• Title/Summary/Keyword: Wheel-rail

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A Study on the Running Characteristic by Rail cant variation (레일 캔트 변화에 따른 주행특성에 관한 연구)

  • Eom, Beom-Gyu;Kim, Young-Gyu;Lee, Seung-Il;Lee, Hi-Sung
    • Proceedings of the KSR Conference
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    • 2011.05a
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    • pp.1142-1147
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    • 2011
  • The rail cant produces a wider bearing area between the wheel and the rail by moving the wheel-rail contact area away from the gauge towards the centre of the railhead, thus improving the wear pattern of the railhead and wheel treads. It is essential to keep the rail cant within the allowable range to ensure optimum track geometry. Neglecting the rail cant geometrical parameters in a track quality evaluation can cause safety of railway vehicle and serviceability problems. In this paper, we examined the effect of the rail cant in general geometry state of the railway track using VI-Rail and analyzed running safety when the railway vehicle passing through curves depending on change of the rail cant and running speed.

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A Running Safety Analysis of Railway Vehicle passing through Curve According to Rail Inclination Change (곡선부 통과열차의 레일 경좌 변화에 따른 주행안전성 해석)

  • Son, Myoung-Sun;Eom, Beom-Gyu;Kang, Bu-Byoung;Lee, Hi-Sung
    • Proceedings of the KSR Conference
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    • 2011.10a
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    • pp.1922-1928
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    • 2011
  • The rail inclination produces a wider bearing area between the wheel and the rail by moving the wheel rail contact area away from the gauge towards the centre of the railhead, thus improving the wear pattern of the railhead and wheel treads. It is essential to keep the rail inclination within the allowable range to ensure optimum track geometry. Neglecting the rail inclination geometrical parameters in a track quality evaluation can cause safety of railway vehicle and serviceability problems. In this paper, we examined the effect of the rail inclination in general geometry state of the railway track using VI-Rail and analyzed running safety when the railway vehicle passing through curves depending on change of the rail inclination and running speed.

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The Static Behavior of Bridge Expansion Joints Due to the Wheel Load (윤하중 재하에 의한 교량 신축이음의 정적거동)

  • Kim, Youngjin;Kwak, Imjong;Cho, Changbaek;Yoon, Hyejin
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.28 no.3A
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    • pp.357-366
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    • 2008
  • This study addresses the analysis of the behavioral characteristics of bridge expansion joints under wheel loading through wheel load test and the proposal of relevant wheel load specifications for expansion joints. To that goal, specimens of rail and finger expansion joints that are widely used in Korea were fabricated and subjected to static wheel load test using a real tire wheel. The wheel load distribution factor in the rail and finger expansion joints in contact with the wheel load was evaluated. The evaluation revealed that the portion of load sustained by the central rail of rail expansion joint was decreasing with larger wheel load, and that the portion of load sustained by the finger expansion joint was practically insensitive to the increase of the contact area and remained nearly constant. Since the wheel load characteristics showed large difference compared to former design specifications, it appears necessary to prepare rational specifications relative to the distribution of the wheel load contact pressure for the design of expansion joints.

Optimisation of Rolling Stock Wheelset Life through Better Understanding of Wheel Tyre Degradation

  • Vermeij, I.;Bontekoe, T.;Liefting, G.;Peen, J.
    • International Journal of Railway
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    • v.1 no.3
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    • pp.83-88
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    • 2008
  • Since the 1990's the fleet of the Dutch Railways showed a dramatic decrease in wheel tyre life. This lifetime reduction led to an unacceptable increase in life cycle costs. Therefore Lloyd's Register Rail has proposed to NedTrain to investigate the possibilities of improving the wheel tyre life. Three improvements were determined as most promising and relatively easy to achieve: - Profile optimisation for Rolling Contact Fatigue (RCF) reduction - a new wheel profile has been developed with a better resistance against rolling contact fatigue of the wheel tread. The profile has been implemented on single deck intercity trains and shows an increase in wheel tyre life of 30%. - Selection of improved wheel tyre materials - combining information from literature and experiences of manufacturers five alternative wheel tyre materials have been selected and are now being tested in practice. - Optimisation of the maintenance strategy - an alternative, preventative maintenance regime has been developed. With this Scraping regime, during short term maintenance every wheel is reprofiled. Higher mileages are reached and savings on life cycle costs up to 50% and more have been achieved. Unplanned maintenance goes down with $30{\sim}60%$. The results from field tests, using a reference group for comparison, and preliminary results after implementation show that the increase in wheel tyre life that is achieved with this project is significant. The results will continue to be monitored using the asset management tool 'Wheel Watch', that was specially developed for this project and is also described in this paper.

