• Title/Summary/Keyword: Railway wheels

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A study on the prediction of wheel wear of railway rolling stock (철도차량 차륜마멸예측에 관한 연구)

  • Kang, Bu-Byoung;Chung, Heung-Chai
    • Proceedings of the KSME Conference
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    • 2003.04a
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    • pp.1270-1276
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    • 2003
  • This paper describes an analytical method for wheel wear prediction. The outputs from vehicle dynamic software are used to calculation the wheel wear. Two calculation examples are shown for a high-speed line and a conventional line. Through the comparison of two cases, we can see the wheel wear characteristics on the conventional line and the high-speed line. The conventional line has many curved tracks that cause severe wheel flange wear. The influences of curve radius on wheel wear are also described considering the operational performance of the high speed trainset. A method of calculation using contact patch work model is presented for determination of the evolution by wear railway wheels.

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The introduction of Speed Qualification Test as regulated by US CFR regarding railway running safety (철도차량 주행안전성관련 미국 연방법규(CFR)에 따른 본선 Speed Qualification Test 개요)

  • Lee, Kang-Wun
    • Proceedings of the KSR Conference
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    • 2010.06a
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    • pp.1-5
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    • 2010
  • The Hyundai Rotem company is due to be conducted the main line Speed Qualification Test as regulated by CFR for SEPTA EMU and SCRRA Bi-level coach project. The regulated test items per 49CFR213.345 are wheel/rail interaction forces and carbody/truck accelerations during running on main line. Therefore the special two sets of instrumented wheelset (IWS) per each project have been made for measuring the interaction forces between wheel and rail at four wheels of one truck during running on main line. In this paper, regarding Speed Qualification Test, the required test items and data analysis method per 49CFR213.345 and the preparation status of instrumented wheelsets (IWS) are introduced.

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An Assessment of Derailment Safety of Railway Vehicle depending on Curve Rail Condition (곡선부 선로 조건에 따른 차량의 탈선안전도평가)

  • Yoo, Hee-Sang;Park, Kwang-Soo;Lee, Hi-Sung
    • Proceedings of the KSR Conference
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    • 2007.11a
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    • pp.953-958
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    • 2007
  • To assess the derailment safety of the Samaeul Train, We developed a fleet analysis model and carried out sensitivity analysis of the variables related to derailment factors with ADAMS/Rail computing analysis method. Depending on the variation of the running speed in curve section, derailment coefficient and wheel load reduction rate are high at right side wheels in slow running speed section and low at left side wheel in high running speed. According to decreasing the radius of curve, derailment coefficient and wheel load decreasing rate are increased. Derailment coefficient is proportional to transition curve length and wheel load decreasing rate is constant. Cant value rising causes wheel load deduction rate rising.

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Computer Simulation of a Train Exiting a Tunnel through a Varying Crosswind

  • Krajnovic, S.
    • International Journal of Railway
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    • v.1 no.3
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    • pp.99-105
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    • 2008
  • Flow around an ICE2 high-speed train exiting a tunnel under the influence of a wind gust has been studied using numerical technique called detached eddy simulation. A wind gust boundary condition was derived to approximate previous experimental observations. The body of the train includes most important details including bogies, plugs, inter-car gaps and rotating wheels on the rail. The maximal yawing and rolling moments which possibly can cause a derailment or overturning were found to occur when approximately one third and one half of the train, respectively, has left the tunnel. These are explained by development of a strong vortex trailing along the upper leeward edge of the train. All aerodynamic forces and moments were monitored during the simulation and the underlying flow structures and mechanisms are explained.

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Design an Anti-Skid System using Fuzzy Model-Based Controller (퍼지 모델 기반 제어기를 이용한 안티 스키드 시스템의 설계)

  • Lee, Sung-Ho;Kim, Young-Guk;Kim, Seog-Won;Park, Jin-Bae
    • Proceedings of the KSR Conference
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    • 2006.11b
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    • pp.1276-1281
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    • 2006
  • In general, the wheel-skid prevention of braking system is very important in modern railway applications. This is because wheel-skid can lead to an increase in noise and vibration from wheels with flat points, as well as an increased braking distance. However conventional anti-skid control has problems because wheel adhension and skid characteristics are very difficult nonlinear systems and time consuming to accurately model. In this paper, we design a fuzzy controller using a model of relation between ahdension and braking force, we show that anti-skid fuzzy controller has a very good performance, performing better than the previous conventional controller.

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A Study on Wheel/Rail Rolling Noise (차륜/레일에 의한 전동음에 관한 연구)

  • 김재철;유원희;문경호;구동회
    • Proceedings of the KSR Conference
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    • 1999.11a
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    • pp.163-171
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    • 1999
  • The major source of railway noises is rolling noise caused by the interaction of the wheels and rails. This rolling noise is generated by the roughness of the wheel/rail surface on tangent tack in the absence of discontinuities, such as wheel flats or rail joints. These roughness cause relative vibrations of the wheel and rail at their contact area. The vibrations generated at the contact area are transmitted through the wheel and rail structures, exciting resonances of the wheel and travelling waves ill tile rail. Then these vibrations radiate noise to the wayside. In this paper, we predict the rolling noise radiated from radial/axial motion of the wheel and vertical/lateral motion of the rail using Remington's analytical model and then compare of the predicted sound pressure and measured one. Although there are some inaccuracy in our predication these results show in good agreement between 500 ㎐ and 3150㎐.

