• 제목/요약/키워드: nondestructive

검색결과 2,605건 처리시간 0.027초

Evaluation of Structural Integrity and Performance Using Nondestructive Testing and Monitoring Techniques

  • Rhim, Hong-Chul
    • 한국지진공학회논문집
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    • 제2권3호
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    • pp.73-81
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    • 1998
  • In this paper, the necessity of developing effective nondestructive testing and monitoring techniques for the evaluation of structural integrity and performance is described. The evaluation of structural integrity and performance is especially important when the structures and subject to abrupt external forces such as earthquake. A prompt and extensive inspection is required over a large area of earthquake-damaged zone. This evaluation process is regarded as a part of performance-based design. In the paper, nondestructive testing and monitoring techniques particularly for concrete structures are presented as methods for the evaluation of structural integrity and performance. The concept of performance-based design is first defined in the paper followed by the role of evaluation of structures in the context of overall performance=based design concept. Among possible techniques for the evaluation, nondestructive testing methods for concrete structures using radar and a concept of using fiber sensor for continuous monitoring of structures are presented.

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Virtual Reality Presentation for Nondestructive Evaluation of Rebar Corrosion in Concrete based on Inverse BEM

  • Kyung, Je-Woon;Yokota, Masaru;Leelalerkiet, V.;Ohtsu, Masayasu
    • 비파괴검사학회지
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    • 제25권3호
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    • pp.157-162
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    • 2005
  • In order to evaluate the corrosion of reinforcing steel-bars (rebar) in concrete, a nondestructive evaluation by the half-cell potential method is currently applied. In this study, potentials measured on a concrete surface are compensated into those on the concrete-rebar interface by the inverse boundary element method (IBEM). Because these potentials are obtained three-dimensionally (3-D), 3-D visualization is desirable. To this end, a visualization system has been developed by using VRML (Virtual Reality Modeling Language). As an application, results of a reinforced concrete (RC) slab with corroded rebars are visualized and discussed.

Laser Lock-in Thermal Wave Imaging for Nondestructive Evaluation

  • An, Yun-Kyu;Sohn, Hoon;Kim, Ji Min
    • 비파괴검사학회지
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    • 제33권4호
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    • pp.317-322
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    • 2013
  • This paper presents a new laser lock-in thermography (LLT) technique for nondestructive evaluation. LLT utilizes a modulated continuous wave laser beam as a heat source to obtain high fidelity thermal wave images even at the presence of background heat disturbances. The thermal waves propagating along the surface and through-the-thickness directions of a structure are visualized using newly developed laser lock-in amplitude and phase images, enhancing the detectability of surface and subsurface defects. The LLT technique is numerically investigated and experimentally validated using thermal images obtained from a steel specimen with low emissivity.

Comparison of Near-Infrared Spectroscopy with Raman Spectroscopy from the Point of Nondestructive Analysis of Biological Materials

  • Takeyuki Tanaka;Hidetoshi Sato;Jung, Young-Mee;Yukihiro Ozaki
    • Near Infrared Analysis
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    • 제1권2호
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    • pp.9-20
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    • 2000
  • Recently, near-infrared (NIR) spectroscopy and Raman spectroscopy have received keen interest as powerful techniques for nondestructive analysis of biological materials. The purpose of this review paper is to compare the advantages of NIR and Raman spectroscopy in the nondestructive analysis. Both methods are quite unique and often complementary. For example. NIR spectroscopy is very useful in monitoring in situ the content of components inside biological materials while Raman spectroscopy is very suitable for identifying micro-components on the surface of biological materials. In this article specific characters of the two spectroscopic methods are discussed first and then several examples of applications of NIR and Raman spectroscopy to the biological nondestructive analysis are introduced.

마이크로/나노 비파괴평가 기술(I): 표면 및 표면직하 검사 (Review of Micro/Nano Nondestructive Evaluation Technique (I): Surface and Subsurface Investigation)

  • 김정석;박익근
    • 비파괴검사학회지
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    • 제32권2호
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    • pp.198-209
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    • 2012
  • 본 논문은 널리 사용되고 있는 표면 미세조직 검사 기술과 표면 및 표면직하의 평가가 가능한 마이크로/나노 비파괴평가 기술을 소개한다. 일반적으로 재료 표면에서의 마이크로/나노 결함과 조직 상태는 벌크재료의 기계적, 물리적, 화학적 특성에 크게 영향을 주게 된다. 표면 미세조직 검사 기술은 이러한 재료의 결함과 조직특성을 신뢰도 높게 평가하는 기술이다. 각 검사기술의 원리와 특징, 응용분야와 개발 등을 소개하였다. 따라서 비파괴산업에서 마이크로/나노 비파괴평가의 적용과 기술 개발이 폭넓게 가능할 것으로 판단된다.

마이크로/나노 비파괴평가 기술(II): 음향특성계측 (Review of Micro/Nano Nondestructive Evaluation Technique (II): Measurement of Acoustic Properties)

  • 김정석;박익근
    • 비파괴검사학회지
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    • 제32권4호
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    • pp.418-430
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    • 2012
  • 본 논문은 재료의 표면검사와 음향특성 측정이 가능한 마이크로/나노 비파괴평가 기술을 소개한다. 이들 기술로 초음파원자현미경과 초음파현미경의 원리와 특징 그리고 응용분야에 대해서 기술하였다. 특히, 이들 기술은 표면과 표면직하의 이미지 관찰 외에도 음향특성을 측정하여 마이크로/나노 구조물 혹은 표면에서의 기계적인 물성평가가 가능한 기술이다. 따라서 기존 비파괴분야와 함께 첨단 산업분야에 있어 마이크로/나노 비파괴평가의 적용과 기술 개발이 향후 폭넓게 가능할 것으로 판단된다.