401 Reduction of Sound Power Radiating from a Thin Plate by Adding a Hollow : Experimental Validation and Improvement of the Optimization Method

Abstract

This paper describes the reduction of sound power radiating from a thin plate by adding a hollow. A rectangular plate with the optimum rectangular hollow was made and was examined with FEM modal analysis and experimental modal analysis. The driving point mobility and sound radiation power of the plate were estimated and measured. It was confirmed that the driving point mobility at the 1st natural frequency reduced by 1.19dB while the sound radiation power increased. A new optimization with an objective function of sound radiation power at the 1st natural frequency was carried out. The sound power then reduced by 3.9dB.