Dispersion analysis of stabilized finite element methods for acoustic fluid interaction with Reissner-Mindlin plates

The application of stabilized finite element methods to model the vibration of elastic plates coupled with an acoustic fluid medium is considered. A c omplex-wavenumber dispersion analysis of acoustic fluid interaction with Re issner-Mindlin plates is performed to quantify the accuracy of stabilized f inite element methods for fluid-loaded plates. Results demonstrate the impr oved accuracy of a recently developed hybrid least-squares (I-ILS) plate cl ement based on a modified Hellinger-Reissner functional. consistently combi ned with residual-based methods for the acoustic fluid, compared to standar d Galerkin and Galerkin gradient least-squares plate elements. The techniqu e of complex wavenumber dispersion analysis is used to examine the accuracy of the discretized system in the representation of free waves for fluid-lo aded plates. The influence of fluid and coupling matrices resulting from co nsistent implementation of pressure loading in the residual for the plate e quation is examined and clarified for the different finite element approxim ations. Copyright (C) 2001 John Wiley & Sons, Ltd.