scholarly journals Low-Frequency Carbody Sway Modelling Based on Low Wheel-Rail Contact Conicity Analysis

2020 ◽  
Vol 2020 ◽  
pp. 1-17
Author(s):  
Yi Wu ◽  
Jing Zeng ◽  
Sheng Qu ◽  
Huailong Shi ◽  
Qunsheng Wang ◽  
...  
Keyword(s):  
High Speed ◽  
Ride Comfort ◽  
Low Frequency ◽  
Fundamental Solutions ◽  
Nonlinear Analyses ◽  
Suspension Parameters ◽  
Hunting Motion ◽  
High Speed Trains ◽  
Rail Line ◽  
Economic Considerations

Low-frequency carbody swaying on China’s high-speed trains is not only an impediment to ride comfort but it may also be an operational risk under some extreme situations. To study the mechanism and mitigate the carbody swaying problem for high-speed trains, a multibody dynamics model was established based on both linear and nonlinear analyses. Whilst it is generally assumed that carbody swaying is predominantly caused by carbody hunting motion, the results in this paper has shown that, under certain boundary conditions, bogie-hunting motion can also lead to low-frequency carbody swaying. This low-frequency swaying phenomenon was also found to be caused by the excessively low wheel-rail contact or mismatched suspension parameters. Parametric optimization analysis was accordingly conducted from the perspective of the wheel-rail contact relationship and the suspension system. The analysis indicated that although optimizing the suspension parameters can meet the requirement of vehicle stability, bogie's vibration worsen when the wheel profiles wear over time. Overall, while rail reprofiling was found to be one of the fundamental solutions to mitigate carbody swaying, it is cost prohibitive for most routine operational applications. Thus, for economic considerations and the fact that low wheel-rail contact conicity is also a contributing factor to carbody swaying, vehicles with worn wheels can also be operated on the rail line, which was successfully verified by the field data presented in this paper.

Nonlinear Vibration and Comfort Analysis of High-Speed Trains Moving Over Railway Bridges

Volume 2 ◽  
2004 ◽  
Author(s):  
M. H. Kargarnovin ◽  
D. Younesian ◽  
D. J. Thompson ◽  
C. J. C. Jones
Keyword(s):  
High Speed ◽  
Ride Comfort ◽  
Beam Theory ◽  
Maximum Acceleration ◽  
Railway Bridges ◽  
Comfort Index ◽  
Power Spectral ◽  
High Speed Trains ◽  
Train Speed ◽  
Track Bridge

The ride comfort of high-speed trains passing over railway bridges is studied in this paper. The effects of some nonlinear parameters in a carriage-track-bridge system are investigated such as the load-stiffening characteristics of the rail-pad and the ballast, rubber elements in the primary and secondary suspensions systems. The influence of the track irregularity and train speed on two comfort indicators, namely Sperling’s comfort index and the maximum acceleration level, are also studied. Timoshenko beam theory is used for modelling the rail and bridge and two layers of parallel damped springs in conjunction with a layer of mass are used to model the rail-pads, sleepers and ballast. A randomly irregular vertical track profile is modelled, characterised by a power spectral density (PSD). The ‘roughness’ is generated for three classes of tracks. Nonlinear Hertz theory is used for modelling the wheel-rail contact.

Evaluation of the Ride Comfort for High Speed Trains in Korea

2006 ◽  
pp. 1589-1592 ◽  
Author(s):  
Young Guk Kim ◽  
Seog Won Kim ◽  
Chan Kyoung Park ◽  
Kyoung Ho Moon ◽  
Tae Won Park
Keyword(s):  
High Speed ◽  
Ride Comfort ◽  
High Speed Trains

Evaluation of the Ride Comfort for High Speed Trains in Korea

2006 ◽  
Vol 321-323 ◽  
pp. 1589-1592 ◽  
Author(s):  
Young Guk Kim ◽  
Seog Won Kim ◽  
Chan Kyoung Park ◽  
Kyoung Ho Moon ◽  
Tae Won Park
Keyword(s):  
Statistical Method ◽  
High Speed ◽  
Ride Comfort ◽  
Lateral Acceleration ◽  
Railway Vehicles ◽  
Longitudinal Acceleration ◽  
High Speed Trains ◽  
Term Evaluation

Evaluation of the ride comfort for railway vehicles can be divided into two classes; the long-term evaluation of ride comfort and the momentary evaluation of ride comfort. In the present paper, the ride comfort of railway vehicles are investigated for high speed trains in Korea. The long-term ride comfort has been analyzed by a statistical method and the momentary ride comfort has been analyzed by using the longitudinal acceleration, the jerk and the stationary lateral acceleration.

