Power Flow Control of a Thin Plate

Abstract

This paper deals with the active control of power flow of a vibrating plate. It is the purpose of this paper to present a wave control method for suppressing vibration of a distributed parameter system such as a beam or a plate. Unlike a conventional modal-based control method, this method has the potential to suppress all vibration modes of a structure. First, from an analytical point of view, this paper presents three kinds of flow patterns appearing in controlled vibration intensity : (1) straight flow patterns from the excitation point to control point, (2) S-shaped flow patterns and (3) vortex flow patterns around the excitation point and control point. Then, the existence of these patterns is verified experimentally. Next, relationships between vibrational and acoustical intensities are discussed, and the acoustic power and acoustic pressure in terms of these patterns are also investigated. Furthermore, the characteristics of the rotational patterns are clarified and a means to generate the vortex of vibration intensity at an arbitrary position on a plate is presented.