Evaluation of the Ride Comfort for High Speed Trains in Korea

Author(s):  
Young Guk Kim ◽  
Seog Won Kim ◽  
Chan Kyoung Park ◽  
Kyoung Ho Moon ◽  
Tae Won Park
Volume 2 ◽  
2004 ◽  
Author(s):  
M. H. Kargarnovin ◽  
D. Younesian ◽  
D. J. Thompson ◽  
C. J. C. Jones

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.


2006 ◽  
Vol 321-323 ◽  
pp. 1589-1592 ◽  
Author(s):  
Young Guk Kim ◽  
Seog Won Kim ◽  
Chan Kyoung Park ◽  
Kyoung Ho Moon ◽  
Tae Won Park

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.


Author(s):  
AN Savoskin ◽  
AA Akishin ◽  
D Yurchenko

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.


Author(s):  
Chunfa Zhao ◽  
Xiaolin Song ◽  
Xiaojia Zhu

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.


2020 ◽  
Vol 28 (4) ◽  
pp. 317-345 ◽  
Author(s):  
Gongquan Tao ◽  
Zefeng Wen ◽  
Xuesong Jin ◽  
Xiaoxuan Yang

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.


Author(s):  
H. Farahpour ◽  
D. Younesian ◽  
E. Esmailzadeh

Ride comfort of high-speed trains is studied using Sperling's comfort index. Dynamic model is developed in the frequency domain and the power spectral density (PSD) of the body acceleration is obtained for four classes of tracks. The obtained acceleration PSD is then filtered using Sperling's filter. The effects of the rail roughness and train speed on the comfort indicators are investigated. A parametric study is also carried out to evaluate the effects of the primary and secondary suspension systems on the comfort indicators.


2021 ◽  
Vol 21 (5) ◽  
pp. 27-31
Author(s):  
Jongchan Park ◽  
Nam-Hyoung Lim

Recently, train speeds have been increased in Korea owing to the expansion of Korea Train eXpress (KTX) operations and development of next-generation high-speed trains. Hence, continuous welded rails (CWRs) that affect the running stability and ride comfort of trains have become essential elements. However, it is difficult to install CWRs on most of the non-ballast bridges constructed since the 1900s owing to the rail additional stress that occurs during installation. As a solution to this problem, the sliding track panel (STP) system that allows longitudinal sliding is proposed. In the application of STP systems, securing the lateral buckling strength is an essential condition. Hence, a finite element analysis model considering the STP system is presented, and the necessity for reinforcement plates is investigated through a pure skeleton-track analysis. The minimum requirements and effects of increasing the stiffness of the reinforcement plates are derived by analyzing the lateral reinforcement plates.


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