A CAE modeling approach for the analysis of vibro-acoustic systems with distributed ASAC control

The aim of this paper is to present a CAE methodology for simulating coupled vibro-acoustic systems and include these models into a closed loop control simulation. This tool provides a reliable simulation procedure that takes into account the vibro-acoustic phenomena as well as the control system since sensors/actuators models and the control algorithms can be included. The focus of the present paper is on the active structural-acoustic control, using piezoelectric patches as sensors and actuators. An initial structural uncoupled finite element model is modified to account for the placement of piezo-patches. The modified structural modal base is then used together with an uncoupled acoustic modal base to derive the fully coupled vibro-acoustic finite element model, which is reduced and formulated as a state-space model. The electro-mechanical coupling between the structure and the sensor/actuator pair is calculated and included in the state-space model. Eventually, a feedback controller is implemented. This smartstructure modeling approach is illustrated for the case of the active reduction of the sound transmission of a firewall between the engine and the passenger compartments of a concrete car-like demonstrator.