• Title/Summary/Keyword: integrity assessment

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Finite Element and Experimental Validation of SINTAP Defect Assessment Procedure for Welded Structure (수치해석과 실험에 의한 SINTAP 용접 구조물 균열 평가법의 검증)

  • 김윤재;김진수
    • Journal of Welding and Joining
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    • v.22 no.1
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    • pp.50-57
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    • 2004
  • This paper provides FE and experimental validation of the defect assessment method for strength mismatched welded structures, resulting from the Brite Euram SINTAP (Structural Integrity Assessment Procedures for European Industry) project. This shows that the proposed method is conservative, and that the degree of conservatism is similar to that embedded in the methods for homogeneous structures. It provides confidence in the use of the proposed SINTAP method for assessing defective weld strength mismatched structures.

Integrity Assessment of Spread Footing Pier for Scour Using Natural Frequency (고유진동수를 이용한 확대기초 교각의 세굴 건전성 평가)

  • Park, Byung-Cheol;Oh, Keum-Ho;Park, Seung-Bum
    • Journal of the Korean Society of Hazard Mitigation
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    • v.5 no.2 s.17
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    • pp.29-35
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    • 2005
  • In Korea more than ninety bridges are collapsed every year by flood, which causes the scour of pier foundation. Researches on the quantitative assessment method to assess the integrity of bridge against scour have not been organized systematically in the bridge design practice and maintenance area. In this study, dynamic characteristics assessment experiments are carried out as an emergency inspection method to assess the integrity of the pier foundation for scour after a flood. According to the dynamic characteristics assessment experiment, which simulates foundation scour of the spread footing pier, foundation scour can be evaluated by the first mode natural frequency of the pier.

The Integrity Assessment Method of Initailly Cracked Structural Components by Reliability Analysis (신뢰성해석에 의한 초기균열을 갖는 구조부재의 건전성 평가방법)

  • S.J. Yim;T.U. Byun
    • Journal of the Society of Naval Architects of Korea
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    • v.30 no.2
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    • pp.161-176
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    • 1993
  • For the purpose of assessing structural integrity at a level of complexity and accuracy appropriate for the situation, integrity assessment methods are formulated with the following methods. One is three-tier assessment method of the revised BSI PD 6493 which considers stable crack growth effect, the others are limit load analysis which estimates the plastic collapse load and stability assessment method which considers stable crack growth of ductile material exactly using J-integral and tearing modulus. Besides, integrity assessments for center cracked panel(CCP) specimen and the circumferential through-cracked pipe are carried out and reliability analysis is accomplished by the first order reliability method which is one of the conventional reliability methods. Also the accuracy of the present method is verified by Monte Carlo method.

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Structural Integrity and Safety Margin Evaluation for Thinned Pipe Component (감육배관의 구조건전성 및 안전여유도 평가 기술)

  • Lee, Sung-Ho;Kim, Tae-Ryong;Kim, Bum-Nyun
    • Proceedings of the KSME Conference
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    • 2004.04a
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    • pp.264-267
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    • 2004
  • Wall thinning of carbon steel pipe components due to Flow-Accelerated Corrosion (FAC) is one of the most serious threats to the integrity of steam cycle piping systems in Nuclear Power Plants (NPP). Since the mid-1990s, secondary side piping systems in Korean NPPs have experienced wall thinning, leakages and ruptures caused by FAC. Korea Electric power Research Institute (KEPRI) and Korea Hydro & Nuclear Power Co., LTD. (KHNP) have conducted a study to develop the methodology for systematic pipe management and established the Korean Thinned Pipe Management Program (TPMP). To effectively maintain the integrity of piping system, FAC engineer should understand the criterions of the structural integrity evaluation and the safety margin assessment for the thinned pipe component. This paper describes the technical items of TPMP, and shows the example of the integrity evaluation and safety margin assessment for three thinned pipe component of a NPP.

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Meteorological Data Integrity for Environmental Impact Assessment in Yongdam Catchment (용담댐시험유역 환경영향평가의 신뢰수준 향상을 위한 기상자료의 품질검정)

  • Lee, Khil-Ha
    • Journal of Environmental Science International
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    • v.29 no.10
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    • pp.981-988
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    • 2020
  • This study presents meteorological data integrity to improve environmental quality assessment in Yongdam catchment. The study examines both extreme ranges of meteorological data measurements and data reliability which include maximum and minimum temperature, relative humidity, dew point temperature, radiation, heat flux. There were some outliers and missing data from the measurements. In addition, the latent heat flux and sensible heat flux data were not reasonable and evapotranspiration data did not match at some points. The accuracy and consistency of data stored in a database for the study were secured from the data integrity. Users need to take caution when using meteorological data from the Yongdam catchment in the preparation of water resources planning, environmental impact assessment, and natural hazards analysis.

