• 제목/요약/키워드: Non-destructive test

검색결과 475건 처리시간 0.025초

비파괴 및 비색법에 의한 주상변압기 절연유의 경년열화 분석 (The Analysis on the Oil Deterioration of Pole-Transformer by Non-Destructive and UV/Visible Method)

  • 곽회로;남영우;윤영자;권혁일;이동준;송일근;권동진
    • 한국조명전기설비학회:학술대회논문집
    • /
    • 한국조명전기설비학회 1995년도 추계학술발표회논문집
    • /
    • pp.115-117
    • /
    • 1995
  • This paper describes the O.T aging analysis by non-destructive electrical and UV/visible method. Non-destructive diagnosis method is tan8 test. Also the new method of the aging analysis, UV/visible method was introduced in this paper and compared with the non-destructive electrical method. The UV/visible test could be useful method for the O.T aging electrical diagnosis such as non-destructive electrical method.

  • PDF

기계 구조물의 안정성 평가를 위한 레이저 초음파법 적용 (A Mechanic Structure Safety Evaluation Using Laser-Based Ultrasonics Application)

  • 김재열;송경석;김창현;고명수
    • 한국공작기계학회:학술대회논문집
    • /
    • 한국공작기계학회 2003년도 추계학술대회
    • /
    • pp.174-179
    • /
    • 2003
  • Non-destructive test on the size and depth of cracks has been required for the safety evaluation of structures. Ultrasonic method based on laser techniques is one of the most popular non-destructive methods which overwhelm PZT based tests. In the present paper, ultrasonic was generated by high powered Q switching Nd:YAG pulse laser. Experiments were carried out using Fabry-Perot interferometer which was intensively discussed in the present study.

  • PDF

코어 및 비파괴 시험에 의한 재생골재 콘크리트의 압축강도 평가에 대한 실험적 연구 (An Experimental Study on the Evaluation of Compressive Strength of Recycled Aggregate Concrete by the Core and the Non-Destructive Testing)

  • 양근혁;김용석;정헌수
    • 한국콘크리트학회:학술대회논문집
    • /
    • 한국콘크리트학회 2005년도 봄학술 발표회 논문집(II)
    • /
    • pp.133-136
    • /
    • 2005
  • Compressive strength of recycled aggregate concrete was tested by the core and by the non-destructive testing. A prediction model of compressive strength considering the replacement level of recycled aggregate was suggested by multi-regression analysis and was compared with test results. Also, Test results showed that the ratio of compressive strength by core and non-destructive testing to actual was somewhat affected by the replacement level of recycled aggregate.

  • PDF

식품분쇄용 세라믹 롤 재료 개발과 기계적 특성평가 (Development of Ceramic Roll Materials for Food Grinding Processing and Evaluation of Mechanical Behavior)

  • 강위수
    • Journal of Biosystems Engineering
    • /
    • 제26권1호
    • /
    • pp.47-56
    • /
    • 2001
  • In order to prevent the possibility of mixing of metal powder during food grinding processing with the metal roll mill this study was conducted to develope the materials of ceramics roll as a substitute of gray cast iron mill. Since the ceramics is brittle material and can be broken easily by a crack, it was needed to develope engineering ceramics roll materials with high elastic modulus and fracture toughness. Adding 0∼50 wt% Al$_2$O$_3$as densification additives to porcelain body material and forming the ceramics an different condition, mechanical properties were evaluated. The material structure’s densification process was analyzed by SEM and XRD. The evaluation of the mechanical properties of ceramics roll materials were compared and analyzed by non-destructive test using Young’s modulus and destructive test using 3-point bending strength and fracture toughness. The results showed several correlative results. Porcelain body material with 40 wt% Al$_2$O$_3$content heated at 1,200$\^{C}$ for 5h was high bulk density of 2.77, Young’s modulus of 118.4Gpa, 3-point bending strength of 137 MPa and fracture toughness of 2.88 MPa$.$m$\^$$\sfrac{1}{2}$/ . After analyzing the relationship between non-destructive test and destructive test, the coefficient of determination was more than 0.9. Therefore, the evaluation of non-destructive test by ultrasonic was turned out to be feasible in evaluating the mechanical properties of ceramics.

  • PDF

초음파 시뮬레이션을 이용한 최적의 탐상조건 (Optimal Test Condition by Ultrasonic Simulation)

  • 허선철;박영철;부명환;강정호
    • 한국해양공학회지
    • /
    • 제13권4호통권35호
    • /
    • pp.45-54
    • /
    • 1999
  • Non destructive test is applied to revise mechanical strength and assume material strength or defect of material, equipment and structure, instead of fracture test. Especially, ultrasonic test has the characteristics such as an excellent permeability high-sensitiveness to fine defect and an almost exact measurement for position, size and direction of inner defect which differ from other non destructive tests. In this study, the program is developed to evaluate optimal testing condition, to distinguish obstacle echo and defect position. This program on the basic of Ray-Tracing model shows generation and processing of ultrasonic pulse. The simulation is compared with testing in the 3 cases of an oblique angle transducer like $45^{\circ},\;60^{\circ}\;and\;70^{\circ}$. The test result for all conditions is well compared with simulation result when relative not is within $0.1{\sim}7.2%$. And the course of several echos is simply assumed through simulation.

