Broadband active structural-acoustic control of a fuselage test-bed using collocated piezoelectric sensors and actuators

We describe structural-acoustic control experiments on a model fuselage test-bed, using collocated pairs of piezoelectric sensors and actuators. The test-bed is a hybrid-scaled model fuselage designed to be representative of complex aircraft structures with rib and stringer construction, which results in a structure with high modal density and complex behavior. The sensor/actuator pairs consist of PVDF film and PZT ceramic sheets bonded to the surface of the model fuselage. Closed-loop control of the fuselage skin was carried out with 30 collocated sensor/actuator pairs, covering approximately 10% of the surface area of the test-bed. The disturbance source is a PZT patch bonded to an adjacent panel. Rate feedback was applied to each collocated pair simultaneously (independent loop closure). Accelerometers attached to the panels and microphones located inside the test-bed were used as performance sensors. The experimental results show a reduction of as much as 20 dB in structural acceleration and up to 10 dB of attenuation in the interior acoustic pressure levels at resonant peaks, over the frequency range of 100-2000 Hz.