Jeffcott裂纹转子弯扭耦合振动特性分析

以重力决定的开闭裂纹模型为研究对象，导出了固定坐标系下该模型的刚度扭阵，建立了裂纹转子弯扭耦合振动微分方程，并对转子裂纹的升速瞬态响应和影响因素进行了计算机仿真研究。结果表明：升速过程中，弯振存在1／3阶和1／2阶亚谐共振现象，扭振出现1／2阶亚谐共振；在弯扭左耦合区，出现弯扭耦合共振；在亚临界转速区，存在1X，2X和3X等倍频分量的弯振和扭振；影响弯扭耦合振动特性的因素很多，包括裂纹刚度、裂纹夹角、质量偏心和阻尼等。

Analysis of Coupled Flexure-Torsion Vibrations of Cracked Jeffcott Rotor

The flexural stiffness matrix of the rotor shaft with a switching crack controlled by weight is derived.The differential equations of coupled flexure torsion vibrations of the shaft are established.The transient response and the factors effecting the coupled vibrations are studied by computer simulation.Numerical results demonstrate that 1/3X and 1/2X sub harmonic resonances of flexural vibration and 1/2X sub harmonic resonance of torsional vibration occur during the increase in rotational speed.A coupled resonance appears in the left coupling region of flexure torsion vibrations.In the sub critical region,flexural vibration and torsional vibration contain 1X,2X,3X...conponents.There are many factors effecting the coupled flexure torsion vibrations,including crack stiffness,crack angle,mass eccentricity,damping and so on.