PORTABLE AND HYBRID LASER GENERATION/AIR-COUPLED DETECTION SYSTEM FOR NON DESTRUCTIVE INSPECTION

摘要

This review presents a portable head instrument, using a hybrid laser generation/air-coupled detection system for ultrasonic non-destructive inspection. The equipment is made of a low-cost Nd:YAG pulsed laser linked to a multimode optic fiber to generate Surface Acoustic Waves (SAW). Instead of a long-pulse detection laser coupled to an interferometer, a small air-coupled ultrasonic transducer is used to perform the detection. A compact probe holder supporting the optical assembly and the air-coupled transducer has been designed, and integrated with an XY scanner system to move the probe above the sample. Inspection tests are carried-out on representative samples, and the performances of the portable head are evaluated for surface and subsurface defect detection in aeronautic composite materials.