基于海尔贝克式排布的电磁铁EMAT研制  

Development of electromagnet EMAT based on Halbach arrangement

作　　者：刘增华[1] 郑坤松 朱艳萍 郭彦弘 何存富[1] Liu Zenghua;Zheng Kunsong;Zhu Yanping;Guo Yanhong;He Cunfu(School of Information Science and Technology,Beijing University of Technology,Beijing 100124,China;College of Mechanical and Energy Engineering,Beijing University of Technology,Beijing 100124,China)

机构地区：[1]北京工业大学信息科学技术学院,北京100124 [2]北京工业大学机械与能源工程学院,北京100124

出　　处：《仪器仪表学报》2024年第8期286-296,共11页Chinese Journal of Scientific Instrument

基　　金：国家自然科学基金(12172015)项目资助。

摘　　要：电磁声传感器由于其结构简单且无需耦合等特点,在超声无损检测领域具备显著的应用潜力。传统的永磁铁式横波电磁声传感器存在诸多缺陷,包括换能效率低、激发超声模态不具一致性,以及在铁磁性试件上检测时吸附力强、难以移动等,这些问题不仅影响了检测结果的准确性,也限制了其应用范围。本研究基于永磁铁海尔贝克式电磁声传感器以及空芯电磁铁电磁声传感器的特点,研制了一种新型的电磁铁横波传感器,实现单侧磁场增强的同时,可实现偏置磁场强度可调。本文采用正交试验的方法对传感器励磁磁铁以及涡流线圈结构参数进行优化,提高了回波信号的幅值。研究结果表明,经过优化后的电磁声传感器对于铝板的检测,可显著增加试件表面产生的垂直磁场强度及分布范围,并大幅降低水平磁场,能够更有效地激发较为纯净的横波。Due to its simple structure and no need of coupling,the electromagnetic acoustic transducer(EMAT)holds significant potential in the field of ultrasonic nondestructive testing.However,traditional permanent magnet iron shear wave EMATs have several drawbacks,including low energy conversion efficiency,inconsistency in the generated ultrasonic modes,strong magnetic attraction,and difficulty in movement.These issues not only impact the accuracy of test results but also limit the range of applications.This study introduces a new type of electromagnet shear wave transducer,combining the features of permanent magnet Halbach EMATs and hollow electromagnet EMATs.This novel design enhances the magnetic field on one side and allows for adjustable bias magnetic field intensity.The study employs an orthogonal experimental method to optimize the structural parameters of the transducer′s excitation magnet and eddy current coil,resulting in improved echo signal amplitude.The findings indicate that the optimized EMAT significantly enhances the intensity and distribution range of the vertical magnetic field on the specimen surface while greatly reducing the horizontal magnetic field,thereby more effectively generating pure shear waves.

关 键 词：电磁铁 海尔贝克式电磁声传感器 横波 正交试验 

分 类 号：TH17[机械工程—机械制造及自动化]