Investigating the Impact of Dispersion Effects on Ultrasonic Detection of Three-Dimensional Stress in Thick Steel Plates

This paper investigates the impact of dispersion effects on a three-dimensional stress detection method for thick steel plates using transverse wave tri-refraction. It examines how phase velocities of quasi-shear and quasi-longitudinal waves vary with stress levels, plate thicknesses, and material properties. Experimental results show that phase velocity changes are relatively stable within the 0-5 MHz frequency range, while significant deviations occur above 5 MHz. The 2.5-5 MHz frequency range is identified as optimal due to its smoother dispersion curves, which enhance detection accuracy. The study also underscores the need to recalibrate specimens with varying thicknesses and materials to ensure precise stress detection.