• Title/Summary/Keyword: Internal Flaw

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A Study on the Safety of Lifting Cable for Construction of Coastal Structures (항만건설을 위한 케이슨 들고리의 안전성에 관한 연구)

  • Kwak, Kae Hwan;Jang, Ki Woong;Kim, Jong Hyo
    • Journal of Korean Society of Steel Construction
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    • v.10 no.1 s.34
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    • pp.85-99
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    • 1998
  • This paper describes an experimental study to examine collapse causes of the lifting cable due to brittle failure of an fitting anchor under the lifting works. Also, in this study an collapse mechanism that was obtained from stress analysis was compared with an actual collapse procedure. Fractographical analysis as well as chemical component test, tension test and Charpy V-Notch impact test for the fractured steel members were carried out. And then, its results were compared with that of normal steel members. Circumferential surface flaws were developed at internal facets of the fitting anchor before tensile stress occurred. Hence, a higher stress than nominal stress was occurred at flaws by stress concentration at the crack tip. Also, stress intensity factor of members increased by crack size of the potential flaws. Because the stress intensity factor at the crack tip was greater than critical values(fracture toughness), brittle fracture occurred under the lifting works. It is judged that the main collapse of the lifting cable is due to brittle fracture of the fitting anchor.

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The Design of the Integrated Module to Cope with Sudden Unintended Acceleration (자동차 급발진을 대비하기 위한 통합 모듈 설계)

  • Cha, Jea-Hui;Jang, Jong-Wook
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2016.10a
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    • pp.221-223
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    • 2016
  • Currently in the automobile market, models with many convenient functions combined with IT have been released. This change has a strength that there could be many convenient and useful functions related to driving while flaws of vehicles caused by malfunctions of these electronic equipments could trigger serious incidents. Among them, the sudden unintended acceleration considered as the most serious is a serious flaw that could threaten driver's life. However, the causes for sudden acceleration incidents have not been clearly investigated with no coping measures. As manufacturers shift the responsibility to drivers' carelessness, drivers' burden is continuously increasing. Thus, this paper designed the system to cope with sudden acceleration incidents by changing conditions of controlling parts like accelerator and brake, and internal image of the driver's seat into data through the integrated module.

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