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

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.

Automated summary

An electromagnetic acoustic transducer (EMAT) for generating and receiving omnidirectional shear-horizontal (OSH) wave in aluminum plate is developed in this study. The proposed OSH-EMAT utilizes static magnetic field and radial alternative eddy current to excite Lorentz force for SH wave generation. Experimental results demonstrate good consistency in performance and the design shows potential for various non-destructive testing applications due to its low cost and convenience.