サイドバンドを用いた非線形超音波法による非破壊検査のための同軸型探触子の提案

抄録

A coaxial ultrasonic transducer was proposed for non-destructive evaluation using sidebands. The coaxial probe was consisted of a ring-type piezoelectric transducer and a disk-type piezoelectric transducer. The sound field distribution of the displacement was numerically calculated by the finite element method when the ratio of the inner diameter of the ring type vibrator to the diameter of the disk type vibrator was changed. In addition, two-frequency ultrasonic waves were transmitted from the coaxial transducer toward a closed-crack located inside the solid, and the sideband components contained in the transmitted waves were detected using the pulse inversion method. It was confi rmed that the proposed coaxial transducer could generate sidebands in a sound field with a closed crack.