• Title, Summary, Keyword: 차륜/레일 접촉

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Wheel/Rail Contact Analysis with Consideration of Friction and Torque (마찰과 토크를 고려한 차륜/레일 접촉 해석)

  • Song, Ki-Seok;Han, Seung-Hee;Choi, Yeon-Sun
    • Journal of the Korean Society for Railway
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    • v.17 no.1
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    • pp.14-18
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    • 2014
  • Wheel/rail contact is a significant problem in railway dynamics. In this paper, the wheel/rail contact is examined analytically and numerically as a contact problem between two cylinders where torque and friction have effect. Furthermore, the contact of a real wheel and rail is investigated numerically where the normal and shear force act. This study demonstrates that the wheel/rail contact is a process that generates traction force through creep where rolling and sliding occurs simultaneously depending on the shape of the wheel and rail, and the friction coefficient between them.

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.

A Study on Numerical Analysis of Wheel-rail Contact Points (차륜과 레일 접촉위치의 수치해석에 관한 연구)

  • Kang, Ju-Seok
    • Journal of the Korean Society for Railway
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    • v.12 no.2
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    • pp.236-242
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    • 2009
  • This paper presents a numerical analysis method to determine flange contact at variable wheel positions. The shapes of the wheel and rail surface functions with surface parameters. The Newton-Rhapson method for wheel-rail contact can provide fast solutions, but may not yield true values at optimization process with the condition that minimum distance is zero can time-consuming. A compound method, combining the Newton-Rhapson methods the optimization process method is proposed to provide exact solutions efficiently.

A Three Dimensional Wheelset Dynamic Analysis considering Wheel-rail Two Point Contact (차륜-레일 2점 접촉을 고려한 3차원 윤축 동역학 해석)

  • Kang, Ju-Seok
    • Journal of the Korean Society for Railway
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    • v.15 no.1
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    • pp.1-8
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    • 2012
  • Wheelset dynamic analysis is a key element to determine the degree of accuracy of railway vehicle dynamics. In this study, a three-dimensional wheelset dynamic analysis is presented in such a way that the precise wheel-rail contact analysis in three-dimension is implemented into the dynamic equations of a wheelset. A numerical procedure that can be used for the analysis of a wheelset dynamics when the wheel-rail two point contact occurs in a cornering maneuver is developed. Numerical solutions of the constraint equations and the dynamics equations of a wheelset are achieved by using Runge-Kutta method. The proposed wheelset dynamic analysis is validated by comparison against results obtained from VI-RAIL analysis.

Simulation of Ratcheting in Wheel-Rail Contact (차륜-레일 구름접촉에 의한 라체팅 모델링)

  • Goo, Byeong-Choon
    • Journal of the Korean Society for Railway
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    • v.11 no.3
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    • pp.311-316
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    • 2008
  • Ratcheting is a cyclic accumulation of strain under a cyclic loading. It is a kind of mechanisms which generate cracks in rail steels. Though some experimental and numerical study has been performed, modeling of ratcheting is still a challenging problem. In this study, an elastic-plastic constitutive equation with non-linear kinematic hardening equation was applied. Contact stresses in wheel-rail were analyzed. Under the tangential stress of the contact stresses, a cyclic stress-strain relation was obtained by using the model. A constant ratcheting strain per cycle was accumulated.

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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