• Title/Summary/Keyword: Cable요소

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The Sensitivity Analysis and Safety Evaluations of Cable Stayed Bridges Based on Probabilistic Finite Element Method (확률유한요소해석에 의한 사장교의 민감도 분석 및 안전성 평가)

  • Han, Sung-Ho;Cho, Tae-Jun;Bang, Myung-Seok
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.11 no.1
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    • pp.141-152
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    • 2007
  • Considering uncertainties of random input data, it is more reasonable to use probabilistic method than the conventional deterministic method for the design of structures or for the assessment of the responses of structures, which are designed as safe even under extreme loads. Therefore, to assess the quantitative effects of the constructed cable stayed bridge by the input random variables, a sensitivity analysis is studied. Using perturbation method, an analysis program is developed for the iterative probabilistic finite element analyses and sensitivity analyses of the cable stayed bridge, except the initial shape analysis. Monte-Carlo Simulations were used for the verification of the developed program. The results of sensitivity analysis shows the governing effects of external loads. Because the results also provide the sensitive effects of the stiffness of members and the magnitudes of prestressing force of cables, the developed

Seismic Analysis of a 3-dimensional Cable-Stayed Bridge with an Unsymmetric Girder Cross-section (주형단면의 비대칭성을 고려한 3차원 사장교의 지진해석)

  • Kim, Chul Young;Chang, Sung Pil
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.12 no.2
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    • pp.11-20
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    • 1992
  • In general, the cross-section of a girder of a bridge has only one axis of symmetry. Therefore, lateral forces such as earthquake and wind may cause torsion coupled with lateral bending in the gider. This induces additional stresses especially in cables arranged in double-planes. Since this effect cannot be considered by using the conventional frame elements, the stiffness and the mass matrices of the geometrically nonlinear thin-walled frame element have to be used in order to model the girder. Theoretical development and verification of the frame element used in this study were made through a-previously presented paper. In this paper, seismic analysis of a three dimensional cable-stayed bridge considering the unsymmetry of the girder cross-section is performed to investigate the coupled flexural-torsional behaviors.

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Analysis of Structures of ONGAMENET's TV Program "From Start to till the End" (온게임넷 TV 프로그램 "켠김에 왕까지" 구조 분석)

  • Han, Sukhee
    • Journal of Korea Game Society
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    • v.16 no.3
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    • pp.45-54
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    • 2016
  • This study analyzes cable TV Program "From Start to Till the End" televised by ONGAMENET from 2009 to 2015. "From Start to Till the End" is a game program that guests try to finish certain game or to complete mission once they started. Unlike other game programs, most of guests are not professional gamers thus it brings out comical challenges and enjoyments. This study examines the several components of video games played in the program. Specifically, those components are categorized according to the genre, platform, nationality, and clear time. In doing so, this study not only unpacks diverse structures of the program but also provides the blueprint of the game program.

The Effect of Swelling Rate for 400kV PPLP Insulated Oil-Filled Electric Power Cable (400kV급 반합성지 전력케이블용 절연지(PPLP)의 팽윤현상이 전기적 성능에 미치는 영향)

  • Park, Se-Eun;Lee, Sang-Jin;Kim, Dong-Wook
    • Proceedings of the KIEE Conference
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    • 2006.07c
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    • pp.1363-1363
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    • 2006
  • PPLP를 절연지로 사용하는 OF 케이블 절연지의 팽윤 특성은 전력 케이블 절연특성에 크게 영향을 줄 뿐만 아니라, 케이블 제조나 운전시에도 영향을 미치므로 매우 중요한 설계 관리 요소이다. 특히 PPLP 케이블 제조시 PPLP의 팽윤 정도에 따라 지권장력의 설정이 달라지므로 반드시 고려해야만 한다. 기존의 일반적인 Kraft지를 절연지로 사용하는 OF 케이블의 경우는 팽윤 현상이 거의 없어 지권장력 설정시 이를 고려하지 않아도 되지만, PPLP는 이를 고려하지 않고 지권을 찬다면 케이블 제조 후 절연지의 끊어짐 현상, 절연층의 butt-gap 현상 둥 Polypropylene laminated paper를 절연지로 사용하는 케이블의 경우, 팽윤 현상의 발생으로 인해 절연파괴가 일어날 수 있다. 그러나 PPLP 절연지를 사용하는 이유는 케이블의 장거리 운전시 기존 Kraft지를 사용했을 때 보다 유전손실이 더 개선될 뿐만 아니라 절연체의 두께를 저감하여 포설이 용이하기 때문이다. 이에 본 논문에서는 PPLP에서 고분자의 팽윤이 일어나는 정도에 따라 결정화도의 변화와 전기적인 성능(체적저항, AC 파괴)과의 연관성을 검토하였다.

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Evaluation of Reliability Index of Governing Load Combination for Design of Cable Supported Bridge Members (케이블교량의 부재 설계를 지배하는 하중조합에 대한 신뢰도지수 평가)

  • Paik, Inyeol;Yoon, Taeyong
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.27 no.6
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    • pp.643-651
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    • 2014
  • In this paper the reliability analyses of the cable-supported bridge design code which is recently issued in Korea are performed and the results are presented. Governing load combinations for the member design and the statistical properties of the main members are introduced and the analysis is performed using an example cable-stayed bridge for which the design is performed following the load and resistance factors defined in the design code. The reliability analysis shows the target reliability index can be achieved by applying load and resistance factors and the application of the resistance modification factor can enhance the reliability level if the importance of the bridge needs to be increased. The sensitivity analysis reveals that decreasing uncertainty of the cable strength is critical for obtaining the target reliability index. The study results show that the design using the load and resistance factors of the code can achieve the target reliability indexes for the design of cable supported bridge.

