequency and mode shape information, as well as an assessment of the predicted mode stability. A predicted unstable vibration mode compares very well to operating mode shape data determined from instrumented tests. Hardware modifications to reduce a brake noise in an aircraft cabin were based on beneficial trends found from exercising the model. Implementation of the hardware modifications on the aircraft successfully suppressed the noise.


Author(s):  
Anutcharee Khuntiptong ◽  
Chak Chantalakhana

In this research study, the high-frequency squeal noise of a brake disc was found to occurred at a frequency of about 15 kHz. The potential root cause has been studied where mode frequency coupling and shape locking mechanism of brake disc and brake pads components are the main investigated topic. From the vehicle field test and the Dynamometer test, the braking condition, friction coefficient and braking pressure, have been confirmed to be used in numerical experiments. The updated finite element model (FEM) with the modal testing data of the existing brake components are formulated for the Complex Eigenvalue Analysis (CEA). In this study, the modification is based on in-board and out-board cheek thickness of the brake disc. Two of nine modifications of the brake disc cheek thickness are proposed with the method of separation the brake disc out-of-plane and in-plane modes and the method of avoiding shape locking between the brake disc and the brake pads modes. The constructed prototypes are verified with the vehicle field test and well agreed with the CEA.


2019 ◽  
Vol 39 (2) ◽  
pp. 368-381 ◽  
Author(s):  
BW Wu ◽  
GX Chen ◽  
JZ Lv ◽  
Q Zhu ◽  
X Kang

In Chinese metro lines, Vanguard fastener system is widely used as vibration damping fastener. However, the rails mounted with this fastener system are deeply affected by rail corrugation. The generation mechanism of corrugation wear at a metro track mounted with Vanguard fastening is revealed through the numerical simulation method. A finite element model including two rails, the track system, and a leading wheelset is set up. The parameter sensitivity analysis is conducted to identify the dominant factors affecting the rail corrugation. Then, the remedy method to suppress the corrugation wear is put forward on the basis of the parameter analysis results. The results indicate that the severe corrugation wear on the inner rail is attributed to the self-sustained vibration of the wheelset–track system aroused by the saturated wheel–rail creep force. The frequency of the rail corrugation calculated by the model is very close to the measured data. The elastic modulus and the damping coefficient of the rubber rest pad in the Vanguard fasteners have a high impact on rail corrugation. Increasing the elastic modulus and the damping coefficient can effectively restrain or even eliminate the rail corrugation. Bringing the damping coefficient of the rubber rest pad above 0.0001 can significantly alleviate the rail corrugation. The influence of the damping and stiffness of the rubber pad under the floating slab track bed is negligible.


Lubricants ◽  
2020 ◽  
Vol 8 (2) ◽  
pp. 18
Author(s):  
Guangxiong Chen

In the present study, the effect of the radius of railway curved tracks on the slip of a wheel on a rail is studied. A 3D finite-element model of a wheelset-track system is established when the creep force between the wheel and rail is saturated. The occurrence propensity of the self-excited vibration of the wheelset-track system is predicted. It is concluded that the radius of curved tracks has a strong effect on the slip of wheels on rails. In the tightly curved tracks, the slip of the wheel of the leading wheelset on the rail always occurs. The wheelset-track system has a strong occurrence propensity for unstable vibrations on the tightly curved tracks. The accuracy of the rail corrugation prediction based on the unstable vibrations of wheelset-track systems is determined to be 85–90% or higher.


Vibration ◽  
2020 ◽  
Vol 3 (4) ◽  
pp. 491-520
Author(s):  
Bingo Masiza Balekwa ◽  
Daramy Vandi Von Kallon

As much as there has been a significant increase in the development of railway systems in recent years, one of the significant drawbacks on this mode of transport is ground-borne vibrations and noise emanating from vehicle-track interaction in service. This greatly affects the ecology and physical surroundings of the railway track. Experimental tests and Finite Element modal and complex eigenvalue analysis are conducted to investigate the dynamics of a traction wheelset and rail track. This is done to establish the correlation between the short pitch rail corrugation in the Belfast to Steelpoort railway line, in the Limpopo Province of South Africa, with railway wheel-tract resonance at low frequencies of excitation. A 3D Finite Element Method (FEM) and complex eigenvalue analysis are used to validate the resonance modes of the wheelset and rail track obtained through experimental modal analysis. Mode shapes are determined for natural frequencies that match the excitation frequency induced by short pitch rail corrugation. The results show that based on average train speeds around track curves, the excitation frequency induced by corrugation matches (quite reasonably) natural frequencies of the wheelset. Whilst the wheelset FEM results are in better agreement, they rather prove the correlation to occur at 100 Hz. In a previous study by the authors, at the average speeds per track curve, the corrugation excitation frequency was found to be 108 Hz. The current study goes further by investigating natural frequencies of rail tracks. Moreover, mode shapes of a traction wheelset and rail tracks are also investigated, and the results are presented herein.


