Propagation characteristics of SH guided wave in steel plate defect detection

Shear Horizontal (SH) wave has two modes in the process of transmission:symmetrical mode and antisymmetric mode, and its phase velocity and group velocity mainly depend on the product of thickness and frequency of specimen. The paper sets up a three-dimensional model for steel plate defects by using COMSOL finite element analysis software, simulates and analyzes the SH0 guided wave propagation characteristics in the steel plate, and concludes that shear horizontal wave has little change in the direction of beam, no dispersion and mode conversion, and high signal to noise ratio in the process of transmission. Meanwhile, we utilize the electromagnetic ultrasonic transducer to generate shear horizontal wave and make an experiment of the crack and weld defect in the steel to test the validity and feasibility of stimulation result, which will provide the basis for the application of ultrasonic guided waves in the plate defect detection.