Abstract:
Using finite element method,the displacement of each segment in a rectangular plate is extracted, and the radiated pressure is calculated by the directive theory of built-up point sources.The directivity patterns of a fabricated flat plate and a stepped plate are measured. It shows that the directivity of the stepped plate radiator is better than that of the flat one.In rectangular plate radiators,directivity pattern along the x-axis of perpendicular to the flat plate exist major lobe, but at the same time in the other direction exist side lobes.Energy distribution is decentralized.In stepped radiator, along the x-axis perpendicular to the stepped plate exist sharper lobe; along the y-axis perpendicular to the stepped plate exist sharper major lobe, although there are side lobes in the other direction, the side lobes are very small,sound energy distribution is concentrated. It shows that the directivity pattern of the stepped rectangular plate radiator is better than that of the rectangular plate radiator. The calculated results are in good agreement with the tested ones.
