Impact of magnetostriction mechanism on frequency manipulation ultrasonic steering in electromagnetic acoustic transducers

• Published in: Electronics letters Vol. 60; no. 1
• Main Author: Li, Yong
• Format: Journal Article
• Language: English
• Published: Stevenage John Wiley & Sons, Inc 01.01.2024; Wiley
• Subjects: acoustic field; acoustic transducers; Acoustics; Conflicts of interest; Directivity; electromagnetic induction; Lorentz force; Magnetic fields; Magnetostriction; non‐destructive testing; Simulation; Steering; Transducers
• ISSN: 0013-5194; 1350-911X
• DOI: 10.1049/ell2.12987

In this paper, the impact of the magnetostriction mechanism is considered as the focus. An axisymmetric FEM model of the spiral‐coil electromagnetic acoustic transducers (EMAT) is established to conduct the simulation. The simulation results demonstrate that the directivity of ultrasonic wave can be controlled by manipulating the frequency. Furthermore, it is found that the direction of the dominant Lorentz force in the rail varies with time, while the magnetostrictive force compels the ultrasonic wave generated by the Lorentz force towards the axis. It effectively illustrates that the combined power of two mechanisms surpasses that of the Lorentz‐force mechanism alone, particularly at low frequencies. The leakage of the reflected energy of the ultrasonic wave generated by electromagnetic acoustic transducers (EMAT) is outside the receiving range and then weakens the amplitude of ultrasonic echo. To reduce the leakage of the reflected energy, this paper takes the impact of magnetostriction mechanism on frequency manipulation ultrasonic steering in EMAT, especially at low frequency.