• 제목/요약/키워드: Cable Force

검색결과 351건 처리시간 0.026초

사장교의 내진설계를 위한 동적해석에 관한 연구 (A Study on Dynaniic Analysis for Earthquake Design of cable-stayed Bridges)

  • 이진휴;이재영;이장춘
    • 한국농공학회지
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    • 제36권1호
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    • pp.103-115
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    • 1994
  • The dynamic earthquake analysis of plane cable-stayed bridge structures was formulated and implemented into a computer program which analyzes plane cable-stayed bridge structu- res subjected to initial cable tensions, member dead and live loads and seismic loads. Cable-stayed bridges were modelled as multi-degrees of freedom systems with lumped- mass. Various earthquake responses such as dynamic deflection, bending moment, shear force and cable tension were investigated by the dynamic analyses in the form of the time history analysis. The time history analysis was based on the mode superposition method. The study revealed that Fan-l type cable-syayed bridges is generally superior to other types for the earthquake proof even though aspects of deflection and section force of each type presents respective advantages and disadvantages. The study provided a method to design the sections of cable-stayed bridges under seismic loads with various design parameters related to structural types. The study is expected to be useful for effective design of cable-stayed bridges with conside- ration of earthquake.

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Optimal sensor placement for cable force monitoring using spatial correlation analysis and bond energy algorithm

  • Li, Shunlong;Dong, Jialin;Lu, Wei;Li, Hui;Xu, Wencheng;Jin, Yao
    • Smart Structures and Systems
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    • 제20권6호
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    • pp.769-780
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    • 2017
  • Cable force monitoring is an essential and critical part of the safety evaluation of cable-supported bridges. A reasonable cable force monitoring scheme, particularly, sensor placement related to accurate safety assessment and budget cost-saving becomes a major concern of bridge administrative authorities. This paper presents optimal sensor placement for cable force monitoring by selecting representative sensor positions, which consider the spatial correlativeness existing in the cable group. The limited sensors would be utilized for maximizing useful information from the monitored bridges. The maximum information coefficient (MIC), mutual information (MI) based kernel density estimation, as well as Pearson coefficients, were all employed to detect potential spatial correlation in the cable group. Compared with the Pearson coefficient and MIC, the mutual information is more suitable for identifying the association existing in cable group and thus, is selected to describe the spatial relevance in this study. Then, the bond energy algorithm, which collects clusters based on the relationship of surrounding elements, is used for the optimal placement of cable sensors. Several optimal placement strategies are discussed with different correlation thresholds for the cable group of Nanjing No.3 Yangtze River Bridge, verifying the effectiveness of the proposed method.

구조용 케이블의 장력 변화에 따른 정착부의 임피던스 특성에 대한 유한요소해석 (Finite Element Analysis on Impedance Parameters of Anchor Plate of Structural Cables Under Cable Force Changes)

  • ;박재형;홍동수;이주원;김정태;나원배
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 2010년도 정기 학술대회
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    • pp.783-786
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    • 2010
  • This paper presents a finite element analysis on impedance parameters of anchor plates of structural cables under the change in cable forces. To achieve the objective, four approaches are implemented as follows: Firstly, theoretical background of electro-mechanical impedance is described. Secondly, anchor plates of structural cables are selected to experimentally examine the relationship between impedance parameters and cable force changes. Thirdly, finite element analysis is performed to verify the experimental results. Fourthly, a comparison between the experimental and numerical analysis on impedance parameters of anchor plate of structural cables under cable force changes is carried out.

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22.9kV 다중 접지 지중 전력 케이블의 가압 상태 진단에 관한 기초 연구 (A Study on Diagnosis of The Energized Status of 22.9kV Multigrounded Underground Power Cable)

  • 김창교;홍진수;정영호
    • 대한전기학회논문지:전기물성ㆍ응용부문C
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    • 제48권10호
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    • pp.699-703
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    • 1999
  • An experimental study to identify the energized status of the 22.9kV underground power cable by the detection of vibration has been performed. We have derived that there exists vibration at double the line frequency in live cables by electromagnetic force. The relative amplitudes of the cable vibration according to the energized status of the cable were calculated by computer simulation. The cable vibration can also be picked up by accelerometer. A prototype was tested on the underground distribution system in Chonan substation, KEPCO. Comparison between simulation results and field test results was performed. The results showed that the energized status of the calble can be identified by measuring the vibration of the cable using accelerometer.

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Effects of tensioning forces on the structural behavior of cable-stayed bridges

  • Lam, Pauline Lin Li;Kang, Thomas H.K.
    • Steel and Composite Structures
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    • 제43권4호
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    • pp.457-464
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    • 2022
  • Optimization in distribution of stay cable forces is one of the most difficult aspects in the design of cable-stayed bridges. This article attempts to examine tension force influence on structural behavior of cable-stayed bridges. For the examination, finite element modeling using nonlinear static and nonlinear modal analyses was completed and compared to structural experimental results. Variables analyzed in this parametric study were: 1) Number of stay cables; 2) Tension of the stay cables, and 3) Stay cable pattern - harp and semi-fan patterns. Though the findings from the analysis are limited to the tested models, the study gives insight on the structural behavior of actual cable stayed bridges.

