Research On Active Control For Flutter Of A Piezoelectric Smart Structure

Active aeroelastic control of piezoelectric smart structure is one of the hotspot in the field of aeroelasticity. The main task of this paper is to study the flutter characteristics of piezoelectric smart box wing. The flutter characteristics of open-loop and close-loop as well as structure characteristics of active aeroelastic control system are deeply analyzed.Based on the classical laminate theory, the quadrilateral plate element which contains 20 displacement DOF and 8 electrical DOF is used to study the structure of piezoelectric smart composite box wing. This paper also deduces the finite element equations of piezoelectric smart box wing via Hamilton principle and an example is presented to demonstrate the validity of the finite element program.The aerodynamic influence coefficient (AIC) matrice is calculated by using the Doublet Lattice Method and approximated as a rational function in time domain by using the new state-space method. The state space equations of the aeroservoelastic system are formulated and the reduction of system equations uses the following process in turn: Model truncation, Minimal realization and Balancing reduction.To increase the flutter speed, H∞-control theory is used to design dynamic output feedback controller which can suppress the disturbance for the reduced system, and the close-loop system is formed by integrating the controller with the reduced system.At last, a single input/single ouput model and a multi input/multi output model of close-loop system are analyzed respectively. The influences of the location of piezoelectric material on the flutter speed are simply discussed. The results indicate that the flutter can be suppressed through active aeroelastic control law design.