Structural vibrations and noise reduction by piezoelectric active control

The present work describes a numerical procedure for the design of a piezoelectric active control system capable of reducing the acoustic emission from forced structural elements. The characterisation of the actively controlled structure is carried out through an integrated electro-elastic Finite Element (FE) approach. Because of the possibility of using piezoelectric layers as self-sensing actuators, a simple and effective collocated control technique is employed; within this framework different control laws are allowed by the use of external electric circuits implementing appropriate measurement conditioning. The acoustic pressure field around the vibrating structure is simulated by using a boundary elements method interfaced to the FE structural model through mobility matrices.