• Title, Summary, Keyword: 이동하중

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Dynamic Analysis of MABB(Multiple Arches Bowstring Bridge) and Single Arch Subjected to Moving Loads (이동하중을 받는 다중아치와 일반아치의 동적거동 분석)

  • Yhim, Sung Soon;Kim, Dong Yong;Son, Suk Ho;Kong, Min Sik
    • Journal of Korean Society of Steel Construction
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    • v.17 no.5
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    • pp.537-547
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    • 2005
  • MABB(Editor's note: Please spell out "MABB" upon first mention)is a new structural type of arch that connects arch ribs and stiffened girders with two internal arches. In this study, the static and dynamic behavior of MABB were analyzed in comparison with those of conventional arches for the investigation of the structural effect of MABB on moving loads. For the purpose of surveying the effect of internal arches on the dynamic behavior of structure, natural frequency and natural vibration mode were investigated and the static and dynamic behavior were analyzed by the method of idealizing train loads as traveling loads consisting of a group of concentrated loads. From the results, the following conclusions were known. First, it is concluded that with MABB, decreasing the section of stiffened girders is possible as compared with conventional arches because the increase of stiffness by internal arches is larger than that of the mass of internal arches. Second, MABB has the advantage of assurance of stability of dynamic behavior because the dynamic behavior of MABB on moving loads is usually investigated in a more stable way than that of conventional arches.

Multi-Damage Detection in RC Bridges Using Differential Evolutionary Algorithm (차분진화 알고리즘을 이용한 다중 손상된 RC교량의 손상평가)

  • Tak, Moon-Ho;Noh, Myung-Hyun;Park, Tae-Hyo;Jang, Han-Teak
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • pp.296-299
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    • 2009
  • 본 논문은 차분진화 알고리즘을 이용한 다중 손상된 RC 슬라브 교량에 대한 시스템 인식(System Identification)기법을 소개한다. 제안된 기법을 이용하여 이동하중에 의한 교량의 동적응답을 기반으로 손상유무, 위치, 크기가 추정된다. ABAQUS를 이용한 손상된 3차원 슬라브 모델을 실험대상으로 하여, 모델로부터 동적응답을 찾아내었다. 차분진화 알고리즘(Differential Evolutioinary algorithm)을 기반으로 동적응답과 Bi-variate Gaussian 함수로 강성저하된 2차원 유한요소 MZC모델을 이용하여 손상된 위치와 크기, 이동하중의 크기와 속도가 추정되었다. 차분진화 알고리즘을 이용한 RC교량의 손상위치와 이동하중에 대한 추정은 3%이내의 오차를 보였고, 이로부터 제안된 방법의 효율성과 정확성이 검증되었다.

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Verification of Damage Detection Using In-Service Time Domain Response (사용중 시간영역응답을 이용한 손상탐지이론의 검증)

  • Choi, Sang-Hyun;Kim, Dae-Hyork;Park, Nam-Hoi
    • Journal of the Korean Society of Hazard Mitigation
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    • v.9 no.5
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    • pp.9-13
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    • 2009
  • Modal parameters including resonant frequencies and mode shapes are heavily utililized in most damage identification throries for structural health monitoring. However, extracting modal parameters from dynamic responses needs postprocessing which inevitably involves errors in curve-fitting resonants as well as transforming the domain of responses. In this paper, the applicability of a damage identification method based on free vibration responses to the in-sevice responses is experimentally verified. The experiment is performed via applying periodic and nonperiodic moving loads to a simply supported beam and displacement responses are measured. The moving load is simulated using steel balls and a downhill device. The damage identification results show that the in-service response may be applicable to identifying damage in the beam.

Experimental Study on Dynamic Responses of Plate-Girder Bridges under Moving Loads (이동하중을 받는 판형교의 동적 거동에 대한 실험적 연구)

  • Yhim, Sung Soon
    • Journal of Korean Society of Steel Construction
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    • v.12 no.4
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    • pp.407-416
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    • 2000
  • This paper presents the dynamical responses of the plate girder bridge subjected to moving load by experimental method. The upper slab of the plate girder bridges is modelled to the plate element and the girder to the beam element. The small-scaled vehicle model is manufactured as moving load and the acryl-bridge model as the plate-girder bridge. The dynamic responses of the plate-girder bridges under the moving load are obtained by the strain gauges, displacement measurements, accelerometer, and dynamic strain measurement. The maximum dynamic responses from the measured data are compared with those from the finite element method. The experimental model test can be used to obtain to the dynamic responses of the plate-girder bridges.

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Bending Moment Characteristics of Flexibly Supported Infinite Beam Subjected to an Axial Force and a Moving Load (이동하중(移動荷重)과 축하중(軸荷重)이 작용(作用)하는 유연(柔軟)한 기초(基礎)위에 지지(支持)된 무한(無限)보의 휨모멘트 특성(特性))

  • Hong, Dong Pyo;Kim, Kwang Sic
    • Journal of The Korean Society of Civil Engineers
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    • v.2 no.3
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    • pp.15-22
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    • 1982
  • This paper presents analytic bending moment solution and resonance diagrams for a uniform beam of infinite length subjected to anaxial force and moving transverse load. Solutions are obtained that are time invariant in a coordinate system moving with the load velocity. The supporting foundation includes damping effects. The influences of the axial force, damping coefficient and load velocity on the beam response are studied. The limiting case of no damping and critial damping are also investigated. The profiles of the mement of the beam is shown graphically for several values of the load speed, the axial force and damping parameters.

