Utilization of Coupling E ects in Compensator Design for Structural Acoustic Systems

The quanti cation and utilization of coupling e ects in a prototypical structural acoustic system are examined in this paper. In typical systems, the coupling mechanisms are manifested in two ways. The rst leads to the transfer of energy from an ambient eld to an adjacent structure and is often responsible for exogenous structural excitation. The second involves the transfer of energy from the vibrating structure to an adjacent eld. This is the source of structure-borne noise and is ultimately the mechanism through which structural actuators are utilized to attenuate noise. The examples presented here demonstrate that in fully coupled systems, both mechanisms should be incorporated to accurately model system dynamics. The examples also illustrate advantages and limitations of compensators which utilize the accurate modeling of the structural coupling. Research supported in part (H.T.B. and M.A.D.) by the Air Force O ce of Scienti c Research under grant AFOSR F49620-95-1-0236, and in part (M.A.D. and R.C.S.) by NASA under grant NAG-1-1600. Research was also supported by NASA under Contract Number NAS1-19480 while H.T.B. and R.C.S. were visiting scientists at ICASE, NASA Langley Research Center.