• 제목, 요약, 키워드: Acoustic Emission

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Efficiency Analysis of Acoustic Emission Control and Diagnostic Products Engineering

  • Irmuhamedova, R.M.;Sagatovo, M.V.
    • Journal of Multimedia Information System
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    • v.2 no.4
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    • pp.317-326
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    • 2015
  • The paper deals with the analysis of the effectiveness of acoustic emission monitoring and diagnostics of engineering products. We discuss the results of the processing results of the field experiment to study the acoustic emission in the alloy and its welded joints in the presence of technological defects. We study the characteristics of the output of acoustic emission signals at different stages of elastic-plastic deformation of alloys. Analyzed acoustic chart and the output waveform of the acoustic emission for the different types of welds. Studies have shown the effectiveness of the Acoustic emission techniques and help improve the accuracy of non-destructive testing systems in problems of automation and control.

침탄치차의 AE법에 의한 크랙발생의 계측에 관한 연구 (A Study on Crack Initiation Measurement of Carburized Gear Tooth by Acoustic Emission)

  • 류성기
    • 한국안전학회지
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    • v.9 no.4
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    • pp.11-16
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    • 1994
  • Acoustic emission technique is applied to the fatigue crack initiation in a carburized gear tooth. Acoustic emission test performed on carburized gear and three-point bending test equal to carburized gear hardness. The marked acoustic emission are detected at the early stage of crack initiation measured by a crack gauge and the final stage just before the tooth failure. The estimated acoustic emission energy rate are characteristic of the measured acoustic emission.

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와이어 인발가공에 있어서 음향방출 발생 특성 (Acoustic Emission Monitoring Fine Wire Drawing Process)

  • 이완규
    • 한국생산제조학회지
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    • v.5 no.1
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    • pp.43-50
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    • 1996
  • From a manufacturing standpoint it would be desirable to monitor the degradation of drawing die, that is essential for the maintenance of die quality, the evaluation of product integrity and the reducing scrap. Acoustic emission is powerful method in monitoring fine wire drawing process, especially in detecting the die fracture at early stage. Experiments also suggested that acoustic emission sigals contained valuable information regarding the stage of a drawing process such as the surface appearance of products and the condition of lubrication. These informations are AE monitoring techniques a possible tool in monitoring the drawing process operation. In order to approach this, this paper discusses the nature of acoustic emission signal presented which illustrate the effects of wire and die material, lubricants, and drawing speed on the generation and the mean voltage level of acoustic emission signal. From these experimental, results, we understanded controlling factors of acoustic emission generation.

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피로균열 성장률과 싸이클당 AE수 증가율간의 상호관계 (Relationship between Fatigue Crack Growth Rate and Total Acoustic Emission Counts per Cycle)

  • 이강용;김형규
    • 대한조선학회지
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    • v.23 no.3
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    • pp.17-26
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    • 1986
  • A new relationship between total acoustic emission counts per cycle and crack growth rate is derived in terms of stress intensity factor to explain the acoustic emission behavior due to fatigue crack growth. The experimental results of the total acoustic emission counts per cycle obtained from aluminium 5,000 series alloy specimens are compared with the theoretical values. Both experimental and theoretical total acoustic emission counts per cycle result in the linear relationship to the crack length.

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The Acoustic Emission Energy Analysis of Subambient Pressure Tri-Pad Slider

  • Pan Galina;Hwang Pyung;Xuan Wu
    • 한국윤활학회:학술대회논문집
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    • pp.139-142
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    • 2004
  • The object of the present work is the acoustic emission energy analysis of subambient pressure tri-pad slider. Head/disk interaction during start/stop and constant speed were detected by using acoustic emission (AE) test system The frequency spectrum analysis is performed using the AE signal obtained during the head/disk interaction Natural frequency analysis was performed using Ansys program. Acoustic emission energy was calculated for the slider modes.

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음향방출 계측에 의한 터빈 제어밸브 내부누설 평가연구 (Study on Evaluation of Internal Leak of Turbine Control Valve in Power Plant Using Acoustic Emission Signal Measurement)

  • 이상국
    • 한국동력기계공학회지
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    • v.12 no.5
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    • pp.65-70
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    • 2008
  • The purpose of this study is to verify availability of the acoustic emission in-situ monitoring method to the internal leak and operating conditions of the turbine major valves relating to safety for turbine operating and prevention of turbine trouble at nuclear power plants. In this study, acoustic emission tests are performed when the pressurized electro-hydraulic control oil flowed through turbine electro-hydraulic controller oil check valve and turbine power/trip fluid solenoid valve in the condition of actual turbine operating. The acoustic emission method was applied to the valves at the site, and the background noise was measured far the abnormal plant condition. To judge for the leak existence ell the object valves, voltage analysis and frequency analysis of acoustic signal emitted from infernal leak in the valve operating condition are performed. It was conformed that acoustic emission method could monitor for valve internal leak to high sensitivity.

