• Title, Summary, Keyword: Acoustic Emission

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Wear Detection of Coated Tool Using Acoustic Emission (음향방출을 이용한 코팅공구의 마멸검출)

  • 맹민재;정준기
    • Transactions of the Korean Society of Machine Tool Engineers
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    • v.10 no.5
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    • pp.9-16
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    • 2001
  • Turning experiments are conducted to investigate characteristics of acoustic emission due to wear of the coated tool. The AE signals are obtained with a sensor attached to tool holder side. Tool states are identified with scanning electron microscopy and optical microscopy. It is demonstrated that the AE signals provide reliable informations about the cutting processes and tool states. Moreover, tool wear can be detected successfully using the AE-RMS.

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State Monitoring of Compressor using AE Signal in Life Test (압축기의 수명실험에서의 AE 신호를 이용한 상태감시)

  • 정지홍;강명창;노태영;이감규
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • pp.56-60
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    • 1997
  • The compressor is one of important elements in refrigeration cycle and play an important role of refrigeration efficiency and quality. This paper analyzes slides in rotary compressors for room air conditioners, monitoring using Acoustic Emission(AE) technique. Reliability of rotary compressors which are factory-tested has been evaluated through visual inspection on taking them apart after long term test, which is life test. This paper describes methods for acquisition and processing of Acoustic Emission(AE) raw signal to monitor state of rotary compressor in Life Test.

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Understanding the Material Removal Mechanisms of Abrasive Water Jet Drilling Process by Acoustic Emission Technique

  • Kwak, Hyo-Sung;Kovacevic, Radovan
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • pp.40-52
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    • 1998
  • Among the non-traditional machining methods, Abrasive waterjet machining process shows big promise in drilling difficult-to-machine materials due to its numerous advantages such as absence of heat affect zone and thermal distortion. Acoustic emission signal technique is used to understand about material removal mechanisms during abrasive waterjet drilling process. More information about the drilling process is derived through frequency decomposition of auto regressive moving average modeling representing acoustic emission signals.

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A Basic Experiment of Head/Disk Interaction of Subambient Tri-Pad Slider by Using Acoustic Emission Test System

  • Pan Galina;Hwang Pyung;Choi Sung-Ryul
    • Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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    • pp.384-387
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    • 2003
  • The object of the present work is the analysis of head/disk interaction during start/stop and constant speed operation using acoustic emission (AE). The frequency spectrum analysis is performed using the AE signal obtained during the head/disk interaction. The FFT (Fast Fourier Transform) analysis of the AE signals is used to understand the interaction between the AE signal and the state of contact.

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Experimental Analysis of Chatter Vibration and Acoustic Emission of Cutting Tool (절삭공구의 채터진동과 음향방출과의 실험적 연구)

  • 이종길
    • Journal of the Korean Society for Precision Engineering
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    • v.12 no.1
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    • pp.112-122
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    • 1995
  • 본 연구에서는 절삭공구가 채터진동을 일으킬때 AE(Acoustic Emission) 신호와 어떤관계가 있는지를 실험적으로 연구하였다. 모달분석을 통하여 절삭공구의 고유진동수 및 모우드형상을 구하였으며, 실제 절삭실험에서는 이송방향 및 절삭방향의 가속도를 계측하여 위상치를 결정하었다. AE신호와 두 가속도 와의 관계를 알기위하여 AE 실험을 하였다. AE신호의 폭발점은 대개 Lissajous loop의 방향전환점에서 관찰 되었다.

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A Study on Comparison of Acoustic Emission, Ultrasonic Testing and Crack Gauge Method in 3-point Bending Testing (3점 굽힘시험에 있어서 AE, 초음파, 크랙게이지법의 비교연구)

  • Han, E.K.;Kim, K.S.;Park, J.S.
    • Journal of the Korean Society for Nondestructive Testing
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    • v.10 no.1
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    • pp.65-72
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    • 1990
  • Comparison of acoustic emission, ultrasonic testing and crack gauge in 3-point bending testing have been studied. As the results, COD is indirectly assumed by strain gauge rate and grid pitch width when crack gauge grid is out. Acoustic emission is qualitatively able to measure crack growth by total count but ultrasonic testing has a difficulty in measuring it because of echo height fluctuation according to the change and pressure of UT. probe.

