• 한국구조물진단유지관리공학회 논문집
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• 제12권6호
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• pp.173-179
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• 2008

비파괴시험에 의한 콘크리트 압축강도 추정시 반발경도법은 콘크리트 타설 후 시간경과에 따라 재령계수를 적용하고 있으나 초음파속도법은 적용되지 않고 있다. 재령경과에 따른 콘크리트 초음파속도의 변화에 대한 재령계수 적용의 필요성에 대하여 검토해야함에도 불구하고 그에 대한 연구가 거의 없는 실정이다. 따라서 본 연구는 콘크리트 초음파속도를 측정하여 강도 추정식에 적용될 재령계수를 산정하기 위한 실험을 실시한 결과, 초음파속도는 콘크리트 경화에 따라 재령 초기 기준치에 비교하면 급격한 변화를 보여 재령계수를 반드시 적용해야 한다는 것을 알 수 있었으며 실험결과에 의해 콘크리트 초음파속도의 재령계수를 제안하였다.

• Journal of the Korean Wood Science and Technology
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• 제31권2호
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• pp.58-68
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• 2003

목조 고건축물의 안전성 평가를 위해서는 먼저 부재의 성능평가가 선행되어야 한다. 지금까지의 목재 부재의 성능평가는 육안에 의한 경험적 방법에 의존하였다. 하지만 과학적이고 합리적인 비파괴 방법을 적용하여 구조부재의 성능을 평가할 수 있다면 구조물의 안전성 해석은 더욱 정확해지고 합리적이 될 것이다. 이를 위해 본 연구에서는 목조 고건축물의 여러 구조 부재 중 기둥에 대해 비파괴 평가법을 적용하여 구조부재의 성능 평가에 대한 가능성을 알아보았다. 이 결과를 이어지는 연구에서 구조물의 안전성 해석의 기초자료로 사용할 예정이다. 특별히 기둥의 노출 환경에 따른 열화의 진행정도를 비파괴 평가법으로 측정하였다. 그 결과 실제 육안에 의한 열화의 관찰과 유사한 결과를 나타내어 비파괴 방법의 적용 가능성을 보여주었다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2013년도 춘계학술대회 논문집
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• pp.1577-1578
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• 2013

• 한국축산식품학회지
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• 제41권4호
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• pp.563-588
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• 2021

Increasing meat demand in terms of both quality and quantity in conjunction with feeding a growing population has resulted in regulatory agencies imposing stringent guidelines on meat quality and safety. Objective and accurate rapid non-destructive detection methods and evaluation techniques based on artificial intelligence have become the research hotspot in recent years and have been widely applied in the meat industry. Therefore, this review surveyed the key technologies of non-destructive detection for meat quality, mainly including ultrasonic technology, machine (computer) vision technology, near-infrared spectroscopy technology, hyperspectral technology, Raman spectra technology, and electronic nose/tongue. The technical characteristics and evaluation methods were compared and analyzed; the practical applications of non-destructive detection technologies in meat quality assessment were explored; and the current challenges and future research directions were discussed. The literature presented in this review clearly demonstrate that previous research on non-destructive technologies are of great significance to ensure consumers' urgent demand for high-quality meat by promoting automatic, real-time inspection and quality control in meat production. In the near future, with ever-growing application requirements and research developments, it is a trend to integrate such systems to provide effective solutions for various grain quality evaluation applications.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2005년도 봄학술 발표회 논문집(I)
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• pp.511-514
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• 2005

Recently, to obtain the reliable data on the state of the structure, various non-destructive techniques are available. The infrared thermography technique is used in detection of cracks, flaws of concrete structures and buildings. In this paper the infrared thermography technique using the difference of surface temperature was studied. Also this paper is case study that the inspection of building's tile using infrared thermal video.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2008년도 추계 학술발표회 제20권2호
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• pp.165-168
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• 2008

콘크리트 시험체 내의 다양한 공동형상을 상세히 검출하기 위해 초음파속도법을 이용하여, 공동형상에 따른 3차원 검사해석을 실시하였다. 내부공동은 무공극 시험체와 정사각형, 직사각형 등 2종의 형식을 3차원 스티로폼 공동형상으로 제작하여, $500{\times}500{\times}500mm$ 크기의 무근콘크리트 시험체 내에 삽입 하였다. 비파괴시험은 초음파속도법에 대한 토모그래피법을 이용하였다. 그 결과, 공동의 형상을 3차원으로 화상화 처리가 가능하여, 콘크리트 내부공동을 보다 상세하게 비파괴검사방법으로 해석할 수 있음을 알 수 있었다.

