Study on the capability in defect detection of an ultrasonic probe which can generate an ultrasonic wave traveling to the circumferential direction installed into a pipe

Abstract

At present, small-diameter metal tubes mainly are inspected an optical endoscope, or eddy current examination. However, due to the limited space of small diameter pipes, there are various difficulties in such inspection systems. Therefore, in this study, the guided wave of wholly vibrates in the direction of tube thickness is selected through modal analysis. Based on this, a unidirectional EMAT based on interference principle is developed to replace the EMAT for optimum inspection, and the non-destructive inspection of scratches in the circumferential direction of small-diameter metal tubes is carried out. If indicated that the modal analysis results coincidence with a experimental result by circumferential scratch.