• Title, Summary, Keyword: Rail Inclination

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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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    • 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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Running Safety Analysis of Railway Vehicle passing through Curve depending on Rail Inclination Change (레일 경좌 변화에 따른 곡선부 통과열차의 주행안전성 해석)

  • Kim, Moon Ki;Eom, Beom Gyu;Lee, Hi Sung
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.23 no.3
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    • pp.199-208
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    • 2013
  • So far today, there is a speed limit by the radius of curve based on operation regulation in domestic railway, however a study for the maximum running speed at the curved section without any derailment would be necessary. The two major factors related to the running safety of railway vehicle are classified as the railway vehicle condition and the track condition. In terms of the rail inclination among many other factors, the determination of rail inclination within the possible limit is necessary for the geometrical structure of the optimum track. The disregard of the geometrical parameter related to the rail inclination may cause a serious problem to the running safety of railway vehicle. This study is focusing on the analyzing of running safety regard to the change of rail inclination among the many other parameters to improve derailment safety, so that there is an affection analysis of the running safety regard to the change of rail inclination in the ideal and geometric track condition. Also There is an affection analysis of the running safety regard to the simultaneous change of rail inclination and the running speed at the curved section. According to analysis results of running safety, In case that the left and right rail inclination are 1/40, the running safety of this condition defined than other conditions. Also, the rail inclination of conventional lines is 1/40, Therefore, the railway vehicle passing through curve is safe when the railway vehicle runs in conventional lines.

Running Safety Analysis of Railway Vehicle depending on Rail Inclination Change on Actual Track of Subway Line No.3 in Seoul (3호선 실제선로 조건에서의 레일경좌 변화에 따른 철도차량 주행안전성 해석)

  • Kim, Tae Geon;Lee, Hi Sung
    • Journal of the Korean Society of Safety
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    • v.31 no.3
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    • pp.130-135
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    • 2016
  • It is very hard to analyze the train derailment safety quantitatively at the curved section because of the diversified affect parameters including the complex interaction between wheel and rail, the train conditions such as the shape of wheel, suspension system, the track conditions such as the radius of curve, cant, transition curve, and the operation conditions, etc. Two major factors related to the running safety of railway vehicle are classified as the railway vehicle and the track condition. In this study, when the railway vehicle passing through curves of actual track condition of subway line NO.3 in seoul ($Yeonsinnae{\leftrightarrow}Gupabal$), the effect that has influence on running safety depending on rail inclination. The analysis result of 1/40 rail inclination condition is more favorable on running safety than other rail inclination conditions because derailment coefficient and wheel unloading ratio are the lowest.

A study on the influence of wheel/rail geometric parameters to equivalent conicity (차륜/레일 기하학적 인자의 등가답면구배에 미치는 영향)

  • Hur Hyun-Moo;Kwon Sung-Tae;Kim Hyung-Jin
    • Proceedings of the KSR Conference
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    • pp.430-434
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    • 2004
  • The geometric parameters between wheel and rail change wheel/rail contact geometry characteristics, and this influence dynamic behavior of rolling stock. So, the selections of optimum geometric parameters between wheel and rail is important for planning of railway system. In this study, we have analyzed the influence of geometric parameters like wheel flange-back distance, gage, and rail inclination to the equivalent conicity relating dynamic behavior. The analyses show the following results. The widening of wheel flange-back distance increase the equivalent conicity, the widening of gage, rail inclination 1/20 compared with rail inclination 1/40 decrease the equivalent conicity.

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Analysis on the Influence of Wheel/Rail Geometric Parameters on the Equivalent/Conicity (차륜/레일 기하학적 인자에 의한 등가답면구배 영향 분석)

  • Hur Hyun-Moo;Kwon Sung-Tae
    • Journal of the Korean Society for Railway
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    • v.8 no.5
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    • pp.490-494
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    • 2005
  • The geometric parameters between wheel and rail change wheel/rail contact geometry characteristics, and this influence dynamic behavior of rolling stock. So, the selections of optimum geometric parameters between wheel and rail is important for planning of railway system. In this study, we have analyzed the influence of geometric parameters like wheel flange-back distance, gage, and rail inclination on the equivalent conicity relating to dynamic behavior. The analyses show the following results. The widening of wheel flange-back distanc, the decrement of gage increase the equivalent conicity and the increment of rail inclination show the sharp change of the equivalent conicity.

