Identifying Critical Elastic Scales in Structural-Acoustic Models

Abstract

The level of detail required for accurate structural acoustic modeling of fluid loaded structures remains an issue of significant debate. Analytical solutions are rarely available, and discrete numerical solutions are typically too complex for ready extraction of physical understanding. In addition, numerical techniques introduce their own explicit scales through the minimum mesh dimension. However, the wavenumber based formulation of the surface variational principle describes the surface pressure and displacement as a comparatively small set of interacting waves. Coupling the SVP with distributed methods of representing structural attachment features provides a means to introduce, control, and investigate features of differing scales. We present here a technique for assessing the critical resolution scales for a fluid loaded two-dimensional plate. For feature attachments, we consider a line-mass elastically suspended by a line-spring from the wetted plate. We then use a spatial expansion for the elastic attachment to the wetted plate. The excitation applied to the plate is taken as a concentrated harmonic force. With the excitation held fixed, the influence of the scale of the feature spatial representation on the radiated power is assessed.