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Femto Slider Head/Disk Interaction Detection by Acoustic Emission and Natural Frequency Analysis

  • Hwang, Pyung;Galina Pan;Xuan Wu
    • KSTLE International Journal
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    • v.6 no.1
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    • pp.17-20
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    • 2005
  • The object of the present work is the natural lre%uency analysis of femto slider, HeaHdisk interaction during starustop and constant speed were detected by using the acoustic emission (AE) test system. The frequency spectrum analysis wasperformed using the AE signal obtained during the head/disk interaction. The FFT (Fast Fourier Transform) analysis of the AEsignals is used to understand the interaction between the AE signal and the state of contact. Natural frequency analysis wasperformed using the ANSYS program. The results indicate acceptable accordance of finite element calculation results with theexperimental results.

Interfacial Properties and Microfailure Degradation Mechanisms of Bioabsorbable Composites for Implant Materials using Micromechanical Technique and Acoustic Emission (Micromechanical시험법과 Acoustic Emission을 이용한 Implant용 생흡수성 복합재료의 계면물성과 미세파괴 분해메카니즘)

  • Kim, Dae-Sik;Park, Joung-Man;Kim, Sung-Ryong
    • Proceedings of the Korean Society For Composite Materials Conference
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    • pp.263-267
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    • 2001
  • The changes of interfacial properties and microfailure degradation mechanisms of bioabsorbable composites with hydrolysis were investigated using micromechanical test and acoustic emission (AE). As hydrolysis time increased, the tensile strength, the modulus and the elongation of PEA and bioactive glass fibers decreased, whereas those of chitosan fiber changed little. Interfacial shear strength (IFSS) of bioactive glass fiber/poly-L-lactide (PLLA) composite was significantly higher than that two other systems. The decreasing rate of IFSS was the fastest in bioactive glass fiber/PLLA composite, whereas that of chitosan fiber/PLLA composite was the slowest. With increasing hydrolysis time, distribution of AE amplitude was narrow, and AE energy decreased gradually.

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A Statistical. Properties of Tensile Behaviors of STS304 Stainless Steel at Elevated Temperature and the Acoustic Emission (STS304 스테인리스강의 고온 인장거동의 통계적 특성과 음향방출)

  • Kwak, Myung-Kyu;Kim, Seon-Jin
    • Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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    • pp.68-74
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    • 2002
  • The tensile tests to identify the statistical tensile properties and the acoustic emission characteristics were conducted for STS304 stainless steel at $600^{\circ}C,\;700^{\circ}C$. From tensile tests performed by constant cross head speed controls with 1mm/min, rates at each elevated temperature, the scatters were observed in tensile strength, reduction of area, elongation and the acoustic emission parameters. The effect of temperature on the scatter of tensile behavior was larger at $700^{\circ}C$. The distributions of tensile properties was well followed in 3-parameter Weibull. The AE counts and energy of the $700^{\circ}C$ specimens were smaller than the $600^{\circ}C$.

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A study on the estimation of fracture toughness of granite by acoustic emission (미소 파괴음 빈도 측정에 의한 화강암의 파괴인성 평가에 관한 연구)

  • 신재근;이상은;임한욱
    • Tunnel and Underground Space
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    • v.10 no.2
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    • pp.227-236
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    • 2000
  • The fracture toughness can be measured by the two testing methods using chevron-notched specimen according to the ISRM Working Group of Commission of Testing Methods. They are chevron bend (CB) test and short rod (SR) test. In this study, the suggested methods (Level I tests) were conducted on the CB and SR specimens of Chuncheon granite. In addition. the J-integral analysis was combined with an acoustic emission technique to determine the fracture toughness. The results from two telling methods were analyzed in terms of the anisotropy and the acoustic emission characteristics.

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