旋转对称结构液－固耦合振动的多级杂交子结构分析

Multilevel Hybrid Substructuring Analysis for Coupling Vibration of Cyclosymmetrical Structures with Surrounding Liquid

对立体空间旋转对称结构在液体中形成的耦合系统（ＣＮ系统）进行统一的群变换及界面协调，推导了对液体多级划分后的组合模态综合过程。进行子结构之间以及向上一级子结构的对接与缩聚，提出了旋转对称结构液－固耦合振动的多级杂交子结构法。完成了立体空间旋转对称结构完全液－固耦合动力特性的群分析。此方法使耦合系统的综合规模大为缩小，计算速度提高数倍。文中通过试验结果证实理论方法的正确性。

Presented in this paper is a multilevel hybrid substructuring technique for the vibration analysis of 3 D liquid solid coupling systems with spatial cyclosymmetry.At the first step,the structure and surrounding liquid are discretized as a multilevel hybrid model by FEM.Then,a unified modal transform on the basis of group theory and the interface conditions between substructures are derived so that the modal reduction and modal synthesis among the substructures in the same level,as well as to the higher level,are performed.The concepts of group analysis and multilevel modal reduction in the technique greatly reduce the computational cost for analyzing complicated problem of coupling vibration of hydraulic turbine wheel and surrounding water.An experiment described in the paper shows the correctness of the codes for proposed technique.