• Title, Summary, Keyword: 차륜 마모

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An Analysis on the Influence of Wheel Flange Wear on the Vibration of EMU (전동차 차륜답면 마모에 따른 차량 진동 특성 영향 분석)

  • Hur, Hyun-Moo;Park, Joon-Hyuk;You, Won-Hee;Park, Tae-Won;Yang, Chil-Sig
    • Journal of the Korean Society for Railway
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    • v.12 no.2
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    • pp.230-235
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    • 2009
  • We have conducted an experimental study to analyze characteristics of the wheel profile wear and an influence of the wheel flange wear on the vehicle's vibration characteristics. In experiment with EMU, wheel profile wear is severe at the beginning of the commercial operation. In this stage, the variations of the wheel dimension parameters and equivalent conicity is changed rapidly. Along with a mileage of the test vehicle, the wear of the wheel flange is increased and also the vibration level of the car-body is increased. The peak-peak mean value of the body vibration is estimated as good level, but the level is approached at the limit of the good level as mileage increases. Especially, the peak-peak maximum value of the body vibration shows the distinct increase of vibration level.

A Study on the Wear Characteristics of R/S Passing through Curves (곡선부 주행 차량의 마모특성에 관한 연구)

  • Lee, Hi-Sung
    • Journal of the Korean Society for Railway
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    • v.10 no.6
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    • pp.772-778
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    • 2007
  • For the wear characteristics assessment of Saemaul train passing through curves, an analysis model for multi-car system has been developed. By using this model and ADAMS/Rail, sensitivity analyses have been conducted for the wear characteristics by changing the related parameters. At low speed, the wear number and the sliding mean of right wheel showed higher than left wheel, while those of left wheel showed higher than right wheel at high speed. According to the decrease of curve radius, the wear number and the sliding mean were increased. When the length of transition curve was increased, the wear number and the sliding mean was increased. And according to increase of cant, the wear number and the sliding mean were increased.

Analysis of Rail Wear Rate according to Wheel/Rail Contact Pressure on Curved Track (곡선부 차륜/레일 접촉압력에 따른 레일마모진전 경향 분석)

  • Sung, Deok-Yong
    • Journal of the Korean Society for Railway
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    • v.20 no.4
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    • pp.512-520
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    • 2017
  • On a typical railway, trains travel using the friction between the wheel and the rail. Contact pressure is generated between the wheel and the rail, and the magnitude of the contact pressure changes depending on the weight, speed, wheel-set hunting, and contact point of the vehicle. In this study, the contact characteristics were analyzed through the finite element analysis for the wheel/rail system on curved track, and fatigue damage and wear rate of wheel/rail according to contact pressure were analyzed through rolling contact fatigue test. Results indicate that, general and heat treated rails showed higher wear rate than wheels, and general and heat treated rail wear rate increased rapidly over a certain number of repetitions. In addition, the general rail wear rate was about 7 ~ 15% higher than that of the heat treated rail, and a regression equation for the rail wear rate with the contact pressure in the contact pressure range of 900 ~ 1,500 MPa was presented.

Rail surface inclined crack growth analysis considering periodic grinding (주기적 마모를 고려한 레일표면 경사균열 진전해석)

  • Jun, Hyun-Kyu;You, Won-Hee;Ham, Young-Sam
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • pp.493-498
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    • 2011
  • 구름접촉피로는 차륜과 레일의 반복적인 접촉으로 인하여 발생하는 표면손상현상으로 점차 증가하는 레일손상 중 하나이다. 접촉마모 및 주기적 그라인딩보다 균열의 성장속도가 더 빨라 균열진전이 시작되는 최소균열크기(minimum crack size for growth)는 레일의 파괴방지 및 유효한 유지보수전략을 수립하는데 기초자료로 활용된다. 본 연구에서는 최소균열크기를 예측하기 위하여 차륜레일의 접촉에 영향을 미치는 주요 파라미터를 변화시키면서 최소균열크기의 변화를 살펴보았다. 이를 위하여 Fletcher와 Kapoor의 "2.5D"모델을 적용한 시뮬레이션 소프트웨어를 개발하였으며, 최대접촉하중(1174MPa), 표면마찰계수(0.1, 0.2, 0.3 and 0.4), 잔류응력, 접촉에 의한 표면마모(1.0nm/cycle), 그라인딩량(0.3mm/10MGT)을 파라미터로 하여 해석을 수행하였다. 해석결과 최소균열크기는 해석조건에 따라 1.41-1.95mm로 계산되었다.

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Dynamic Analysis of Railway Vehicle with Wheel Unbalance (차륜 불평형이 있는 철도차량의 동적해석)

  • Lee, Seung Il;Choi, Yeon-Sun
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.37 no.11
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    • pp.1387-1395
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    • 2013
  • When the center of mass of a railway wheel is not aligned with the geometrical center of the wheel axis, wheel unbalance occurs. If a railway vehicle runs without removing the wheel unbalance, vibrations will be produced. This will also cause wear and damage of the axle bearing. In this study, dynamic analysis of a railway vehicle with wheel unbalance was conducted to examine the reduction in critical speed and the resonance of the car-body and the effect on the magnitude of wheel unbalance was examined. In addition, the calculation of the car-body vibration owing to static and dynamic unbalance in the railway wheel shows that two-plane balancing is necessary.

Characteristics of Wheel Tread for Urban Train Based on Contact Positions (접촉위치에 따른 도시철도 차륜 답면의 특성 변화)

  • Kwon, Seok-Jin;Noh, Hang-Nak;Nam, Yoon-Su;Seo, Jung-Won;Lee, Dong-Hyung
    • Journal of the Korean Society for Railway
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    • v.11 no.6
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    • pp.524-529
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    • 2008
  • The damaged wheel in railway vehicle would cause a poor ride comfort, a rise in the maintenance cost and even fracture of the wheel, which then leads to a tremendous social and economical cost. The defect initiation and crack propagation in wheel may result in the damage of the railway vehicle or derailment. Therefore, it is important to evaluate the characteristics of the wheel tread. In the present paper, the characteristics of wheel tread based on contact positions, running distance and brake pattern are evaluated. The result shows that the damaged wheel tread is remarkably depended on the contact positions between wheel and rail.

Analysis of Vehicle Dynamic Performance after Wheel Reprofiling (차륜 전삭에 따른 차량 동적성능 분석)

  • Hur, Hyunmoo;Ahn, Dahoon;Youn, Suksoon;Choi, Yongwoon
    • Journal of the Korean Society for Railway
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    • v.19 no.5
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    • pp.565-575
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    • 2016
  • Wheel reprofiling is frequently conducted to remove faults such as flange wear, flat areas, and cracks that occur in railway vehicle operation. We analyzed the dynamic performances of a vehicle before and after wheel reprofiling to grasp the influence of reprofiling on the dynamic behavior of the vehicle. We measured the wheel profile of the test vehicle and conducted a running test to analyze the vibration and comfort characteristics of the test vehicle. The result of the test indicated that vibration of the test vehicle after wheel reprofiling was reduced compared to that before wheel reprofiling. And, comfort level of the test vehicle after wheel reprofiling was improved by about 3dB laterally and vertically. Consequently, the positive effect of wheel reprofiling on the dynamic performance of vehicle was verified.