• International Journal of Railway
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• 제8권1호
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• pp.1-4
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• 2015

An accurate measurement of the train-track interaction forces is important for track performance evaluation. In the field calibration test as a wheel load measurement process, the calibration system creates a different boundary condition in comparison with that in the train wheel passage. This study aims to evaluate a reliability of the field calibration test in the process of wheel load measurement. Finite element models were developed to compare the deformed shapes, bending moment and shear force profiles on the rail section. The analysis results revealed that the deformed shapes and their associated bending moment profiles on the rail are significantly different in two numerical simulations of the calibration test and the train wheel load passage. However, the shear stress profile on the rail section of the strain gauge installation in the field was almost identical, which may imply that the current calibration test is sufficiently reliable.

• 한국산학기술학회논문지
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• 제13권5호
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• pp.1954-1962
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• 2012

최근 유럽과 아시아 사이의 물류 증가는 철도수송에 있어서 사회적/경제적으로 좋은 기회이며, 동시에 커다란 도전이 될 수 있다. 유라시아 대륙에는 다양한 궤간이 존재하고 있다. 이러한 궤간의 차이는 철도에 의한 화물수송시 장애요인중의 하나이다. 궤간 차이를 극복하기 위한 방법은 수송 화물의 유형에 따라 달라질 수 있으며, 국경 지점에 보관 창고 및 환적 설비와 같은 넓은 기반 시설과 많은 운영 인력수요와 같은 철도 수송 시스템의 운영에 많은 영향을 준다. 따라서 철도 수송 시스템의 효율성은 복잡한 하역 및 교환 기술에 관련된 궤간 극복 방법에 매우 의존한다. 본 논문은 궤간 극복 방법에 대한 기술적 평가를 기반으로 수송 시나리오의 효율성을 검토하고, 각 시나리오의 운영에서 요구되는 기술적 요소들을 기술하였다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 춘계학술대회 논문집
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• pp.1142-1147
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• 2011

The rail cant produces a wider bearing area between the wheel and the rail by moving the wheel-rail contact area away from the gauge towards the centre of the railhead, thus improving the wear pattern of the railhead and wheel treads. It is essential to keep the rail cant within the allowable range to ensure optimum track geometry. Neglecting the rail cant geometrical parameters in a track quality evaluation can cause safety of railway vehicle and serviceability problems. In this paper, we examined the effect of the rail cant in general geometry state of the railway track using VI-Rail and analyzed running safety when the railway vehicle passing through curves depending on change of the rail cant and running speed.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 정기총회 및 추계학술대회 논문집
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• pp.1922-1928
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• 2011

The rail inclination produces a wider bearing area between the wheel and the rail by moving the wheel rail contact area away from the gauge towards the centre of the railhead, thus improving the wear pattern of the railhead and wheel treads. It is essential to keep the rail inclination within the allowable range to ensure optimum track geometry. Neglecting the rail inclination geometrical parameters in a track quality evaluation can cause safety of railway vehicle and serviceability problems. In this paper, we examined the effect of the rail inclination in general geometry state of the railway track using VI-Rail and analyzed running safety when the railway vehicle passing through curves depending on change of the rail inclination and running speed.

• 한국철도학회논문집
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• 제9권4호
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• pp.461-466
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• 2006

In order to transport cargo rapidly and safely from the trans-Korean railway to the trans-Siberian railway having a different gauge, a gauge-changeable freight wagon can be used. Because the wagon is expected to run in South Korea, North Korea and Russia, it should have good dynamic performance in these railways. In this paper, the dynamic characteristics of a gauge-changeable freight wagon was analyzed numerically using ADAMS/Rail in each condition of the railways having different gauges and rail profiles. The wagon makes use of load sensitive friction damping and has highly nonlinear behaviour, which is modeled in detail as the full nonlinear dynamic model. It is shown that the running behaviour of the wagon is sensitive to changes in the rail gauge and profiles, however the assessment quantities from the point of view of safety, track fatigue and running behaviour are less than the limit valves.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 추계학술대회 논문집
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• pp.278-282
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• 2007

