• 제목/요약/키워드: cable stiffness

검색결과 190건 처리시간 0.023초

월드컵경기장 지지케이블의 장력추정을 위한 진동법의 적용성 평가 (Application of Vibration Method for Estimation of Tension Force of Stay Cables in World-Cup Stadiums)

  • 장극관
    • 한국구조물진단유지관리공학회 논문집
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    • 제13권6호통권58호
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    • pp.156-165
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    • 2009
  • 본 연구에서는 대공간 구조물로서 2002년 건축된 6개 월드컵경기장 인장케이블의 특성과 관련하여 케이블의 고유진동수와 이를 이용한 기존 이론식들의 적용성에 대하여 실험적으로 검토하였다. 실험결과, 케이블의 휨강성을 고려함으로서 8%이내의 정확도를 가지고 케이블의 인장력을 추정할 수 있는 것으로 나타났으나 휨강성의 영향이 큰 범위(${\xi}{\leq}7$)에 있어서는 추정오차가 증가하는 경향을 나타내고 있어 이 범위에 대해서는 추가적인 연구가 필요한 것으로 사료되며, 다중진동모드를 사용하더라도 단일진동모드를 사용하는 경우와 비교하여 장력추정 오차는 크게 개선할 수 없는 것으로 나타났다.

마찰복원형 지진격리장치가 설치된 케이블교량의 성능 기반 내진설계법 개선(I-실 교량 실험 결과 분석) (Improvement of the Performance Based Seismic Design Method of Cable Supported Bridges with Resilient-Friction Base Isolation Systems (I- Analysis of Field Testing of Cable Supported Bridge))

  • 길흥배;박선규;한경봉;윤완석
    • 한국지진공학회논문집
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    • 제24권4호
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    • pp.157-167
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    • 2020
  • In this study, a field bridge test was conducted to find the dynamic properties of cable supported bridges with resilient-friction base isolation systems (R-FBI). Various ambient vibration tests were performed to estimate dynamic properties of a test bridge using trucks in a non-transportation state before opening of the bridge and by ordinary traffic loadings about one year later after opening of the bridge. The dynamic properties found from the results of the tests were compared with an analysis model. From the result of the ambient vibration tests of the cable supported bridge with R-FBI, it was confirmed that the dynamic properties were sensitive to the stiffness of the R-FBI in the bridge, and the seismic analysis model of the test bridge using the effective stiffness of the R-FBI was insufficient for reflecting the dynamic behavior of the bridge. In the case of cable supported bridges, the seismic design must follow the "Korean Highway Bridge Design Code (Limit State Design) for Cable supported bridges." Therefore, in order to reflect the actual behavior characteristics of the R-FBI installed on cable-supported bridges, an improved seismic design procedure should be proposed.

케이블 횡진동을 고려한 3차원 사장교의 동적거동 (Dynamic Response of 3-D Cable-Stayed Bridge Considering the Sway Vibrational Effect of Stays)

  • 성익현
    • 한국철도학회논문집
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    • 제2권3호
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    • pp.36-45
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    • 1999
  • The basic idea of cable-stayed girder bridges is the utilization of high strength cables to provide intermediate supports for the bridge girder so that the girder can span a much longer distance. In the cable-stayed bridge, the cables exhibit nonlinear behavior because of the change in sag, due to the dead weight of the cable, which occurs with changing tension in the cable resulting from the movement of the end points of the cable as the bridge is loaded. Techniques required for the static analysis of cable-stayed bridges has been developed by many researchers. However, little work has been done on the dynamic analysis of such structures. To investigate the characteristics of the dynamic response of long-span cable-stayed bridges due to various dynamic loadings likes moving traffic loads. two different 3-D cable-stayed bridge models are considered in this study. Two models are exactly the same in structural configurations but different in finite element discretization. Modal analysis is conducted using the deformed dead-load tangent stiffness matrix. A new concept was presented by using divided a cable into several elements in order to study the effect of the cable vibration (both in-plane and swinging) on the overall bridge dynamics. The result of this study demonstrates the importance of cable vibration on the overall bridge dynamics.

