Active flutter control of composite plate with embedded and surface bonded piezoelectric composites

ABSTRACT A novel idea of combining two kinds of el ectro-mechanical couplings to build Active Flutter Suppression (AFS) strategy for composite structures is presented. The commercially available MFC and a newly proposed shear actuated fiber composite (SAFC) are considered. MFC i nduces normal strains and SAFC can be made to couple the transverse shear strains. A four noded plate element is employed to build the clamped-free active laminated plate with four MFC and SAFC each. The stiffness, mass, actuator and sensor matrices are obtained from the electro- mechanical coupling analysis. The open loop flutter velocity is computed using the linear aer odynamic panel theory (DLM). Further, the structural and unsteady aerodynamic matrices ar e represented in state-space form to build the aero-servo-elastic plant. Presently, the unsteady aerodynamics is approximated using a rational poly nomial approach. A Linear Quadratic Gaussian control is designed to perform the closed loop flutter calculations. The actuation authority is maintained same through applied control voltage, while evaluating the performance of MFC and SAFC. The results have significantly encouraged the concept of simultaneously targeting the normal and shear strains of aeroelastically excited modes through electro-mechanical couplings to build an effici ent active flutter suppression system. Key words : Macro Fiber Composite (MFC), Shear Actuated Fibe r Composite (SAFC), Active Flutter Suppression (AFS)