Dynamics and optimization of a new double-axle flexible bogie for high-speed trains

2017 ◽  
Vol 232 (5) ◽  
pp. 1549-1558
Author(s):  
AN Savoskin ◽  
AA Akishin ◽  
D Yurchenko
Keyword(s):  
Numerical Optimization ◽  
High Speed ◽  
Ride Comfort ◽  
Radius Of Curvature ◽  
High Speed Trains

This paper is focused on the discussion of a new double-axle flexible bogie for high-speed trains. The main feature of the flexible bogie is that it consists of two sub-bogies connected with diagonal links. Moreover, an elastic connection between the carriage and both wheelsets is introduced. These features, which help to increase the flexibility of the bogie while passing tracks with a low radius of curvature, are numerically studied in this paper. The results demonstrate the huge potential of the bogie and its ability to travel without significant oscillations at a speed of 432 km/h. Numerical optimization of the bogie’s parameters is performed in order to maximize ride comfort.

Temperature Deformation Analysis of CRTS II Ballastless Slab Track

2013 ◽  
Author(s):  
Chunfa Zhao ◽  
Xiaolin Song ◽  
Xiaojia Zhu
Keyword(s):  
High Speed ◽  
Ride Comfort ◽  
Precast Concrete ◽  
Extreme Temperature ◽  
Temperature Deformation ◽  
Deformation Analysis ◽  
High Speed Trains ◽  
Temperature Deformations ◽  
Cohesive Zone Elements ◽  
Track Slab

Two finite element models of CRTS II ballastless track superstructure were developed to simulate temperature deformations of the precast concrete track slab. One of the models considered the fully bonding interface between the track slab and the cement asphalt mortar layers, while the other uses cohesive zone elements to simulate possible interfacial separation and slip. Warp deformations of the track slab under various temperature loads were calculated using both models. Numerical results show that the track slab glued fully to the mortar layers can approximately hold regular geometry shape even if it bears extreme temperature gradient loads. Although deteriorated mortar layers could increase significantly temperature deformations of the track slab, warp deformations of the track slab are still quite small and the rail harmonic irregularities due to the temperature deformations are tiny. It can be concluded that temperature deformations of CRTS II track slab have little effect on running safety and ride comfort of high-speed trains.

scholarly journals Polygonisation of railway wheels: a critical review

2020 ◽  
Vol 28 (4) ◽  
pp. 317-345 ◽  
Author(s):  
Gongquan Tao ◽  
Zefeng Wen ◽  
Xuesong Jin ◽  
Xiaoxuan Yang
Keyword(s):  
Critical Review ◽  
High Speed ◽  
Natural Vibration ◽  
Ride Comfort ◽  
Railway Vehicle ◽  
Formation Mechanisms ◽  
Simulation Methods ◽  
Track System ◽  
High Speed Trains ◽  
Railway Wheels

AbstractPolygonisation is a common nonuniform wear phenomenon occurring in railway vehicle wheels and has a severe impact on the vehicle–track system, ride comfort, and lineside residents. This paper first summarizes periodic defects of the wheels, including wheel polygonisation and wheel corrugation, occurring in railways worldwide. Thereafter, the effects of wheel polygonisation on the wheel–rail interaction, noise and vibration, and fatigue failure of the vehicle and track components are reviewed. Based on the different causes, the formation mechanisms of periodic wheel defects are classified into three categories: (1) initial defects of wheels, (2) natural vibration of the vehicle–track system, and (3) thermoelastic instability. In addition, the simulation methods of wheel polygonisation evolution and countermeasures to mitigate wheel polygonisation are presented. Emphasis is given to the characteristics, effects, causes, and solutions of wheel polygonisation in metro vehicles, locomotives, and high-speed trains in China. Finally, the guidance is provided on further understanding the formation mechanisms, monitoring technology, and maintenance criterion of wheel polygonisation.

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