非对称转子动力学特性数值模拟
Numerical Study on the Dynamic Characteristics of Asymmetric Rotor System

基于ANSYS 的非线性瞬态动力学模块，以旋转位移约束模拟转动的方式数值计算了重力作用下径向非对称转子的振动特性，得到了重力引起的低速倍频共振、转子各方向振动相同的结论．外载分别考虑重力和不平衡力，研究了重力和不平衡力对系统振动的影响，结果表明系统的1 倍频和2 倍频振动不存在相互作用．最后研究了非对称转子的不平衡响应特性，得到了相同轴向位置不同相位的加重，转子的振幅和相位响应差别很大的结论，针对此结论提出了一种简单有效的基于影响系数法的非对称转子动平衡方法．通过实验验证了所采用的计算模型准确性，所得到的结论对卧螺离心机的故障诊断和高速动平衡具有一定的指导意义．
Based on the nonlinear transient dynamics analysis of ANSYS，vibration characteristics of radial asymmetric rotor under gravity were simulated while rotation was expressed as rotary displacement constraint．The result indicates that the rotor resonates at a low speed by two-time frequency(2f，f is working frequency)，which is caused by gravity，and the vibrations in different directions are identical．Through loading gravity and unbalanced force respectively， no interactions are found between f and 2f vibrations．The unbalance response characteristics of radial asymmetric rotor were studied at last．And it shows that for the unbalanced mass at the same axial but in different phase locations，the amplitude and phase responses of the rotor are of great difference．Based on the result， a simple but effective method based on influence coefficient method applicable to the dynamic balance of asymmetric rotor is proposed．The accuracy of the finite element model is verified by experiments and the results of simulation have certain significance to the fault diagnosis and the high-speed dynamic balancing technique of the decanter centrifuge