ABSTRACT

Laser Shearography is a full field, non-contact, non-contaminating NDE method and offers near real time inspection of surface and subsurface anomalies in materials or structures by imaging submicroscopic deformation derivatives of a test part surface when an appropriate stress is applied. The laser shearography system can be used in the field under ambient conditions. It has been applied to detect fine cracks in masonry and concrete structures with a resolution better than 10 microns. Shearography interferometry nondestructive testing refers to the use of a laser based imaging interferometer to detect, measure and analyze surface and subsurface anomalies in materials or structures by imaging submicroscopic deformation derivatives of a test part surface when an appropriate stress is applied. The field of view (FOV) for a shearography camera depends on the maximum allowable defect size, camera resolution, laser illumination power, the ability to uniformly apply a stress change to the test part over the FOV and background noise.