Ultrasonic shot peening is similar to conventional shot peening in that it uses hard spherical balls propelled against a metal part to produce a surface layer with residual compressive stress. I'm not familiar with how Abaqus models the effects of shot peening, but I assume it requires providing inputs for the same process variables used for conventional shot peening such as shot size/material properties, incidence angle of the shot, intensity of the shot blast, surface coverage, etc. The surface geometry of the part will have a big effect on the results you will obtain from any shot peen process. Ideally, the shot blast should be directed perpendicular to the part surface for best results. Once you define the surface geometry that will be peened, you need to contact a vendor that performs the process to get an idea of the process parameters that would be used for your particular application.