SUPPRESSION OF NONLINEAR PANEL FLUTTER WITH PIEZOELECTRIC ACTUATORS USING FINITE-ELEMENT METHOD

An optimal control design is presented to actively suppress large-amplitude, limit-cycle flutter motions of rectangular isotropic plates at supersonic speeds using piezoelectric actuators. The nonlinear panel flutter equations based an the finite element method are derived for isotropic prates with piezoelectric Layers subjected to aerodynamic and thermal loads. A model reduction is performed to the finite element system equations of motion for the control design and the time domain simulation. An optimal controller is developed based on the linearized modal equations, and the norms of the feedback control gain are employed to provide the optimal shape and location of the piezoelectric actuators. Numerical simulations based on the reduced nonlinear panel flutter model show that the critical dynamic pressure can be increased three to four times by the piezoelectric actuation. Within the increased critical dynamic pressure, the limit cycle motions can be completely suppressed. The results demonstrate that piezoelectric materials are effective in panel flutter suppression.