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Cable vibration control with internal and external dampers: Theoretical analysis and field test validation

  • Di, Fangdian;Sun, Limin;Chen, Lin
    • Smart Structures and Systems
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    • 제26권5호
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    • pp.575-589
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    • 2020
  • For vibration control of stay cables in cable-stayed bridges, viscous dampers are frequently used, and they are regularly installed between the cable and the bridge deck. In practice, neoprene rubber bushings (or of other types) are also widely installed inside the cable guide pipe, mainly for reducing the bending stresses of the cable near its anchorages. Therefore, it is important to understand the effect of the bushings on the performance of the external damper. Besides, for long cables, external dampers installed at a single position near a cable end can no longer provide enough damping due to the sag effect and the limited installation distance. It is thus of interest to improve cable damping by additionally installing dampers inside the guide pipe. This paper hence studies the combined effects of an external damper and an internal damper (which can also model the bushings) on a stay cable. The internal damper is assumed to be a High Damping Rubber (HDR) damper, and the external damper is considered to be a viscous damper with intrinsic stiffness, and the cable sag is also considered. Both the cases when the two dampers are installed close to one cable end and respectively close to the two cable ends are studied. Asymptotic design formulas are derived for both cases considering that the dampers are close to the cable ends. It is shown that when the two dampers are placed close to different cable ends, their combined damping effects are approximately the sum of their separate contributions, regardless of small cable sag and damper intrinsic stiffness. When the two dampers are installed close to the same end, maximum damping that can be achieved by the external damper is generally degraded, regardless of properties of the HDR damper. Field tests on an existing cable-stayed bridge have further validated the influence of the internal damper on the performance of the external damper. The results suggest that the HDR is optimally placed in the guide pipe of the cable-pylon anchorage when installing viscous dampers at one position is insufficient. When an HDR damper or the bushing has to be installed near the external damper, their combined damping effects need to be evaluated using the presented methods.

케이블 트러스 지붕 시스템의 역학적 특성 (Mechanical Characteristics of Cable Truss Roof Systems)

  • 박강근;이동우
    • 한국공간구조학회논문집
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    • 제16권2호
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    • pp.89-96
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    • 2016
  • Cable structures are lightweight structures of flexible type, cable members have only axial stiffness related to tension, they can carry neither bending nor compression. This study is the analysis of cable truss systems are composed of upper and low cables by connecting bracing cables, the structural principle is based on a tensegrity system by using bracing tension members, discontinuous compression members and continuous tension members. A hanging roof of cable truss system is too flexible against vertical loads, most cable members are stabilized by connecting the prestressed upper and lower cable by bracing cables. A cable truss roof system is formed by adding a set of cables with reverse curvature to the suspension cables. With the sets of cables having opposite curvature to each other, cable truss is able to carry vertical load in both upward and downward direction with equal effectiveness, and then a cable truss acts as load bearing elements by the assemble of ridge cables, valley cables and bracing cables. This paper will be shown the geometric non-linear analysis result of cable truss systems with various sag ratio for deflections and tensile forces, the analytical results are compared with the results of other researchers.

Design formulas for vibration control of sagged cables using passive MR dampers

  • Duan, Yuanfeng;Ni, Yi-Qing;Zhang, Hongmei;Spencer, Billie F. Jr.;Ko, Jan-Ming;Dong, Shenghao
    • Smart Structures and Systems
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    • 제23권6호
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    • pp.537-551
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    • 2019
  • In this paper, a method for analyzing the damping performance of stay cables incorporating magnetorheological (MR) dampers in the passive control mode is developed taking into account the cable sag and inclination, the damper coefficient, stiffness and mass, and the stiffness of damper support. Both numerical and asymptotic solutions are obtained from complex modal analysis. With the asymptotic solution, analytical formulas that evaluate the equivalent damping ratio of the sagged cable-damper system in consideration of all the above parameters are derived. The main thrust of the present study is to develop an general design formula and a universal curve for the optimal design of MR dampers for adjustable passive control of sagged cables. Two sag-affecting coefficients are derived to reflect the effects of cable sag on the maximum attainable damping ratio and the optimal damper coefficient. For the cable configurations commonly used in cable-stayed bridges, the sag-affecting coefficients are directly expressed in terms of the sag-extensibility parameter to facilitate the control design. A case study on adjustable passive vibration control of the longest cable (536 m) on Stonecutters Bridge is carried out to demonstrate the influence of the sag for the damper design, and to figure out the necessity of adjustability of damper coefficients for achieving maximum damping ratio for different vibration modes.

