• Title, Summary, Keyword: 케이블 강성

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Abnormal Response Analysis of a Cable-Stayed Bridge using Gradual Bilinear Method (Gradual Bilinear Method를 이용한 사장교의 케이블 손상응답 해석)

  • Kim, Byeong-Cheol;Park, Ki-Tae;Kim, Tae-Heon;Hwang, Ji-Hyun
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.18 no.6
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    • pp.60-71
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    • 2014
  • Cable-stayed bridge, which is one of the representative long-spanned bridge, needs prompt maintenances when a stay cable is damaged because it may cause structural failure of the entire bridge. Many researches are being conducted to develop abnormal behavior detection algorithms for the purpose of shortening the reaction time after the occurrence of structural damage. To improve the accuracy of the damage detection algorithm, ample observation data from various kinds of damage responses is needed. However, it is difficult to measure an abnormal response by damaging an existing bridge, numerical simulation can be an effective alternative. In most previous studies, which simulate the damage responses of a cable-stayed bridge, the damages has been considered as a load variation without regard to its stiffness variation. The analyses of using these simplification could not calculate exact responses of damaged structure, though it may reserve a sufficient accuracy for the purpose of bridge design. This study suggests Gradual Bilinear Method (GBM) which simulate the damage responses of cable-stayed bridge considering the stiffness and mass variation, and develops an analysis program. The developed program is verified from the responses of a simple model. The responses of a existing cable-stayed bridge model are analyzed with respect to the fracture delay time and damage ratio. The results of this study can be used to develop and verify the highly accurate abnormal behavior detection algorithm for safety management of architecture/large structures.

345KV 반합성지(PPLP) 절연 OF 케이블의 개발

  • 김종원;최창수;강성호;이갑종
    • 전기의세계
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    • v.42 no.2
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    • pp.60-68
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    • 1993
  • 본 Report는 345KV 반합성지 (PPL) 절연 SELF CONTANED OIL FILLED CABLE 개발에 대해 1992년 8월 30일-9월 5일에 프랑스 파리에서 개최된 제34차 CIGRE 대회에서 발표된 내용을 재 정리한 것이다.

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Strengthening of Reinforced Concrete Continuous Beams in Flexure by Partial External Unbonded Tendons (철근콘크리트 연속보에서 부분프리스트레스 도입에 의한 휨보강 효과)

  • Yun, Hyun-Do;Yang, Il-Seung;Lim, Jea-Hyung;Moon, Jeong-Ho
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.10 no.1
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    • pp.165-172
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    • 2006
  • A variety of techniques for strengthening have been developed, including pate bonding, external prestressing and overslabbing. Expecially, a strengthening technique for reinforced concrete beams using external unbonded reinforcement offers advantages in speed and simplicity of installation. The purpose of this paper is to investigate the capabilities of a new retrofitting technique, namely external prestressing(out-cable), for flexural strengthening of beams. Results of 2 physical tests (external Post-tension and out-cable system specimen) on strengthened reinforced concrete continuous beams are reported and compared. It is shown that the out-cable system can provide strength enhancement.

Passive Control System for Mitigation of Cable Vibration in Cable-Stayed Bridges (사장교의 케이블 진동저감을 위한 수동 제어시스템)

  • Hwang, Inho;Lee, Jong Seh
    • Journal of The Korean Society of Civil Engineers
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    • v.26 no.5A
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    • pp.881-885
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    • 2006
  • Rain-wind induced cable vibration can cause serious problems in cable-stayed bridges. Externally attached dampers have been used to provide an effective means to suppress the vibration of relatively short stay-cables. For very long stay-cables, however, such damper systems are rendered ineffective, as the dampers need to be attached near the end of cables for aesthetic reasons. This paper investigates a new control system to mitigate the cable vibration. The proposed control system which consists of a laminated rubber bearing and an internal damper may be installed inside of the cable anchorage. A simple analytical model of the cable-damper system is developed first based on the taut string representation of the cable. The response of a cable with the proposed control system is obtained and then compared to those of the cable with and without an external passive damper. The proposed stay-cable vibration control system is shown to perform better than the optimal passive viscous damper, thereby demonstrating its applicability in large cable-stayed bridges for mitigation of rain-wind induced vibration of stay-cables.

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Nonlinear Dynamic Analysis on Low-Tension Towed Cable by Finite Difference Method (유한차분법을 이용한 저장력 예인케이블의 비선형 동적해석)

  • Han-Il Park;Dong-Ho Jung
    • Journal of the Society of Naval Architects of Korea
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    • v.39 no.1
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    • pp.28-37
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    • 2002
  • In this study nonlinear dynamic behaviors of towed tow-tension cables are numerically analysed. In the case of a taut cable analysis, a bending stiffness term is usually neglected due to its minor effect but it plays an important role in a low-tension cable analysis. A low-tension cable may experience large displacements due to relatively small restoring forces and thus the effects of fluid and geometric non-linearities become predominant. The bending stiffness and non-linearity effects are considered in this work. In order to obtain dynamic behaviors of a towed low-tension cable, three-dimensional nonlinear dynamic equation is described and discretized by employing a finite difference method. An implicit method and Newton-Raphson iteration are adopted for the time integration and nonlinear solutions. For the calculation of huge size of matrices. block tri-diagonal matrix method is applied, which is much faster than the well-known Gauss-Jordan method in two point boundary value problems. Some case studies are carried out and the results of numerical simulations are compared with those of a in-house program of WHOI Cable with good agreements.

