航空发动机高压转子-滚动轴承系统非线性动力响应分析

NONLINEAR DYNAMIC RESPONSES OF A HIGH PRESSURE ROTOR-ROLLING BEARING SYSTEM FOR AN AEROENGINE

基于有限元方法建立了航空发动机高压转子-滚动轴承系统的高维动力学模型,该模型考虑滚动轴承的非线性支撑力,转子的剪切变形、陀螺力矩和转动惯量.利用自适应步长Newmark-β方法计算了转子随转速变化的不平衡响应,得到了不同转速区间转子的振动特征.针对低转速区出现的VC(Varying Compliance)振动现象,计算分析了不同转速下转子不平衡量、轴承游隙对VC振动幅值的影响.结果表明:随着转速的升高,VC振动幅值先减小再增大,之后再减小直至基本消失;增大轴承游隙会使转子VC振动幅值增大,而转子VC振动幅值对不平衡量的变化并不敏感.

The nonlinear governing equations of motion with high dimensional DOF are established for an aero engine rotor-bearing system based on finite element method,in which the nonlinear force of the rolling bearing,the shear deformation,gyroscopic moment and moment of inertia of the rotor are taken into account.The adaptive step Newmark-βalgorithm is employed to analyze the unbalance response of the rotor at various rotating speeds.The effect of unbalance and clearance of the bearing on the amplitude of VC(Varying Compliance)vibration is obtained.The results show that the amplitude of VC vibration decreases at first with the increasing of rotating speed.As the rotating speed is further increased,the amplitude begins to increase and then decreases again until it disappears.The amplitude of VC vibration increases while the clearance of the bearing is increased.However,the amplitude of VC vibration is insensitive to the change of unbalance.