• 제목, 요약, 키워드: Rail stress

검색결과 251건 처리시간 0.056초

고속철도 레일의 피로수명에 영향을 미치는 매개변수 연구 (The Parametric Study Effecting on the Fatigue Life of Rail on High Speed Railway)

  • 박용걸;강윤석;고동춘;성덕룡
    • 한국철도학회논문집
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    • v.12 no.3
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    • pp.396-404
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    • 2009
  • 고속열차의 개발과 함께 구름접촉피로에 의한 레일의 피로균열 및 피로파괴에 대한 연구를 통해 주행안정성을 확보할 수 있는 방안 마련이 필요하다. 따라서 본 연구에서는 Eisenmann의 근사계산식(실용식)을 이용하여 속도, 차륜반경, 궤도지지강성, 침목간격, 축중, 궤도품질에 따른 레일내부 발생응력을 검토하였다. 또한, 유한요소해석을 통해 초기균열의 길이 및 각도, 온도에 따라 레일두부에서 발생하는 전단응력을 검토하여 모드별 응력확대계수를 도출하였다. 이로써 고속철도 레일의 피로수명에 영향을 미치는 주요인자들을 확인하였다.

레일 연마의 품질보증과 최적 연마 전략 (Quality Assurance of Rail grinding and Optimize grinding Strategy)

  • 이학규;이종수;이기승;조선규
    • 한국철도학회:학술대회논문집
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    • pp.283-289
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    • 2004
  • Rail defects(Corrugation, shelling, etc) are occurred by the Rail with wheel contact stress. Rail grinding is maintaining of optimal rail profile to use special rail grinding machine to remove rail defect. The benefits of rail grinding enforcement, improve track safety, improve track steering and rail life, improve ride comfort and reduce noise, etc. Actually when rail grinding plan apply to field track, we should consider a lot of function before determination, such as grinding method, grinding pass number, removing metal volume, etc. because each track has various characteristics. Therefore it is important that the determination of rail grinding strategy for optimum and economic before enforcement.

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궤도강성변화구간의 레일압력 분포에 관한 연구 (Rail Pressure on the Changing Point of Track Modulus)

  • 이기승;천진녕;김성칠;권순섭
    • 한국철도학회:학술대회논문집
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    • pp.228-233
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    • 2002
  • The transition between bridge or tunnel and plain track has different rail pressure and distributed stress on formation. This paper shows distribution of rail pressure on transition at which spring stiffness are changed. By this study, it is revealed that the changing into relatively high stiffness causes increased rail pressure visibly and draw up dynamic track force. A medium stiffness structure and reinforced rail could be effective for reducing track force on the transition.

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도시철도에서 열차제동하중이 레일표면 열화에 미치는 영향 (An Effect on Braking Force for Degradation of Rail Surface in the Urban Railway)

  • 양태경;오희완;성덕룡;최진유;박용걸
    • 한국철도학회:학술대회논문집
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    • pp.2135-2146
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    • 2011
  • The rail surface irregularity is generated severely by train braking effect in the section of station. The braking force increases slip rate and friction factors caused by wheel-rail contact points. It brings rail surface irregularity as well. In this study, interactions between wheel and rail were investigated using rolling contact fatigue theory and mechanism of rail degradation through fracture mechanics. For the more, the Von-Mises stress occurred on the rail due to the interaction between wheel and rail was analyzed using 3-D finite element method. The amounts of surface irregularity of rail were measured according to accumulated passing tonnage in urban railway in fields. Therefore, the maintenance of rail should be separated by running and braking sections to prevent RCF defects.

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PC Girder 및 Steel Girder가 자기부상열차 직선 궤도의 응력해석에 미치는 영향 (Influence of PC Girder and Steel Girder on Stress Analysis for Maglev straight Track)

  • 노규석;이종민;조흥제
    • 한국정밀공학회:학술대회논문집
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    • pp.653-656
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    • 2005
  • Maglev straight track composes of guide rail, back iron, power rail and girder. Above all, girder is important. So this study analyzes the influence of PC girder and steel girder on stress analysis fur Maglev straight track, and to study the stress analysis the finite element method is utilized.

