Vibroacoustic Independent Contributors and Active Control of Vibration and Sound in Double Walls: Part II. Cluster Control

Abstract

This paper is the second of two dealing with independent contributors to the structural kinetic and acoustic potential energy: vibroacoustic modes and clusters. In this paper, the theory of clusters is applied to a symmetric double wall composed of a pair of uniform flat panels, separated by an air gap and connected by mechanical springs, where the receiver panel is coupled to an enclosure. It is found that in the symmetric double wall, shapes of the uncoupled structural modes of the panels are clustered into an even or odd function, and these clusters independently contribute to both the structural kinetic energy of the panels and the acoustic potential energy in the air gap and the enclosure. Spatial filters to extract the individual clusters from the measured velocities of the panels are derived for the symmetric double wall. The performance of the active control system, using each cluster as the error criterion, is numerically simulated.