• Title, Summary, Keyword: effective beating interval

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Resonance Phenomenon according to the relationship between Span Length of the Bridge and Effective Beating Interval of High-Speed Train (교량의 지간장과 고속전철하중 유효타격간격 사이의 관계에 따른 공진현상)

  • 김성일;곽종원;장승필
    • Journal of the Earthquake Engineering Society of Korea
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    • v.3 no.2
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    • pp.67-76
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    • 1999
  • Resonance of the bridge can be occurred with the coincidence between a natural frequency of the bridge and a crossing frequency of moving loads which is determined from the speed and effective beating interval of the vehicle. In case of the railway bridge, the effective beating interval of the vehicle is fixed under the passage of specific trains. In the present study, resonance and cancellation of the bridge subjected to moving high-speed train are analyzed with the variations of span length. A steel-concrete composite railway bridge is idealized by the combinations of plate elements and space frame elements. High-speed train is idealized with moving constant forces and a 3-dimensional full modelling. From analyzing dynamic responses of D.M.F of vertical displacement, maximum vertical acceleration of the slab, and end rotation according to the variations of span length of the bridge, design criteria of span length of the bridge which satisfies dynamic safety is discussed.

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A Study on the Optimal Span Length Selection of Conventional Railway Bridges considering Resonance Suppression (공진소멸 현상을 이용한 기존선 철도교량의 지간 최적화를 위한 연구)

  • Kim Sungil;Chung Wonseok;Choi Eunsoo
    • Journal of the Korean Society for Railway
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    • v.8 no.2
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    • pp.137-144
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    • 2005
  • The possibility of resonance exists always in railway bridges unlike highway bridges because railway bridges are loaded repeatedly by specific trains which has equidistant wheel loads. Resonance phenomenon of the bridge can be broken out when exciting frequencies by tram determined from the speed and effective beating internal coincides with natural frequencies of the bridge Excessive fluctuations of dynamic displacements and accelerations by resonance cause unpleasant passenger comfort and instability of railway structures. On the other hand, resonance suppression phenomenon that all the previous loads which pass through the bridge sum to zero can be occurred. In case we apply this resonance suppression properly, design of stable railway bridge from dynamics point of view can be made. In the present study, most dominant beating internal of conventional trams will be find. A(ter that. specific span length of the bridge which derives resonance suppression can be selected for railway bridges which accomplishes superior dynamic behavior.