抄録
This paper presents a concept for reduction of structure-borne sound by vibrational energy flow control. The modal forms of the structural intensity (SI) are expressed by superposition of the product of weight coefficient and cross-modal function. The weight coefficient mainly depends on excitation conditions. The cross-modal function also mainly depends on structural mode shapes. Hence the increase of the weight coefficient by selecting an arbitary excitation point can generate a desired SI distribution. We have also proposed the concept for reducing radiation sound from the parts of machinery by using the SI concept, which is based on the interruption and promotion of the transmitted power. The vortex-type SI distribution is used for the power interruption and the straight-type SI distribution is for the power promotion. In this paper the concept is applied to reduce the structure-borne sound from a plate-like structure with some vibration transfer paths. It is shown that the transmitted power can be reduced by the roundabout-type SI dixtribution as well as the vortex-type SI distribution.
