• 한국철도학회논문집
• /
• 제14권6호
• /
• pp.535-544
• /
• 2011

레일 표면 결함이 발생할 경우 매우 높은 충격하중이 발생하여 레일 피로 진전 또는 레일 파단에 이를 수 있고 레일이 파단될 경우 열차탈선 등 대형 사고가 발생할 수 있으므로 레일 결함부에 대한 관리기준의 정립이 매우 중요하다. 본 연구에서는 차량-궤도 동적 상호작용 해석 프로그램을 이용하여, 실제 고속철도 자갈궤도에서 결함이 발생한 43개 지점에서 측정된 레일요철을 입력값으로 하여, 요철 깊이에 따른 충격 윤중과 레일 휨응력을 산정하였다. 궤도틀림을 감안하여 윤중 및 레일 휨응력의 한계값을 설정하고, 해석결과로부터 얻은 윤중 및 레일 휨응력 최대값과 결함 깊이 및 폭과의 상관관계를 분석함으로써 레일 표면 결함부에 대한 관리기준을 제시하였다. 분석 결과, 허용할 수 있는 요철 깊이는 충격 윤중에 의하여 발생할 수 있는 레일 두부의 소성 변형을 방지하기 위하여 관리되어야 하며, 엄격한 조건을 평가할 경우 그 값은 0.2mm 정도가 적당함을 알 수 있었다.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2006년도 춘계학술대회 논문집
• /
• pp.41-42
• /
• 2006

The important factor to evaluate the running safety of a railway vehicle would be the interaction force between wheel and rail(derailment coefficient), for which is one of important factors to check the running safety of a railway vehicle that may cause a tragic accident. In this paper, analysis of coupling term between vertical load and lateral load for install load cell to wheel-set. This result is going to be utilized in formality that verify running safety of tilting vehicles.

• Steel and Composite Structures
• /
• 제37권3호
• /
• pp.291-306
• /
• 2020

The noise from the elevated lines of rail transit has become a growing problem. This paper presents a new method for the rapid prediction of the structure-borne noise from steel or composite bridges, based on the receptance and Statistical Energy Analysis (SEA), which is essential to the study of the generation mechanism and the design of a low-noise bridge. First, the vertical track-bridge coupled vibration equations in the frequency domain are constructed by simplifying the rail and the bridge as an infinite Timoshenko beam and a finite Euler-Bernoulli beam respectively. Second, all wheel/rail forces acting upon the track are computed by taking a moving wheel-rail roughness spectrum as the excitation to the train-track-bridge system. The displacements of rail and bridge are obtained by substituting wheel/rail forces into the track-bridge coupled vibration equations, and all spring forces on the bridge are calculated by multiplying the stiffness by the deformation of each spring. Then, the input power to the bridge in the SEA model is derived from spring forces and the bridge receptance. The vibration response of the bridge is derived from the solution to the power balance equations of the bridge, and then the structure-borne noise from the bridge is obtained. Finally, a tri-span continuous steel-concrete composite bridge is taken as a numerical example, and the theoretical calculations in terms of the vibration and noise induced by a passing train agree well with the field measurements, verifying the method. The influence of various factors on wheel/rail and spring forces is investigated to simplify the train-track-bridge interaction calculation for predicting the vibration and noise from steel or composite bridges.

• 대한기계학회논문집A
• /
• 제38권7호
• /
• pp.699-709
• /
• 2014

본 논문에서는 단일윤축 탈선이론을 적용하여 측풍 조건에서 주행 중인 철도차량의 탈선을 예측하는 방법을 제시하였다. 기존 연구에서는 측풍에 의한 탈선은 모두 전복탈선이라고 가정하여 탈선 예측 이론을 개발하였다. 그러나 이러한 가정은 특수한 주행조건하에서 차륜 타고오름 탈선의 가능성을 무시하고 있다. 또 기존의 측풍 탈선 이론은 주행 중 발생하는 차륜-궤도 사이의 마찰력, 동적상호작용과 같은 주행조건이 탈선에 미치는 영향을 고려할 수 없었다. 본 논문의 방법은 차륜-궤도 사이의 동적 영향, 횡가속도 및 켄트 영향, 측풍 영향 등을 동시에 고려할 수 있었다. 본 이론의 결과를 기존 이론 및 시뮬레이션 결과와 비교하여 타당성을 검증하였다.

