抄録
Nonlinear ultrasound is expected to detect the closed crack tip using a large displacements ultrasonic measurement system. As the more advanced technique we have developed the laminated transducer system up to 700 kHz in frequency. In this study, a new high frequency laminated transducer of MHz range was developed for the use of industrial steel structures. New fabricate procedures relate to the thin element thickness due to the high frequency ultrasound were applied. As the result we can fabricate the 2.9 MHz laminated transducer using the 5 MHz elements.