Three Dimensional Finite Element Inverse Analysis of Rectangular Cup and S-Rail Forming Processes using a Direct Mesh Mapping Method (직접 격자 사상법을 이용한 직사각컵 및 S-Rail 성형공정의 3차원 유한요소 역해석)

  • Kim S. H.;Huh H.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • pp.81-84
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    • 2001
  • An inverse finite element approach is employed for more capability to design the optimum blank shape from the desired final shape with small amount of computation time and effort. In some drawing or stamping simulation with inverse method, it is difficult to apply inverse scheme due to the large aspect ratio or steep vertical angle of inclination. The reason is that initial guesses are hard to make out with present method for those cases. In this paper, a direct mesh marring scheme to generate initial guess on the sliding constraint surface described by finite element patches is suggested for one step inverse analysis to calculate initial blank shape. Radial type mapping is adopted for the simulation of rectangular cup drawing process with large aspect ratio and parallel type mapping for the simulation of S-Rail forming process with steep vertical angle of inclination.

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Calculating the Contact Stress Resulting from Lateral Movement of the Wheel on Rail by Applying Hertz Theory

  • Ashofteh, Roya Sadat
    • International Journal of Railway
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    • v.6 no.4
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    • pp.148-154
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    • 2013
  • This article has tried to review the maximum contact stresses in the contact area of the wheel and rail as a result of lateral movement of the wheel on rail by taking advantage from Hertz theory. Since wheel movement on rail is accompanied by lateral movement due to wheel profile conisity, so the contact point of wheel and rail is not constant and the contact stresses are therefore changeable in every single moment. Since the shape of rail profile and rail inclination, wheel diameter and the mechanical properties of the wheel and rail are effective on the stresses of contact area, these parameters have been studied by applying Hertz theory. This article aims to calculate the contact stresses in different parts on the wheel surface by using Hertz theory.

Running Safety Analysis of Railway Vehicle Depending on Railway Inclination Change Under Actual Track Conditions (실제 선로조건에서의 레일 경좌 변화에 따른 철도차량의 주행안전성 해석)

  • Kim, Moon Ki;Eom, Beom Gyu;Lee, Hi Sung
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.37 no.11
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    • pp.1437-1443
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    • 2013
  • Railways are currently subject to the enforcement of speed limits for each curve as prescribed by the Railway Operating Rules in Korea. However, research is required to determine the maximum speed of trains passing through each curve that allows them to run without the risk of derailment in relation to the speed enhancement of existing railway tracks. In addition, factors affecting the running safety of railway vehicles can be classified into those in terms of vehicle aspects and those in terms of track aspects. This study sought to analyze the running safety of railway vehicles according to changes in the inclination of the rail from among the factors affecting the enhancement of safety against derailment. To increase the speed of trains passing through curves that have high derailment risk, this study also analyzed the running safety of railway vehicles according to the inclination of the rail and changes in running speed while a vehicle passes through each curve section in both the up and the down train line sections between Namsunghyun and Chungdo, which represent the actual conditions of railway tracks.

An experimental study on the impingement spray of a common-rail diesel injector (1) -macroscopic characteristics- (커먼레일식 디젤 인젝터의 충돌 분무에 대한 실험적 연구(1) -거시적 분무 발달 과정-)

  • Lee, C.S.;Park, S.W.;Seo, S.H.
    • Journal of ILASS-Korea
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    • v.8 no.3
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    • pp.10-18
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    • 2003
  • In this paper, experimental study on the wan impingement spray of the common-rail diesel injector is performed. To examine the effect of various factors on the development of spray impinging on the wall, experiments were conducted at the various injection pressures. ambient pressures, wan distances from the injector tip, wall temperatures, and angles of wall inclination. The behaviors of the impingement spray ate visualized by using laser sheet methods and a ICCD camera. It is shown that the spray path penetration of the wall impingement spray increases with the increase of injection pressure, wall distance. wall temperature, wall angle. On the other hand the spray path penetration of the wan impingement spray decreases with the increase of ambient pressure.

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An experimental study on the impingement spray of a common-rail diesel injector (2) -atomization characteristics- (커먼레일식 디젤 인젝터의 충돌 분무에 대한 실험적 연구(2) -미립화 특성-)

  • Lee, C.S.;Park, S.W.;Seo, S.H.
    • Journal of ILASS-Korea
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    • v.8 no.3
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    • pp.19-26
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    • 2003
  • In this study, experimental study on atomization characteristics of the fuel spray impinging on the wall was at different wall distances and angles of wall inclination. The fuel injection system was composed based on the common rail system. and the injection signal was synchronized by the delay generator. The atomization characteristics of the injected spray were analyzed in terms of the SMD and velocities which were measured by using the phase Doppler particle analyzer system. It is revealed that the free spray is atomized actively above 50mm form the injector tip. In the cases of the impinged spray, the 5MD and velocity of the impinged spray are smaller than those of the free spray. The impinged spray has the maximum near the 35mm of the radial distance from the injector axis, and the atomization performance is enhanced with the decrease of the wall distance.

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