• Title, Summary, Keyword: 궤도틀림

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Analysis method for the Measured Track Geometry Data using Wavelet Transform (웨이브렛 변환을 이용한 궤도틀림 분석)

  • Lee, In-Kyu;Kim, Sung-Il;Yeo, In-Ho
    • Journal of the Korean Society for Railway
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    • v.9 no.2
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    • pp.187-192
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    • 2006
  • The regularity of railway track alignment is a crucial component fur maintaining travel safety and the smoothness of passenger ride. The conventional spectral analysis has been considered to estimate the severity of the track irregularity from measured data. The time domain data used to be changed into the frequency domain by Fourier transform. Because the measuring points can be regarded as the time points, the spatial-frequency can be introduced instead of the time-frequency. Although FFT(Fast Fourier Transform) and/or PSD(Power Spectral Density) function could provide fairly localized information within frequency domain, but chronical configurations of data could be missed. In this study, we attempt to apply the Morlet wavelet transform for the purpose of a frequency-time-domain analysis rather than a frequency-domain analysis. The applicability of wavelet transform is examined for the estimation of the track irregularity with real measured track data on the section of Kyoung-bu line by EM-120 measuring vehicle. It is shown that the wavelet transform can be an effective tool to manage the track irregularity.

Comparison of Chord method with Surveying in Track irregularity Measurement (측량과 현방식 궤도틀림 측정 비교)

  • Lee, Jee-Ha;Lee, Sang-Jin
    • Proceedings of the KSR Conference
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    • pp.1647-1652
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    • 2008
  • Track geometry consists of tangent and curved lines, which caused undesirable changes in initial track geometry by traffic loads. The bigger the changes are, the worse the riding comfort and running stability of train. This is so-called track irregularity and is the most important quality parameters of ballasted track. To be able to objectively assess track irregularity, track geometry should be able to be measured. Practically, railway companies use moving chord method, this method determine versine values via a chord. The versine is the vertical distance to curve measured in the middle of the chord. This type of method measures only versine of track irregularity curve by transfer function from specific property of measuring tool. In this report, review the characteristics of two types of measuring tools by comparing the measurements. The one is GRP-1000 system, optical surveying system with Total station and lazar prism trolly. This calculates track geometry by surveying absolute coordinates of two points each on both rail heads. The other is Trackmaster, measures versine with 2m of chord length.

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Three Dimensional Dynamic Interaction Analysis of Actively Controlled High Speed Maglev-Guideway Structure (초고속 자기부상열차의 열차-가이드웨이 3차원 상호작용 해석)

  • Min, Dong-Ju;Jung, Myung-Rag;Kim, Hae-Ne-Rae;Kim, Moon-Young
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • pp.727-730
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    • 2011
  • 본 논문에서는 3차원 자기부상열차에 대한 열차-가이드웨이 상호작용 해석기법을 제시하고자 한다. 수직 및 수평방향 변위, 피칭, 롤링 그리고 요잉에 대한 자유도를 각 보기와 차체에 대해 고려하여 총 25자 유도 자기부상열차에 대한 운동방정식을 유도하였다. 제어방식으로는 UTM01에 적용된 제어기법을 이용하였고, 궤도 틀림을 고려하기 위하여 미국 FRA에 적용하고 있는 궤도 불규칙성에 대한 밀도 스펙트럼 함수를 이용하여 조도를 생성하였다. 같은 조건하에 2차원 모델과 3차원 모델의 동적응답 결과를 비교하여 타당성을 확인하였고, 2차원 모델에서 고려할 수 없는 수평방향 조도를 도입하였을 때 수직방향 부상공극에는 두드러진 영향을 미치지 않았으나, 수평방향 부상변위에 있어서 중요하게 작용함을 확인하였다.

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A Study of the Long Wave Track Defect Analysis for High Speed Railway (고속철도의 장파장 제도틀림 분석에 대한 연구)

  • Kang Kee-Dong
    • Journal of the Korean Society for Railway
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    • v.8 no.2
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    • pp.111-115
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    • 2005
  • The Study provides the technical background and calculation method f3r the long wave track defect. On high speed railway, It is necessary to manage the long wave band up to 80m track defect fur improving a riding quality. For this reason, Track recording methods for highspeed railway are used 10m and 30m recording bases, these are covered middle wave band and long wave band successfully. Extended base recording data is calculated by geometrical model and this data provides a good result for KTX riding index.

