Radiation Noise Reduction of a Plate like Structure by Structural Optimization

Abstract:

Analysis was done to find out the main factors to the radiation noise of a plate structure. Results show that the distribution shape of the vibration velocity can be the main factor when the frequency is low; while in the high frequency domain, the sound power almost only depends on the amplitude of the vibration velocity. Hereby, ‘shape optimization’ and ‘amplitude optimization’ were proposed to optimize the thickness distribution of the plate, so that the sound power could be reduced. Then, a rectangle plate was used to verify and evaluate these two optimization methods. Numeric results show the shape optimization method has a good performance when the frequency is not very high, and the amplitude optimization method brings a steady improvement of the sound radiation when the frequency is high.

Key words:plate structure;sound radiation modes;radiation character;optimization