裂纹转子弯扭耦合振动的理论研究

以水平放置Jeffcott裂纹转子为研究对象，建立了弯扭耦合振动的非线性运动微分方程，并用数值方法分析了该转子系统的动力响应。结果表明，弯扭耦合振动是通过不平衡量来实现的，不平衡偏心较大时，扭转对弯曲振动的影响主要体现在高转速部分，且随裂纹深度的增加，受影响的转速下限降低，当裂纹较深，转速较高时，扭转对弯曲振动有明显的影响，使频谱图和轴心轨迹都发生较大的变化，且对转速的变化极为敏感，因此在故障诊断时必须对扭转的耦合作用高度重视。

Bending-torsional coupled vibration of a cracked rotor

The bending torsional coupled vibration of a level Jeffcott rotor containing a transverse crack was investigated. The nonlinear differential equation of bending torsional vibration of a cracked rotor was derived, and the dynamical behaviors of the cracked rotor are analyzed. The Numerical analysis demonstrated that the coupled vibration was caused by the eccentricity. When the eccentricity is great, the torsion influences the higher rotative velocity of the bending greatly, and the deeper the crack is, the lower the influenced is. When the rate of rotative velocity is higher and the crack is deeper, the running orbit of the cracked rotor and the spectral response are influenced greatly, and are sensitive to the change of. The torsional vibration must be considered when rotation machineries are diagnosed.