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전단변형과 시간변화 이동자기력을 고려한 레일의 강제진동모델링 (Forced Vibration Modeling of Rail Considering Shear Deformation and Moving Magnetic Load)

  • 김준수;김성종;이혁;하성규;이영현
    • 대한기계학회논문집A
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    • v.37 no.12
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    • pp.1547-1557
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    • 2013
  • 시간변화 이동자기력이 작용하는 레일의 변형을 티모센코 보 이론(Timoshenko beam theory)로 가정하였으며, 보의 진동특성에 영향을 미치는 탄성체기초의 감쇠효과 및 강성을 고려하였다. 푸리에 급수와 수치해석을 이용해 강제진동모델의 동적응답과 임계속도를 구하였다. 레일의 진동모델을 유한요소 해석 및 오일러 보 이론(Euler beam theory)과 비교 검증하였다. 강제진동모델을 이용하여 레일의 영구변형을 예측하였으며, 실험결과 레일표면의 영구변형 및 마모를 확인하였다. 보의 설계변수인 레일의 형상, 재료, 탄성체 기초의 감쇠효과 및 강성이 레일의 임계속도 및 레일의 처짐, 축 방향 응력, 전단 응력에 미치는 영향에 대한 매개변수적 연구를 진행하였으며, 보의 설계방향을 얻을 수 있었다.

지반-구조물 상호작용을 고려한 교량상 장대레일의 비선형 지진응답해석 (Nonlinear earthquake response analysis of CWR on bridge considering soil-structure interaction.)

  • 신한철;조선규;양신추;최준성
    • 한국철도학회:학술대회논문집
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    • pp.733-738
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    • 2004
  • Recently continuous welded rail is generally used to ensure running performances and to overcome the problems such as structural vulnerability and fastener damage at the rail expansion joint. Though the use of continuous welded rail on bridge has the advantage of decreasing the vibration and damage of rail, it still the risk of buckling and breaking of rail due to change of temperature, starting and/or breaking force, axial stress concentration and so on. So, VIC code and many methods has been developed by researchers considering rail-bridge interaction. Although there are many research concerning stability of continuous welded rail about temperature change on bridge and starting and/or breaking force, the study of continuous welded mil for earthquake load is still unsufficient. In this study, the nonlinear seismic response analysis of continuous welded rail on bridge considering soil-structure interaction, geotechnical characteristic of foundation and earthquake isolation equipment has been performed to examine the stability of continuous welded rail.

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레일 매립궤도의 특성과 노면철도에 적용 가능성에 관한 연구 (Embedded Rail Track on the LRT(Tram))

  • 이기승;김성칠;백진기;고동춘
    • 한국철도학회:학술대회논문집
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    • pp.394-399
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    • 2005
  • Embedded rail track can be described as a track structure that is completely covered within pavement. Rail supported continually on a concrete slab or concrete plinth. There are many kinds of types such as non-resilient track and resilient track, super resilient embedded track (floating slab). Embedded rail track is generally the standard for light rail transit routes because this track has many advantages such as reducing noise, maintenance cost and weight of track. In this paper, decision of track profile is restricted by the optimum levels of the flangeway and the gap between the rail head and the pavement surface of depressing tread zone. By result of this study, embedded rail track can reduce corrosion of rail, internal stress and rail deflection.

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차륜/레일 접촉에 의한 차륜의 잔류응력 평가 (Evaluation of Residual Stress of railway wheel by rolling contact)

  • 서정원;구병춘;정흥채
    • 한국철도학회논문집
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    • v.6 no.2
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    • pp.142-148
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    • 2003
  • A wheel and axle failure can cause a derailment with its attendant loss of life and property. The service conditions of railway vehicles have become severe in recent years due to a general increase in operating speeds. Damages of railway wheel are a spatting by wheel/rail contact and thermal crack by braking heat etc. One of the main source of damage is a residual stress. therefore it is important to evaluate exactly. A Residual stress of wheel is formed at the process of heat treatment when manufacturing. it is changed by contact stress developed by wheel/rail contact. Distributions of residual stress vary according to a magnitude of wheel load, a magnitude of friction when acceleration and deceleration. The objective of this paper is to estimate the influence of wheel motion on the residual stress distribution in the vicinity of the running surface.

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

  • 구병춘
    • 한국철도학회논문집
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    • v.11 no.3
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    • pp.311-316
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    • 2008
  • 일정한 크기의 응력이 반복적으로 작용할 때 매 사이클마다 변형이 증가하는 현상을 라체팅이라고 한다. 라체팅은 레일이나 차륜의 균열발생 기구의 하나이지만 실험적, 이론적 측면에서 아직 많은 연구를 필요로 하는 분야이다. 레일의 경우 접선력 방향으로 소성변형이 축적되는 것으로 알려져 있다. 본 연구에서는 차륜-레일의 구름 접촉에서 발생하는 응력의 이론해에 대해 살펴보고, 라체팅을 모델링 할 수 있는 비선형 이동 경화법칙을 사용하는 탄소성 구성방정식을 적용하여 라체팅 현상을 모델링 하였다. 일정 크기의 접촉력이 반복적으로 작용할 때 매 사이클마다 일정 크기의 소성변형이 발생하였다.