Weld quality inspection of small-diameter thin-walled pipes by a laser ultrasonic method.

Defect inspection of small-diameter thin-walled pipes is a difficult problem in the field of nondestructive testing. In this paper, a new detection method based on laser ultrasonics and guided circumferential wave technology is proposed and used to inspect the defects in pipes. First, a theoretical model based on the theory of acoustic propagation in solids is proposed for the small-diameter thin-walled pipes.