Structural acoustic response reduction of a fluid-loaded beam using unequally-spaced concentrated masses

Abstract

A method based on optimization techniques has been developed to determine locations of concentrated masses required to reduce the vibration level and total acoustic radiation power from a fluid-loaded structure. The method is demonstrated using a simply supported, fluid-loaded beam driven by a harmonic point force. In the optimization procedure, the unequally spaced concentrated mass locations are the design variables and the designated location of vibration level and the radiated acoustic power serve as the objective functions, respectively. Results show that the displacement response and total radiated acoustic power can be reduced or controlled due to the presence of the concentrated masses in an optimal arrangement. Although the reduction in vibroacoustic response by using concentrated masses is not so efficient as expected, satisfactory results in local vibration confinement are achieved and the radiated acoustic power is reduced more than 5 dB at certain frequencies.