Reliable full-field reconstruction of Lamb waves with shearography

Stroboscopic shearography techniques, including double pulse shearography, are able to image transient Lamb waves to support non-destructive testing of structures and materials. The amplitude of the signal measured with these techniques is known to depend on optical shear distance and direction but the experimental demonstrations presented in the literature are limited. We present improved experimental results that show the dependence of signal amplitude on shear distance. By carefully selecting the shear distance, we are able to visualize a defect with shearographic measurement of transient Lamb waves.