Nonlinear vibration phenomenon of an aircraft rub-impact rotor system due to hovering flight

• We model an aircraft rub-impact rotor system, where the effect of hovering flight is considered as a maneuver load.
• We investigate the effect of the maneuver load on the nonlinear dynamics of the system.
• Maneuver load can result in the rub-impact of the system even in the case of small eccentricity.
• The sub-harmonic resonance of the system can occur due to the maneuver load.
• The quasi periodic motions of the system caused by the maneuver load are obtained.

This paper focuses on the nonlinear vibration phenomenon caused by aircraft hovering flight in a rub-impact rotor system supported by two general supports with cubic stiffness. The effect of aircraft hovering flight on the rotor system is considered as a maneuver load to formulate the equations of motion, which might result in periodic response instability to the rotor system even the eccentricity is small. The dynamic responses of the system under maneuver load are presented by bifurcation diagrams and the corresponding Lyapunov exponent spectrums. Numerical analyses are carried out to detect the periodic, sub-harmonic and quasi-periodic motions of the system, which are presented by orbit diagrams, phase trajectories, Poincare maps and amplitude power spectrums. The results obtained in this paper will contribute an understanding of the nonlinear dynamic behaviors of aircraft rotor systems in maneuvering flight.