南京航空航天大学学报（英文版）2025，Vol.42Issue(6)：841-851,11.DOI:10.16356/j.1005-1120.2025.06.010
基于曲折线圈电磁超声换能器的A0波增强改进方法
Improved Approach Based on Meander Line Coil Electromagnetic Acoustic Transducers for A0 Wave Enhancement
摘要
Abstract
In traditional meander line coil electromagnetic acoustic transducer(MLC-EMAT)structures,the bias magnetic field is usually set to be along the normal direction of plate surface.However,since the particle vibration of the antisymmetric Lamb wave is always dominated by out-of-plane components,using bias magnetic field perpendicular to plate surface is kind of inefficient.In this paper,the performance of both the normal bias magnetic field EMAT(NB-EMAT)and the parallel bias magnetic field EMAT(PB-EMAT)for transmitting and receiving A0 mode Lamb waves are thoroughly studied.The mechanisms of these two structures are elaborated.First,the finite element models of both structures are established.The magnetic fields of these two EMATs are numerically calculated and the results are compared with experiments.Then,the Lorentz force distributions excited by the two EMATs are compared to prove the feasibility of improving the excitation efficiency of MLC-EMAT by selecting the direction of bias magnetic field.Furthermore,the excitation efficiencies of NB-EMAT and PB-EMAT are quantitatively analyzed and compared in simulation software.Results show that the excitation efficiency of PB-EMAT is 108%higher than NB-EMAT.Finally,several groups of comparative experiments are conducted to verify the conclusion obtained through numerical calculation.Experimental results show that by simply replacing the tradition NB-EMAT with PB-EMAT,the excitation efficiency can be greatly increased by more than 50%.If PB-EMATs are used as both the receiver and transmitter,the excitation efficiency can be further increased by 113%.关键词
电磁超声换能器/曲折线圈/兰姆波/A0波/平行偏置磁场Key words
electromagnetic acoustic transducer/meander line coil/Lamb wave/A0 wave/parallel bias magnetic field分类
通用工业技术引用本文复制引用
吕宗民,关伟,张应红,钱征华..基于曲折线圈电磁超声换能器的A0波增强改进方法[J].南京航空航天大学学报（英文版）,2025,42(6):841-851,11.基金项目
This work was supported by the Foun-dation of Guangxi Key Laboratory of Manufacturing System and Advanced Manufacturing Technology(No.17-259-05-005Z)and Innovation Project of GUET Graduate Education(No.2025YCXS016). （No.17-259-05-005Z）
