Laser ultrasonic technique applied to inspect fatigue crack

The present paper describes a study of the detection and monitoring of fatigue crack growth using laser ultrasonic technique. Rayleigh wave propagating along material surface allow in principle for the efficient non-destructive testing of surface-breaking fatigue crack and subsurface crack. Artificial cracks with various width and depth were produced on the aluminum plates, which were used to simulate the monitoring of fatigue crack. Experiments results shows fatigue crack detection and growth monitoring is possible for laser ultrasonic technique. The sensitivity and repeatability of the measurements were ascertained, having the potential for fatigue crack detection and easy to access fastener locations. Good agreement was observed between the experimental results and theoretical prediction.