Analysis i Required Frequency Band of Electric-Structural-Acoustic Coupled System.

Abstract

When an acoustic field in an enclosed space is controlled using the structural vibration control by the piezoelectric actuator, electric system, structural system and acoustic system are influenced each other. Thus this system must be considered as electric-structural-acoustic coupled system. In this paper, the analysis in the required frequency band of electric-structural acoustic coupled system has been carried out. In this analysis, the structural vibration is approximated by the superposition of the electric-structural coupled vibration modes which are included in the required frequency band, and the truncated frequency band are compensated by the residual terms. This truncation method is the application of the authers' previous method. As a numerical example, a flexible rectangular prism model is taken up and the vibration of structure, the voltage of piezoelectric actuator and the sound pressure in the model are calculated using the proposed method. It is shown that the analysis of coupled system has reached the accurate results comparing with the one of nucoupled system, the calculated results using the proposed method agree with the exact ones which are obtained by using the full frequency band, and calculation time is saved.