A panel with matched polyvinylidene fluoride volume velocity sensor and uniform force actuator for the active control of sound transmission

This paper presents a theoretical and experimental study of a smart panel designed for active structural acoustic control. The system consists of a clamped aluminium. panel I nim thick with dimensions 414 mm X 314 nim. Polyvinylidene fluoride films 0.5 mm. thick with a quadratic electrode shape are bonded to either side of the plate, to form a matched volume velocity sensor and uniform force actuator pair. In this paper the design of the smart panel is described in detail. The main properties of the frequency response from distributed actuator to distributed sensor are then discussed with reference to the requirements for direct velocity feedback control. In particular, three problems encountered in the measurement of the transfer function between the sensor and actuator are addressed: first, the unwanted coupling between the sensor and actuator via in-plane plate vibration; second, the high-frequency effects produced by the non-perfect shaping of the actuator and sensor electrodes; third, the phase delays due to the measurement equipment chain.