Experimental verification of finite-difference model for ultrasonic evaluation of complex structures

A numerical model which combines time-domain finite-difference scattering calculations with analytic propagation calculations was developed to simulate pulse echo responses of ultrasonic transducers inspecting complex structures. The accuracy and applicability of such a model were verified experimentally by comparing the simulated responses of an ideal, 2-D (finite-width, infinitely long) transducer against the measured waveforms. The experiment was a pulse-echo immersion (water) measurement. The transducer was rectangular, with an active region roughly 3 wavelengths wide (in water) and 30 wavelengths long, and was positioned between 10 and 20 wavelengths from the target structure