摘要
An analysis has been developed to predict the transient aeroelastic response of gimballed tiltrotors during shipboard engage/disengage operations. A multi blade gimballed rotor is modeled with slender elastic beams rigidly attached to a hub and undergoing flap bending, lag bending, elastic twist, and axial deflection. The gimbal restraint is simulated using a conditional rotational spring. Blade element theory is used to calculate quasi steady loads in linear and nonlinear regimes. The rotor equations of motion are formulated using Hamiltons principle and spatially discretized using the finite element method. The discretized rotor equations of motion are integrated in the modal space for a specified rotor speed run up profile. Studies for a 1/5 size aeroelastically scaled tiltrotor model are conducted to validate the analysis and investigate the transient response and loads of the gimballed rotor during engagement. Blade bending moment and hub moment predictions indicated that gimbal restraint impacts can induce high transient loads on the rotor blades and hub.
An analysis has been developed to predict the transient aeroelastic response of gimballed tiltrotors during shipboard engage/disengage operations. A multi blade gimballed rotor is modeled with slender elastic beams rigidly attached to a hub and undergoing flap bending, lag bending, elastic twist, and axial deflection. The gimbal restraint is simulated using a conditional rotational spring. Blade element theory is used to calculate quasi steady loads in linear and nonlinear regimes. The rotor equations of motion are formulated using Hamiltons principle and spatially discretized using the finite element method. The discretized rotor equations of motion are integrated in the modal space for a specified rotor speed run up profile. Studies for a 1/5 size aeroelastically scaled tiltrotor model are conducted to validate the analysis and investigate the transient response and loads of the gimballed rotor during engagement. Blade bending moment and hub moment predictions indicated that gimbal restraint impacts can induce high transient loads on the rotor blades and hub.
