• Title, Summary, Keyword: 레일 불균일

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Levitation Controller Performance Analysis according to Vehicle Speed (차량 속력에 따른 부상제어기 성능 해석)

  • Kim, Hong-Ju;Kim, Choon-Kyung;Kwon, Soon-Man
    • Proceedings of the KIEE Conference
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    • pp.458-459
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    • 2008
  • 이 논문은 자기부상열차 속력에 따른 부상제어기 성능을 분석한다. 현재 실용화 사업은 시속 110km/h 속력으로 부상공극 8 mm 기준으로 상하 3 mm 이하 변화를 목표로 개발 중에 있다. 부상제어기의 안정성에 영향을 미치는 외란으로는 가이드웨어 처짐, 크로스아암에 의한 레일 처짐, 레일 불균일, 레일 연결부 단차 등이 있다. 이러한 외란이 복합적으로 작용하지만, 설계 단계에서 각각의 영향을 단순화하여 독립적으로 그 영향을 분석할 필요가 있다. 본 논문에서는 차량속력에 따른 가이드웨어 처짐이 부상제어기에 미치는 영향을 분석한다. 하나의 전자석과 유연레일을 모델링하고 상태궤환을 갖는 제어기를 제안하여 속력에 따른 부상공극 변화를 관찰한다. 모의시험 결과 12 mm 레일의 휘어짐 상황에서 속력에 따라 부상 공극 변화가 커지지만, 실용화 사업의 목표를 달성함을 알 수 있었다.

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Measuring Technique For Acoustic Roughness of Rail Surface With Homogeneous Displacement Sensors (동일 변위센서를 사용한 레일표면 음향조도의 측정방법)

  • Jeong, Wootae;Jang, Seungho;Kho, Hyo-In
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.16 no.11
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    • pp.7941-7948
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    • 2015
  • Rolling noises during train operation are caused by vibration excited from irregularities of surface roughness between wheel and rail. Therefore, a proper measurement and analysis techniques of acoustic roughness between wheel and rail surface are required for transmission, prediction, and analysis of the train rolling noise. However, since current measuring devices and methods use trolley-based manual handling devices, the measurements induce unstable measuring speed and vibrational interface that increases errors and disturbances. In this paper, a new automatic rail surface exploring platform with a speed controller has been developed for improving measurement accuracy and reducing inconsistency of measurements. In addition, we propose a data integration method of the rail surface roughness with multiple homogeneous displacement sensors and verified the accuracy of the integrated data through standard test-bed railway track investigation.

Ride Comfort Analysis of High-Speed Train with Flexible Car Bodies (차체의 유연성을 고려한 고속철도 차량 승차감 해석)

  • Shin, Bum-Sik;Choi, Yeon-Sun;Koo, Ja-Choon;Lee, Sang-Won;Lee, Sung-Il
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.35 no.4
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    • pp.341-346
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    • 2011
  • In the development of high-speed trains, ride comfort is an important factor that determines the quality of the train. In this study, the ride comforts of high-speed trains with rigid and flexible car bodies were evaluated. The rail irregularity is used as an exciting source of the car-body bounce motion. The complex extruded structures of the car-body are modeled as shell structures using the calculated equivalent stiffness of the flexible model. The numerical results show that the ride of the rigid-body model improves as the speed increases, which is unreasonable. In contrast, the relationship between ride comfort and speed in the case of flexible-body model is reasonable. Thus, it is confirmed that the flexibility of the car body needs to be taken into consideration while fabricating a high-speed train.

Vibration Analysis and Mitigable Countermeasures of Semi High-speed Subway Electric Trains (준고속 도시철도의 진동분석 및 저감대책)

  • Park, Ki-Soo;Choi, Yeon-Sun
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.18 no.10
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    • pp.1014-1023
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    • 2008
  • Subway electric trains need to be faster for accommodation of long distance passengers. The faster run of the existing trains results in deterioration of ride quality due to noise and vibration. To reduce the noise and vibration of the electric train, a running test of the electric train was performed and an ADAMS/Rail model was set up to verify the running test results. The experimental results show that the sources of the cabin noise and vibration basically comes from the irregularity of the railroad track and the deterioration of the connection part between cabin and bogie. Consequently for mitigation of noise and vibration of the electric train, the redesign of the center pivot with softer stiffness and the minimization of rail irregularity are necessary. the frequent maintenance of the train will lead to better comport.

Dynamic Interaction of Track and Train System on Open Gap by Rail Breaks (레일 파단시 장대레일 개구부에서의 궤도-차량 동적상호작용)

  • Kang, Yun Suk;Kang, Young Jong;Yang, Shin Chu
    • Journal of The Korean Society of Civil Engineers
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    • v.28 no.6D
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    • pp.895-904
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    • 2008
  • CWR (Continuous Welded Rail) may be broken when a temperature drop below the neutral temperature changes in axial force, causing tensile fracture and rail gap, in winter. Rail-breaks may lead to the damage of the rail and wheel by dynamic load, and the reduction of running safety if not detected before the passage of a train. In this study, the track and train coupled model with open gap for dynamic interaction analysis, is proposed. Linear track and train systems is coupled by the nonlinear Herzian contact spring and the complete system matrices of total track-train system is constructed. And the interaction phenomenon considering open gap, was defined by assigning the irregularity functions between the two sides of a gap. Time history analysis, which have an iteration scheme such as $Newmark-{\beta}$ method based on Modified Newton-Raphson methods, was performed to solve the nonlinear equation. Finally, numerical studies are performed to assess the effect of various parameters of system, apply to various speeds, open gap size and the support stiffness of rail.

