Analytical and Experimental Investigation of Flutter Suppression by Piezoelectric Actuation

The objective of this research was to analytically and experimentally study the capabilities of piezoelectric plate actuators for suppressing utter. Piezoelectric materials are characterized by their ability to produce voltage when subjected to a mechanical strain. The converse piezoelectric e ect can be utilized to actuate a structure by applying a voltage. For this investigation, a two-degree-of-freedom wind tunnel model was designed, analyzed, and tested. The model consisted of a rigid wing and a exible mount system that permitted a translational and a rotational degree of freedom. The model was designed such that utter was encountered within the testing envelope of the wind tunnel. Actuators made of piezoelectric material were a xed to leaf springs of the mount system. Command signals, applied to the piezoelectric actuators, exerted control over the damping and sti ness properties. A mathematical aeroservoelastic model was constructed by using nite element methods, laminated plate theory, and aeroelastic analysis tools. Plant characteristics were determined from this model and veri ed by open loop experimental tests. A utter suppression control law was designed and implemented on a digital control computer. Closed loop utter testing was conducted. The experimental results represent the rst time that adaptive materials have been used to actively suppress utter. They demonstrate that small, carefully placed actuating plates can be used e ectively to control aeroelastic response.