Abstract: Restraint modal reduction method for dynamic analysis of 3D finite element asymmetric rotor bearing system，which is of high efficiency and accuracy，was proposed based on the modal reduction theory. The concept and principle of the restraint modal reduction method were firstly introduced and the reduced order time-varying coefficient governing equations of the asymmetric rotor bearing system were presented. Then，the accuracy of the proposed method was studied via the modal analysis of a simple asymmetric rotor bearing model. Numerical study shows that the accuracy of the presented method is mainly affected by the modal truncation order and the restraint factor. When the value of the restraint factor is in the interval 0.01 ~ 0.1，great reduction accuracy can be obtained by the proposed method.

Key words: Rotordynamics；Model order reduction；Asymmetric rotor；3D finite element

摘要： 为了对3D有限元模拟的非对称转子支承系统进行减缩，基于模态减缩理论，提出了一种高效率、高精度的约束模态减缩方法。对约束模态减缩方法的概念及原理进行介绍，并给出非对称转子支承周期时变系统运动微分方程的约束模态减缩形式；以简单非对称转子支承系统的模态特性分析为例，对提出的模型减缩方法的精度进行研究。研究表明约束模态减缩方法的减缩精度，主要受模态截断阶次和约束因子两个因素影响。约束因子在0.01 ~ 0.1之间取值时，此模型减缩方法具有很高的减缩精度。

关键词: 转子动力学；模型减缩；非对称转子；3D有限元