Enhancement of selectivity in nonlinear ultrasonic imaging of closed cracks using amplitude difference phased array

Yoshikazu Ohara, Yohei Shintaku, Satoshi Horinouchi, Masako Ikeuchi, Kazushi Yamanaka

Research output: Contribution to journalArticle

38 Citations (Scopus)

Abstract

Subharmonic waves realize a high selectivity for closed cracks. However, when a short-burst wave is used to achieve a high temporal resolution, not only closed cracks but also linear scatterers appear in the subharmonic image owing to leakage in frequency filtering. They are ghosts that degrade the selectivity for closed crack in the subharmonic image. Here, we propose an amplitude difference phased array (ADPA), where the ghosts are eliminated by subtracting a subharmonic image at a small input multiplied by the input amplitude ratio from that at a large input. We verified the ADPA method by a two-dimensional simulation based on the finite difference time domain (FDTD) method with damped double nodes (DDNs) for subharmonic imaging of closed cracks. Furthermore, the ADPA method was experimentally verified in a closed-crack specimen.

Original languageEnglish
Article number07GB18
JournalJapanese journal of applied physics
Volume51
Issue number7 PART2
DOIs
Publication statusPublished - 2012 Jul 1

ASJC Scopus subject areas

  • Engineering(all)
  • Physics and Astronomy(all)

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