Vibrations of and sound radiation from sandwich plates in heavy fluid loading conditions

A problem of forced vibrations of a sandwich plate submerged in a fluid (an acoustic medium) is formulated as a coupled problem of structural acoustic s. Two-dimensional (plane) formulation relevant to cylindrical bending of a plate is explored. Dynamics of a sandwich beam (a sandwich plate in cylind rical bending) is described in the framework of the sixth-order theory of m ulti-layered plates. Asymptotic analysis of the dispersion polynomial is pe rformed in the low frequency and the low module limits for an isolated infi nitely long beam. Green's functions for flexural vibrations are obtained an alytically and thus explicitly contain the principal parameters of beam's c omposition. Forced vibrations of a fluid-loaded beam in a rigid baffle are considered. Both the interaction between an acoustic medium and a plate and the interaction between a plate and its boundaries are described by bounda ry integral equations assembled in a two-level system. Eigenfrequencies of a fluid-loaded beam are detected by maximum of the radiated acoustic power. A semi-analytical sensitivity analysis of the objective function selected as a radiated acoustic power to the parameters of beam's composition is per formed. (C) 2000 Elsevier Science Ltd. All rights reserved.