• 기술사
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• 제33권6호
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• pp.23-29
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• 2000

The nondestructive tests(NDT) are widely applied at various industrial job sites to detect defects and flaws early and thus to diagnose the quality and integrity of components, structures and systems. This paper discusses the R&MD history of various nondestructive testing techniques, their applications and many technical as well as safety issues identified, particularly in the performance of radiography. Also discussed are the principles of inspection methods and NDT qualifications that should be applied at the industrial job sites. As a result, this paper provides suggestions for improvement in Government programs to promote th NDT industry, for more systematic operation through a direct with the owner, and also for improvement in working conditions for NDT workers.

• 비파괴검사학회지
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• 제15권3호
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• pp.482-490
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• 1995

• 비파괴검사학회지
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• 제23권6호
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• pp.616-621
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• 2003

There are various Non-Destructive Evaluation (NDE) techniques used for measurement of residual stresses in material, such as magnetic methods, X-ray diffraction, Ultrasonic velocity measurement etc. The capabilities, applications and limitations of these techniques for evaluation of cold work/plastic deformation were studied and compared. Mild steel plates were subjected to different degree of cold deformation and were analyzed by Magneto-mechanical Acoustic Emission (MAE), Barkhausen Noise (BN) and magnetic properties (hysteresis loop parameters analysis). Further, these specimens were analyzed by X-ray diffraction and ultrasonic velocity measurements. The microhardness measurement and microstructure studies of these cold worked plates were also carried out. The results of all these studies and comparison of different techniques are discussed in this paper.

• 비파괴검사학회지
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• 제8권1호
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• pp.44-48
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• 1988

Quality and economy in radiography can be achieved by using the right techniques and the film material available on the market. Pre-packing with or without lead, under vacuum or not, play an important role provided the right kinds of procedures are applied. The author explains some of the ways used by different N.D.T.companies to achieve the best quality in an economical way.

• 비파괴검사학회지
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• 제21권2호
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• pp.177-181
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• 2001

광학적 비접촉 비파괴검사 방법인 ESPI, Shearography를 이용한 측정은 자동차나 항공기산업 등에서 최근 폭넓게 이용되고 있다. 빠른 측정 속도와 측정 대상의 전 영역을 한번에 측정할 수 있는 장점을 가진 Shearography를 이용한 비파괴검사 방법을 기존의 광계측법인 ESPI와 비교하였다. 또한 이러한 장점을 살려 산업현장에서 수행한 여러 가지 비파괴검사 사례를 제시하였다.

• 비파괴검사학회지
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• 제28권6호
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• pp.524-530
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• 2008

The spin valve tunneling magnetoresistance (SV-TMR) sensor performance is analyzed using Stoner-Wohlfarth model for the detection of eddy current signals in nondestructive testing applications. The SV-TMR response in terms of the applied AC magnetic field dominantly generates the second harmonic amplitude in hard axis direction. The second harmonic eddy current signal detection using SV-TMR sensor shows higher performance than that of the coil sensor at lower frequencies. The SV-TMR sensor with high sensitivity gives a good solution to improve the low frequency performance in comparison with the inductive coil sensors. Therefore, the low frequency eddy current techniques based on SV-TMR sensors are specially useful in the detection of hidden defects, and it can be applied to detect the deeply embedded flaws or discontinuities in the conductive materials.

• 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.

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2005년도 춘계학술발표대회 논문집
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• pp.269-272
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• 2005

Nondestructive damage sensing and load transferring mechanism of Ni nanowire strands and multi-wall carbon nanotube (MWCNT)/epoxy composites were investigated using electro-micromechanical techniques. MWCNT composite was especially prepared for high volume contents, 50 vol % of reinforcement. Electro-micromechanical techniques were applied to measure apparent modulus and contact resistance of Ni nanocomposites with their alignment and different diameters, and adding contents. Applied cyclic load affected on apparent modulus and electrical properties on nanocomposites due to various inherent properties of each CNMs. Contact resistivity on humidity sensing was a good indicator for monitoring as for multifunctional applications. Further study on actuation as well as sensing will be investigated for the following work continuously.

• 비파괴검사학회지
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• 제18권4호
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• pp.304-312
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• 1998

비파괴검사중의 하나인 초음파 탐상검사는 교량, 발전설비 및 석유화학플랜트 등의 각종 다양한 구조물들의 안전성 확보를 위한 내부결함 및 손상평가를 위하여 일반적으로 폭넓게 사용되고 있다. 초음파를 이용한 데 파괴 평가 기술은 각종 구조물에 존재하는 내부결함에 의한 산란신호를 통해 건전성을 평가하는 기법이므로 결함의 신뢰성 녹은 정량적 평가를 위해서는 결함으로부터의 초음파 산란산호특성에 대한 기본적 이해가 필수적이며 따라서 이를 위한 모델링 수치해석 연구가 요구된다. 본 연구에서는 동탄성 경계요소법을 이용하여 무한체내에 존재하는 다중기공 결함에 의한 초음파 수평횡파의 근거리 산란특성에 대하여 결함의 형상과 결함사이의 상호작용을 고려하여 해석하였다. 본 연구에서 얻어진 결과들은 결함검출 민감도의 개선 및 역변환 해석에 의한 정량적 비파괴 평가에 큰 도움을 줄 수 있다.

• 비파괴검사학회지
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• 제20권2호
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• pp.116-129
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• 2000

초음파검사에서 발생하는 물리적 현상의 복잡성을 고려할 때, 이를 이론적으로 모델링하기 위해 수치적인 기법을 이용하는 것이 효과적인 경우가 많다. 본 논문에서는 초음파검사를 수치적으로 모델링하는 기법들에 대하여 개괄적으로 살펴보고, 특히 유한차분법과 유한요소법에 대하여 상세히 알아본다. 즉, 유한차분법과 유한요소법을 이용한 해석의 개요를 설명하고, 이들의 적용시 고려사항 및 문제점에 대해 알아 본 후, 기존의 연구결과 중 중요한 것들을 참고문헌으로 열거하고 몇 가지 예를 소개한다. 계속되는 컴퓨터의 기술적 발전으로 인하여 초음파검사에 대한 수치적 모델링 기법의 신뢰성과 편의성이 지속적으로 증대될 것으로 기대된다.