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Alternate Energy: Gravity Powered Rail Transportation Systems

  • Bojji, Rajaram
    • International Journal of Railway
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    • v.2 no.1
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    • pp.22-29
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    • 2009
  • A simple pendulum shows how efficient gravity is in recovering energy. Any transportation is a linearly oscillating system; every load gains kinetic energy, but loses the same to come to a stop. The Gravity Power Towers comprise of a set of vertically moving heavy masses coupled, through microprocessor controlled continuously variable gear and cable system, to a horizontally rolling unit on wheels either on rail or road. The heavy masses move vertically up against gravity gaining potential energy while stopping a moving mass; move down under gravity force, giving out energy. The Tower thus accelerates or sustains the speed a rolling unit, and while decelerating, recover the kinetic energy. Speeds of 360 kmph can be attained. Recovery of energy varies from 98.5-70%; the longer the distance between stops, the lesser is recovery. The economical, omnipresent & eternal Gravity Power grants energy independence to many a nation. Global warming reduces.

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Fault Diagnosis of a High-speed Railway Reduction Unit Using Analysis of Vibration Characteristics (고속철도차량 감속구동장치의 이상진단을 위한 진동특성분석)

  • Ji, Hae Young;Lee, Kang Ho;Kim, Jae Chul;Lee, Dong Hyoung;Moon, Kyoung Ho
    • Journal of the Korean Society for Railway
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    • v.16 no.1
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    • pp.26-31
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    • 2013
  • The reduction unit is one of the most important components for railway vehicles because the torque of the motor must be transmitted to the wheels of the vehicle by the reduction unit. The faults in the reduction units of high-speed trains are caused by damage such as gear, fatigue. These have serious impacts on safety of the train during operation. To address this development of a system for monitoring, fault diagnosis of the reduction unit is needed to keep the vehicle running safely. Before that can be accomplished, it is most important to understand the vibration characteristics of the reduction unit in a normal state. Vibration diagnosis technology using characteristic-analysis of vibration waveform and frequency is known to be the most effective method for fault diagnosis. In this paper, we analyzed the vibration characteristics of the reduction units two Korean high-speed trains (KTX and KTX II), under normal conditions, by two test methods (driving gear test, full-vehicle test).

A Study on the Measurement of New Concept for the Contact Force between Rail and Wheel (신개념의 레일.차륜간 접촉력 측정에 관한 연구)

  • Hong, Yong-Ki;You, Won-Hee;Lee, Hi-Sung
    • Journal of the Korean Society for Railway
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    • v.10 no.6
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    • pp.806-811
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    • 2007
  • The derailment is defined as phenomena in which the wheels run off the rail due to inordinate lateral force generated when wheel flange contacts with the rail. Derailment coefficient is typical standard assessing running safety and derailment. The traditional method measuring by strain gage adhered to wheels is very complicated and easy to fail. It also requires too much cost and higher measurement technique. Therefore it can hardly ensure safety because we can't confirm at which time we need to identify safety. In this paper, we principally researched the method measuring easily wheel load generated by contacts between wheel flange and the rail, and lateral force. Correlation of vibration and displacement which was related physical amounts of wheel load and lateral force, was investigated and analyzed through analysis, experiment and measurement. And it is presents new measurement method of derailment coefficient which can estimate derailment possibility only by movement of vibration and displacement, by which we understand the rate for acceleration and displacement to contribute wheel load and lateral force and compare actual data of wheel load and lateral force measured from wheel.

Coupled Vibration of Moving Mass-Elastically Supported Beam Considering the Contact Stiffness (An Ananlytical Model of the Contact Force Fluctuation between Wheel and Rail) (이동질량-탄성지지무한보의 연성진동해석 (차륜.레일간의 접촉력 변동의 해석모델))

  • ;曄道 佳明;須田 義大;大野 進一
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 1995.10a
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    • pp.197-200
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    • 1995
  • Corrugation of railway track can be caused by the various dynamic behavior of travelling wheels and track. In this paper, the coupled vibrations of travelling wheel and railway track are analyzed as the cause of corrugations. To analyze the coupled vibrations, the track supported by the sleepers and the traveling wheel are identified to the elastically supported infinite beam and the spring-mass system which runs at constant speed. The Hertzian contact spring is considered betwen the infinite beam and spring-mass system. The dynamic responses of elastically supported infinite beam and spring-mass system are calculated. The cause and development of rail corrugation are discussed in the view point of contact force fluctuation affected by the elastic supports and the corrugated surface profile of the track. By the obtained results, the possibilities of resonance are checked between the excitation by the corrugated surface profile and the natural frequency of contact spring-moving mass system. It may be thought to a development of railway corrugation.

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