Nonlinear Equations for Bending of Rotating Beams with Application to Linear Flap-Lag Stability of Hingeless Rotors

摘要: The nonlinear partial differential equations for the flapping and lead-lag degrees of freedom a torisonally rigid, rotating cantilevered beam are derived. These linearized about an equilibrium condition to study flap-lag stability characteristics hingeless helicopter rotor blades with zero twist uniform mass stiffness in hovering flight condition. results indicate that these configurations stable because effect elastic coupling more than compensates destabilizing Coriolis aerodynamic coupling. higher bending modes on damping was found be small common, centrally hinged, spring restrained, rigid blade approximation shown resonably satisfactory determining stability. pre-cone generally stabilizing effects rotary inertia were negligible.