• Title/Summary/Keyword: Electronic Laser Interferometry

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The Development of In-Plane Displacement Measurement System on Laser Speckle Interferometry (레이저 스페클 간섭법을 이용한 면내변위 측정시스템 개발)

  • Yoon H.S.;Kim K.S.;Park C.J.;Choi T.H.;Choi J.S.
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2005.06a
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    • pp.556-560
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    • 2005
  • The measurement method by Laser Speckle Interferometry which uses the interference law which will grow precedes and with it explains a resolution measurement ability and together the change of place arrowhead and general measurement, at real-time measurement sensitivity it has application boat song from candle precise measurement field it is increasing. But, currently the domestic application technique to sleeps and optical science military merit by optical science interferometer and directness it composes purchases to the level which it applies the expensive commercial business equipment the outside and in spite of the technical ripple effect is deficient even in many strong point. The hazard which complements like this problem point form technical development it leads from the research which it sees and an application degree and to sleep as the measurement equipment which tries to develop the small-sized optical science interference sensor and an interpretation program it raises it does.

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A study on real time measuring microscopic movements in sinusoidal phase modulating interferometry using a laser diode (레이저 다이오드를 이용한 정현파 위상변조 간섭에 의한 실시간 극미세 진동 측정에 관한 연구)

  • 구자남;염정덕;지철근
    • Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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    • 1990.10a
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    • pp.23-27
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    • 1990
  • A new signal processing system for real time displacement measurement in sinusoidal phase modulating interferometry is described. Although sinusoidal phase modulating interferometry is effective in measuring with high accuracy the displacement of an object, conventional signal processing takes a long time. In this method, detection of the object's displacement is easily achieved by sampling the interference signal at those times that satisfy certain conditions and by processing the sampled signals with electric circuits in real time. The delay time of this signal processing system is < 45${\mu}$s. Specially in this paper we describe all electronic circuit and optical system design

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A study on real time measuring microscopic movements in sinusoidal phase modulating interferometry using a laser diode (레이저 다이오드를 이용한 정현파 위상변조 간섭에 의한 실시간 극미세 진동 측정에 관한 연구)

  • 강성철;진상규;지철근
    • Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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    • 1991.10a
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    • pp.33-37
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    • 1991
  • A now signal precessing system for real time displacement measurement in sinusoidal phase modulating interferometry is described. Although sinusoidal phase modulating interferometry is effective in measuring with high accuracy the displacement of an object, conventional signal processing takes along time. In this method, detection of the object's displacement is easily achieved by sampling the interference signal at those times that satisfy certain conditions and by processing the sampled signals with electric circuits in real time. the delay time of this signal processing system is < 45 $\mu$s. Specially in this paper we describe all electronic circuit and optical system design

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Application of Laser Interferometry for Assessment of Surface Residual Stress by Determination of Stress-free State (무잔류 응력상태 결정을 통한 표면 잔류응력장 평가에의 레이저 간섭계 적용)

  • 김동원;이낙규;나경환;권동일
    • Journal of the Semiconductor & Display Technology
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    • v.3 no.2
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    • pp.35-40
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    • 2004
  • The total relaxed stress in annealing and the thermal strain/stress were obtained from the identification of the residual stress-free state using electronic speckle pattern interferometry (ESPI). The residual stress fields in case of both single and film / substrate systems were modeled using the thermo-elastic theory and the relationship between relaxed stresses and displacements. We mapped the surface residual stress fields on the indented bulk Cu and the 0.5 $\mu\textrm{m}$ Au film by ESPI. In indented Cu, the normal and shear residual stress are distributed over -1.7 GPa to 700 MPa and -800 GPa to 600 MPa respectively around the indented point and in deposited Au film on Si wafer, the tensile residual stress is uniformly distributed on the Au film from 500 MPa to 800 MPa. Also we measured the residual stress by the x-ray diffractometer (XRD) for the verification of above residual stress results by ESPI...

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Welding Characteristics of Inconel 600 using a high power CW Nd:YAG Laser (고출력 CW Nd:YAG 레이저를 이용한 인코넬 600의 용접 특성)

  • Yoo Young-Tae;Shin Ho-Jun;Lim Kie-Gon
    • Transactions of the Korean Society of Machine Tool Engineers
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    • v.13 no.6
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    • pp.119-126
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    • 2004
  • The welding characteristics of Inconel 600 Alloy using a continuous wave Nd:YAG laser are experimentally investigated. The major process parameters studied in the present laser welding experiment were the positions of focus, laser power and travel speed of laser bean We measured the fusion zone size and its shape using an optical microscope for the observation of cross-sectional area. We performed two tests regarding the tension and the micro hardness for welding quality estimation. Then we measured residual stress in welds by electronic speckle pattern interferometry(ESPI). In conclusion the optimum butt welding process parameters were 0.5mm focus position, 1.6kW laser power, 1m/min travel speed and 5.5$\ell$/min assist gas discharge.