Stress analysis model for un-bonded umbilical cables

  • Chen, Xiqia;Fu, Shixiao;Song, Leijian;Zhong, Qian;Huang, Xiaoping
    • Ocean Systems Engineering
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    • 제3권2호
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    • pp.97-122
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    • 2013
  • For the optimization design and strength evaluation of the umbilical cable, the calculation of cross section stress is of great importance and very time consuming. To calculate the cross section stress under combined tension and bending loads, a new integrated analytical model of umbilical cable is presented in this paper. Based on the Hook's law, the axial strain of helical components serves as the tensile stress. Considering the effects of friction between helical components, the bending stress is divided into elastic bending stress and friction stress. For the former, the elastic bending stress, the curvature of helical components is deduced; and for the latter, the shear stress before and after the slipping of helical components is determined. This new analytical model is validated by the experimental results of an umbilical cable. Further, this model is applied to estimate the extreme strength and fatigue life of the umbilical cable used in South China Sea.

케이블 돔의 구조물의 동적 비선형 해석 (The Dynamic Analysis of Cable Dome Structures)

  • 서준호;한상을;이상주
    • 한국공간정보시스템학회:학술대회논문집
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    • 한국공간정보시스템학회 2004년도 춘계 학술발표회 논문집 제1권1호(통권1호)
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    • pp.113-122
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    • 2004
  • Cable domes deform very largely because of the characteristics of flexible hybrid system and pre-tension, and include geometrical non-linearity in those structural behavior. Especially wind load is more dominant than seismic load, because cable domes are flexible structures whose bending stiffness is very small and self-weight is very light. Therefore, in this paper, the Modified Stiffly Stable Method is applied to analyze the nonlinear dynamic behavior of cable domes and compared these results with ones of the $Newmark-{\beta}$ Method which is generally used. The Seoul Olympic Gymnastic Arena is taken as an numerical example and three kinds of models with giving each different intensity of pre-tension are selected. And dynamic nonlinear behavior of cable domes are analyzed by artificial spectrum of wind velocity wave which is similar to actual wind loads.

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진도대교 케이블 댐퍼시스템 설계 및 검증실험 (The Design of Cable Damper System far Jindo Bridge and its Field Verification Test)

  • 서주원;김남식;안상섭;정원
    • 한국지진공학회:학술대회논문집
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    • 한국지진공학회 2001년도 추계 학술발표회 논문집 Proceedings of EESK Conference-Fall 2001
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    • pp.302-310
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    • 2001
  • In order to lessen cable vibration, new cable damper system with high damping rubber was developed using the basis of the LRB design scheme. The analysis model of cable damper system incorporate voigt-kelvin damper model into the nonlinear cable analysis model. To achieve maximum damping capacity both reducing damper stiffness and developing high damping rubber were performed. As a result of verification test, the high damping rubber damper shows its effectiveness in improving cable damping capacity.

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3차원 케이블망의 초기평형상태 결정 및 정적 비선형 유한요소해석 (Static Non-linear Finite Element Analysis of Spatial Cable Networks)

  • 김문영;김남일;안상섭
    • 전산구조공학
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    • 제11권1호
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    • pp.179-190
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    • 1998
  • 두개의 케이블요소를 이용한 3차원 케이블망의 정적 비선형 유한요소해석기법을 제시한다. 먼저, 공간 트러스요소와 탄성현수선 케이블요소(elastic catenary cable element)의 접선강도행렬과 질량행렬을 유도하는 과정을 간략히 요약한다. 지점 변위를 일으키고 자중을 받는 케이블망의 초기평형 상태를 결정하기 위하여, Newton-Raphson 반복법에 근거한 하중증분법과 현수케이블요소를 적용하는 경우에 viscous damping을 고려한 dynamic relaxation법을 제시한다. 또한 초기의 정적평형상태를 기준으로 추가하중에 대한 케이블망의 정적 비선형해석을 수행한다. 지점변위와 외력을 받는 케이블 구조에 대하여 비선형해석을 수행하고, 해석결과들을 기존의 문헌의 결과와 비교, 검토하므로써 본 논문에서 제시한 이론 및 해석방법의 타당성을 입증한다.

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