• Proceedings of the Korean Reliability Society Conference
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• 2001.06a
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• pp.245-255
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• 2001

원전 가동전/가동중검사 결과의 신뢰도(reliability)는 원전 배관기기의 건전성에 직결되는 것으로써 결함 발견 시 적용되는 파괴역학해석(FMA)은 비파괴검사 결과에 대한 100%의 신뢰를 전제하고 있다. 그러나 비파괴검사가 어느 정도 신뢰성을 가지고 있는지에 대한 평가가 국내에서는 거의 수행된 바가 없었다. 따라서, 본 연구에서는 원전의 비파괴검사 규제 요건의 기술적 근거를 확보하고, 원전 기기 건전성 평가 및 안전성 향상을 위한 합리적 규제지침을 수립하기 위하여 국내 원전 가동중검사(ISI)에 적용되거나 일반 산업계에 적용되고 있는 초음파탐상검사에 대하여 기량검증 Round Robin Test에 의한 통계적 신뢰도를 평가하고자 한다. 이를 위해 초음파검사 PD-RRT 결과의 통계적 신뢰도 평가 모델을 고찰하고, 결함검출성능 평가, 결함크기 측정 평가, 팀 오차 분석 등 초음파검사 PD-RRT 결과의 통계적 신뢰도를 평가하였다.

• Defense and Technology
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• no.10 s.164
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• pp.38-42
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• 1992

복합재 압력용기의 제작 및 사용중에 발생하는 결함(손상)의 비파괴검사를 통해 구조물의 건전성을 평가하는 것은 제품의 품질보증 관점에서 아주 중요합니다. 복합재에서는 여러 종류의 결함이 동시에 존재할수 있으며, 결함-기계적 성질-비파괴특성 사이의 상호관계는 완전히 알려져 있지 않습니다. 이글에서는 복합재 연소관에 존재하는 결함의 위험도와 결함 탐지를 위한 비파괴 검사 기법에 대해 먼저 살펴보았습니다. Filament Winding으로 제조한 복합재 연소관의 Proof Testing과 관련해 음향방출(AE)법에 의한 최근의 연구결과를 살펴본 다음, 연소관의 신뢰도 확보를 위한 비파괴 평가 방법에 대해 앞으로의 연구 방향을 제시하였습니다

• Journal of the Korean Society for Nondestructive Testing
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• v.32 no.2
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• pp.198-209
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• 2012

The present paper reviews the widely used surface microstructural investigation technique and micro/nano nondestructive evaluation(NDE) technique which is able to evaluate the surface and subsurface. In general, the micro/nano defects and microstructural state of surface have great influence on the mechanical, physical, and chemical properties of bulk materials. The investigation technique of surface microstructure is possible to evaluate the defects and microstructural state with high reliability. The various applications and developments of each inspection technique have been introduced. Consequently, it is thought that the technique developments and applications of micro/nano NDE in nondestructive industries are extensively possible hereafter.

• Journal of the Korean Society for Nondestructive Testing
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• v.21 no.6
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• pp.607-611
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• 2001

Ultrasonic inspection system consist of the operator, equipment and procedure. The reliability of results in ultrasonic inspection is affected by its ability. Furthermore, the reliability of nondestructive testing is influenced by the inspection environment, materials and types of defect. Therefore, it is very difficult to estimate the reliability of NDT due to the various factors. In this study, the probability of detection by logistic probability model and Monte Carlo simulation is used for the reliability assessment of ultrasonic inspection. The utility of the NDT reliability assesment is verified by the analysis of the data from round robin test nth these models.