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Studies on ILSS and Acoustic Emission Properties of Carbon-Carbon Composites

  • Park, Soo-Jin
    • Carbon letters
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    • v.1 no.2
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    • pp.60-63
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    • 2000
  • In this work, the carbon fibers-reinforced carbon matrix composites made with different carbon char yields of phenolic resin matrix have been characterized by mechanical flexural tests for acoustic emission properties. The composites had been fabricated in the form of two-dimensional polyacrylonitrile based carbon fibers during the carbonization process. It was found that the composites made with the carbon char yield-rich of resin matrix result in better mechanical interfacial properties, i.e., the interlaminar shear strength (ILSS) of the composites. The data obtained from the acoustic emission monitored appeared to show that the composites made with carbon char yield-rich were also more ductile. From the acoustic emission results, the primary composite failure was largely depended on the debonding at interfaces between fibers and matrix. The interlaminar shear strengths of the composites were correlated with the acoustic emission results.

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2차원 절삭과정에서의 Acoustic Emission과 절삭 파라미터 사이의 관계 (Relationship between Acoustic Emission and Cutting Parameters of the Orthogonal Cutting Process)

  • 최성주;강명순
    • 오토저널
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    • v.9 no.2
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    • pp.47-57
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    • 1987
  • The objective of this study is to establish the comprehensive analytical relationship between acoustic emission and fundamental parameters of the orthogonal cutting process. The sources of acoustic emission in the orthogonal metal cutting process was identified as deformation in the shear zone and sliding friction at the chip-tool interface. The validity of this relationship is evaluated by a series of tests varing cutting speed and rake angle for A16063 tube. Strong dependence of the RMS voltage of acoustic emission on cutting speed and rake angle was observed. It was also found that the percentage contribution of AE energy at each zone for the total AE activity is constant in accordance with the change of cutting speed. The relationship between the RMS of acoustic emission and the fundamental cutting parameters was modified in order to be utilized independent of rake angle.

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음향방출법을 이용한 스테인레스강 피로수명 예측 (Fatigue Life Prediction of Stainless Steel Using Acoustic Emission)

  • 김용환;정창규;양유창;한경섭
    • 대한기계학회:학술대회논문집
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    • pp.193-198
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    • 2001
  • The feasibility of the acoustic emission technique in predicting the residual fatigue life of STS304 stainless steel is presented. Acoustic emission was continuously monitored during the fatigue tests. Considerable acoustic emission occurred during the first few cycles. Acoustic Emission increased rapidly at about 90% of the fatigue life, clear and ample warning of impending fatigue failure was observed. Fatigue damage accumulation was evaluated in terms of an AE cumulative counts. The AE cumulative counts may be taken as an indicator of fatigue cumulative damage. Fatigue damages corresponding to 20, 40, 60 and 80% of the total life were induced at a cyclic stress amplitude. The specimens with and without fatigue damage were subjected to tensile tests. In tensile tests, the total cumulative counts were reduced with increasing fatigue damage. It was observed that the residual tensile strength of material did not change significantly with prior cyclic loading damages.

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Damage and fracture processes of concrete using acoustic emission parameters

  • Fan, Xiangqian;Hu, Shaowei;Lu, Jun
    • Computers and Concrete
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    • v.18 no.2
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    • pp.267-278
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    • 2016
  • In order to observe the internal damage of concrete in real time, we introduced acoustic emission nondestructive detecting technology into a series of fracture tests; the test results revealed the whole process that concrete undergoes when it sustains damage that leads to failure, according to the change rules of the acoustic emission parameters. The results showed that both the initiation and unstable loads can be accurately determined using the abrupt change of the acoustic emission rate curves and the turning point of the acoustic emission parameters' accumulative curves. The whole process, from damage to failure, includes five phases, beginning with damage, such as cracking, a stable crack growth process, a critical unstable stage, and unstable propagation. The brittle fracture characteristics of concrete change when steel bars are joined, because the steel bars and the concrete structure bond, which causes an increase in the acoustic emission signals within the fracture process of the reinforced concrete. The unstable propagation stage is also extended. Our research results provide a valid methodology and technical explanations, which can help researchers to monitor the cracking process of concrete structures, in real time, during actual projects.