S0302-2-1 非線形超音波計測のための8chフェイズドアレイシステム([S0302-2]超音波非破壊評価の高精度化(2))

Abstract

In industrial ultrasonic inspection, closed defects (cracks) result in misdetection or underestimation in sizing of the defects. Nonlinear ultrasound especially sub-harmonic ultrasound has been expected to detect closed defects due to the large displacement of incident wave. However, applicable displacement of incident ultrasound at defect is 100 nm peak-to-peak at most which considered insufficient comparing to the industrial crack tip displacement. In this study, we focused on phased array technique, and fabricated an 8ch phased array system which can excite 600Vp-p successive wave. We observed the fundamental travelling behavior of ultrasound combined with the prototyped transducers and investigated the availability of the phased array techniques to enhance the amplitude of incident waves.