3-D有限元转子系统动力减缩的部件模态综合方法及应用

Component mode synthesis for dynamic reduction of 3-D finite element rotor system and its application

为了对3-D有限元转子模型进行动力学减缩,提出基于部件模态综合的旋转子结构方法.该方法利用实模态振型矩阵减缩子结构自由度,不同转速下的减缩陀螺矩阵由转速系数乘以单位转速的减缩陀螺矩阵得到.与复模态减缩相比,避免了重复求解变换矩阵的缺点,减缩精度优于基于Guyan减缩的旋转子结构法.利用该方法减缩了某航空发动机转子模型87%的自由度数.经比较,由Campbell图所得临界转速的最大误差为0.04%,稳态不平衡响应计算结果与原模型也几乎完全相同,使用的内存和计算时间均不到原模型的20%,验证结果证明该方法可行.

Rotating substructure m posed to reduce 3-D finite element rotor truncate the degrees of freedom of the got by multiplying a speed coefficient （damped） mode reduction method, it＇s ethod based on component mode synthesis was pro- model. Planar （undamped） mode matrix was used to substructure and the reduced gyroscopic matrix was to the unit reduced ones. Compared with complex no need to recalculate the truncation matrix, and it＇s more accurate than Guyan reduction method. 87% degrees of freedom of an aero-engine rotor model was reduced. The maximum critical speed error got from Campbell diagram is 0.04 %. Unbalance response calculated by the reduced model is almost the same as the original＇s, and less than 20% RAM （random access memory） and computation time is used. All the results show that the proposed method is valid.