失调对叶片-轮盘耦合系统振动影响的预测

 叶片 -轮盘系统的周期对称性经常由于制造、材料,以及非均匀磨损和其它因素而被破坏,引起系统出现失调现象,表现为结构特性的微小变化可能导致叶片振幅和响应的急剧增大。而失调也导致此类周期对称性结构振动特性计算的复杂化。利用有限元通用程序和模态综合技术,建立失调叶片 -轮盘耦合系统三维有限元模型,对一个有1 6个叶片的叶片 -轮盘耦合系统进行了振动特性计算分析,给出了叶片分散度和耦合度对振动特性的影响。

DIRECT PREDICTION OF THE EFFECTS OF MISTUNING ON VIBRATION OF BLADED DISK ASSEMBLIES

The rotational periodicity of bladed disk assemblies can be destroyed by manufacturing process, material, a consequence of in service wear and other reasons, so it will lead to mistuning or disorder called by literature. It is found that, unlike the tuned system having a particular number of several nodal diameters, the mistuned bladed disk system has modes, which are always complex in shape. Slight variations in the geometry and material properties of the system can cause large changes in its mode, and, consequently, its dynamic response. In this paper, based on the modal synthesis technique and general finite element program, a 3D FE model of a mistuned bladed disk system with 16 blades has been set up for the determination of the free vibration characteristics. The effects of frequency standard deviation and coupling strength on vibration are also given.