DYNAMICS OF FLUID-COUPLED NEIGHBORING DISPARATE SUBSTRUCTURES AT LOW-FREQUENCIES

This paper examines the structural dynamics of a class of fluid-couple d substructures at low frequencies. To do this, it is stipulated that the fluid motion is essentially inertial and that substructures are di sparate in size. The smaller structure is the driven substructure. Clo sed form example solutions may be obtained for a class of problems whe n the substructure is an acoustically compact strip of vanishing thick ness that is adjacent to a shell with a radius of curvature that is la rge in comparison with the width of the strip. Two examples are consid ered: that of a rectangular plate window in a baffle driven by a force d nearby elastic strip, and that of a cylindrical shell driven by an e xterior coaxial ring. The latter example is selected (a) to remove cer tain cross modal coupling issues that are provoked by the finite windo w example, and (b) to permit a simple illustrative example of how fini te element analysis may be invoked to solve problems in which one of t he structures may be structurally complex. (C) 1997 Published by Elsev ier Science Ltd.