Sr. Hahn et Aa. Ferri, SENSITIVITY ANALYSIS OF COUPLED STRUCTURAL-ACOUSTIC PROBLEMS USING PERTURBATION TECHNIQUES, The Journal of the Acoustical Society of America, 101(2), 1997, pp. 918-924
The analysis of acoustic radiation and scattering from submerged elast
ic structures is an important and challenging problem. Often, numerica
l solutions are hampered by the fact that the acoustic pressure field
can be very sensitive to structural detail. In this paper, a procedure
for obtaining the sensitivity of a structural-acoustic system to stru
ctural perturbations is presented. The theoretical development assumes
a finite element description of the structure and a boundary element
description of the fluid. The analysis includes full coupling between
the fluid and the structure, and can accommodate both internal and/or
external fluid regions. The types of perturbations are limited to thos
e that do not alter the geometry of the wetted surface, but are otherw
ise completely general in nature. The technique is then applied to aco
ustic scattering from a cylindrical shell. Two perturbations are consi
dered: A change in the shell thickness and a change in the elastic mod
ulus. The effect of these structural perturbations on the surface pres
sure, surface normal velocity, and scattered pressure are examined for
plane-wave scattering. (C) 1997 Acoustical Society of America.