Design of a new type of omnidirectional shear-horizontal EMAT by the use of half-ring magnets and PCB technology

Yinghong Zhang; Wenlong Liu; Nian Li; Zhenghua Qian; Bin Wang; Dianzi Liu; Xiangyu Li

doi:10.1016/j.ultras.2021.106465

Design of a new type of omnidirectional shear-horizontal EMAT by the use of half-ring magnets and PCB technology

Ultrasonics. 2021 Aug:115:106465. doi: 10.1016/j.ultras.2021.106465. Epub 2021 May 13.

Authors

Yinghong Zhang¹, Wenlong Liu², Nian Li³, Zhenghua Qian⁴, Bin Wang³, Dianzi Liu⁵, Xiangyu Li⁶

Affiliations

¹ State Key Laboratory of Mechanics and Control of Mechanical Structures, College of Aerospace Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China; School of Mechanical and Electrical Engineering, Guilin University of Electronic Technology, Guilin 541004, China.
² School of Mechanical and Electrical Engineering, Guilin University of Electronic Technology, Guilin 541004, China.
³ State Key Laboratory of Mechanics and Control of Mechanical Structures, College of Aerospace Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China.
⁴ State Key Laboratory of Mechanics and Control of Mechanical Structures, College of Aerospace Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China. Electronic address: qianzh@nuaa.edu.cn.
⁵ School of Engineering, University of East Anglia, UK.
⁶ Applied Mechanics and Structure Safety Key Laboratory of Sichuan Province, School of Mechanics and Engineering, Southwest Jiaotong University, Chengdu 610031, China.

PMID: 34015692
DOI: 10.1016/j.ultras.2021.106465

Abstract

In this paper, an electromagnetic acoustic transducer (EMAT) for generating and receiving omnidirectional shear-horizontal (OSH) wave in aluminum plate is developed. The proposed OSH-EMAT consists of a specially designed printed circuit board (PCB) coil and a pair of half-ring magnets. Vertical oriented static magnetic field and the radial alternative eddy current are applied to excite the Lorentz force along the circumferential direction. A three-dimensional finite element model has been established to simulate the distributions of the static magnetic flux, the eddy current, and the exciting process of SH wave. Further experimental results show that the proposed electromagnetic ultrasonic transducer has good consistency in the performance of omnidirectional excitation and reception. The new OSH-EMAT design has the potential for many non-destructive testing applications owing to its low cost, acceptable accuracy and convenient processing and fabrication.

Keywords: Electromagnetic acoustic transducer; Guided wave; Omnidirectional transducer; Shear-horizontal wave.