Measuring and testing – Vibration – Sensing apparatus
Patent
1995-10-12
1997-03-04
Oda, Christine K.
Measuring and testing
Vibration
Sensing apparatus
73655, G01N 2900
Patent
active
056081669
ABSTRACT:
A method and apparatus for generating and detecting ultrasound on a workpiece utilizing a long pulse laser. A modulated pulsed laser beam is directed at the workpiece. The pulse duration is defined to be the time of propagation of ultrasound from a generation location to a flaw or discontinuity to be detected within the workpiece and then to a detection location, or, the time of propagation of ultrasound directly from the generation location to the detection location. A second pulsed laser beam, having a pulse duration longer than the ultrasonic propagation time, is also directed at the workpiece. After receiving phase modulated light from second pulsed laser beam reflected or scattered by the workpiece, phase modulated light is demodulated to obtain a demodulation signal representative of the ultrasonic motion at the surface of the workpiece. The demodulation signal is then electronically processed.
REFERENCES:
patent: 4633715 (1987-01-01), Monchalin
patent: 4659224 (1987-04-01), Monchalin
patent: 4966459 (1990-10-01), Monchalin et al.
patent: 5080491 (1992-01-01), Monchalin
patent: 5131748 (1992-07-01), Monchalin et al.
patent: 5137361 (1992-08-01), Heon et al.
Modulated Laser Array Sources for Generation of Narrowband and Directed Ultrasound. James W. Wagner; Andrew D. W. McKie; James B. Spicer; and John B. Deaton, Jr. Journal of Nondestructive Evaluation, vol. 9, No. 4, 1990 (no month).
Progress in Pulsed Laser Array Techniques for Generation of Acoustic Waves. Todd W. Murray; James W. Wagner. Review of Progress in Quantitative Nondesructive Evaluation vol. 13, pp. 532-539, 1994 (no month).
Temporal modulation of a laser source for the generation of ultrasounic waves. R. Pierce; C. Ume; and J. Jarzynski. Ultrasonics 1995 vol. 33. No.. 2. (no month) pp. 133-137.
New technique of photodisplacement imaging using one laser for both excitation and detection. Chen L.; Yang K. H.; Zhang S. Y. Applied Physics Letter vol. 50. No. 19. pp. 1349-1351, May 1987.
Holographic currents and the non-steady-state photoelectromotive force in cubic photorefractive crystals. L. A. Sokolov; S. I. Stepanov; and G. S. Trofimov. Optical Society of America vol. 9. No. 1/Jan. 1992, pp. 173-176.
Photodisplacement techniques for defect detection. Y. Martin Y; E. A. Ash. Philosophical Transactions of the Royal Society of London, vol. 320, No. 1554, pp. 257-269, 1986 (no month).
Blouin Alain
Monchalin Jean-Pierre
National Research Council of Canada
Oda Christine K.
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