摘要
针对曲折线圈电磁超声换能器(EMAT)换能效率和信噪比低的问题,建立了点聚焦EMAT的三维声场有限元模型,通过瞬态和稳态分析,分析了激励频率、线圈匝数和导线长度对点聚焦EMAT的声场聚焦特性以及缺陷回波特征的影响规律。搭建了0.5 MHz点聚焦EMAT检测系统,用于铝板中不同直径的圆孔检测,并与传统的曲折线圈EMAT进行对比。结果表明:采用点聚焦表面波EMAT,可以极大程度地提高信噪比和缺陷检测能力。
The conversion efficiency of a meander coil EMAT is extremely low. In order to solve the problem, a three-dimensional finite element model for the sound field of a focused Rayleigh wave EMAT was established. Based on the transient and steady-state analysis, effects of excitation frequency, coil turns and length of the coil conductor on focusing characteristics and reflection echoes of defects were discussed. A 0.5 MHz point-focused surface wave EMAT was developed to detect holes of various diameters in aluminum, and it was also compared to a traditional meander coil EMAT. Result shows that signal to noise ratio （SNR） and flaw detectability can be greatly enhanced by a point-focused Rayleigh wave EMAT.
作者
陈巍巍
石文泽
陈尧
陈果
龙盛蓉
卢超
CHEN Weiwei;SHI Wenze;CHEN Yao;CHEN Guo;LONG Shengrong;LU Chao(Key Laboratory of Nondestructive Testing,Ministry of Education,Nanchang Hangkong University,Nanchang 330063.China)
出处
《无损检测》
2018年第10期16-21,共6页
Nondestructive Testing
基金
国家自然科学基金资助项目(51705231
51265044
51705232)
江西省优势科技创新基金资助项目(20171BCB24008)
关键词
点聚焦表面波
电磁超声
声场特性
信噪比
point-focused Rayleigh wave
EMAT
sound field characteristies
signal-to-noise ratio
