Comparison of normal and phase stepping shearographic NDE

A. Andhee, J. Gryzagoridis, D. Findeis, Peter J. Shull, Andrew L. Gyekenyesi, Aftab A. Mufti
2005 Nondestructive Evaluation and Health Monitoring of Aerospace Materials, Composites, and Civil Infrastructure IV  
The paper presents results of non-destructive testing of composite main rotor helicopter blade calibration specimens using the laser based optical NDE technique known as Shearography. The tests were performed initially using the already well established near real-time non-destructive technique of Shearography, with the specimens perturbed during testing for a few seconds using the hot air from a domestic hair dryer. Subsequent to modification of the shearing device utilized in the shearographic
more » ... n the shearographic setup, phase stepping of one of the sheared images to be captured by the CCD camera was enabled and identical tests were performed on the composite main rotor helicopter blade specimens. Considerable enhancement of the images manifesting or depicting the defects on the specimens is noted suggesting that phase stepping is a desirable enhancement technique to the traditional Shearographic setup.
doi:10.1117/12.599570 fatcat:wwpudssa3rez7jrgk4grbaxnm4