A new time-averaged frame subtraction technique is introduced for vibration analysis by digital speckle shearing interferometry. The technique permits the enhancement of fringes by subtracting two Bessel fringe patterns at different forcing levels. Compared with the phase-shift method, this method is more efficient and easier to implement for qualitative vibration measurement, providing a means for fast inspection of plate vibration behavior. It is also capable of tracing contours of zero strain and locating antinodes on vibrating plates.
- Digital shearography
- Time-averaged speckle pattern shearing interferometry
- Vibration mode shape
- Zero-strain distribution
ASJC Scopus subject areas
- Atomic and Molecular Physics, and Optics