Impact sound radiated from a viscoelastically supported circular plate.

Abstract

The impact noise radiated from a circular plate which is struck by a ball is studied ex perimentallyand theoretically. The impact sound of a plate viscoelastically supported at its edges is compared with that of a clamped plate. The followings are found:The impact sound of the viscoelastic support consists of the initial peak and the free vibra tionsound, and this is similar to the clamp condition. The viscoelastic support is effective to reduce the maximum level of the impact sound, when the plate is thin in comparison with its diameter or the level of the free vibration sound is sufficiently higher than that of the initial peak. Further there is an optimal value of the stiffness of the viscoelastic material to minimize the impact sound. However the viscoelastic support is not effective to reduce the maximum level of the impact sound, when the plate is thick in comparison with its diameter or there is little level difference between the initial peak and the free vibration sound.