科创中国

原文链接：万方

• 摘要：

  The fundamental shear horizontal(SH0) wave has several unique features that are attractive for long-range nondestructive testing(NDT). By a careful design of the geometric configuration, electromagnetic acoustic transducers(EMATs) have the capability to generate a wide range of guided wave modes, such as Lamb waves and shear-horizontal(SH) waves in plates. However, the performance of EMATs is influenced by their parameters. To evaluate the performance of periodic permanent magnet(PPM) EMATs, a distributed-line-source model is developed to calculate the angular acoustic field cross-section in the far-field. Numerical analysis is conducted to investigate the performance of such EMATs with different geometric parameters, such as period and number of magnet arrays, and inner and outer coil widths. Such parameters have a great influence on the directivity of the generated SH0 waves that arises mainly in the amplitude and width of both main and side lobes. According to the numerical analysis, these parameters are optimized to obtain better directivity. Optimized PPM EMATs are designed and used for NDT of strip plates. Experimental results show that the lateral boundary of the strip plate has no perceivable influence on SH0-wave propagation, thus validating their used in NDT. The proposed model predicts the radiation pattern of PPM EMATs, and can be used for their parameter optimization.

• 关键词：

  electromagnetic acoustic transducers shear-horizontal waves strip plate nondestructive testing

• 作者单位：

  Electric Power Research Institute of Guangdong Power Grid Corporation, Guangzhou 510600, China%College of Mechanical Engineering and Applied Electronics Technology, Beijing University of Technology,Beijing 100124, China

• 基金项目：

  National Natural Science Foundation of China(Grant .51075012,10772008)%Beijing Municipal Natural Science Foundation of China(Grant1122005)

• 来源期刊：

  中国机械工程学报

• 年，卷(期)：

  201427002