Analysis and structure design of a flexible lamellate hinge for unmanned aerial vehicle control surface

A concept of a flexible lamellar hinge for UAV (unmanned aerial vehicle) control surfaces is presented. The flexible lamellar hinge is a strip of lamellar jointing stabilizer and control surface, it can increase the aerodynamics efficiency of the control surface by preventing airflow turbulence through gap between stabilizer and control surface. The results of the model test in the wind tunnel show that the aerodynamics efficiency of the control surface using flexible lamellar hinge increases about 40 percent than that of the traditional ones. The design objectives of a flexible lamellar hinge include to meet the demand of control surface movement and to support control surface and its aerodynamics load. The lamellar hinge is designed as thin GFRP (glass-fiber reinforced polymer) laminates. The principle of control surface movement is analyzed. Different from traditional control surface, it is not rotary movement on fixed axis. When control surface is moving, the lamellar hinge is bent into column shape, and column radius and center of curvature vary with the movement of control surface. We also gave the motion equation of point in control surface for control mechanism design. The key point in designing flexible lamellar hinge structure is bending rigidity and/or flexural rigidity, it is achieved by composite laminates design. The flexibility of control surface can be calculated in term of cantilever theory. We designed a flexible lamellar hinge for a certain type of UAV.