This work proposes a comprehensive numerical dynamic model of a flexible-rotor bearing system based on the Hertzian and cubic polynomial nonlinear contact force methods. The model can consider the influences of the nonlinear bearing contact forces and unbalanced force caused by the rotor offset. The displacements and spectrums of the flexible-rotor bearing system from the Hertzian and cubic polynomial nonlinear contact force methods are discussed. The influences of the radial clearance, eccentricity, mass, and deformation of the rotor on the frequency–amplitude characteristics of the flexible-rotor bearing system considering a large speed range are analyzed. The results show that the dynamic and vibration characteristics of the flexible-rotor bearing system from the Hertzian and cubic polynomial nonlinear contact force methods are different. The differences of the frequency–amplitude characteristics between the flexible- and rigid-rotor bearing system are small in a lower speed stage; however, their differences are very large in a higher speed stage. This method can be applied to the nonlinear dynamic modeling and simulation of the flexible-rotor bearing system, which can predict the dynamics and prevent the system failures during the design processing of rotor system.

这项工作提出了基于赫兹和三次多项式非线性接触力方法的柔性转子轴承系统的综合数值动力学模型。该模型可以考虑转子偏移引起的非线性轴承接触力和不平衡力的影响。讨论了来自赫兹和三次多项式非线性接触力方法的柔性转子轴承系统的位移和频谱。分析了转子径向游隙、偏心距、质量和变形对考虑大转速范围的柔性转子轴承系统频幅特性的影响。结果表明，赫兹和三次多项式非线性接触力方法的柔性转子轴承系统的动态和振动特性是不同的。软转子轴承系统与刚转子轴承系统在低速阶段的频幅特性差异较小；但是，在更高的速度阶段，它们的差异非常大。该方法可应用于柔性转子轴承系统的非线性动力学建模与仿真，可在转子系统设计过程中进行动力学预测，防止系统失效。