• Title, Summary, Keyword: 레일

Search Result 5,351, Processing Time 0.065 seconds

Development of the 3D Rail Profile Reconstruction Method Improving the Measurement Accuracy of Railway Abrasion (레일 마모도의 측정 정밀도 향상을 위한 3차원 레일 프로파일 재구성 기법 개발)

  • Ahn, Sung-Hyuk;Kim, Man-Cheol
    • Proceedings of the KSR Conference
    • /
    • /
    • pp.533-539
    • /
    • 2010
  • The The contactless railway abrasion measurement system have to satisfy two conditions to increase the measurement accuracy as follows. The laser region projected on the rail have to be extracted without the geometrical distortion. The mapping of the acquired laser region data on the rail profile have to be matched with the cross section of rail, exactly. But, the conventional railway abrasion measurement system is required the post image processing with a camera model and a perspective transform for the exact mapping between the cross section of rail and the coordinate data extracted from a line laser region or the raw image obtained from a camera because the image captured from the camera has an oblique viewpoint. So, the measured rail profile data had limits to the measurement accuracy because of a discontinuity point. In this Paper, we propose the 3D rail profile reconstruction method to increase the accuracy of the railway abrasion measurement system applying the modified camera model and perspective transform to the image obtained from the bidirectional rail.

  • PDF

장대레일 축력해석

  • 강동욱;정근영
    • Proceedings of the Computational Structural Engineering Institute Conference
    • /
    • /
    • pp.631-645
    • /
    • 2002
  • ●정의 정척레일을 연속 용접하여 1개의 레일길이를 200m 이상으로 부설한 레일 ●장대레일화 - 차량 시동/제동하중에 의한 교축방향 수평력 작용 - 기존 : 수평력 배분을 위해 단순교로 시공(레일 이음매) - 현재 : 장대레일화 ● 장점 -유지보수비 절감 -승차감 향상(충격/소음 저감) -고속화 및 운행 안전성 향상 ●단점 -큰 레일 축력(파단/좌굴) -교량부, 급곡선부, 분기부 - 장대레일 종하중(하부구조) (중략)

  • PDF

레일을 중심으로 한 철도의 기원 및 발전 과정(II)

  • 서사범
    • Journal of the Korean Society for Railway
    • /
    • v.2 no.4
    • /
    • pp.5-16
    • /
    • 1999
  • 1830년에는 영국의 Clarence가 16.4 kg/m의 압연레일을 제작하였다. 이것은 그후 영국에서 널리 사용되었던 우두(牛頭)레일(bull-head rail)이라 부르는 형의 원조라고도 한다. 1837년에는 영국의 J. Locke가 그림 9와 같은 쌍두(雙頭)레일(double head rail)을 고안하였다. 쌍두레일은 두부와 저부가 같은 단면으로 하여 레일 교환시에 상하를 전도하여 다시 사용할 목적이 있었다. 그러나, 목적에 반하여 경년(經年)과 함께 레일 하부의 레일을 지지하는 체어(chair)부에 접하는 개소가 손상하기 때문에 저부를 주행면으로 사용하기에는 지장이 생기기 쉽고, 이때문에 영국에서는 1844년에 고안된 우두레일로 바뀌었다. 이것은 두부와 저부의 단면이 대칭적이지 않고 두부가 약간 크다. 이 레일은 제조상 비교적 압연이 용이하고 냉각이 보다 빠르기 때문에 똑바른 레일을 얻기가 쉽지만, 레일의 횡방향 안정성 등에 문제가 있다. (중략)

  • PDF

Investigation of the Maintenance Criteria for the Rail Surface Defects in High-Speed Railways (고속철도 레일 표면 결함 관리기준에 관한 연구)

  • Yang, Sin-Chu;Jang, Seung-Yup
    • Journal of the Korean Society for Railway
    • /
    • v.14 no.6
    • /
    • pp.535-544
    • /
    • 2011
  • The rail surface defects can cause the high impact load on the track and lead to the progress of the rail fatigue damage and the rail break. In case of the rail break, there is a great deal of risk for derailment, and thus the maintenance criteria for the rail surface defects are of great importance. In this study, using the dynamic train-track interaction analysis program, the impact wheel loads and rail bending stresses according to the depths of the surface defects have been calculated with the input data of the rail surface irregularities measured at 43 spots with surface defects in the ballasted track of high-speed railway. Considering the irregularity of track geometry, the allowable limits of wheel load and rail bending stress have been set, and the maintenance criteria for the rail surface defects was suggested by analyzing the relationship of the maximum values of wheel load and rail bending stress versus depth and width of rail surface defect. The analysis results suggest that the allowable depth of the surface defect is determined approximately 0.2mm from the limit of the impact wheel load.

Rail Grinding Criteria of Kyeong-Bu High-Speed Line for Effective Rail Maintenance (레일유지관리 효율화를 위한 경부 고속선 레일 연마 기준(안))

  • Kim, Man-Cheol;Kang, Tae-Ku
    • Journal of the Korean Society for Railway
    • /
    • v.11 no.3
    • /
    • pp.272-279
    • /
    • 2008
  • The importance of maintenance of rail surface defects is increasing more according to the KTX operation. That is because during high speed operation of rolling stock, rail surface defects may cause shortened fatigue life of rail, acceleration of track degradation and reduced ride comfort. The paper was intended to study the establishment of rail grinding criteria of high-speed railway lines considering the KTX operation circumstances. For this, the specimens of UIC 60 rail on Kyeong-Bu high-speed operation lines were collected and they were tested for metallographic structure and measured for the hardness. As the factors affecting RCF causing the defects of rail surface, passing tonnage, running speed and track condition are considered.

