小失谐对整体叶盘结构动态特性的影响

基于失谐叶盘频差提出了小失谐的概念,总结了其在实际工程叶盘中的表现形式。以扇区3自由度集中参数叶盘模型为对象,系统研究小失谐对不同模态族的模态局部化和响应幅值放大的影响。研究表明:小失谐在模态族最高节径处同样会造成严重的振动局部化现象。当失谐强度为0.001时,模态局部化因子达到17；当失谐强度为0.007时,响应幅值放大可达1.8。小失谐对叶盘结构动态特性的影响显著,在设计和使用中应予以重视。 

Influences of small mistuning on dynamic characteristicsof bladed disks

The mistuning strength referred to as “small mistuning” was defined based on the frequency differences between the tuned and mistuned bladed disk. The existence and distribution of the small mistuning in industrial bladed disks were introduced. A lumped parameter bladed disk model with three-degree-of-freedom (3-DOF) in each sector was used as an example to investigate the effects of small mistuning on the dynamic characteristics. The results indicated that small mistuning can lead to severe vibration localization at the maximum nodal diameter. For the studied example, mistuning strength 0.001 can lead to a modal localization factor 17, and mistuning strength 0.007 can lead to a maximum amplitude amplification factor 1.8. Therefore, special attention must be paid to small mistuning during design and service stages of the bladed disk structures.