Improved method of imaging defect in noncontact and nondestructive technique by high-intensity aerial burst ultrasonic wave and optical equipment

Abstract

We propose a noncontact and nondestructive method of imaging by using high-intensity aerial ultrasonic waves and optical equipment. This method identifies defects in an imaged area by analysis of the velocity distribution of vibration on the surface of an object continuously irradiated by aerial ultrasonic waves. In a previous study, a related method was applied but could not exactly image the defect shape and size because the vibration mode at the target's surface is generated by a continuous wave that depends on the boundary between the defective area and the defect-free area. By avoiding this problem, the proposed method allows exact imaging of the defect shape and size. In this report, we simulate results from the proposed underlying principle and conduct an experiment based on the proposed principle.