SHEAROGRAPHY: A Full-Field Measurement Technique and Application in Non-Destructive Testing

This paper reviews shearography and its applications in nondestructive testing. Shearography is a laser-based technique for full-field and non-contacting measurement of surface deformation (displacement or strains). The technique can be used for strain measurement, design verification and optimization, material characterization, residual stress evaluation, leak detection, vibration studies and 3-D shape measurement. Despite being a relative young technique, it has already received considerable industrial acceptance for nondestructive testing. One major difference of shearography from other non-destructive testing techniques is the mechanics of revealing flaws. Shearography reveals defects in an object by identifying defect-induced deformation anomalies which are more relevant to structural weakness.