摘要
目前电磁超声换能器(electromagnetic acoustictransducer,EMAT)建模方法中存在有限元法计算时间较长,解析法建模不完整的问题。通过将圆柱永磁体等效为电流环并采用截断区域特征函数展开(truncated region eigen-function expansion,TREE)方法,建立螺旋线圈EMAT完整解析模型,得到涡流、磁场、力场和线圈阻抗的表达式。随后以铝板探伤为背景,应用该模型分析静磁场及其产生的洛伦兹力分布规律,得到永磁体直径是线圈的1.5～2倍,厚度与其直径相等的设计原则;对比分析静磁场洛伦兹力和交变磁场洛伦兹力的频率、大小和分布规律。最后,结合有限元法和实验验证了模型和分析结果的有效性。
In the current modeling process of electromagnetic acoustic transducers（EMATs）,the finite element method and analytical calculation are widely applied.However,it takes long time for finite element calculation,and some previous analytical models are incomplete.By introducing a current loop instead of the permanent magnet and adopting the truncated region eigenfunction expansion（TREE） method,a complete analytical model of spiral coil EMAT with permanent magnet is established.The eddy-current,magnetic flux density,Lorenz force and impedance of coil can be obtained by this model.Based on this model,by analyzing the distribution of static magnetic field and the generated Lorenz forces,the design principle of magnet is put forward that the proper diameter is 1.5～2 times of the coil’s diameter and the proper thickness is equal to its diameter.Finally,the frequency,magnitude and distribution of static and dynamic magnetic Lorenz forces are compared.The validity of the model and the analysis results are verified by combining finite-element and experiment methods.
出处
《中国电机工程学报》
EI
CSCD
北大核心
2013年第18期147-154,3,共8页
Proceedings of the CSEE
基金
国防科技工业技术基础科研项目(Z162010T002)~~
关键词
电磁超声换能器
解析建模
螺旋线圈
永磁体
electromagnetic acoustic transducer（EMAT）
analytical modeling
spiral coil
permanent magnet
