失调叶片-轮盘系统耦合振动分析
Vibration Analysis of Mistuned Bladed Disc of Steam Turbine
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摘要: 为了研究失调叶片-轮盘系统振动特性,建立了某汽轮机失调叶片-轮盘的三维实体有限元模型,研究了离心力对失调叶片-轮盘系统振动的影响;利用概率分析方法,研究了所有叶片弹性模量在5%误差范围内随机失调叶片-轮盘振动情况.结果表明,离心力对失调叶片-轮盘系统局部化振动有减弱作用;所有叶片弹性模量在5%误差范围的随机失调系统,其固有频率与非失调相差很小,即失调叶盘系统可以按照循环对称结构进行模态分析.Abstract: Cyclic symmetry in bladed disc is often destroyed by difference in blade structural properties and this results in mistuning. The effect of centrifugal force on the mistuning of bladed disc was investigated by three dimensional finite element analyses. Vibration characteristics of mistuned bladed disc caused by random Young's moduli in all blades were also investigated by probability method. The results indicate that the centrifugal force reduces the localization. As Young's moduli of blades are in the tolerance of 5%, the bladed disc can be treated as a cyclic symmetry structure.