Author(s):  
G. X. Chen ◽  
Z. R. Zhou

In the paper, a new mechanism for squealing vibration based on the time delay concept of friction is introduced. Firstly, several test results on the time delay between the varying normal force and the consequent varying friction are presented and discussed. Secondly, the motion stability of a friction system with the time delay is analyzed in theory. The result shows that the friction system may become unstable in the presence of the time delay. Thirdly, the advantages and disadvantage of the new mechanism are discussed. The remaining part of the paper will present several research advances in the application of friction-induced vibration theory in the railway industry. In the authors’ work, a finite element model of friction self-excited vibration of a railway wheelset-track system is established. The motion stability of the model is analyzed. Numerical results show that friction between the wheel and rail easily causes self-excited vibration of a railway wheelset-track system. The relation between the rail corrugation and friction-induced vibration is discussed. Finally, the field test results in Subway line 4 of Beijing are presented. The test results show that there exists self-excited vibration of a railway wheelset-track system when vehicles negotiate sharp curved tracks.


2021 ◽  
pp. 107754632110388
Author(s):  
Bowen Wu ◽  
Ting Liu ◽  
Jiabao Pan ◽  
Rongyun Zhang

Rail corrugation is very serious in Cologne egg fastener track; effective control measures are still lacking. The cause of the corrugation wear on a curved metro track is analyzed based on the friction-induced vibration theory. A finite element model is established to study the frequency domain and time domain features of the friction-induced oscillation of this system. The influences of the fastener spacing and the fastener support length on the corrugation wear are investigated to develop countermeasures. The simulation results show that the friction-induced vibration of the wheel-track system is the wavelength-fixed mechanism of the corrugation wear of rail of the curved Cologne egg fastener track. There are two reasons why the low rail corrugation wear is more serious. The contact resultant force between the low rail and the wheel is obviously bigger than that between the wheel and the high rail, resulting in a higher wear rate of the low rail. The contact force fluctuation of the low rail caused by the friction-induced vibration is more severe, resulting in a higher corrugation wear evolution speed on the low rail. The friction-induced oscillation cannot be eliminated only by adjusting the fastener support length and spacing. However, the long-wavelength corrugation wear instead of the more harmful short-wavelength corrugation wear can be produced by adjusting the fastener support length and the fastener spacing to alleviate the influence of corrugation wear on the vehicle-track system.


2007 ◽  
Vol 35 (3) ◽  
pp. 165-182 ◽  
Author(s):  
Maik Brinkmeier ◽  
Udo Nackenhorst ◽  
Heiner Volk

Abstract The sound radiating from rolling tires is the most important source of traffic noise in urban regions. In this contribution a detailed finite element approach for the dynamics of tire/road systems is presented with emphasis on rolling noise prediction. The analysis is split into sequential steps, namely, the nonlinear analysis of the stationary rolling problem within an arbitrary Lagrangian Eulerian framework, and a subsequent analysis of the transient dynamic response due to the excitation caused by road surface roughness. Here, a modal superposition approach is employed using complex eigenvalue analysis. Finally, the sound radiation analysis of the rolling tire/road system is performed.


2018 ◽  
Vol 153 ◽  
pp. 06006
Author(s):  
Jiatong Ye ◽  
Hua Huang ◽  
Chenchen He ◽  
Guangyuan Liu

In this paper, a finite element model of membrane air spring in the vehicle is established, and its vertical stiffness characteristics under a certain inflation pressure are analysed. The result of finite element simulation method is compared with the result of the air spring bench test. The accuracy and reliability of the finite element simulation method in nonlinear analysis of air spring system are verified. In addition, according to the finite element method, the influence of the installation of the air spring limit sleeve on its stiffness is verified.


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