多自由度碰磨转子系统非线性动力学特性分析

大型旋转机械转子、静碰摩故障具有高维非线性特征，由此产生的机械故障时有发生。根据某航空发动机转子，考虑非对称圆盘的陀螺力矩效应条件下，利用拉格朗日原理建立8个自由度弹性支撑转子系统的碰磨动力学模型。研究表明，当系统发生碰磨时，其幅频特性有明显变化；引进改进的POD方法成功将具有碰磨故障的系统降维为具有两个自由度低维非线性系统。数值模拟结果显示降维系统具有与原系统一致的非线性动力学特征，表明本方法对解决高维非线性问题具有较好的有效性。此外，还利用C-L方法对其进行分岔分析，讨论了系统参数与系统动态行为之间的关系，得到了含碰磨故障转子各种不同分岔模式，准确反映了碰磨转子的动力学特征。

Bifurcation analysis for nonlinear rubbing faults multi-degree-of-freedom rotor system

Rubbing fault is an often occurred complex high-dimensional nonlinear problem in large rotating machinery system .In this paper , a rotor system of an aero engine was modeled into an eight degree of freedom nonlinear system with gyroscopic moment effect using La-grange method.The investigations to the modeled system showed the nonlinear rubbing fault characteristics .This high dimensional nonlinear system could be reduced into a two degree of freedom system by introducing the modified POD method .Numerical simulations demonstra-ted the efficiency of the method by comparison with the computed results given for both the o-riginal and the reduced systems .C-L method was also employed to obtain the dynamical behaviors of the reduced system , which reflected the natural property of the rubbing fault .