Visualization and evaluation of ultrasonic wave generation by various types of probes

The authors present visualized ultrasonic waves generated by various types of transducers. They have developed an ultrasonic wave visualization system based on the synthesized photoelastic method, using a stroboscopic light source and a digital image processing computer. The visualized images do not include the pattern of residual stress, which exists in the test piece and is visualized simultaneously with the ultrasonic waves; the visualized ultrasonic waves can thus be observed very clearly. Results are presented on the following: (1) generation of longitudinal waves by normal probes, (2) generation of shear waves by angle probes and reflection of these waves, (3) emitted waves from an angle longitudinal wave probe and their corner reflection, (4) ultrasonic wave refraction in immersion testing, (5) beam focusing in immersion testing, and (6) generation of a high-frequency 50-MHz longitudinal wave