2019年中国声学学会青年人才托举工程项目交流会在南昌召开

为改善电磁超声换能器(electromagnetic acoustic transducer,EMAT)激发横波的特性,提出一种基于正交试验的优化方法,并利用有限元仿真软件COMSOL Multiphysics建立了横波EMAT的有限元模型,应用正交试验和极差分析法,分析了线圈各参数对电磁超声横波的近场长度和半扩散角的影响,比较了线圈各参数影响程度的大小。结果表明,激励电流的频率和线圈的尺寸对横波的传播特性有着明显影响,提高频率会使得横波的近场长度增大及半扩散角减小；其次,减小导线的宽度及间距,以缩小线圈尺寸能有效改善横波的传播特性。

Optimum design of coil in electromagnetic acoustic shear wave transducers

In order to improve the characteristics of transverse wave stimulated by electromagnetic acoustic transducer, an optimization method using orthogonal test was introduced. Finite element mode of transverse wave EMAT was established. The orthogonal test and extreme difference analysis were applied to consider the parameters of the coil, which impact on the near field length and half diffusion angle of electromagnetic acoustic transverse wave. The result shows that the frequency of exciting current and the size of coil have obvious influence on the propagation characteristics of the shear wave. Increasing the frequency will increase the near field length and decrease the half diffusion angle of the shear wave. Reducing the width and spacing of the wire to reduce the size of the coil can effectively improve the propagation characteristics of the shear wave.