Resonance Frequency Analysis to Laser Welding Condition by Time-average ESPI (Time-average ESPI에 의한 레이저용접 조건에 따른 공진주파수 특성 분석)

  • 이유황;김경석;정성욱;최태호
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 2004.10a
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    • pp.245-249
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    • 2004
  • This paper describes the vibration characteristics of Nd:YAG laser welding plates analyzed time-average Electronic Speckle Pattern Interferometry(ESPI). In laser welding, the travel speed has influence on a mechanical properties, such as elastic modules, response frequencies and so on, which is resulted on a residual stress of the welding zone. the response frequencies related to elastic modules are determined by time-average ESPI and the results, as compared to each condition, are used to estimate optimal condition of travel speed.

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A Study on the Reliability Evaluation of Thermal Deformation of Electronic Product Package by ESPI (ESPI를 이용한 전자제품 패키지 열변형 신뢰성 평가에 관한 연구)

  • Cho Ji-Hyun;Lee Jae-Hyuk;Park Sang-Young;Jang Joong-Soon;Kim Gwang-Sub
    • Journal of Applied Reliability
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    • v.5 no.4
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    • pp.439-450
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    • 2005
  • Thermal deformation of Digital Television effect friction noise directly. However there was no methods to find and to solve the thermal friction noise which is huge problem in Digital Television In this study, to figure out occurrence cause of friction noise of the product, we measured thermal deformation of the product to organize a triggering device united with Laser Doppler Vibrometer(LDV) which turned occurrence moment of thermal friction noise into a possibility to measure. In conclusion, we could offer an effective information of design, and ensured ESPI(Electronic Speckle Pattern Interferometry) measure technique which is more detailed than the past way.

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Application of Laser Interferometry for Assessment of Surface Residual Stress by Determination of Stress-free State (무잔류 응력상태 결정을 통한 표면 잔류응력장 평가에의 레이저 간섭계 적용)

  • Kim, Dong-Won;Lee, Nak-Kyu;Choi, Tae-Hoon;Na, Kyong-Hoan;Kwon, Dong-Il
    • Proceedings of the KSME Conference
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    • 2003.04a
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    • pp.25-30
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    • 2003
  • The total relaxed stress in annealing and the thermal strain/stress were obtained from the identification of the residual stress-free state using electronic speckle pattern interferometry (ESPI). The residual stress fields in case of both single and film/substrate systems were modeled using the thermo-elastic theory and the relationship between relaxed stresses and displacements. We mapped the surface residual stress fields on the indented bulk Cu and the 0.5 ${\mu}m$ Au film by ESPI. In indented Cu, the normal and shear residual stress are distributed over -1.7 GPa to 700 MPa and -800 GPa to 600 MPa respectively around the indented point and in deposited Au film on Si wafer, the tensile residual stress is uniformly distributed on the Au film from 500 MPa to 800 MPa. Also we measured the residual stress by the x-ray diffractometer (XRD) for the verification of above residual stress results by ESPI.

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The Strain Measurement of One Point Spot Welded Zone Using the 3-D ESPI (3-D ESPI법을 이용한 단점용접부의 변형률 측정)

  • Cha, Y.H.;Kang, D.J.;Jang, H.;Jang, K.C.;Sung, S.B.
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.32 no.7
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    • pp.597-601
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    • 2008
  • Currently knowledge of strain in welds has mainly been obtained from strain gaging method: that is directly attaching most of the material to the gage. The very few non-contact methods are still in the early stage. One of the non-contact methods is by the use of the laser that has high-level of the accuracy for the measurement, and this laser also has excellent characteristics on which many studies for its applications are focused throughout the many fields. A method of study is on the measurement of the strain caused by the characteristics of the spot welded zone which is used with 3-D ESPI system that is functionally modified through the laser ESPI(Electronic Speckle Pattern Interferometry) system. This system employed the SGCC 1.2t which are mainly used for the steel plate such as automobile, structure, building material and electronic appliances.

Evaluation of Residual Stress on Pipe Welded Joints Using Laser Interferometry (레이저 간섭계를 이용한 배관 용접부 잔류응력 평가)

  • Chang, Ho-Seob;Na, Man-Gyun;Kim, Koung-Suk
    • Journal of the Korean Society for Nondestructive Testing
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    • v.34 no.1
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    • pp.18-22
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    • 2014
  • Residual stresses that occur during the welding process, are the main cause of failure and defects in welded structures. This paper, presents the use of an electronic processing laser speckle interferometer to measure the residual stress of a welded pipe for a nuclear power plant. A tensile testing machine was used to evaluate a welded pipe that failed in compression. The inform plane deformation and modulus of elasticity of the base metal and welds were measured using an interferometer. Varying the load on the welded pipe had a larger effect on the deformation of the base metal the other properties of the base metal and welds. The elastic moduli of the base metal and weld of the welded pipe were 202.46 and 212.14 GPa, respectively, the residual stress was measured to be 6.29 MPa.