• Title/Summary/Keyword: Cable Force

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A simplified analysis of the behavior of suspension bridges under live load

  • Stavridis, Leonidas T.
    • Structural Engineering and Mechanics
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    • v.30 no.5
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    • pp.559-576
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    • 2008
  • Having established the initial geometry and cable force of a typical three span suspension bridge under permanent load, the additional maximum response of the cable and the stiffening girder due to live load are determined, by means of an analytic procedure, considering the girder first hinged at its ends and then continuous through the main towers. The problem of interaction between the cable and the stiffening girder is examined taking under due consideration the second order effects, whereby, through the analogy to a fictitious tensioned beam under transverse load, a closed -form solution is achieved by means of a simple quadratic equation. It is found that the behavior of the whole system is governed by five simple dimensionless parameters which enable a quick determination of all the relevant design magnitudes of the bridge. Moreover, by introducing these parameters, a set of diagrams is presented, which enable the estimation of the influence of the geometric and loading data on the response and permit its immediate evaluation for preliminary design purposes.

Analysis of 32m aerostat gust load using non-linear cable equation (비선형 테더 방정식을 이용한 에어로스탯 돌풍하중해석)

  • Kang, Wang-Gu;Lee, In;Kim, Dong-Min
    • Proceedings of the KSME Conference
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    • 2008.11a
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    • pp.757-761
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    • 2008
  • The aerostat dynamic equation of motion has been built including the tether cable dynamic effects. A numerical program to solve the derived equation of motion has been developed. The dynamic motion of the 32m aerostat has been analyzed under discrete gust and continuous turbulence. The aerostat behaviors under discrete gust which represents a deterministic approach for determining design loads for manned aircraft are solved to verify the effect of aerostat mechanical properties on the aerostat dynamic behavior. Continuous turbulences are simulated for each given altitude, translational mean wind velocity and gust intensity. Dynamic behaviors of the 32m aerostat are simulated for each continuous turbulence conditions. Translational and vertical velocity and pitching behavior and tether reaction force are monitored for each simulation.

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A Study on Dynamic Response Analysis of the Cable-Stayed Bridge Using the Stochastic Finite Element Method (확률유한요소법을 이응한 사장교의 동적응답해석)

  • 한성호;정인수;김진홍;신재철
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2003.10a
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    • pp.365-372
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    • 2003
  • In this study, the program which determine the initial cable tension force by tile initial shape analysis for cable stayed bridge is developed. Also, DSFEMP(Dynamic Stochastic Finite Element Analysis Program) is developed to consider the variance of random variables at each step of dynamic response analysis, not use existing methods that apply to the theory of reliability at the final step of structural analysis. In addition, the output from the developed program was compared with the results from DMCSP(Direct Monte Carlo Simulation Program) to prove its validity.

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A Study on the Bifurcation Characteristics of Hybrid Cable Domes under Axisymmetric Load (축대칭 하중을 받는 Hybrid 케이블 돔의 Bifurcation 특성에 관한 연구)

  • 김승덕;백인성;김형석
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2003.10a
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    • pp.277-284
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    • 2003
  • One of important problem, in large space structure, is to overcome the self-weight of roof structure. This problem can be solved with using tension members effectively. Thus the rapid progress of hybrid structure, that makes effective use of the means of settling, has a good effect on realizing the large space. These systems of hybrid structure have the advantages of light weight and its own internal redundancy, but are occurred unstable phenomenon such as bifurcation or snap-through buckling, when the load level is come to the critical point. Among the hybrid structure, cable dome is shown the strong nonlinearity of unstable phenomenon in accordance with the external force. Therefore, the purpose of this study is to analyze and verify comparatively the unstable phenomenon of the Geiger and Flower type cable dome structures under axismmetric load.

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The Development of Swivel Unit for Spot Welding Robots (스폿용접 로봇용 스위블 유닛의 개발)

  • Kim, Yong-Seok;Park, Sung-Ho;Yang, Soon-Young
    • Transactions of the Korean Society of Machine Tool Engineers
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    • v.17 no.4
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    • pp.119-125
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    • 2008
  • A new type of swivel unit is suggested in order to complement weak points of the existing. This new type of Swivel unit is developed by adopting a spring type cable which has elasticity and restoring force. To minimize the troubles in the process of manufacturing during operating the new type system, strength analysis and the check of interference between parts are accomplished with CATIA. The check of rotating performance is also carried out to determine the diameter and length of spring type cable by SimDesigner motion analysis. Swivel unit used in the robot spot welding is developed with spring type cable and its usefulness in the industrial field is verified through experiments. This system has been registered for patent.

Estimation of Tension Forces of Assembly Stay Cables Connected with Massive Anchorage Block (중량 앵커리지 블록과 연결된 조립 스테이 케이블의 장력 추정)

  • Jeong, Woon;Kim, Nam-Sik
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2004.11a
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    • pp.435-440
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    • 2004
  • In this paper, the tension of assembly stay cable connected with massive anchorage block was calculated through back analysis of in-situ frequencies measured from a stadium structure. Direct approach to back analysis is adopted using the univariate method among the direct search methods as an optimization technique. The univariate method can search the optimal tension without regard to the initial ones and has a rapid convergence rate. To verify the reliability of back analysis, Tension formulas proposed by Zui et al. and Shimada were used. Tensions estimated by three methods are compared with the design tension, and are in a reasonable agreement with an error of more or less than 15%. Therefore, it is shown that back analysis applied in this paper is appropriate for estimation of cable tension force.