  • PDF

비파괴 시험에 의한 재생골재 콘크리트의 압축강도 평가 (An Evaluation of the Compressive Strength of Recycled Aggregate Concrete by the Non-Destructive Testing)

  • 정헌수
    • 한국건축시공학회지
    • /
    • 제4권4호
    • /
    • pp.63-70
    • /
    • 2004
  • The objective of this study is to evaluate the compressive strength of recycled aggregate concrete by the non-destructive testing. Main experimental variables were the replacement level of recycled aggregate and blast-furnace slag, which were divided into two series according to recycled aggregate maximum size. Test results showed that a recycled aggregate had a significant influence on the non-destructive testing results, such as rebound number, Ultrasonic pulse velocity, and frequency. A prediction model of compressive strength considering the replacement level of recycled aggregate was suggested by multi-regression analysis and was compared with test results.

파괴시험을 통한 복합재 구조물의 건전성 입증 (Destructive Test to Ensure Integrity of Composite Structure)

  • 양현덕;정덕영;이경철;진영권
    • 항공우주기술
    • /
    • 제6권1호
    • /
    • pp.230-236
    • /
    • 2007
  • 항공기용 복합재 구조물의 제작에 대한 품질관리는 자재의 입고에서부터 제품의 제작과정에 이르는 모든 단계에서의 검사, 시험 및 모니터링을 포함한다. 이러한 품질관리 활동은 설계의 목적에 적합하게 이루어졌는지 확인하기 위한 것이다. 품질에 영향을 미치는 인자들은 자재, 입고검사, 보관 및 시효관리, 작업환경의 관리, 시험, 검사 및 기록의 관리 등이 있다. 본 연구에서는 항공기 복합재 구조물에서 파괴시험을 통한 공정의 적합성 입증방법과 품질관리방법을 고찰하였으며 이를 바탕으로 복잡한 복합재 구조물에 대한 비파괴검사 방법의 신뢰성을 확보하고 복합재의 설계요구조건을 확인할 수 있는 기법을 제시하였다.

  • PDF

충격반향시험에 의한 콘크리트 터널 라이닝 내부결함 및 두께 조사 (Inspection for Internal Flaw and Thickness of Concrete Tunnel Lining Using Impact Echo Test)

  • 김영근;이용호;정한중
    • 터널과지하공간
    • /
    • 제7권3호
    • /
    • pp.230-237
    • /
    • 1997
  • As concrete structure is getting old and decrepit, its inspection and diagnosis is getting important. Therefore, it is necessary to estimate the soundness of structure using non-destructive tests for effective repairs and maintenances. But, applications of non-destructive tests in tunnel have been used restrictively, due to accessibility only from one side in tunnel lining and presence of tunnel installations. Recently, the various non-destructive techniques have been studied. Especially, ground penetrating radar(GPR) and impact echo (IE) methods have been researched for tunnel inspection. In this study, the applicability of impact echo test in tunnel lining inspection has been investigated. This paper described the tunnel inspection for lining thickness and internal flaw using impact echo tests. Model tests were carried out using impact echo test systems on two concrete models, Model I is measuring for lining thickness, Model II is detecting for internal flaw. Also, the test were applied for lining inspections in a tunnel constructed by NATM. From the results of impact echo tests, we have concluded that impact echo test is a very useful and effective technique for inspecting the concrete tunnel linings.

  • PDF

Inspection of Weld Bead using High Speed Laser Vision Sensor

  • Lee, H.;Ahn, S.;Sung, K.;Rhee, S.
    • International Journal of Korean Welding Society
    • /
    • 제3권2호
    • /
    • pp.53-59
    • /
    • 2003
  • Visual inspection using laser vision sensor was proposed for fast and economic inspection and was verified experimentally. Welding is one of the most important manufacturing processes for automotive and electronics industries as well as heavy industries. The weld zone influences the reliability of the products. There are two kinds of weld inspection tests, destructive and non­destructive test. Even though the destructive test is much more reliable, the product should be destroyed, and hence the non­destructive test such as ultrasonic or X­ray test was used to overcome this problem. However, these tests are not used for real time inspection.

  • PDF

비파괴 충격파를 이용한 아스팔트 공시체의 수분민감도 평가 (Evaluation for Moisture Susceptibility of Asphalt Mixtures using Non-Destructive Impact Wave)

  • 장병관;김도완;문성호;장영선
    • 한국도로학회논문집
    • /
    • 제15권3호
    • /
    • pp.53-63
    • /
    • 2013
  • PURPOSES : This study is to evaluate moisture susceptibility of asphalt mixtures by using non-destructive impact wave and to determine durability so as to decrease the gap between before and after freezing in the future. METHODS : Using non-destructive impact wave, this study is to determine the dynamic modulus of asphalt specimen. Furthermore, the results obtained from two experiment accelerometers are used for the dynamic modulus determination. The dynamic moduli of specimens are compared with those of the freezing-thawing specimens. RESULTS : Test results showed that the dynamic modulus before freezing and thawing environment loads at each temperature dropped about 3.7% after the environmental loads. Furthermore, correlation analysis indicates that transition of dynamic modulus at each point is about 89.59%. CONCLUSIONS: Evaluation of asphalt mixtures using non-destructive impact wave has excellent repeatability and simple equipment for the test. Consequently, the method in the study will be useful for evaluating the characteristics of a various asphalt mixtures.