Accession Number : ADA324437

Title :   Transducer-Baffle Interactions.

Descriptive Note : Master's thesis, 1 Oct 91-30 Sep 94,

Corporate Author : GEORGIA INST OF TECH ATLANTA SCHOOL OF MECHANICAL ENGINEERING

Personal Author(s) : Marshall, Laurie D. ; Jarzynski, Jacek

PDF Url : ADA324437

Report Date : 21 JUN 1996

Pagination or Media Count : 150

Abstract : A finite element (FE) code was used to model the radiation of sound from a piezoactive ceramic (PZT) projector located near an elastic baffle (a cylindrical shell). The use of a finite element code allows, for the first time, to simultaneously model the elastic response of the baffle, the piezoelectric response of the projector, and their interaction. The present study was limited to two projector - baffled configurations - a plane strain configuration and an axisymmetric finite shell configuration. Both of these configurations could be modeled with the two dimensional (2D) version of the SARA finite element code using a reasonable number of finite elements. (3) Three different sizes of piezoelectric projector were modeled, with 4.3deg, 9,Odeg, and 180 angular extent. For the 4.5deg and 9.Odeg projectors the TVR in the forward direction is not significantly affected by the presence of the baffle. (4) The 180 projector was the only source which showed significant deviations from ideal source performance. In particular, the TVR for this projector in the vicinity of the baffle is significantly different from the TVR under free field conditions. The 180 projector is the only source modeled whose dimensions (width) are comparable to the flexural (shortest) wavelength in the baffle, and in the PZT projector.

Descriptors :   *SONAR TRANSDUCERS, *BAFFLES, FINITE ELEMENT ANALYSIS, ELASTIC PROPERTIES, THESES, SHELLS(STRUCTURAL FORMS), FREE FIELD, AXISYMMETRIC, UNDERWATER ACOUSTICS, PIEZOELECTRIC TRANSDUCERS.

Subject Categories : Acoustic Detection and Detectors

Distribution Statement : APPROVED FOR PUBLIC RELEASE