轮盘外缘含裂纹的叶盘结构振动特性研究

Vibration Characteristics Analysis of Bladed Disks with Crack on Disk Outer Edge

针对叶盘结构因轮盘外缘出现径向开口裂纹而导致的振动特性变化,基于有限元方法研究了叶盘的固有特性与响应特性,得到轮盘裂纹位置、长度对叶盘振动特性的影响规律,并对固有特性进行实验验证。研究表明:在固有特性方面,轮盘外缘裂纹位置越靠近叶根,裂纹长度越长,对比完好叶盘,叶盘固有频率下降越大,模态局部化参数越大;在频率转向区,叶盘模态局部化参数增大更加明显。在受迫振动响应方面,在频率转向区,轮盘裂纹使叶盘的共振频率分离,共振频率区变宽;裂纹位置越靠近叶根,裂纹长度越长,叶盘振动响应局部化参数越大。

Aiming at the changes in vibration characteristics of bladed disk due to radial opening cracks at the outer edge of the disk, this paper studies the natural characteristics and response characteristics of the blade disk using the finite element method, and experiments are carried out to verify the natural characteristics simulation results. The influence law of different position and length cracks on the vibration characteristics of the bladed disk with cracks is obtained. The research result shows that: in terms of natural characteristics, the crack closer is to the root, the longer the length, the greater the natural frequency reduction of the disk, and the greater the modal localization parameters(MLP);In the frequency veering area, MLP increase more obviously. In terms of forced vibration response, in the frequency veering area, the disk crack separates the resonance frequency and the resonance frequency range becomes wider, the crack closer is to the root, the longer the length, the larger the vibration response localization parameter.