Rl. Stpierre et Gh. Koopman, A DESIGN METHOD FOR MINIMIZING THE SOUND POWER RADIATED FROM PLATES BY ADDING OPTIMALLY SIZED, DISCRETE MASSES, Journal of mechnical design, 117, 1995, pp. 243-251
In this paper a novel method for minimizing the sound power radiated f
rom a structure is presented. The method involves placing strategicall
y sized masses at specific locations on the structure's surface. The m
inimization procedure modifies the shapes of the resonant modes of the
structure in the frequency range of interest such that they are force
d to radiate sound inefficiently. Because of this, they are referred t
o as ''weak radiator'' mode shapes. The method uses an optimization pr
ocedure that directly minimizes the radiated sound power from the surf
ace of a plate in an infinite baffle. The procedure can be carried out
for a single frequency or over a range of frequencies. Analytical sen
sitivities of sound power with respect to the design variables are dev
eloped and used in the optimization algorithm. Results on various test
cases show sound power reductions of 10 dB or more even when several
resonances are included in the frequency band. An acoustic intensity p
robe is used to experimentally verify the results for one test case. T
he experiment confirms the sound power reductions predicted by the opt
imization program.