Abstract: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.