사장교의 초기형상해석을 위한 개선된 초기부재력법 및 TCUD법의 비교연구 (Comparison Study of An Improved Initial Force and TCUD Method for Initial Shape Analysis of Cable-Stayed Bridges)

  • 김동영;조경식;김문영
    • 한국전산구조공학회논문집
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    • 제25권1호
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    • pp.101-108
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    • 2012
  • 사장교 시스템의 초기형상해석이라 함은 주형의 수직 처짐과 휨모멘트, 주탑의 수평변위와 휨모멘트를 최소화하면서, 고정하중과 평형을 이룰 수 있는 케이블의 장력과 무응력길이를 결정하는 방법으로 이 때, 케이블이 정착되는 주형의 수평위치, 주탑의 수직위치가 목표형상에 부합할 필요가 있다. 본 연구에서는 고정하중을 받는 사장교의 초기형상을 효율적이고 합리적으로 결정하기 위하여 개선된 초기부재력법과 TCUD법의 비교연구 결과를 제시하고자 한다. 주형과 주탑의 케이블 정착부에서 힘의 평형조건을 이용하여 주형의 수직처짐과 주탑의 수평변위를 효과적으로 제어할 수 있는 절점평형법을 초기 부재력법에 적용하여 초기치에 민감한 기존 초기부재력법을 개선한다. 또한 개선된 TCUD법을 이용한 초기형상해석 수행결과와 비교함으로서 두 방법의 정확성을 입증하고자 한다.

지중 2회선 154 kV 송전케이블의 정상 및 지락고장에 따른 전자기력 분포에 관한 연구 (Study on the Distribution of Electromagnetic Force for 154 kV Power Transmission Cable on Dual Underground Lines by Normal and Earth Fault Current)

  • 김희민;김소영;임상현;박관수
    • KEPCO Journal on Electric Power and Energy
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    • 제1권1호
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    • pp.21-27
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    • 2015
  • The goal of this study is the size and distribution of the electromagnetic force generated by the current flowing through the second underground line of 154kV power transmission cables by using electromagnetic finite element analysis. So we interpret how mutually electromagnetic force has an effect on the comparable judgement of Trefoil, Duct and Flat, which shows in a numerical arrangement. 154kV OF 1200SQ Cable 1.281km not only is applicable to modeling for underground transmission cable but also examine the effect of line to line, phase to phase and size and direction of the electromagnetic force preparing for the occurrence of normal state and single-phase earth fault, which are arranged in trefoil, duct and flat formation between sections. As showing how the trajectory, and size distribution of the electromagnetic force translate as the arrangement of the cables when a steady-state current and a fault current flows on the underground cables, I hope that when Underground transmission is designed, this data will be useful information.

다층 케이블 돔형 구조물의 자기평형을 위한 부재력 비율 결정 (Determination of Member Force Ratios for Self-equilibrium State of Multi-Layered Cable Dome Type Structures)

  • 김재열
    • 한국공간구조학회논문집
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    • 제13권2호
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    • pp.75-82
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    • 2013
  • For each cable component in a cable dome structure, pre-tension is needed for stability of whole the structure. The summation of these pre-tension at each joint should be zero to achieve the self equilibrium structure. The first step in cable dome structure analysis is to find the ratio of pre-tension in each member which can produce a stable and structure on self-equilibrium. In this paper, a new method based on the basic principle of closed force polygon for equilibrium system is proposed for the determination of self-equilibrium mode of cable dome structure. A single layer cable dome and two multi layer type domes have been analyzed. The ratios of cable members are determined by the presented method, and check the validation of the results by numerical calculation.

진동법을 이용한 인장 케이블의 장력 추정에 관한 연구 (Evaluation of Tension Force of Stay Cables Using Vibration Method)

  • 김남식;정운
    • 한국소음진동공학회논문집
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    • 제12권12호
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    • pp.956-963
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    • 2002
  • In a recent construction industry, cable supported structures such as a cable-stayed bridge or space stadium have been increasingly constructed according to rapidly upgrade their related technologies. Generally stay cables as a critical member need to be rearranged for being satisfied with design tension forces. In this purpose, a vibration method has been applied to estimate the tension forces exerted on existing stay cables. In this study, cable vibration tests were tarried out to evaluate the cable tension forces comparing with theoretical and practical formulas. Using the measured frequencies obtained from free vibration and Impulsive tests, an accuracy of the estimated tension forces is confirmed according to use the first single mode only or higher multiple modes.

송전케이블 삼상단락 실증시험을 통한 전자력 대책방안 연구 (The Study on Countermeasures of Electromagnetic Force by Three Phase Short-Circuit Test of Underground Transmission Cable)

  • 강지원;박흥석;윤종건;김양상;홍동석;장우석
    • 전기학회논문지
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    • 제58권12호
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    • pp.2342-2348
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    • 2009
  • Even though underground transmission cable is an essential transmission method to supply stable power for downtown and population center, the interaction of electromagnetic force by fault current is very large comparing to overhead transmission line due to restricted installation space such as tunnel, and close consideration is required for it. This paper presents countermeasures to reduce and release the effect of electromagnetic force with rope binding and installation of spacer and describes its efficacy through three phase short-circuit test, which will be utilized as basic materials for improvement and development of cleat, hanger, etc. to reduce and release effect of electromagnetic force in the future.