Research is currently underway on the development of smart aircraft panels for the reduction of interior cabin noise. This research seeks to adapt previous Active Structural Acoustic Control (ASAC) research on flat plates with attached piezoelectric actuators to the curved panels that compose the exterior skin of an aircraft. In order to predict accurately the closed loop performance of ASAC systems for interior cabin noise reduction, efforts are being made to consider complicating factors in the dynamics of aircraft panels. As part of this research, a state-space model of a curved piezostructure was developed and used to investigate the effects of curvature on panel dynamics. Panel curvature was shown to increase control system bandwidth and to affect transducer coupling. In the present work, the effects of internal pressure loading on the dynamics of a curved piezostructure are investigated through the extension of the previously developed state-space model. The internal pressure model is verified based upon previous work. Pressure loading is shown to increase panel stiffness, thus increasing the natural frequencies of the panel. Further, pressure loading is shown to affect certain modes more than others, resulting in modal reordering. The increased natural frequencies and the model reordering significantly affect control system bandwidth and raise further issues in control design.
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