Paper
22 June 2004 Digital shearography using stroboscopic illumination in addition to time average method
Wolfgang Steinchen, Ymin Gan, Gerhard Kupfer, Peter Maeckel
Author Affiliations +
Proceedings Volume 5503, Sixth International Conference on Vibration Measurements by Laser Techniques: Advances and Applications; (2004) https://doi.org/10.1117/12.579571
Event: Sixth International Conference on Vibration Measurements by Laser Techniques: Advances and Applications, 2004, Ancona, Italy
Abstract
One of the most interesting and useful applications of shearographic interferometry is the detection, visualization and measurement of the mechanical vibration of opaque objects. Until now the time-average shearography is a qualitative interferometric method for determining the oscillating loadings. The detected gradient of the deformation can be determined by changing the shearing distance. The fringes of the moving object are often faded and become clearer by filtering with FFT and against an uniform background intensity. The fringes formed in time-average shearography of sinusoidal motions have an irradiance described by the Bessel function J02. Quantitative interpretation of the shearogram requires a more precise analysis. Such a technique for extending or decreasing the sensitivity of vibration measurements and for determining the relative phase of vibration across the object surface is the stroboscopic illumination. Stroboscopic shearographic interferometry is a technique which compensates the deficiencies of time-average shearography at the expense of some increase in experimental complexity. However more complex is the recording of stroboscopic shearograms by using two pulses from a double-pulse laser.
© (2004) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Wolfgang Steinchen, Ymin Gan, Gerhard Kupfer, and Peter Maeckel "Digital shearography using stroboscopic illumination in addition to time average method", Proc. SPIE 5503, Sixth International Conference on Vibration Measurements by Laser Techniques: Advances and Applications, (22 June 2004); https://doi.org/10.1117/12.579571
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Cited by 2 scholarly publications.
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KEYWORDS
Shearography

Semiconductor lasers

Fringe analysis

Bessel functions

Interferometry

Vibrometry

Pulsed laser operation

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