Propagation and Scattering of High-Frequency and Pulsed Signals in the Presence of a Concave Boundary

摘要: High-frequency waves traveling circumferentially along the concave side of a cylindrically curved material surface can serve as diagnostic tool for imperfections on or near surface. The propagation and scattering are expressed conveniently by ray fields but such description becomes invalid rays that cling close to It is then necessary account collectively in terms guided (whispering gallery) modes canonical integrals. resulting hybrid ray-mode formulation, which be used incident field well secondary excited imperfection, physically appealing numerically efficient. Under transient conditions, similar scheme employed combine made fields, suited high-frequency portion signal spectrum, with body resonances singularity expansion method (SEM) more effective at lower frequencies. purpose this paper call attention these techniques, have so far been developed electromagnetics acoustics, emphasize their physical content, indicate how they might exploited non-destructive diagnostics.