A Study on Three-dimensional Dynamic Analysis of a Towing Cable for Marine Survey Instruments (해양탐사장비 예인케이블의 3차원 동적해석에 관한 연구)

  • 정동호;김종규;박한일
    • The Sea
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    • v.8 no.2
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    • pp.203-209
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    • 2003
  • In this study, the configuration and tension of a towing cable for side-scan sonar are predicted in an ambient flow and at an unsteady towing condition. The governing equation of three-dimensional dynamic analysis for a flexible cable is solved using a finite difference method. We successfully predict the configuration and tension of a side-scan sonar and designed the towing system. It is found in static analyses that the side-scan sonar must be towed to keep a its stable depth at a reasonable speed. The study also reveals in the transient analyses that the dominant component affecting the top tension is the tangential drag force for the larger towing speed than the critical speed, and the soft weight of a towed instrument for the smaller towing speed than. It should be maneuvered for a towing vessel with good consideration for the impact effect in a cable due to tension peak when a towing speed is suddenly increase. The developed program can be applicable for three-dimensional dynamic analysis of a towing system for various marine survey instruments.

Determination of the Accurate Effective Length for Buckling Design of Cable-Supported Bridges (케이블지지교량의 좌굴설계를 위한 유효좌굴길이 산정)

  • Jin, Man Sik;Kyoung, Yong Soo;Lee, Myung Jae;Kim, Moon Young
    • Journal of Korean Society of Steel Construction
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    • v.16 no.3
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    • pp.355-363
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    • 2004
  • In order to obtain the effective length factor of beam-column members of plane frames, this paper extensively used an alignment chart approach, based on the nomograph given in LRFD-AISC specification commentaries. However, it should be noted that various simplifications and assumptions were introduced in constructing the alignment chart. To overcome the practical limitations of the alignment chart, this paper proposes a simple but accurate procedure that determined the effective buckling length for stability design of main members of cable-supported bridges. This method requires the full system buckling analysis. The numerical examples showing the suitability of the present scheme are discussed and some conclusions are drawn.

Back Analysis Technique for the Estimation of Tension Force on Hanger Cables (역해석기법을 이용한 행어케이블의 장력 추정)

  • Kim, Nam-Sik;Park, Dong-Uk;Park, Yong-Myung;Cheung, Jin-Hwan
    • Journal of the Earthquake Engineering Society of Korea
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    • v.11 no.3
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    • pp.1-10
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    • 2007
  • In general, the tension forces of hanger cable in suspension bridges play an important role in evaluating the bridge conditions. The vibration method, as a conventional one, has been widely applied to estimate the tension forces by using the measured frequencies on hanger cables. However, the vibration method is not applicable to short hanger cables because the fiequencies of short cables are severely sensitive to flexural rigidity. Thus, in this study, the tension forces of short hanger cables, of which the length is shorter than 10 meters, were estimated through back analysis of the cable fiequencies measured from Gwang-An suspension bridge in Korea. Direct approach to back analysis is adopted using the univariate method among the direct search methods as an optimization technique. The univariate method is able to search the optimal tension forces without regard to the initial ones and has a rapid convergence rate. To verify the feasibility of back analysis, the results from back analysis and vibration method are compared with the design tension forces. From the comparison, it can be inferred that back analysis results are more reasonable agreement with the design tension forces of short hanger cable. Therefore, it is concluded that back analysis applied in this study is an appropriate tool for estimating tension forces of short hanger cables.

Estimation of tension force of stay cables using vibration method (진동법을 이용한 지지케이블의 장력추정)

  • Chang, Kug-Kwan;Jin, Byung-Chang;Chun, Young-Soo;Han, Tae-Kyung;Kang, Woo-Goo
    • Proceedings of the Korea Concrete Institute Conference
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    • pp.77-78
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    • 2009
  • This study is to consider the character of cables in six World-Cup stadiums constructed in 2002 in Korea and to inspect problem on application of existing theory. The result of experiment shows that it is possible to determine the tension force of the real cables with an accuracy of 10${\sim}$60 by taking the cable bending stiffness. However, the reliance of the tension force experimentally determined could be changed in tension in the cable.

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Trends of Human Body Communications (인체통신 기술 현황 및 전망)

  • Kang, S.W.;Park, H.I.;Park, K.H.
    • Electronics and Telecommunications Trends
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    • v.28 no.2
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    • pp.70-76
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    • 2013
  • 인체통신 기술은 유선통신 기술에서와 같이 기기들 간의 연결을 위한 다양한 형태의 케이블이 필요하지 않으므로 기존 유선통신 기술에 비해 편리한 우월성을 가진다. 그렇지만 보안성과 신뢰성은 유선통신의 장점을 넘을 수는 없을 것이다. 무선통신 기술은 초기 네트워크를 구성하기 위하여 서로 복잡하게 주고 받는 절차단계가 필요한 반면, 인체통신 기술은 사용자의 간단한 접촉만으로 통신이 서로 이루어지기 때문에 보다 더 간편하게 연결되며, 사용자 중심의 서비스를 용이하게 제공할 수 있다. 본고는 최근의 인체통신 기술의 기술 동향과 시장 전망 및 표준화 동향을 살펴보고자 한다.

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