Tabaru M.,CRL Hitachi |
Azuma T.,CRL Hitachi |
Hashiba K.,CRL Hitachi |
Maruyama T.,Hitachi Construction Machinery |
Kenbo Y.,Hitachi Construction Machinery
Proceedings - IEEE Ultrasonics Symposium | Year: 2010
We have studied the acoustic characteristics of echoes reflected from microvoid areas. Artificial-defect samples with air gap widths of 30, 50, and 70 mwere developed. Echo signals from the samples were obtained in a pulse-echoexperiment with a high-frequency ultrasonic probe (center frequency: 200 MHz).Wave propagation for an artificial-defect model was also simulated by using afinite element method. Calculation and experimental results confirmed that phaseshifts and ringing are useful for distinguishing between normal and defectivesamples. Simulation results show that defect detection is possible for gapwidths of less than 10 m. © 2010 IEEE.