Strain actuated aeroelastic control

The preliminary design of a wing with strain actuation and conventional flap actuation for vibration and flutter suppression experiments is completed. A two degree of freedom typical section model with steady aerodynamics is used to gain an understanding of the fundamentals of the strain actuated aeroelastic control problem. Actuation issues and the effects of fiber and geometric sweep are examined using the typical section. Controllers are designed using the Linear Quadratic Regulator (LQR) method and observers are designed using the Kalman filter. The results are verified through a series of parameter variations and the incorporation of unsteady aerodynamics. With the typical section analyses as a foundation, the actual design is begun. The functional requirements and the design parameters are explicitly outlined. Non-parametric studies are used to determine several of the geometric design parameters. Specifically, a scaling analysis is used to determine the piezoelectric thickness and the spar thickness. Three parametric trade studies are used to determine the remainder of the design parameters. A five mode Rayleigh-Ritz analysis with two dimensional unsteady strip theory aerodynamics is used for all of the parametric trade studies. The first trade study examines the interaction of the fiber and the geometric sweep. The effect of fiber and geometric sweep on the stability characteristics, the piezoelectric actuation, and the relative authority of LQR controllers using piezoelectric actuation or conventional flap actuation is observed. The second trade study consists of the design of a tip mass flutter stopper. The final trade study investigates the influence of taper on the dynamics of the wing. Thesis Supervisor: Dr. Edward F. Crawley Title: Professor of Aeronautics and Astronautics MacVicar Faculty Fellow