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Estimation of Contact Fatigue Initiation Lifetime of an Urban Railway Wheel (도시철도 차륜의 접촉피로 초기수명 평가)

  • Ahn, Jong-Gon;You, In-Dong;Kwon, Seok-Jin;Kim, Ho-Kyung
    • Tribology and Lubricants
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    • v.28 no.1
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    • pp.19-26
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    • 2012
  • Rolling contact fatigue of an urban railway wheel was analysed during its rolling. A FEM analysis was performed using a 3D modelling of rail and wheel, considering the slope of the rail and nonlinear isotropic and kinematic hardening behavior of the rail and the wheel. The maximum von-Mises stress and contact pressure between the rail and wheel were 656.9 MPa and 1111.4 MPa, respectively, under axial load of 85 kN with friction coefficient of 0. The fatigue initiation life prediction relationships by strain-lifetime (${\varepsilon}$-N) and Smith-Watson-Topper method were drawn for the wheel steel as follows: $N_i=7.35{\times}10^6{\times}SWT^{-3.56}$ and $N_i=5.41{\times}10^{-9}{\times}(\frac{{\Delta}{\varepsilon}}{2})^{-5.77}$. The fatigue lifetimes of the wheel due to rolling contact were determined to be infinite by ${\varepsilon}$-N and SWT methods.

A study on the Shape Design Contact Characteristic of Wheel-Rail for Rollng Stock (2) (철도차량용 휠과 레일의 접촉특성 해석 및 형상설계에 관한 연구 (2))

  • Seong, Gi-Deuk;Yang, Won-Ho;Jo, Myeong-Rae;Heo, Seong-Pil
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.24 no.5 s.176
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    • pp.1238-1245
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    • 2000
  • One of the main causes of severe wear or crack initiation in wheel and rail is the contact stress due to wheel-rail contact. First, we obtain contact stress due to the rail mounting slope using the finite element method. Second, the shape design based on more reasonable contact stress analysis rather th~n a general Hertzian contact theory is investigated in order to reduce the contact stress. The optimum -design is performed using the simple 2-D finite element model and its results are verified by 311) finite element analysis.

Cause and Counterplan of Wheel Climb Derailment at Low Speed on Curves (곡선부 저속주행시 타오르기 탈선의 원인과 대책)

  • Ham, Young-Sam;You, Won-Hee
    • Proceedings of the KSR Conference
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    • 2007.11a
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    • pp.1031-1035
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    • 2007
  • When vehicles running, vertical force and lateral force act except load of vehicles to rail and wheel. This force happens by complex motion at running. If mark vertical force by P and lateral force by Q, derailment coefficient displays Q/P, most important indicator pointer of running safety judgment. If Q is grown than P from derailment coefficient, than arrived to derailment because wheel climb or jumps over rail. Wheel climb derailment among kind of derailment is when attack angle is +, wheel and rail strike and flange rides to rail. This derailment occurs much in curved line and occurs in low speed. In this study, occurred when running at low speed on curved line, analyze cause of derailment and presented the countermeasure plan.

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Stress Analysis in the Elastic-Plastic Analysis of Railway Wheels

  • Ashofteh, Roya Sadat;Mohammadnia, Ali
    • International Journal of Railway
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    • v.7 no.1
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    • pp.1-7
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    • 2014
  • Fatigue and wear in wheels is often due to the forces and loading. These certainly have fundamental effects on reducing the wheel life and increasing the costs related to repairing and maintenance. Modeling and stress analysis of a wheel sample existing in the Iranian fleet have been performed in its contact with U33 and UIC60 rails. The results have been reviewed and analyzed in elastic and elastic-plastic phase and under static (railcar weight) and quasi static loads. Moreover, effects of wheel diameter, axle load, wheel material, rail type are analyzed.