TRANSMISSION OF ELASTIC-WAVES FROM A CYLINDER TO AN ATTACHED FLAT-PLATE

Equations are reviewed for elastic waves propagating along a lossless circular cylinder. Most of these waves involve coupled axial, circumferential and out-of-surface (bending) displacements. Equations are also developed for outward travelling waves on a lossless flat plate, for which the radial and transverse motions are in general coupled, but are uncoupled from bending displacements. Consideration of the boundary conditions at the junction of a cylinder and an attached plate having a matching cut-out leads to a set of equations from which are found reflected and transmitted wave amplitudes resulting from an incoming wave on the cylinder impinging on the junction. From these are calculated the coupling loss factors relating diffuse resonant fields on the cylinder to power transmitted to in-plane and bending waves on the plate. A complication arises in the definition of the coupling loss factors because of the coupling of the various displacements of the cylinder waves. Graphs of coupling loss factors against frequency are presented for two configurations, and the theory is compared with the limited amount of experimental data available. (C) 1995 Academic Press Limited