多跨碰摩转子系统分析的降维增量谐波平衡法

多跨碰摩转子系统所建有限元动力学模型自由度很多,严重降低响应预测时的计算效率.为了提高计算效率,同时保证计算精度,提出结合固定界面模态综合法的降维增量谐波平衡法.首先利用固定界面模态综合法降低多跨碰摩转子系统的自由度数目,再利用增量谐波平衡法求解降维后系统的稳态响应,最后还原回原系统的响应.该方法不仅能够直接获得稳态解,还可以与弧长法相结合从而求得非稳定解.对双跨转子系统进行仿真试验,结果表明该方法在主模态数较小时即可保证计算精度并且具有很高的效率.

Dimension-Reduced Incremental Harmonic Balance Method for Multi-span Rubbing Rotor System

The finite element model of multi-span rubbing rotor system has a large number of degrees of freedom，which affects the efficiency of the numerical simulation seriously. To overcome this problem and remain the accuracy of numerical simulation at the same time， a new dimension-reduced incremental harmonic balance method combining the fixed interface component mode synthesis method was presented. Firstly， the degree of freedom was reduced by the fixed interface component mode synthesis method， and then the incremental harmonic balance method was applied to obtain the stable state response of the dimension-reduced system， and at last the response of the original rotor system can be obtained. The method can not only get the stable state solution directly， but also be combined with the arc-length method to obtain the unstable state response. The results show that a two-span rotor system can reach good accuracy and high efficiency with few dominant modes.