• Title/Summary/Keyword: partial Event Tree Analysis(ETA)

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System Reliability-Based Safety Assessment of Steel Cable-Stayed Bridges (체계신뢰성방법에 기초한 강사장교의 안전도평가)

  • 조효남;임종권;박경훈
    • Computational Structural Engineering
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    • v.11 no.4
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    • pp.351-360
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    • 1998
  • 본 논문에서는 실용적 체계신뢰성에 기초한 강사장교의 안전도평가를 위한 체계적인 모형을 제안하였다. 공용중인 강사장교의 시스템 안전도평가를 위하여 요소신뢰성해석을 위한 케이블, 주형 그리고 주탑의 한계 상태모형과 각 요소들간의 조합파괴를 포함하는 주파괴경로를 정의할 수 있는 체계신뢰성해석 모형을 제안하였다. 요소신뢰성해석을 위한 수치해석기법으로는 AFOSM(Advanced First Order Second Moment) 방법을 사용하였고, 체계신뢰성해석을 위해서는 부분 ETA(partial Event Tree Analysis) 모형을 사용하였다. 제안된 방법의 타당성을 고찰하기 위하여 진도대교의 안전도 평가에 적용하였다. 부분 ETA 모혀을 사용한 체계신뢰성 평가 방법은 기존의 요소신뢰성 방법에 비해 구조물의 여용성을 충분히 반영하는 상당히 합리적이며 실제적인 결과를 보여주는 실용적인 방법으로 판단된다.

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Analysis of Electrical Accident for Outlet Circuit of Laboratory on ETA (ETA를 통한 연구실험실 콘센트회로의 전기재해 분석)

  • Kim, Doo-Hyun;Kim, Sung-Chul;Park, Jong-Young;Kim, Sang-Chul
    • Journal of the Korean Society of Safety
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    • v.32 no.2
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    • pp.27-33
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    • 2017
  • This study is intended to identify issues on the basis of investigating the actual state of laboratory environment and outlet circuit, and derive end states by expressing sequences from the initiating event of disaster to accident in leakage current, poor contact and overload through ETA(event tree analysis). To this end, this study investigated the actual state of electric equipment of laboratory at universities in all parts of country. And it is shown that most of them are failure in electric work and user negligence in the investigation of actual state. It is found that there is earth fault and defect in wire diameter in the failure of electric work and the problem of partial disconnection due to wire bundling and poor contact in user negligence. Outlet-related component, failure rate and initiating events are composed of a total of 41 initiating events, i.e., 30 internal initiating events and 11 external initiating events. And end states are composed of a total of 15 parts, i.e., 3 electric power parts and 12 safety parts. Earthing class 3 is the most important safety device against leakage current (initiating event). And in case of poor contact, it is necessary for manager to check thoroughly because there is no safety device. In case of overload/overcurrent, when high-capacity equipment is connected, a molded case circuit breaker, safety device, worked. However, in most cases, it is verified that this doesn't work. This study can be utilized as electric equipment safety guide for laboratory safety manager and managers.

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.