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Applicability estimation for cable assembling method of shield tunnel using field test construction (현장 조립 시험시공을 통한 쉴드터널 강연선 체결 기술의 적용성 평가)

  • Kim, Dong-Min;Ma, Sang-Joon;Lee, Young-Sub
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.17 no.1
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    • pp.11-23
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    • 2015
  • In this study, the new segment assembling method using cable tensible force was developed to improve the problem of bolt assembling method of shield tunnel. In the field test construction, cable assembling method reduced the assembling time of segment in comparison with bolt assembling method because of guide role of segment shear-key. In the result of measuring the necessary time for segment assembling process, it took 420sec to assemble one segment in bolt method and 400sec to assemble one segment in cable method, but in case of using the cable automatic feeder, it could reduce the necessary time as 60sec in comparison with bolt assembling method. The cable automatic system modeling using BIM, that connected shield TBM also will be utilized in the area of design TBM, excavation plan, method process understanding, construction management and so on.

Optimization of Sensor Location for Real-Time Damage assessment of Cable in the cable-Stayed Bridge (사장교 케이블의 실시간 손상평가를 위한 센서 배치의 최적화)

  • Geon-Hyeok Bang;Gwang-Hee Heo;Jae-Hoon Lee;Yu-Jae Lee
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.27 no.6
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    • pp.172-181
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    • 2023
  • In this study, real-time damage evaluation of cable-stayed bridges was conducted for cable damage. ICP type acceleration sensors were used for real-time damage assessment of cable-stayed bridges, and Kinetic Energy Optimization Techniques (KEOT) were used to select the optimal conditions for the location and quantity of the sensors. When a structure vibrates by an external force, KEOT measures the value of the maximum deformation energy to determine the optimal measurement position and the quantity of sensors. The damage conditions in this study were limited to cable breakage, and cable damage was caused by dividing the cable-stayed bridge into four sections. Through FE structural analysis, a virtual model similar to the actual model was created in the real-time damage evaluation method of cable. After applying random oscillation waves to the generated virtual model and model structure, cable damage to the model structure was caused. The two data were compared by defining the response output from the virtual model as a corruption-free response and the response measured from the real model as a corruption-free data. The degree of damage was evaluated by applying the data of the damaged cable-stayed bridge to the Improved Mahalanobis Distance (IMD) theory from the data of the intact cable-stayed bridge. As a result of evaluating damage with IMD theory, it was identified as a useful damage evaluation technology that can properly find damage by section in real time and apply it to real-time monitoring.

Study on mechanical behaviors of cable-supported ribbed beam composite slab structure during construction phase

  • Qiao, W.T.;An, Q.;Wang, D.;Zhao, M.S.
    • Steel and Composite Structures
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    • v.21 no.1
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    • pp.177-194
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    • 2016
  • The cable-supported ribbed beam composite slab structure (CBS) is a new type of pre-stressed hybrid structure. The standard construction method of CBS including five steps and two key phases are proposed in this paper. The theoretical analysis and experimental research on a 1:5 scaled model were carried out. First, the tensioning construction method based on deformation control was applied to pre-stress the cables. The research results indicate that the actual tensile force applied to the cable is slightly larger than the theoretical value, and the error is about 6.8%. Subsequently, three support dismantling schemes are discussed. Scheme one indicates that each span of CBS has certain level of mechanical independence such that the construction of a span is not significantly affected by the adjacent spans. It is shown that dismantling from the middle to the ends is an optimal support dismantling method. The experimental research also indicates that by using this method, the CBS behaves identically with the numerical analysis results during the construction and service.

Probabilistic Structural Safety Assessment Considering the Initial Shape and Non-linearity of Steel Cable-Stayed Bridges (강사장교의 초기형상과 비선형성을 고려한 확률론적 구조안전성 평가)

  • Bang, Myung-Seok;Han, Sung-Ho;Lee, Woo-Sang;Lee, Chin-Ok
    • Journal of the Korean Society of Safety
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    • v.25 no.3
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    • pp.91-99
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    • 2010
  • In this study, the advanced numerical algorithm is developed which can performed the static and dynamic stochastic finite element analysis by considering the effect of uncertainties included in the member stiffness of steel cable-stayed bridges and seismic load. After conducting the linear and nonlinear initial shape analysis, the advanced numerical algorithm is the assessment tool which can performed structural the response analysis considering the static linearity and non-linearity of before or after induced intial tensile force, and examined the reliability assessment more efficiently. The verification of the developed numerical algorithm is evaluated by analyzing the regression analysis and coefficient of correlation using the direct monte carlo simulation. Also, the dynamic response characteristic and coefficient of variation of the steel cable-stayed bridge is calculated by considering the uncertainty of random variables using the developed numerical algorithm. In addition, the quantitative structural safety of the steel cable-stayed bridges is evaluated by conducting the reliability assessment based upon the dynamic stochastic finite element analysis result.