The riding comfort and the durability of train are effected by the rail irregularities such as track gauge, superelevation, alignment, longitudinal level, twist, cant and cross level. Inspection and estimation of irregularities are very important to maintain the rail condition. Generally, the EM120 has been utilized to measure the rail irregularities once a month in Korea. However, the EM120 can be operated at night time only, because the inspection speed of EM120 is much slower than the speed of high-speed trains. Also, the EM120 is too slow to inspect effectively for the whole commercial line. Therefore, we have mounted the track inspection system on the High-Speed Rolling Stock 350 eXperimental (HSR350X) and measured the rail irregularities to confirm the condition of a rail while running 300km/h. In this paper, the track inspection system mounted on HSR350X is mainly considered, and the measured results through test run are introduced.

• International Journal of Railway
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• 제2권2호
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• pp.43-49
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• 2009

Wear and rolling contact fatigue (RCF) defects are most important causes of rail damage, and often interaction competitive at present railway track. Head check is one of rolling contact fatigue (RCF) defects, and generally occurs in mild circular curves and transition curves that are set at both ends of sharp circular curves. Wear tends to limit the crack growth of head checks by removing the material from the RCF surface. In order to clarify the conditions of the occurrence and growth of head checks, the authors measured the interacting forces between wheels and rails and the angle of attack of wheelset, and carried out contact analyses using the actual profile data of wheels and rails. The effects of the lateral force, the contact geometry, and the wear rate at rail gauge comer on the formation of head checks were also analyzed by using the worn profiles of actual wheels and rails and the data obtained by a track inspection car. Some specific range of wear rate at the gauge comer was identified as having close relation with occurrence of head checks.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2004년도 춘계학술대회 논문집
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• pp.1065-1070
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• 2004

When the track designer analyze the track structure uses many known & unknown parameters. Unknown parameters, equivalent rail support spring factor, unit rail support spring factor, track damping coefficient, should be assumed. Known parameters are section properties (area, section factor, etc), material properties(modulus of elasticity, mass, etc) and track conditions(wheel load, loading conditions, gauge, etc.). In the assumption of track design parameters, some parameters can be overestimated or under estimated. The purpose of this study is to verify design parameters used in track design, in the way of experimental measurements. Data of displacements, banding stresses, loads, accelerations are measurable at track site. From these data, unknown parameters are derived. Compare these assumed and derived parameters, estimate the entire track stability.

• 한국강구조학회 논문집
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• 제17권5호통권78호
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• pp.519-526
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• 2005

혹서기에 레일의 높은 온도 상승(최대 $60^{\circ}C$)으로 인해 장대레일 궤도에는 매우 큰 압축력이 작용하게 된다. 이러한 압축력은 장대레일 궤도의 좌굴을 발생시키기도 한다. 본 연구에서는 장대레일 궤도의 좌굴에 영향을 미치는 많은 요소들 중에서 도상 횡저항력 그리고 도상 종저항력이 궤도 좌굴에 미치는 영향을 파악하기 위한 연구를 수행하였다. 또한 줄틀림과 궤간틀림의 민감도를 분석하였다.

• 한국철도학회논문집
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• 제15권4호
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• pp.334-342
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• 2012

유라시아 대륙에는 다양한 궤간이 존재하고 있다. 이런 차이는 서로 다른 궤간의 접속점에서 화물을 환적하거나 혹은 차량 운행 조립체를 교환하여야 하는 등 철도수송 시스템의 운영에 많은 영향을 준다. 그러므로, 철도 수송 시스템의 효율성은 복잡한 하역 및 교환 기술에 관련된 궤간 극복 방법에 매우 의존한다. 본 논문은 대륙철도 연결을 통한 국제 화물 수송에서 발생되는 1520/1435mm 궤간차이를 극복하기 위한 철도 수송 시스템의 효율성 평가를 목적으로 하였다. 먼저 궤간 변경지점에서 현재 수행되고 있는 수송 시스템을 간략하게 설명하고, 교환 기술에 대한 사전 분석을 수행하였다. LCC 모델에 기초하여 리프트에 의한 대차교환 방식과 자동궤간가변 시스템의 효율성을 비교평가 하였다.