Vibration analysis by means of digital speckle pattern shearing interferometry (digital shearography)

摘要

Digital speckle pattern shearing interferometry is described as a robust measuring method due to its simple optical setup and the insensitivity against ambient disturbances. It has been used in industry for nondestructive testing and strain measuring. This paper explores the possibilities for vibration analysis using digital speckle pattern shearing interferometry. The measuring device performing both time-average and stroboscopic methods is described. The time average digital speckle pattern shearing interferometry in conjunction with the stroboscopic technique is suited well for both qualitative and quantitative vibration analysis. The determination of the dynamic deformation and the strain fields from the phase map of shearogram is demonstrated, and some preliminary results are shown.