An Acoustic Variational Principle and Component Mode Synthesis Applied to the Analysis of Acoustic Radiation from a Concentrically Stiffened Plate

This study concerns the effects of circumferential ring stiffeners on the vibration and acoustic radiation of a submerged circular elastic plate supported by an infinite rigid baffle. The analysis employs variational principles, in which surface pressure and velocity are represented by assumed modal functions. It is shown that the use of a Fourier series expansion of the Green’s function, along with Bessel function pressure modes, greatly simplifies computation of the fluid-structure interaction. Two structural formulations are addressed, differing by whether the connection between the plate and stiffeners is implicitly or explicitly enforced. The results for surface response are used in conjunction with the Kirchhoff-Helmholtz integral theorem to evaluate near- and farfield pressures. An example of a single stiffener illustrates the influence of stiffener location on radiated power.