基于谐波分量的转子系统碰摩故障定量诊断方法

Method for Detecting Rubbing Fault in Rotor System Based on Harmonic Components

提出一种利用碰摩转子系统响应中的高次谐波分量进行碰摩位置和碰摩力定量诊断的新方法。基于谐波平衡理论分析碰摩故障转子系统的动力学特性,证明了碰摩故障转子系统中任意两节点之间高次谐波分量之比等于无故障转子系统频率响应矩阵的相关元素之比。根据此关系,提出转子系统碰摩故障模型诊断方法和步骤:利用正常转子系统与故障转子系统响应的任意一阶谐波分量之差,结合转子系统的动力学模型,就可以诊断出碰摩的位置;进而可以根据故障转子系统响应的各次谐波分量还原出碰摩力分量。为验证该方法的有效性,对一转子系统进行偏碰和整周碰摩时的数值仿真,并分析支撑刚度及噪声对诊断方法的影响;又在模型转子试验台上进行了试验。该方法仅利用一个转速下两个节点的振动响应即可实现碰摩故障的在线定量诊断,因此便于在实际旋转机械上实行。

A new quantitative diagnosing method for rotor system is proposed,in which the super-harmonic response of the rubbing rotor system is used for rubbing location and rubbing force identification.The harmonic balance theory is applied to study the dynamic of the rubbing rotor system,and it＇s revealed that the ratio of the super-harmonic frequency responses of any two nodes in the rubbing rotor system is equal to the ratio of the corresponding elements in the frequency response matrix of the pre-fault rotor system.The new model based rubbing identification method and the procedures are presented by utilizing this relationship： using the residual responses between the responses of the fault system and that of the pre-fault system,and by combining the dynamic model of the rotor system,the rubbing location can be obtained;then the rubbing forces can be obtained by using the harmonic components of the rubbing rotor responses.In order to test the efficiency of the presented detection method,numerical simulations are carried out and the effects by the supporting stiffness and noise are analyzed,and experiments based on a rotor test rig are also carried out.Using this method,the rubbing location and rubbing forces can be identified by using measured vibration responses of only two nodes in one operation speed,so it＇s easy to apply in real rotating machinery.