中文摘要：

基于有限元法,建立考虑松动、碰摩及松动—碰摩耦合故障的转子—轴承系统的动力学模型,其中松动故障采用分段线性刚度和阻尼模型,转定子碰摩采用点—点接触模型。通过增广的拉格朗日方法来处理接触约束条件,修订的库仑摩擦模型来模拟转定子之间摩擦。考虑不同转速对松动、碰摩及松动—碰摩转子系统动力学特性的影响,并对比三者之间的异同点。研究表明,碰摩在耦合故障中处于主导地位,而松动主要影响松动端局部振动处于从属地位;松动—碰摩耦合故障响应在低转速和高转速与单一碰摩故障类似,在中间转速存在一些差别,但总体运动趋势基本一致;与单一松动故障相比发现,碰摩能够减小松动引起的低频振动,主要激发高频振动。研究结果可为转子系统耦合碰摩故障诊断提供依据。

英文摘要：

Based on the finite element method,three dynamic models are established considering pedestal looseness,rub-impact between rotor and stator,coupling fault of both,respectively.The pedestal looseness fault is simulated using piecewise linear stiffness and damping models,the rub-impact fault is simulated by adopting a point-point contact model.By adopting the augmented Lagrangian method to deal with contact constraint conditions and revised coulomb friction model to simulate rotor-stator frictional characteristics,the responses of the rotor system with three faults are analyzed at different rotating speeds,respectively.And similarities and differences for three faults are compared.The results show that rub-impact is in a dominant position and pedestal looseness subordinate position due to its effect only involving local scope of loose pedestal;the responses of coupling fault is the same as the single rub-impact at lower and higher speeds,different at intermediate speeds;the lower frequency vibrations caused by pedestal looseness disappear and high frequency components appear due to the effect of rub-impact comparing with single pedestal looseness.The results can provide a theoretical foundation for the diagnosis of coupled rub-impact fault.