关键词: 振动与波, 非线性振动, 直升机, 无轴承旋翼, 有限元分析, 气弹稳定性, 参数分析

Abstract: A new model of bearingless rotors for aeroelastic stability analysis was presented based on finite-state unsteady aerodynamics. Nonlinear strain-displacement relations were built using Green-Lagrange strain tensor. The blades were modeled as a multiple-load-path system and the finite element equations of dynamics for bearingless rotors were obtained from Hamilton’s principle. Finite-state induced flow model was used to evaluate unsteady aerodynamics effect. The nature of complex eigenvalues of flutter equations of blades was employed to judge the aeroelastic stability of the rotors. Effect of structural parameters on the aeroelastic stability of the bearingless rotors in hover was investigated. It is shown that the numerical results of the stability analysis using this model can more precisely agree with those of experiments using dynamic inflow model or uniform inflow model. Hub pre-conical angle, blade’s chordwise stiffness and flapwise stiffness have substantial influence on aeroelastic stability of bearingless rotors.

Key words: vibration and wave, nonlinear vibration, helicopter, bearingless rotor, finite element analysis, aeroelastic stability, parametric analysis