Windowing of Full Wavefield Data in Multiple Domains to Characterize Angle-Beam Shear Wave Scattering

Angle beam ultrasonic inspection methods are frequently based on shear waves that are generated using conventional longitudinal transducers and a wedge. Full wavefield imaging can be employed to measure such waves on the surface of a plate-like specimen after they have scattered from a feature or defect of interest, and multiple shear wave arrivals, or "skips," are readily visible due to beam spread. Because of the complexity of the total wavefield, which also includes Rayleigh and longitudinal waves, it is challenging to experimentally quantify scattering from the primary skip of interest. Proposed here is a methodology to isolate shear wave scattering from a through-hole caused by a specific shear wave skip. By combining 3-D Fourier filters and space-time windows, the forward and backward scattering can be readily quantified as a function of measurement direction. Results are shown for several hole sizes of interest.