1
|
Nakahata K, Karakawa K, Ogi K, Mizukami K, Ohira K, Maruyama M, Wada S, Namita T, Shiina T. Three-dimensional SAFT imaging for anisotropic materials using photoacoustic microscopy. Ultrasonics 2019; 98:82-87. [PMID: 31207475 DOI: 10.1016/j.ultras.2019.05.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/22/2018] [Revised: 03/01/2019] [Accepted: 05/19/2019] [Indexed: 06/09/2023]
Abstract
A pulsed laser illuminates a target zone that causes rapid thermoelastic expansion, generating broadband high-frequency ultrasonic wave (photoacoustic wave, PA wave). We developed a PA microscopy (PAM) with a confocal area of laser and ultrasonic wave for applications in nondestructive testing (NDT). The synthetic aperture focusing technique (SAFT) is applied in the PAM for the three-dimensional (3D) imaging of interior flaws. Here, we report proof-of-concept experiments for the NDT of a subsurface flaw in a thin laminar material. Graphical abstract (a) shows a specimen of carbon-fiber-reinforced plastic (CFRP) with an artificial delamination. Here, it should be noted that the group velocity varies directionally due to the strong anisotropy of the CFRP specimen (see Graphical abstract (b)). By considering the group velocity distribution in the SAFT, the shape and location of the subsurface delamination were accurately estimated as shown in Graphical abstract (c). Coating the surface of the CFRP specimen with a light-absorbent material improved the amplitude of the PA wave. This finding showed that the signal-to-noise ratio of the waves scattered from the flaws can be improved.
Collapse
Affiliation(s)
- K Nakahata
- Graduate School of Science and Engineering, Ehime University, 3 Bunkyo, Matsuyama, Ehime 790-8577, Japan.
| | - K Karakawa
- Graduate School of Science and Engineering, Ehime University, 3 Bunkyo, Matsuyama, Ehime 790-8577, Japan
| | - K Ogi
- Graduate School of Science and Engineering, Ehime University, 3 Bunkyo, Matsuyama, Ehime 790-8577, Japan
| | - K Mizukami
- Graduate School of Science and Engineering, Ehime University, 3 Bunkyo, Matsuyama, Ehime 790-8577, Japan
| | - K Ohira
- Research and Development Center, Japan Probe Co., Ltd., 1-1-14 Nakamura, Yokohama, Kanagawa 232-0033, Japan
| | - M Maruyama
- Center for Advanced Photonics, RIKEN, 2-1, Hirosawa, Wako, Saitama 351-0198, Japan
| | - S Wada
- Center for Advanced Photonics, RIKEN, 2-1, Hirosawa, Wako, Saitama 351-0198, Japan
| | - T Namita
- Graduate School of Medicine, Kyoto University, 53 Shogoin Kawahara-cho, Sakyo-ku, Kyoto, Kyoto 606-8507, Japan
| | - T Shiina
- Graduate School of Medicine, Kyoto University, 53 Shogoin Kawahara-cho, Sakyo-ku, Kyoto, Kyoto 606-8507, Japan
| |
Collapse
|