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Estimation of Moving Loads by Measuring Dynamic Response (동적 거동계측을 통한 이동하중 추정)

  • Cho, Jae Yong;Shin, Soobong;Choi, Kwang-Kyu;Kwon, Soon-Jung
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.11 no.4
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    • pp.129-137
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    • 2007
  • An algorithm is proposed for estimating axle loads of trucks moving over a bridge by measuring dynamic responses. The bridge was modeled by a beam structure in the current applications of the proposed algorithm. Among the state vectors, measured acceleration was used and displacement was computed from measured strain at the same location. Nodal force vectors were computed by using a ready-made database of equivalent nodal force transformation matrix. The algorithm was examined through simulation studies and laboratory experiments. The effects of measurement noise and velocity error were investigated through simulation studies.

Application of Response Spectrum Method for Analysis of a Floor System Subjected to Dynamic Loads on Multiple Locations (복수 절점에 가진되는 건물 바닥판의 해석을 위한 응답스펙트럼 해석법의 응용)

  • 김태호;이동근
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.15 no.1
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    • pp.21-32
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    • 2002
  • In general, the response spectrum analysis method (R.S.A) is widely used for seismic analysis of building structure. But, it is not common to apply R.S.A for the analysis of structural vibration caused by dynamic loads of equipments, machines and moving leads, etc. The time history analysis method(T.H.A) for the vibration analysis, compared with R.S.A, is very complex, difficult and time consuming. So the application of R.S.A, that is convenient to calculate maximum responses for structural vibration, is proposed in this study. At first, the procedure for the application of the R.S.A to calculate of the maximum vibration response induced by dynamic load applied on the single point is described. And then, the process, which can save the time and the memory for calculation of the maximum vibration response induced by dynamic loads on the multi-point is proposed, and the maximum structural response caused by moving loads are obtained. Lastly, the accuracy of the proposed method is verified by comparing the results of R.S.A to T.H.A for some example models.

Development of Moving Force Identification Algorithm Using Moment Influence Lines at Multiple-Axes and Density Estimation Function (다축모멘트 영향선과 밀도추정함수를 사용한 이동하중식별 알고리듬의 개발)

  • Jeong, Ji-Weon;Shin, Soobong
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.10 no.6
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    • pp.87-94
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    • 2006
  • Estimating moving vehicle loads is important in modeling design loads for bridge design and construction. The paper proposes a moving force identification algorithm using moment influence lines measured at multi-axes. Density estimation function was applied to estimate more than two wheel loads when estimated load values fluctuated severely. The algorithm has been examined through simulation studies on a simple-span plate-girder bridge. Influences of measurement noise and error in velocity on the identification results were investigated in the simulation study. Also, laboratory experiments were carried out to examine the algorithm. The load identification capability was dependent on the type and speed of moving loads, but the developed algorithm could identify loads within 10% error in maximum.

Dynamic Analysis for a Arch Railway Bridge Considering Real Train Loads (실 열차하중을 고려한 아치 교량의 동적해석)

  • Kim, Jung-Hun;Lee, Joo-Tak;Lee, Myeong-Sup;Kang, Young-Jong
    • 한국방재학회:학술대회논문집
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    • pp.77.2-77.2
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    • 2010
  • 고속열차(KTX)를 지지하는 구조물은 차량과 지속적인 접촉을 갖는 구조를 가지고 있으므로 고속열차의 운행 안정성(동적거동)을 고려한 설계가 필요하다. 또한, 상부 구조물은 고속열차의 연행이동집중하중을 지지하며, 이러한 하중조건을 갖는 차량이 운행할 때 상부 구조물은 설계 기준사항들을 만족해야한다. 호남고속철도 설계지침에 의하면 고속열차(KTX)의 운행 안정성을 평가하기 위한 항목들로 대상 교량의 고유진동수, 상판 수직가속도, 면틀림 그리고 승차감을 고려한 연직처침 등이 요구된다. 따라서, 본 연구에서는 KTX의 실 열차하중을 고려하여 연행이동집중하중으로 아치 교량의 동적거동을 검토하였으며, 호남고속철도 설계지침을 적용하여 대상 교량의 운행 안정성을 평가하였다.

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Dynamic Analysis for Railway Bridge Considering Urban Maglev Train (도시형 자기부상열차 하중을 고려한 철도교량 동적해석)

  • Kim, Jung-Hun;Cha, Kyung-Ryul;Lee, Ung-Hee;Kang, Young-Jong
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • pp.481-484
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    • 2011
  • 최근 철도는 미래의 핵심교통수단이자 저탄소 녹색성장을 대표하는 교통수단으로 주목받고 있다. 그 중 자기부상열차는 바퀴 마찰에 따른 소음 진동 분진이 없는 차세대 교통수단이며, 이를 지지하는 구조물(교량)은 열차의 운행 안정성(동적거동)을 고려한 설계가 필요하다. 또한, 상부 구조물은 자기부상열차의 연행이동등분포하중을 지지하며, 이러한 하중조건을 갖는 차량이 운행할 때 상부 구조물은 설계기준사항들을 만족해야한다. 도시형 자기부상철도 토목구조물 설계기준에 의하면 도시형 자기부상철도의 운행 안정성(동적거동)을 평가하기 위한 항목들로 대상 구조물의 고유진동수, 승차감을 고려한 연직처짐 등이 요구된다. 따라서, 본 연구에서는 자기부상열차의 실 열차하중을 고려하여 연행이동등분포하중으로 철도교량의 동적거동을 검토하였으며, 설계기준을 적용하여 대상 철도 교량의 운행 안정성을 평가하였다.

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