Active aeroelastic panels with optimum self -straining actuators
The objective of this research is to examine the ability of self-straining actuators to create panel deflections and their effect on panel flutter speed. Two configurations of piezoelectric actuators were used to create deflections by bonding them to one surface of an aerodynamic panel: a rectangular patch and discrete grid stiffeners. A Rayleigh-Ritz program was developed to analyze the static deflection, free vibration, flutter behavior, and deflection under airloads of the panel for both actuator configurations. A formal optimization of the patch actuator to produce maximum panel deflection was performed for aluminum and steel host panels with simply supported and clamped boundary conditions and several different aspect ratios. It was found that by allowing the actuator to have two independent layers (but still single-sided), slightly more deflection could be produced than with a single layer actuator. Stiffener configurations were studied with varying numbers, cross section size and shape, and orientations that were parallel to the x-axis, parallel to the y-axis, and parallel to both axes. It was found that no optimum combination of stiffener parameters existed to produce the maximum deflection in a panel, unlike the patch actuators. For low numbers of stifferners, a rectangular cross section and placing them parallel to the y-axis produced the most deflection. Placing the stiffeners parallel to the x-axis, or in the flow direction, was the most beneficial for increasing the flutter dynamic pressure for the panel. The rectangular stiffener cross section increased the dynamic pressure more than the square cross section. Different patch actuator sizes, panel locations, and activation levels were examined for their effect on flutter dynamic pressure. Although the patch was always able to increase the flutter dynamic pressure, the amount of the increase was very dependent on patch size, location, and activation level. ^
Major Professor: Terrence A. Weisshaar, Purdue University.