A Pseudo-3D Model for Electromagnetic Acoustic Transducers (EMATs)

• Published in: Applied sciences Vol. 8; no. 3; p. 450
• Main Authors: Yin, Wuliang, Xie, Yuedong, Qu, Zhigang, Liu, Zenghua
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 01.03.2018
• Subjects: Acoustics; Analytical solutions; beam directivity; Defects; EMATs; Exact solutions; Excitation; FDTD; Lorentz force; Mathematical models; Nondestructive testing; Rayleigh waves; Simulation; Transducers; Ultrasound; Wire; Beijing China; New York; United States > US; China
• ISSN: 2076-3417; 2076-3417
• DOI: 10.3390/app8030450

[...]the classic Dodd and Deeds solution [20] to the vector potential is described, and the strategy of adapting the circular analytical solutions for a straight wire is introduced (Section 2.1.1). [...]at a working frequency of 1 MHz, the distribution of A from the FEM is not smooth compared to that from the analytical solution; the reason is that the FEM is affected by the elements density and numerical approximation is unavoidable, etc. [...]the adapted analytical method presents a more accurate result compared to FEM, especially for a high working frequency. 2.1.3. In this section, F, which is used as the force source, is imported to the EMAT-US model to produce ultrasound (Figure 6). Since F is calculated in the frequency domain and FDTD is a time-domain solver, the excitation signal for the EMAT-US model is a time sequence signal with the peak equalling the peak values of F. The excitation signal used is a Gaussian-modulated sinusoidal with a fractional width of 0.18. [...]the EMAT-US model on the vertical plane of the sample uses an approximated model with only point sources (Lorentz force density) to generate Rayleigh waves.