• 한국철도학회:학술대회논문집
• /
• 한국철도학회 1999년도 춘계학술대회 논문집
• /
• pp.398-405
• /
• 1999

Large dynamic forces are generated between wheel and rail due to rail surface irregularities at rail welded part. The effects become more and more significant in the view of the present tendency to train speed increasing. Therefore, the purpose of this paper is to derive useful guides for the effective and economical maintenance of rail welded parts through the wheel and rail interaction analyses. A typical shape for the irregularity of rail welded part is assumed to make the analysis quantitative. The effects of the irregularity depth and train speed on the train and track behaviors are investigated.

• 한국철도학회:학술대회논문집
• /
• 한국철도학회 2004년도 춘계학술대회 논문집
• /
• pp.789-797
• /
• 2004

The wear and defects on the wheel tread are caused by the interface between wheel and rail, the suspension system on bogie, the track condition and etc, which are interacted with complex mechanism. Because of the difficulty of analysis of wheel and rail interaction, the measuring data are necessary for improvement of wheel design and maintenance of train. On this case study, the pattern of wheel wears and defects are presented and lifetime of wheel and the reprofiling period are estimated on a basis of the measured results.

• 한국철도학회논문집
• /
• 제18권4호
• /
• pp.363-373
• /
• 2015

본 논문은 휠-레일 사이의 접촉메카니즘을 이용하여 휠과 레일 사이의 분리를 허용하고, 횡 방향으로의 플랜지 접촉을 허용하는 비선형 동적 상호작용 해석법을 제시하는데 그 목적이 있다. 먼저 휠-레일 사이의 상호작용력을 압축스프링으로 이상화한 스프링 모델과 휠-레일 사이가 항상 접촉하고 있다는 가정하에 적용되는 non-jump모델에 대해 간략히 소개한 후 접촉메카니즘을 이용한 비선형 접촉모델에 대해 기술한다. 위 3가지 모델에 대한 수치해석 결과를 비교하기 위하여, 단순보 위를 지나가는 KTX열차에 대해 휠-레일 사이의 상호작용력을 각각 적용하여 동적 응답을 비교 분석하였다. 또한 특정 조건하에 플랜지 접촉을 강제 발생시켜 횡방향 응답의 변화를 살펴보았다.

• 한국안전학회지
• /
• 제33권2호
• /
• pp.145-151
• /
• 2018

In this study, the track-bridge interaction analysis was performed using an analytical model considering the track structure, thereby taking into account the linear conditions (R=650 m, cant variation $160{\pm}60mm$) and the dynamic characteristics of the bridge. As a result of the study, the allowable speed on the example bridge considered was calculated at 200 km/h based on vertical deflection, vertical acceleration, and irregularity in longitudinal level, but was also evaluated at 170km/h based on the coefficient of derailment, wheel load reduction, and lateral displacement of the rail head. It is considered desirable to set the speed 170km/h to the speed limit in order to secure the safety of both the bridge and the track. It is judged that there will be no problems with ensuring rail protection and train stability in the speed band.

• 한국소음진동공학회논문집
• /
• 제13권1호
• /
• pp.56-62
• /
• 2003

The major noise source for the conventional train is the rolling noise caused by the interaction of the wheels and rails during the train passage on the tangent track. In order to control the rolling noise, the noise radiated from wheels, rails and sleepers should be analyzed and predicted. In this paper, a prediction method of wheel/rail rolling noise generated by the roughness of the wheel/rail surface is described, where the method is considering the effect of noise radiated by sleepers and the effect of ground. The method is applied to the Korean railway system, and the sound pressure level (SPL) predicted by the proposed method is compared with the measured SPL. Overall. the result shows good agreement between the predicted and measured values.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2004년도 추계학술대회 논문집
• /
• pp.119-122
• /
• 2004

Since a derailment of rolling stocks results in huge losses in properties and lives, the measurement of a derailment coefficient is a very important test item to estimate the running safety of rolling stocks. For a measurement of the derailment measurement of forces between the wheel and rail a measuring wheel-set should be made first. The process to make a measuring wheel-set has some stages for correct measurement. They are as follows; a finite element analysis of a wheel to find a position of holes at which vertical force shall be measured, a finite element analysis for the position of strain gauges.