Affiliations: [a] School of Mechanical Science and Engineering, Huazhong University of Science and Technology, Wuhan, Hubei, China | [b] CNPC Research Institute of Safety and Environment Technology, Beijing, China
Correspondence:
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Corresponding author: Xinjun Wu, School of Mechanical Science and Engineering, Huazhong University of Science and Technology, Wuhan, Hubei, China. E-mail: xinjunwu@hust.edu.cn
Abstract: The EMAT (electromagnetic acoustic transducer) has been used to measure the thickness of the metallic plate in some industries recently. Comparing with the piezoelectric transducer, its low energy conversion efficiency due to the lift-off effect limits its further application. Based on the eddy current energy partition, the distances between the copper sheet and the coils are studied. In consideration of the influence of magnetic flux density, a principle about the energy conversion efficiency and the coils position is proposed. The optimal distances between the copper sheet and the coils under a certain lift-off are obtained through a series of simulation and experiment. The results offer a method for the EMAT structure design.
Keywords: EMAT, energy partition, conversion efficiency lift-off effects
