Novel electromagnetic acoustic transducer for measuring the thickness of small specimen areas

Article type: Research Article

Authors: Sun, Hongjun^a | Urayama, Ryoichi^b | Hashimoto, Mitsuo^b | Kojima, Fumio^b | Uchimoto, Tetsuya^{b; c} | Takagi, Toshiyuki^{b; c;}

Affiliations: [a] Graduate School of Engineering, Tohoku University, Sendai, Miyagi, Japan | [b] Institute of Fluid Science, Tohoku University, Sendai, Miyagi, Japan | [c] ELyTMaX UMI 3757, CNRS – Université de Lyon – Tohoku University, International Joint Unit, Tohoku University, Sendai, Japan

Correspondence: [*] Corresponding author: Toshiyuki Takagi, Institute of Fluid Science, Tohoku University, 2-1-1 Katahira, Aoba, Sendai, Miyagi 980-8577, Japan. E-mail: [email protected]

Abstract: Intense ultrasonic waves are required to accurately measure the thickness of corroded specimen at a given point. The most intense part of the ultrasonic wave should be at the measurement point itself. In this paper, finite element simulation is used to optimize the structure of the classic racetrack coil bulk wave electromagnetic acoustic transducer to produce more intense, concentrated ultrasonic waves in a smaller area. In addition, a new magnet configuration is used that increases the wave intensity. Compared with the classic magnet configuration, the maximum amplitude of the ultrasonic wave is increased by 21%.

Keywords: Electromagnetic acoustic transducer, racetrack coil, magnet configuration

DOI: 10.3233/JAE-171106

Journal: International Journal of Applied Electromagnetics and Mechanics, vol. 59, no. 4, pp. 1495-1504, 2019