一体化转子系统动力分析的预应力模态综合法

A Prestressed Component Mode Synthesis Method for Dynamics Analysis of Blisk-Shaft Integrated Rotor

针对盘片轴一体化转子系统的大规模网格问题,提出用于该类结构动力分析的预应力模态综合法.对前两级整体叶盘进行静、动频分析,给出了影响一体化结构动力分析精度的模态截断数的选取原则,同时验证了本文方法的准确性.计算了盘片轴一体化转子系统的静、动频,给出了旋转作用对该系统模态的影响.比较整体叶盘与一体化转子的模态结果发现,引入转轴的作用使叶片振型对应的动频降低,且一体化转子振型中存在叶片、轮盘及转轴之间的耦合振型,这阐释了利用预应力模态综合法进行大规模网格盘片轴一体化结构动力分析的重要性.

Dynamicallty analyzing a blisk-shaft integrated rotor has to solve the problem of large scale finite element mesh. So, a prestressed component mode synthesis method was proposed, with which the static and rotating frequencies of the first two blisks were calculated. The principle for choosing the modal truncation number, which influenced the accuracy of the dynamics analysis of the blisk-shaft integrated rotor, was presented. By comparing the static frequency with rotating one of the blisk-shaft integrated rotor, the effect of rotation on the modal characteristics of the system was figured out. Modal analysis of the blisks and the blisk-shaft integrated rotor indicates that the rotating frequency corresponding to the blade modes is reduced due to the effect of the shaft, and the coupling modes among the blades, disk and shaft are found, which illustrates the importance of the dynamics analysis of blisk-shaft integrated rotor with large scale finite element mesh.