STRUCTURAL WAVE REFLECTION COEFFICIENTS OF CYLINDRICAL-SHELL TERMINATIONS - NUMERICAL EXTRACTION AND RECIPROCITY CONSTRAINTS

A fluid-loaded cylindrical shell guides vibratory energy along its axi al direction in the form of a finite set of distinct traveling wave ty pes. On a finite shell, the energy incident upon a termination is redi rected into reflected waves of all types and into sound radiated into the farfield. (The total field near the termination also includes vari ous evanescent components.) Reflection coefficients relate the amplitu des of individual reflected wave types to the amplitudes of individual incident wave types. In this paper, values for the reflection coeffic ients of several terminations have been extracted from results of fini te element analysis for the forced response of a finite structure exci ted by a variety of different sources. The numerical results exhibit g ood agreement with the analytical constraints consequent to the princi ple of reciprocity. The constraints are developed here by an analysis adaptable to other multimodal waveguides by appropriate modification o f detail. (C) 1997 Acoustical Society of America.