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Design Method of Multiwavelength EMATs Based on Spatial Domain Harmonic Control.
- Source :
-
IEEE Transactions on Ultrasonics Ferroelectrics & Frequency Control . Jun2021, Vol. 68 Issue 6, p2259-2270. 12p. - Publication Year :
- 2021
-
Abstract
- Conventional electromagnetic acoustic transducers (EMATs) are generally only used to generate and detect guided waves with a single wavelength, which increases their sensitivity at that particular wavelength but limits their application scenarios and the accuracy of defect assessment. This article proposes a design method for multiwavelength EMATs based on spatial-domain harmonic control. First, the EMAT model is analyzed, where it is then outlined that the eddy-current density distribution of the specimen is equivalent to the spatial low-pass filtering of the coil-current density distribution. This shows that the multiwavelength guided waves can be achieved as long as the spatial distribution of the coil-current density contains those multiple harmonics that are desired. It is then proposed that the structure of the EMAT coil is equivalent to the spatial sampled pulse sequences of a spatial signal. The coil parameter design based on pulse modulation technology is proposed. Taking a dual-wavelength EMAT design for Lamb waves as an example, details of the coil parameter design are presented. The simulation and experiment with the dual-wavelength EMAT proved the correctness of the proposed method. Finally, an experiment with a three-wavelength EMAT demonstrated the feasibility of the proposed method in designing multiwavelength EMATs. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 08853010
- Volume :
- 68
- Issue :
- 6
- Database :
- Academic Search Index
- Journal :
- IEEE Transactions on Ultrasonics Ferroelectrics & Frequency Control
- Publication Type :
- Academic Journal
- Accession number :
- 150557838
- Full Text :
- https://doi.org/10.1109/TUFFC.2021.3055871