• 비파괴검사학회지
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• 제20권4호
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• pp.290-295
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• 2000

최근 역타시공법 등에 의한 콘크리트 구조물의 시공이 증가 추세에 있다. 이 경우, 자주 발생되는 신 구타설 콘크리트 시공이음부의 공극은 향후 구조물의 구조적인 특성과 내구성 등에 큰 영향을 미치게 된다. 그러나 현재 제안되고 있는 비파괴 검사법으로는 효과적으로 이음부 공극을 평가하기에 많은 한계가 있다. 본 연구에서는 시공이음부의 콘크리트 충전상태를 평가하기 위해 철골철근 콘크리트와 무근 콘크리트 시험체내에 공극을 모의제작한 후, 초음파속도 측정을 실시하고, 화상처리기법을 이용하여 비교적 용이하게 해석 가능한 방법에 대해 검토하였다.

• 한국안전학회지
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• 제21권4호
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• pp.42-48
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• 2006

The strategies of maintenance and operation are usually established based on the number of flaws and their size distribution obtained from nondestructive inspection in order to preserve safety of the plant. But non destructive inspection results are different from the physical flaws which really exist in the equipments. In case of a single inspection, it is easy to estimate the number of physical flaws using the POD curve. However, we may be faced with some difficulties in obtaining the number of physical flaws from the periodic in-service non destructive inspection data. In this study a simple method for estimating the number of physical flaws from periodic in-service nondestructive inspection data was proposed. In order to obtain the flaw growth history, the flaw growth was simulated using the Monte Carlo method and the flaw size and the corresponding POD value were obtained for each flaw at each periodic inspection time. The flaw growth rate used in the simulation was statistically calculated from the in-service inspection data. By repeating the simulation numerous flaw growth data could be generated and the effective POD curve was obtained as a function of flaw size. From the effective POD curve the number of physical flaws was obtained. The usefulness and convenience of the proposed method was evaluated from several applications and satisfactory results were obtained.

• 시스템엔지니어링학술지
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• 제12권1호
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• pp.59-71
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• 2016

The Nuclear and Fossil Steam Turbines record a considerable number of failures annually. Some of these failures reported are as result of blade failure. The failure of the L-0 blade in a Steam Turbine is one of the most reported blade failure in Nuclear and Fossil steam turbines. This paper seeks to identify the best Non Destructive Evaluation (NDE) method or methods to be used in the steam turbine L-0 blades inspection process. The development of systems engineering processes presents an opportunity to apply NDE inspection to the L-0 blades. This process apply computer modelling of the L-0 using ANSYS and by simulating the stresses experienced by the L-0 blade during operation it is possible to identify the most susceptible areas for crack formation and growth. The results from these models compared to industry data for validation. The analysis of these results used to predict the most probable failure location and failure modes. Therefore NDE inspection can be applied to these areas with greater degree of accuracy. This would be beneficial in the increasing the accuracy in the detection of cracks and hence save inspection time and the overall inspection cost. Furthermore, not only the location for crack formation and NDE inspection determined but also best the NDE inspection technique/techniques to be applied appropriately on the L-0 blade are prescribed.

• Journal of Mechanical Science and Technology
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• 제14권10호
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• pp.1072-1080
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• 2000

Leakage magnetic flux (LMF) is widely used for non-contact detection of cracks. The combination of optics and LMF offers advantages such as real time inspection, elimination of electrical noise, high spatial resolution, etc. This paper describes a new nondestructive evaluation method based on an original magneto-optical inspection system, which uses a magneto-optical sensor, LMF, and an improved magnetization method. The improved magnetization method has the following characteristics: high observation sensitivity, independence of the crack orientation, and precise transcription of the geometry of a complex crack. The use of vertical magnetization enables the visualization of the length and width of a crack. The inspection system provides the images of the crack, and shows a possibility for the computation of its depth.