Review of Non-Destructive Evaluation Technologies for Rail Inspection (철도 레일의 결함 검출을 위한 비파괴탐상 기술)

  • Han, Soon-Woo;Cho, Seung-Hyun
    • Journal of the Korean Society for Nondestructive Testing
    • /
    • v.31 no.4
    • /
    • pp.398-413
    • /
    • 2011
  • For railway safety, it is very important to detect damages of rails at their early stage because any undetected damage in a rail can break the rail and cause a serious railway accident. In this paper, several NDT applicable to rail inspections are described. Major damage types in rails are discussed first and the rail inspection technology using conventional piezoelectric ultrasonic transducers, which is widely adopted for damage detection of rails, is explained. Other NDT being researched or tested for rail inspection are also discussed as complementary technologies to the concurrent contact type ultrasonic inspection. Characteristics of each rail inspection technologies are evaluated in order to provide requirements for future development of a new rail inspection method.

The Fatigue Life Evaluation of CWR based on the Rail Grinding (레일연마를 고려한 장대레일의 피로수명 평가)

  • Kong, Sun-Young;Sung, Deok-Yong;Park, Yong-Gul
    • Journal of The Korean Society of Civil Engineers
    • /
    • v.35 no.5
    • /
    • pp.1191-1198
    • /
    • 2015
  • In this study, vehicle/track interaction analysis by the Saemaul powered vehicle was carried out. The prediction equation for the bending stress of rail was estimated using the rail bending stress by the rail surface irregularities at welds. Also, the fatigue analysis using a S-N curve of welds in the conventional railway was carried out. We estimated the fatigue life of CWR by the fracture probability. By the rail grinding, the fatigue life of CWR was evaluated in consideration to reduce the rail bending stress through removing the rail surface irregularities. Therefore, it presented the fatigue life of CWR according to the rail grinding execution plan in the conventional railway.

Theoretical Analysis on the Array Microphone Measurement for Noise from Rails (배열 마이크로폰을 이용한 레일 방사 소음 측정에 관한 이론 해석)

  • Ryue, Jungsoo;Jang, Seungho;Kwon, Hyu-Sang
    • The Journal of the Acoustical Society of Korea
    • /
    • v.33 no.4
    • /
    • pp.238-247
    • /
    • 2014
  • In this paper, rail vibration and its sound radiation are investigated, then the rail noise measurement by using microphone array is explored theoretically. A concrete slab track for domestic high speed trains is modeled as a Timoshenko beam on elastic support, regarding the moving of the excitation force on the rail. From the radiation characteristics of rail noise generated by a line source, the effect of moving load on sound radiation is obtained. Also it is found that the beam angle of the microphone array is a prominent factor to measure the rail noise level reliably because the rail noise propagates as a plane wave. In this investigation, a proper beam angle for the rail noise measurement by microphone array is suggested.

Safety Evaluation on Interaction between Track and Bridge in Continuous Welded Railway Bridge Considering Seismic Load (지진하중을 고려한 장대레일교량의 궤도-교량 상호작용에 대한 안전성 평가)

  • Shim, Yoon-Bo;Kim, Yun-Tae;Kim, Sang-Chel
    • Journal of the Korea institute for structural maintenance and inspection
    • /
    • v.20 no.2
    • /
    • pp.40-48
    • /
    • 2016
  • To observe the rail-slab interaction in continuous welded railway(CWR) bridge when earthquake occurs, additional axial rail stresses and relative longitudinal displacements between rail and bridge deck were calculated with input of various load combinations and 3 different types of seismic loads to an analytical model. As results of analysis, it can be found that standard response spectrum proposed by Korea Rail(KR) network authority for earthquake design showed less additional axial rail stresses than allowable levels, but greater relative longitudinal displacement between rail and bridge deck, which means that adjustment of relative longitudinal displacement within a standard level is much more difficult than axial train stress. Additionally, if a large-scaled earthquake as occurred at Kobe, Japan comes up, then both of additional axial rail stress and relative displacement in rail-bridge deck may exceed allowable levels, which indicates to make proper design guides against sudden earthquake occurrence.

Design of Metamodel for 5 Layer Information on Business Process Framework (비즈니스 프로세스 프레임워크 5-레이어 정보의 메타모델 설계)

  • Seo, Chae-Yun;Moon, So Young;Kim, Dong-Ho;Kim, R. youngchul
    • Proceedings of the Korea Information Processing Society Conference
    • /
    • /
    • pp.1575-1577
    • /
    • 2012
  • 비즈니스 프로세스 프레임워크(Business Process Framework) 레이어 모델링 정보를 레파지토리에 저장하기위해서는 BPF 5-레이어의 복잡한 구조를 수작업으로 분석해야하는 어려움이 있다. 그래서 각 레이어 모델링 정보를 레파지토리에 효율적으로 저장하기 위해 비즈니스 프로세스 프레임워크 5-레이어 정보 메타모델을 제안한다. 제안한 메타모델 기반으로 레이어 정보를 모델링한다. 모델링된 레이어 정보를 모델변환하여 XMI(XML Metadata Interchange)로 변환하고 그 데이터를 레파지토리에 저장한다. 이 방법을 통해 레이어 정보를 모델링하고, XMI로 변환하면 정보를 쉽고 효율적으로 레파지토리에 저장이 가능하다.

  • PDF