Accession Number : ADA311761

Title :   Application of the Finite Element/Boundary Element Approach to the Analysis of Radiation and Scattering from Fluid-Loaded Elastic and Piezoelectric Structures.

Descriptive Note : Final rept.,

Corporate Author : NAVAL UNDERSEA WARFARE CENTER NEWPORT DIV RI

Personal Author(s) : McCollum, Michele D. ; Montgomery, Robert E.

PDF Url : ADA311761

Report Date : 15 FEB 1996

Pagination or Media Count : 134

Abstract : To understand the behavior of realistic fluid loaded elastic or piezoelectric structures, it is often necessary to use numerical techniques. The approach chosen by many Navy modelers has been to combine a finite element model of the structure with a combined Helmholtz integral equation formulation (CHIEF) boundary element model of the wetted surface. CHIEF computes a matrix that describes the interactions through the fluid of the elements on the wetted surface. The CHIEF matrix can be combined with the structural matrices from any finite element program to obtain the fluid loaded response, in the frequency domain, of a device or structure. This approach has been used to compute the harmonic response to mechanical force, an applied potential, and an incident acoustic plane wave. The most recent enhancement to the finite element/CHIEF combination is the estimation of the in fluid eigenfrequency of a Specific mode of the structure. Some of these procedures have been documented in various Navy reports, while the most recent applications have been described in journal articles. The purpose of this document is to present all the procedures in one publication, and explain and demonstrate their use for the benefit of the prospective modeler or designer.

Descriptors :   *FINITE ELEMENT ANALYSIS, *BOUNDARY VALUE PROBLEMS, *ACOUSTIC SCATTERING, MATHEMATICAL MODELS, VIBRATION, FORMULATIONS, HARMONICS, ELASTIC PROPERTIES, WETTING, PIEZOELECTRIC MATERIALS, FLUIDS, NUMERICAL METHODS AND PROCEDURES, FREQUENCY DOMAIN, PLANE WAVES, FORCE(MECHANICS), HELMHOLTZ EQUATIONS.

Subject Categories : Acoustics

Distribution Statement : APPROVED FOR PUBLIC RELEASE