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A Study of Dynamic Behavior of Track and Train Interaction on Rail Open Gap (레일 개구부에서의 궤도-차량 상호작용에 대한 연구)

  • Kang, Yun Suk;Kang, Young Jong;Yang, Shin Chu;Cho, Sun Kyu;Han, Sang Yun
    • Journal of Korean Society of Steel Construction
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    • v.19 no.4
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    • pp.345-355
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    • 2007
  • During winter, the CWR (continuous welded rail) may be broken when a temperature drop below the neutral level changes the axial force, causing tensile fracture and creating a rail gap. The passage of a train on a rail with an open gap may lead to very costly derailments. In this paper, the use of a track-and-train-coupled model whose rail has an open gap is proposed for dynamic interaction analysis. Linear track and train systems were coupled in this study by a nonlinear Herzian contact spring, and the complete system matrices of the total track-train system were constructed. Moreover, the interaction phenomenon considering the presence of an open gap in the rail was toughly defined by assigning the irregularity functions between the two sides of the gap. Time history analysis, which has an iteration scheme such as the Newmark-$\beta$ method (based on the Modified Newton-Raphson methods), was conducted to solve the nonlinear equation. .Finally, numerical studies were conducted to assess the effect of the various parameters of the system when applied to various speeds, open-gap sizes, and support stiffnesses of the rail.

Synthesis and Characterization of Sulfonated Polyetherimide (Sulfonated Polyetherimide 합성 및 특성)

  • 김완주;최남석;최중구;김인철;김종호;탁태문
    • Membrane Journal
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    • v.9 no.1
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    • pp.10-16
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    • 1999
  • In this study, polyetherimide with pellet state was sulfonated with a chlorosulfonic acid. The volume ratio of carbon tetrachloride (CCI$_4$/1,2-dichloroethane (DCE) was 5/1. Therefore, sulfonated polyetherimide of anionic charge and more hydrophilicity were produced. The optimum reaction conditions of sulfonation were that PES/CSA mole ratio was I/I, temperature were lO$^{\circ}$ and reaction time were 3hr. SPEls having ion capacity in the range of 0.2-1.2meq/mg were synthesized. Through FT-IR, sulfonic acid peak was shown at 1020cm$^{-1}$ and 1170cm$^{-1}$ Polymer dispersity index was broad and we confirmed that PEl was hydrophilzed in the measure of contact angle.

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Synthesis of Sulfonated Polyethersulfone Membrane Material for Ultrafiltration by Heterogeneous Sulfonation and Fouling Reduction Effect (불균일계 술폰화에 의한 한외여과용 폴리에테르 술폰 막소재 합성과 fouling 감소효과)

  • 김인철;최중구;최남석;김종호;탁태문
    • Membrane Journal
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    • v.8 no.4
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    • pp.210-219
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    • 1998
  • Sulfonated poly(ether sulfone)(SPES) of various ion exchange capacity (IEC) was prepared by heterogeneous sulfonation with chlorosulfonic acid (CSA) to make hydrophilic ultrafiltration membrane for reducing fouling. The effects of CSA concentration, reaction temperature and reaction time has been investigated. The reaction was effective when the temperature is above 10$\circ$C and the CSA concentration is over 0.05 mol, although polymer chain has been significantly degraded. The substitution of sulfonic acid groups was characterized by FTIR and $^1$H-NMR. Transport properties and fouling test have been conducted to the modified SPES ultrafiltration rnembranrs by heterogeneors method. Membranes were obtained using DCM and PVP as a non-solvent and pore forming agent, respectively. Flux reduced and rejection increased with ion exchange capacity. Finger-like structure was disappeared and the thickness of top layer was increased. Dense membrane by non-solvent DCM and porous membrane by pore forming agent PVP was prepared. Fouling was reduced with increasing ion exchange capacity because of hydrophilicity.

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Critical speed analysis of the High-Speed EMU (분산형 고속전철의 임계속도 해석)

  • Shin, Bum-Sik;Lee, Seung-Il;Lee, Sang-Won;Koo, Ja-Choon;Choi, Yeon-Sun
    • Proceedings of the KSME Conference
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    • pp.973-978
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    • 2008
  • This study concerned on the critical speed due to hunting and snake motion train to ensure the stability. First, the critical speed was calculated by using a numerical model, and calculated the critical speed of the vehicle through the simulation with the use of ADAMS/RAII. Also, the snake motion was confirmed through a modal analysis and running simulation. The calculated results, show that the rail irregularity becomes the influential factors of the stability since it is the direct source of excitation of the vehicle.

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Impact Test for Measurement of the Carbody Bending Modes of Railway Vehicle (철도차량 차체 굽힘모드 측정을 위한 충격시험)

  • Shin, Bum-Sik;Choi, Yeon-Sun
    • Journal of the Korean Society for Railway
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    • v.15 no.5
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    • pp.423-428
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    • 2012
  • As the speed of high speed train increases, the prediction of ride comfort becomes important. The exciting frequencies due to rail irregularity in high-speed train closes to the second and third natural frequencies of the carbody. The dynamic characteristics of railway vehicles should be checked by modal analysis numerically and experimentally. In this study the bending test for railway vehicle is reviewed and the impact test is suggested to find the natural frequencies and the mode shapes of the carbody. The validity of the impact test is checked with the test for a sample plate which reflects the aspect ratio of the original carbody. The bending test by the impact and the displacement methods of JIS E7105 for a prototype carbody were done in the field and compared. The results show that the impact test can find more accurate natural frequencies and the mode shapes of the carbody than those of the displacement method.