ASA 126th Meeting Denver 1993 October 4-8

3aSA7. A spectral description for the effects of multiple point masses in fluid-loaded plates.

Kenneth A. Cunefare Jerry H. Ginsberg John Babish

The George W. Woodruff School of Mech. Eng., Georgia Inst. of Technol., Atlanta, GA 30332-0405

The wave-number-based formulation of the surface variational principle describes the surface pressure and displacement as a comparatively small set of interacting waves. It enables one to pose questions of parametric sensitivity from a global perspective. A two-dimensional problem of an elastic plate in an infinite baffle with pinned boundary conditions is considered. A series of line masses attached to the plate, at regular and irregular spacings is considered. The specific mass distribution is replaced in the SVP formulation by an arbitrary continuous distribution along the length of the plate. The functional form of this distribution is described using a spectral Fourier series, whose ascending orders represent successive stages in refinement of the scale to which a model describes inertial effects. The excitation applied to the plate is taken as a concentrated harmonic force. With the excitation held fixed, the influence of each spectral component of inertial distribution on the surface response and radiated power are assessed. Evaluations carried out for a range of frequencies shed light on how small scale inertial heterogeneities can influence macroscopic radiation features.