The use of tuned absorbers in minimizing sound power from vibrating structures

Abstract

This paper presents a methodologyfor designing quiet shell structures through tie use of multiple tuned resonators. The method combines an ftite element method vibration prediction code, a boundary element methd sound power prediction code and a combined stochastic / gradient-based optfition algorithm for opttiing the locations and parameters of the tuned absorbers, A design example has been optimixed a thin shell covering a motor / gearbox. It is dernonstiated that the addition of a small amount of weight (130g, or 1.6V0of the weight of the shell) w produce substantial reductions in sound power (13 @in the targeted 1/3 octave band centered at 125 =.