Stability of CWR Tracks according to the Characteristics of the Probability Distribution of the Neutral Temperature (중립온도의 확률분포 특성에 따른 CWR 궤도의 안정성)

  • Bae, Hyun-Ung;Choi, Jin-Yu;Kim, Myoung-Su;Lee, Chin-Ok;Lim, Nam-Hyoung
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • pp.489-492
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    • 2011
  • 장대레일 궤도의 부동구간에서 발생되는 과도한 축력은 혹서기 궤도의 좌굴을 유발시켜 주행하는 열차의 안정성을 위협할 수 있다. 궤도 제원을 제외한 압축응력과 관련된 레일온도 인자, 궤도 강성과 관련된 도상저항력, 궤도의 초기결함인 궤도틀림과 같은 인자들은 기후조건, 궤도 운영조건, 유지관리조건 등에 의해 임의적으로 변동되는 불확실성이 높은 궤도 매개변수이다. 그러므로 장대레일 궤도의 좌굴은 불확실성이 높은 현상임을 알 수 있다. 따라서 궤도 매개변수들의 불확실성 및 임의성을 합리적으로 고려하기 위해서는 확률론적 접근방법의 적용이 필수적이라 할 수 있다. 본 논문에서는 기존 본 연구진에 의해 개발된 장대레일 궤도의 좌굴확률 평가시스템을 이용하여 장대레일 축력을 산정하기 위한 필수요소인 중립온도의 확률분포 특성에 따른 좌굴 안정성을 분석하였다.

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Technical Trend of Track Irregularities Measuring Systems and Its Application (궤도 검측 시스템의 현황과 응용)

  • Kim, Sang-Soo;Kim, Young-Mo;Han, Young-Jea;Park, Choon-Su
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • pp.139-142
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    • 2005
  • High speed railway, KTX has started commercial service last you and passengers is increasing. To secure the safety and reliability of high speed railway, it is necessary to inspect and maintain the rail regularities. Several methods of measuring track irregularities are developed in other railway advanced countries. In this paper, we introduce foreign track Inspection methods and application scheme to Koreans.

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Comparison of Ride Comfort between Korean and European High Speed Railway by using Continuous Comfort Method (Continuous Comfort 방법을 이용한 국내외 고속철도 승차감 비교)

  • Choi, Il-Yoon;Um, Ju-Hwan;Lee, Jun Suk;Choi, Min-Ji;Lim, Jihoon
    • Journal of the Korean Society for Railway
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    • v.18 no.3
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    • pp.203-211
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    • 2015
  • Ride comfort of a vehicle can be utilized to maintain the track geometry and track irregularities because ride comfort of the rolling stock is affected by the characteristics of the vehicle and track. Ride comfort was evaluated according to the measured floor acceleration data of vehicles for a Korean high speed line as well as European high speed lines using Continuous comfort method which can be applied to track maintenance. The exceedance distribution of the ride comfort was quantitatively analyzed by the vehicle speed, the ride comfort of the Korean high speed line was compared with that of European high speed lines. It is shown that the ride comfort of Korean high speed line is better than that of European high speed lines, which indicates that the Korean track geometry and track irregularities are properly maintained.

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
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    • v.14 no.6
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    • pp.535-544
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    • 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.

A Study on the Track Irregularity Index for the Estimation of Track Quality (궤도품질평가를 위한 궤도틀림 지표에 대한 연구)

  • 오지택;한승용
    • Proceedings of the KSR Conference
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    • pp.450-457
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    • 2000
  • This paper establishes a scheme to estimate track quality using standard deviation and deterioration rate of track irregularities. To provide index of quality, standard deviation and deterioration rate of track irregularities are analyed. As an index, standard deviation and deterioration rate were applied to decision of corrective maintenance and replacement maintenance, respectively. Further, this paper proposes a basic scheme for a modernization of mechanize track maintenance that using MTT(Multiple Tie Tamper) and Ballast Cleaner.

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조건에 부응하는 궤도구조

  • 이기승
    • Journal of the Korean Society for Railway
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    • v.5 no.3
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    • pp.15-21
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    • 2002
  • 옆의 사진을 보고 무엇을 느낄 수 있나\ulcorner 시속 30~40km/h의 열차가 레일이음매에서 발생하는 충격음을 내며 지나가고 있다. 여행 중 및 사람과 정다운 대화를 하면서 여행 그 자체를 즐기고 있다. 때로는 차장과 대화를 하면서 기관사를 신뢰하고, 안전하다는 믿음으로 여행을 한다. 가끔은 큰소리로 기적을 울려지지만 소음이라기 보다는 오히려 열차다운 면이기에 더욱 정이 간다. 느리다고 불평하는 사람도 없고, 궤도틀림으로 인한 진동이 심하다고 나무라는 사람도 없다. (중략)