Macro-Fiber Composite Actuated Thin Clamped-Free Benders and Thin Simply-Supported Morphing Airfoils

摘要

A type of piezoceramic composite actuator commonly known as Macro-Fiber Composite (MFC) is used for actuation in a variable camber airfoil design. First, a distributed parameter electromechanical model is proposed to predict the structural response to voltage actuation of clamped-free thin cantilevered beams. The structural frequency response behavior is investigated experimentally for cantilevered unimorph MFC actuated benders with aluminum, brass and steel substrate materials of different thicknesses. Second, the study focuses on actuation modeling and response characterization under aerodynamic loads for flat plate airfoils with variable pinned boundary conditions. Thin unimorph/bimorph benders are pinned in two variable locations along the chordwise direction. Two extreme examples are: 1) Airfoil pinned at its leading edge and at its trailing edge; 2) A clamped-free airfoil. Any combination in between the two extremes is also evaluated for geometric and aerodynamic response. Finally, wind tunnel experiments are conducted on a 1.2% thick, 127 mm chord MFC actuated bimorph airfoil.