ULTRASONIC IMAGING OF SMALL SURFACE-BREAKING DEFECTS USING SCANNING LASER SOURCE TECHNIQUE

摘要

The Scanning Laser Source (SLS) technique is based on monitoring the changes in the laser generated ultrasonic signal as the source is scanned over the area of inspection. The SLS imaging scanning system includes a portable Nd-YAG laser, free space or fiberized scanners, an ultrasonic detector, and signal processing software. High resolution ultrasonic images of small EDM notches and fatigue cracks on flat and curved specimens are presented. A Mass-Spring Lattice Model is adopted as the numerical method for the simulation and visualization of the SLS technique. The SLS imaging system offers an effective solution for high resolution non-contact inspection of critical components of complicate shape.