• Journal of Korean Society of Steel Construction
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• v.15 no.1
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• pp.41-50
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• 2003

Nondestructive Damage Evaluation (NDE) techniques yield the damage location and its size from the modal characteristics of pre-damaged and post-damaged structures. To predict the system reliability of the aging structure, results from the NDE are integrated into the element/component failure probabilities. The element/component failure probabilities can be calculated from failure functions for each element/component with the aid of techniques from a structural reliability analysis. In this paper, a method to estimate the system reliability of a structure that is based on the reliabilities of elements/components in a given structure is presented. The efficacy of the combination of the nondestructive damage detection and the structural reliability evaluation is demonstrated using pre-damaged and post-damaged modal data obtained from numerical simulations of a rigid frame.

• Journal of the Korean Society for Nondestructive Testing
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• v.29 no.2
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• pp.162-170
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• 2009

As one of promising solutions to overcome high oil price and energy crisis, the construction market of high value-added LNG plants is spotlighted world widely. The purpose of this manuscript is to introduce domestic activities to develop risk assessment technology against overseas monopolization. After analyzing relevant specific features and their technical levels, risk assessment program, non-destructive reliability evaluation strategy and safety criteria unification class are derived as core technologies. These IT-based convergence technologies can be used for enhancement of LNG plant efficiency, in which the modular parts are related to a system with artificial optimized algorithms as well as diverse databases of facility inspection and diagnosis fields.

• Journal of the Korea institute for structural maintenance and inspection
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• v.11 no.3
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• pp.167-175
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• 2007

The relations between data from test methods and conditions in structural elements are considered. NDE(Nondestructive Evaluation) methods are joint application of a test and a basis for interpretation of data obtained in the test. Correct assessments of conditions of elements depend on the inaccuracy and variability in the test data and on the uncertainty of correlations between attributes(what is measured) and conditions(what is sought in the inspection). A full description of the performance of NDE methods considers the relation of test data to condition of elements. The quality of the test data itself is important, but equally important is the interpretation that occurs after the test. To make the decision of the performance of NDE methods, this paper presents mathematical basis to measure the reliability of NDE methods.

• Proceedings of the Korean Nuclear Society Conference
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• 2002.10a
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• pp.347.1-347
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• 2002

• Journal of the Korea institute for structural maintenance and inspection
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• v.19 no.4
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• pp.25-34
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• 2015

Proposed equation is used many time in calculation of concrete compressive strength using the non-destructive testing at precision safety diagnosis. Most of proposed equation is suggested in abroad and have an error to estimate concrete compressive strength in the domestic. Therefor, proposed equation is low reliability to estimate concrete compressive and it has a significant effect in reliability of precision safety diagnosis. Nevertheless, It is possible to increase the reliability through a number of experiments from this problem that occurs in some localized part. This paper is proposed assessment formula of reliability related core compressive strength to increase the reliability. It is verified that reliability of proposed assessment formula is useful by probabilistic techniques. It is compared with each graphs of concrete compressive strength of proposed equation. It has been found that the present methods are very efficient.

• Journal of Welding and Joining
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• v.11 no.2
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• pp.1-12
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• 1993

용접과 관련되는 분야에서, 재료평가와 비파괴 검사법으로서의 Acoustic Emission의 응용을 살펴 보았다. 재료 평가법으로서의 AE는 다른 시험방법들이 검출해 내지 못하는 재료 내부에서의 미시적인 현상들을 정량적으로 평가할 수 있는 장점을 가지고 있다. 앞으로 새로운 용접재료의 개발이라든지, 고도의 신뢰성이 요구되는 용접부위의 정량적인 평가를 위해서 AE의 응용은 중요한 정보들을 제공하게 될 것이다. 한편 용접구조물의 비파괴적 평가법으로서의 AE는 균열의 동적인 거동 및 균열의 위치를 검지할 수 있다는 장점 때문에 응용범위는 더욱 넓어질 것이다. 여기서 유의하여야 할 점은, 목적으로 하는 AE신호를 수만배 까지 증폭시키는 과정에서 환경잡음의 영향을 무시할 수 없는 경우에는 우선적으로 잡음을 적극적으로 제거하는 고도의 연구도 함께 병행되어야 한다는 것이다.