Application of FAD on Pressure Tube for the Probabilitic Integrity Assessment (파손평가선도를 이용한 압력관 결함의 확률론적 건전성 평가)

  • Kwak, Sang-Log;Wang, Jong-Bae;Park, Youn-Won;Lee, Joon-Seong
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.28 no.3
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    • pp.289-295
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    • 2004
  • Pressure tubes are major component of nuclear reactor, but only selected samples are periodically examined due to numerous numbers of tubes. Current in-service inspection result show there is high probability of flaw existence at uninspected pressure tube. Probabilistic analysis is applied in this study for the integrity assessment of uninspected pressure tube. All the current integrity evaluations procedures are based on conventional deterministic approaches. So it is expected that the results obtained are too conservative to perform a rational evaluation of lifetime. More realistic failure criteria, based on FAD are also proposed for the probabilistic analysis. As a result of this study failure probabilities for various conditions are calculated, and examined application of FAD and LBB concept.

Proof Load Test and Integrity Assessment of Segmental PC Box-girder Bridges (Segmental PC 박스거더교의 검증재하시험 및 건전성평가)

  • 조효남;임종권;옥승범;지광습
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 1995.10a
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    • pp.132-141
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    • 1995
  • This study is intended to propose practical but systematic and rational approaches for proof load test and integrity assessment of segmental PC box-girder bridges. The proposed models cover the whole range of field tests and assessment of such as inspections, nondestructive tests, static and dynamic load tests, structural analysis, and integrity assessment for the evaluation of load carrying capacity, serviceability, and durability of PC box-girder bridges. They are applied to a newly constructed precast segmental PC box-girder bridge which is a part of the Seoul interior circuit elevated expressway.

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Modelling and integrity assessment of shear connectors in precast cast-in-situ concrete bridges

  • Moyo, Pilate;Sibanda, Bongani;Beushausen, Hans
    • Structural Engineering and Mechanics
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    • v.42 no.1
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    • pp.55-72
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    • 2012
  • Precast-cast insitu concrete bridge construction is widely practiced for small to medium span structures. These bridges consist of precast pre-stressed concrete beams of various cross-sections with a cast in-situ reinforced concrete slab. The connection between the beams and the slab is via shear links often included during the manufacturing process of the beams. This form of construction is attractive as it provides for standardisation, reduced formwork and construction time. The assessment of the integrity of shear connectors in existing bridges is a major challenge. A procedure for assessment of shear connectors based on vibration testing and finite element model updating is proposed. The technique is applied successfully to a scaled model bridge model and an existing bridge structure.

An Effect on the Structural Integrity Assessment of Steam Generator Tubes with Resolution of Rotating Pancake Coils for Multiple Cracks (회전형 탐촉자의 다중균열 분해능이 증기발생기 전열관의 구조건전성 평가에 미치는 영향)

  • Kang, Yong-Seok;Cheon, Keun-Young;Nam, Min-Woo;Park, Jai-Hak
    • Journal of the Korean Society for Nondestructive Testing
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    • v.34 no.5
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    • pp.356-361
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    • 2014
  • The eddy current testing performance directly affects the results of a steam generator tube integrity assessment because the integrity assessment of defected tubes is conducted based on eddy current testing results. This means that it may not be possible to accurately discriminate between adjacent flaws. This paper presents an investigation on the resolution of rotating pancake coils with multiple cracks and the effects on the structural integrity assessment of steam generator tubes.

Effects of Rotated Endotracheal Tube Fixation Method on Unplanned Extubation, Oral Mucosa and Facial Skin Integrity in ICU Patients (기관내관 순환고정방법이 중환자실 환자의 비계획적 발관 및 구강.안면 피부 통합성에 미치는 효과)

  • Choi, Young-Soon;Chae, Young-Ran
    • Journal of Korean Academy of Nursing
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    • v.42 no.1
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    • pp.116-124
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    • 2012
  • Purpose: The study was done to compare effects of two endotracheal tube (ET tube) fixation methods (rotated fixation versus conventional) on unplanned extubation and skin integrity for orally intubated patients in intensive care units. Methods: The research design was a non-equivalent control group with repeated measures design. Participants were 80 patients; 40 participants assigned to each group. ET tube for the experimental participants fixed with rotated method every morning. Unplanned extubation was assessed by bedside nurses using the unplanned extubation report form. Oral mucosa and facial skin integrity were assessed using oral assessment guide and facial skin integrity assessment guide at day 3, 7, 10 and 14. Results: There was no difference in the unplanned extubation rate between the two groups. Oral mucosa impairment scores for the rotated fixation method were significantly lower at day 7 (p=.044), 10 (p=.048) and day 14 (p=.037). Also facial skin integrity impairment scores for the same group were significantly lower at day 7 (p=.010), 10 (p=.003), and 14 (p=.002). Conclusion: Results of the study suggest that the rotated fixation method is effective for these patients, to prevent impairment of oral mucosa and facial skin integrity. Further research is needed to prevent unplanned extubation.