有挤压油膜阻尼器支承的多故障转子系统的非线性特性研究

研究了有挤压油膜阻尼器、转子与静子碰摩和转轴上的横向裂纹等多种非线性因素作用下的转子系统的非线性响应特征。数值研究发现 ,这类转子系统具有丰富的非线性特性 ,三条通向混沌的道路都存在 ,即阵发性通向混沌、倍周期分叉通向混沌和拟周期通向混沌的道路。系统响应的最大振幅曲线包含了大量的跳跃现象 ,发生这些跳跃所对应的参数点与周期解分叉的参数点相重合 (以前已经发现了这种跳跃现象 ,但没有发现与周期解分叉有关系 )。保持不平衡参数在一个小区间内能够使系统抑制多种故障引起的振幅 ,并使系统能够保持稳定的周期一解。较大的挤压油膜阻尼器参数对系统的振动有明显的抑制作用。当裂纹正方向与不平衡方向成反方向时 ,系统具有最小的振动幅度。

Study on the Nonlinear Characteristics of an SFD Supported Rotor System with Impact-Rub and a Transverse Crack

The nonlinear behaviors of a rotor system with squeezed film damper (SFD),transverse crack and rub-impact is studied. It is found that there are three ways to enter into chaos: the first way is from quasi-period,the second is from intermittence,and the third is from double period bifurcation. There are a lot of leap phenomena in the maximum amplitude response of the rotor system. The parameters when the jump phenomenon appears is the same as those for the periodic bifurcation. (Such phenomena have been reported before,but the relation between the parameters has not been found.) The influence of the faults can be suppressed by keeping the unbalance parameter in a small region. At the same time,the system possesses a stable period-1 response. The greater parameters of SFD will be better to decrease the vibration of rotor system. The amplitude of the rotor system reaches the smallest when the direction of the crack center is opposite to that of the unbalance.