外转子支点不同心的双转子系统振动特性

根据航空发动机双转子的结构特点建立双转子系统模型及振动方程。将外转子支点不同心的影响转化为支承上的等效不同心弯矩，并通过力矩分解处理得到系统的振动方程。 利用求解效率较高的二维谐波平衡法进行求解，并采用Runge-Kutta 法验证其求解精度。 研究结果表明，外转子支点不同心使系统的幅频响应产生新的共振区，在该共振区内系统的振动响应中包含2倍频成分；随着不同心偏差量的增大，2倍频响应成分愈加明显，并逐渐成为系统振动响应的主导频率。此外，转子轴心轨迹形状改变显著。研究成果可作为不同心故障的动力学特征和诊断依据。
Abstract：In this paper,a dual-rotor system model and its equation were established according to the structure and misalignment,which was transformed into equivalent bending-moment acting on out-dial.The Harmonic balance method was applying to solve equations with high-efficiency. The precision was verified by the Runge-Kutta algorithm.The misalignment resulted in fulcrum-offset,which was investigated by orbits and frequency spectrum.The results show that some new resonance region appeared when 2X frequency component plays an important role,which comes with the increase of the offset.Besides,with the increase of the offset,the rotor orbits get lager and twisted.These characteristics make help to failure diagnosis of misalignment.