ESTIMATION AND MEASUREMENT OF THE SOUND POWER RADIATING FROM A CIRCULAR PLATE WITH A SOLID SHAFT SUBJECTED TO A 3-DIMENSIONAL LOAD

The overall aim of this research is to establish an effective method f or accurately estimating the airborne noise power radiating from gear blanks. For this purpose, the basic theory for estimating the frequenc y response of radiating sound power was proposed in a previous paper, and was applied to a circular plate with a solid shaft subjected to an axial load, in which the circular plate was a simple model of gear bl anks. In this paper the basic theory is extended to circular plates ex cited three-dimensionally, similar to that for helical gears. The theo ry includes the rigid-body modes of vibration as well as the natural m odes of flexural vibration of the circular plates. The estimated sound powers agreed well with the values measured by the sound intensity me thod. Also, an interesting result is obtained; sound power radiating f rom a circular plate with a helical tooth is proportional to sin(2) be ta, where beta is the helix angle. In other words, the axial force has large influence on the sound power radiated due to the rigid-body and flexural vibrations of the circular plate.