Abstract:To address the inefficiencies of ultrasonic bulk wave thickness measurement and insufficient quantitative capability of guided wave detection, a Halbach array electromagnetic ultrasonic transducer integrating shear wave and shear horizontal (SH) guided wave is proposed for metal plate detection. It has the ability to excite both shear-wave and SH0 guided wave without increasing the dimension of the transducer, which combines the functions of high-precision fixed-point thickness measurement and regional defect detection. The transducer prototype was modeled and optimized for magnet array and coil arrangement through finite element simulation, followed by manufacturing and assembly based on the optimized results. Experimental platforms were established for SH wave detection and shear wave thickness measurement function respectively. The experimental results show that the transducer can effectively identify the echoes caused by the iron block adhering to the sample when the size of the block is larger than 35 mm× 10 mm× 20 mm, and the average thickness measurement error is less than 1. 2% . This study combines the deep penetration and high accuracy of ultrasonic bulk wave point thickness measurement with the long-range, non-dispersive scanning capability of SH waves, thereby enhancing the transducer′s detection efficiency and functionality. The transducer shows significant potential for industrial applications.