• Title/Summary/Keyword: Nondestructive

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Use of Nondestructive Evaluation Methods in Bridge Management Systems (교량유지관리시스템에 있어서 비파괴 시험의 효율적 활용 방안)

  • 심형섭
    • Proceedings of the Korea Concrete Institute Conference
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    • 2000.10b
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    • pp.1291-1296
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    • 2000
  • A basis for the direct use of data from nondestructive evaluation methods in bridge management systems is presented. Bridge management systems use integer-valued condition ratings to recognize conditions of bridge elements, to model progression of deterioration, and to determine repair needs. Data from nondestructive evaluation methods can inform management systems on the extent of damage, on the initiation of deterioration processes, and on the exposure of bridge elements to aggressive agents. In addition, data obtained through nondestructive evaluation methods allow the formation of models of specific deterioration process. The use of these data in bridge management systems requires redefinition of condition ratings together with the creation of procedures for automated interpretation of data. By these action, nondestructive evaluation methods are directly used to assign condition ratings, and condition ratings are made into terse form of NDE data that are compatible with present day bridge management systems. This paper reports work in progress to strategic use of nondestructive evaluation methods in bridge management system.

Korean Round-Robin Tests Result for New International Program to Assess the Reliability of Emerging Nondestructive Techniques

  • Kim, Kyung Cho;Kim, Jin Gyum;Kang, Sung Sik;Jhung, Myung Jo
    • Nuclear Engineering and Technology
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    • v.49 no.3
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    • pp.651-661
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    • 2017
  • The Korea Institute of Nuclear Safety, as a representative organization of Korea, in February 2012 participated in an international Program to Assess the Reliability of Emerging Nondestructive Techniques initiated by the U.S. Nuclear Regulatory Commission. The goal of the Program to Assess the Reliability of Emerging Nondestructive Techniques is to investigate the performance of emerging and prospective novel nondestructive techniques to find flaws in nickel-alloy welds and base materials. In this article, Korean round-robin test results were evaluated with respect to the test blocks and various nondestructive examination techniques. The test blocks were prepared to simulate large-bore dissimilar metal welds, small-bore dissimilar metal welds, and bottom-mounted instrumentation penetration welds in nuclear power plants. Also, lessons learned from the Korean round-robin test were summarized and discussed.

A study on appropriate nondestructive inspection methods of gear units for rolling stock (전동차 대치차 기어의 적절한 탐상법에 관한 연구)

  • Lee, Jae-Il;Lee, Min-Yeol;Lee, Won-Hak;Son, Young-Jin
    • Proceedings of the KSR Conference
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    • 2010.06a
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    • pp.571-582
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    • 2010
  • Typically nondestructive inspection methods of the large gear units are applied to penetrate non-destructive inspection. Nondestructive penetrating inspection put into the small openings of the defect to penetration liquid, remove to excess penetration liquid on the surface of the gear units, spread with developing solution and we can find the small defect by coating with penetration liquid. However, this method has so many issues because of penetrate nondestructive tests on the gear assembly. The steep angle of screw is hard to achieved full penetration and has the problem to remove the excess. In contrast, the magnetic nondestructive inspection is easy to detect subsurface defects and subtle defects. According to the inspection results the stress concentrates in gear surface, some internal defects and microscopic flaws exist on the gear units are not found to penetrate the nondestructive inspection, but magnetic nondestructive inspection could have found many defect. Therefore, a reasonable method of nondestructive inspection for the large gear units is suitable to magnetic nondestructive inspection.

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Detection and Evaluation Technique of Hydrogen Attack (수소손상 검출과 평가기술)

  • Won, Soon-Ho;Hyun, Yang-Ki;Lee, Jong-O;Cho, Kyung-Shik;Lee, Jae-Do
    • Journal of the Korean Society for Nondestructive Testing
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    • v.22 no.1
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    • pp.32-37
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    • 2002
  • The presence of hydrogen in industrial plants is a source of damage. Hydrogen attack is one such form of degradation and often causing large tube ruptures that necessitate an immediate shutdown. Hydrogen attack may reduce the fracture toughness as well as the strength of steels. This reduction is caused partially by the presence of cavities and microcracks at the grain boundaries. In the past several techniques have been used with limited results. This paper describes the application of an ultrasonic velocity and attenuation in hydrogen damage. Ultrasonic tests showed a decrease in wave velocity and an increase in attenuation. Such results demonstrate the potential for ultrasonic nondestructive testing to quantify damage. Based on this study, reliable recommendation is suggested to detect hydrogen attack.