A Study on the Modal Parameters for Cable System of Bridge (교량 케이블시스템의 모드변수에 관한 연구)

  • Lee, Hyunchol;Jo, Yeong-hoon;Kim, Jinsoo;Park, Kyoungho
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.23 no.5
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    • pp.48-59
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    • 2019
  • In recent years, the type of bridge where cables such as suspension bridge and cable-stayed bridge are the main factors in the construction of long-range bridges has been soaring. The effects of cables on these structures are very large, and for structural analysis, it is necessary to study the cable and the structural changes according to the mode characteristics of the cables. In particular, cables are directly connected to camber adjustment, which conveys load effects on girders to tower, and are important components in the overall structure, and since the initial tension on the construction is compared with the tension over time, this study was conducted to help identify the condition of the bridge's aging and abnormalities. Therefore, in this study, the characteristics of the mode from the mode analysis through the impact hammer to the mass of the cable and the change in the length of the cable are analyzed.

A study on the effect of cable improvement renovating an old aircraft (노후 항공기 개조 시 케이블 개량에 따른 효과 연구)

  • Lee, Gwang-suk;Yoon, In-bok;Jang, In-dong
    • Journal of IKEEE
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    • v.26 no.2
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    • pp.257-264
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    • 2022
  • As it takes a lot of time and money to develop an aircraft, an environment for renovating and using existing operating aircraft has been created. As a result, many old aircraft were renovated, and due to the aging of the aircraft, more demanding cable requirements were required for renovation projects, and as the number of equipment inside the aircraft gradually increased, the difficulty of system integration increased. In order to solve the difficulties of system integration through systematization of verification procedures, this paper explains VSWR, I-loss, which are the main indicators of antenna cable modification, and explains DTF, one of the problem detection methods. It also explains the elements required for cable design, the environment to be measured, and procedures, and introduces the overall process and effect of antenna cable improvement through demonstration cases.

Shaping Formation and Behaviour Characteristic for SCST Structure by Cable-tensioning (Cable-tensioning에 의한 SCST 구조의 형상 형성과 거동 특성)

  • Kim, Jin-Woo;Kwon, Min-Ho
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.28 no.6A
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    • pp.819-825
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    • 2008
  • This paper describes the shaping formation and the erection of SCST structure by cable-tensioning. It could be a fast and economical method for constructing the space structure consisted with uniform pyramids by cable-tensioning of the cable in bottom chords. In the initial layout, the top chords and web members are left at their true length, the bottom chords are given gaps in proportion to the desired final shape. The feasibility of the proposed shaping method and the reliability of the established geometric model were confirmed with nonlinear finite element analysis and an experimental investigation on small scale and full size test models. As a result, the behaviour characteristic of MERO joint is very significant in shaping analysis of space structure. This study suggests the most reasonable modeling technique for the prediction of shaping in practices. And it is shown the characteristic of the behavior in shaping test for practical design purposes.

Erection Sequence Analysis of Suspension Bridge Considering to Sliding of Main Cable (주케이블의 슬라이딩을 고려한 현수교의 시공단계 해석)

  • Yhim, Sung-Soon;Kong, Min-Sik;Kim, Byeong-Cheol
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.13 no.3 s.55
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    • pp.164-172
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    • 2009
  • Anchors and saddles are used to have sufficient geometrical rigidity and make target configuration of main cable of suspension bridge. Neglecting the sliding effect at saddles, points at them have been idealized as fixed nodes in lots of former studies. In general, sliding effects are reported to show significant structural behaviors of main cable and cause to the different responses of bridges. During early erection steps of the suspension bridge, especially, the sliding effect occurs easily because there is large difference of cable tension between main and side span in removing set-back ropes or not applying set-back. This study presents the finite element analysis considering to cable sliding effect and shows the comparison of differences between sliding and non-sliding at election sequence. The analysis of sliding between main cables and saddles needs to obtain more realistic responses because the analysis result can represent unfavorably different responses of bridges. Moreover, the sliding analysis method and results in this study can be used to basic criteria in engineering design and construction steps.

Probabilistic Safety Analysis of Cable-Stayed Bridge Using Measured Data (계측데이터를 이용한 사장교의 확률적 안전도 분석)

  • Yoon, Man-Geun;Cho, Hyo-Nam
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.12 no.3
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    • pp.175-182
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    • 2008
  • In this paper, through the study and consideration of the recently prominent monitoring of cable stayed-bridge, practical but reasonable suggested for the evaluation of the probabilistic safety of the bridges using probable measured data from monitoring measurement system. It is shown in the paper that the live load effects can be evaluated using measured data of cable-stayed bridge and this the realistic probabilistic safety of the cable-stayed bridge could be assessed in term of element reliability and system reliability. As a practical method for the evalution of the system reliability of system cable-stayed bridges partial ETA method is uesd, which can find the critical failure path including combined failure modes of cable, deck and pylon. Compared with the conventional safety analysis method, the propsed approach may be considered as the practical method that shows the considerably actual and reasonable results the system redundancy of the structure.