Effects of initial stress state on the subsurface stress distribution after ultrasonic impact treatment on thick specimens

Thick welded specimens with different initial stress states were prepared and treated with the ultrasonic impact treatment (UIT). The subsurface stresses before and after UIT were measured by the X-ray diffraction (XRD) method combined with layer removal. The measured results were corrected based on the finite element correction method. The effects of initial high tensile stress and low compressive stress on the in-depth after-UIT stress...