Hybrid model for inspection of complex structures

Integration of finite-difference (FD) scattering calculations with an independent transducer characterization achieves an efficient and accurate simulation of ultrasonic inspection of complex structures. The emphasis is on immersion experiments where the transducer is stood-off from the structure under inspection by many wavelengths. In this case, propagation from the transducer to the structure and back again would needlessly suffer from grid dispersion and expend computational resources if modeled by FD. The integration introduces the desired transducer field into the grid, and uses reciprocity to model reception. The integration relies on high-quality absorbing FD boundary conditions (ABCs), a FD feedback method for setting source weights, and an application of reciprocity to the time-domain, stress-velocity, staggered-grid FD calculations