含预紧力失谐的叶盘结构振动局部化问题研究

Vibration response localization of bladed disk with pretightening mistuning

在工程实践中发现叶盘结构存在一种新的失谐——预紧力失谐,基于一个含预紧力的叶盘结构连续参数模型,对比分析了预紧力失谐和刚度失谐下叶盘结构的振动特性,揭示了预紧力失谐对叶盘结构振动响应局部化的影响规律。研究发现,预紧力失谐不会导致模态局部化,但能导致叶盘结构出现振动响应局部化,在相同失谐强度下,预紧力失谐所导致的叶盘结构振动响应局部化程度与固有参数失谐相当。因此,预紧力失谐不能通过传统的检测手段如模态实验来发现。这些结果一方面完善了失谐叶盘结构的研究内容,一方面为叶盘结构的设计和制造提供了理论指导。

A new kind of mistuning--pre-tightening mistuning was found in the bladed disk based on the engineering practice. The characteristics of bladed disk with pre-tightening mistuning and stiffness mistuning was compared and analyzed based on a continu- ous parameter model of bladed disk, and the effect of pre-tightening mistuning on the vibration response localization of bladed disk was researched. The result shows that pre-tightening mistuning can make vibration response localization appear in bladed disk as well as stiffness mistuning. Sometimes, the vibration response localiza- tion of bladed disk is more sensitive to stiffness mistuning than to pre-tightening mistuning. Compared with stiffness mistuning, the pre-tightening mistuning could not change the natural characteristics of bladed disk. As a result, the pre-tightening mistuning can not be detected by traditional method, such as the frequency test. The result could not only complete the study content of bladed disk, but also conduct the design and manufacture of bladed disk.