叶片失谐对叶盘结构振动特性的影响

叶片失谐在实际叶盘结构中是不可避免的,并严重影响叶盘的振动特性.文章将失谐叶盘的模态及受迫振动响应投影到谐调叶盘模态空间,并提出一种节径谱的研究方法,通过关于不同节径的谐调模态的组合来描述失谐叶盘模态和受迫响应.基于叶盘集中参数模型,分析了叶片刚度失谐对叶盘频率转向区内外的模态振型及受迫响应等特性的影响规律.研究表明,节径谱的研究方法能够较为准确地捕捉失谐对叶盘结构振动特性的影响作用,对建立失谐与谐调叶盘结构振动特性之间的内在联系具有重要意义.

Exploring Key Features of Blade Mistuning Effects on Vibration Characteristics of Bladed Disks

Aim. In our opinion, existing literature has not paid due attention to exploring the key features of blade mistuning effects on the vibration characteristics of bladed disks. The nodal diameter spectrum method explored by us can,we believe, catch such key features. Section 1 of the full paper explains in some detail nodal diameter spectrum method, whose core consists of: (1) the modes and forced responses of the bladed disk are projected to the mode space of the tuned bladed disk counterpart; (2) the mistuned mode shapes and forced responses are expressed through the combination of tuned modes at each nodal diameter. Section 2 proposes a lumped parameter model of a bladed disk for applying the nodal diameter spectrum method. On the basis of sections 1 and 2, section 3 gives the simulation results and then their analysis; the simulation results, given in Figs. 4 through 19, include the vibration characteristics of mode shapes and forced responses of the bladed disk in and outside the frequency veering region. The analysis of the presented simulation results does show preliminarily that the nodal diameter spectrum method can catch the key features of blade mistuning effects on vibration characteristics of bladed disks