Comparison between control strategies for active constrained layer damping treatment to control the sound radiation from a vibrating structure

Abstract

A comparative study is presented of three control strategies for active constrained layer damping (ACLD) treatments to control the sound radiation from a vibrating planar structure. The first control strategy is one commonly used in most existing studies of ACLD for structural vibration control; i.e., the error signal to be minimized for the controller is the vibration response sensed by point transducers, and a proportional derivative controller is employed where the sensor signal and the voltage output is related by real-valued feedback gains. The second control strategy is similar to the first, except that the real-valued control gains are substituted by complex-valued ones. In the third control strategy, the discrete structural acoustic sensing approach is introduced for observing the sound radiation from the structure, and the estimated sound power constitutes the controller input. The control gains aiming to reduce the sound radiation from a simply-supported beam are optimized respectively for the three control strategies, and the control performances are compared. Numerical results show that using the complex-valued control gain in the controller design is always better than using real-valued gain. Furthermore, the ACLD treatments adopting the third control strategy require lowest control efforts.