叶盘结构盘片耦合振动特性的参数敏感性

Parametric sensitivity for coupling vibration characteristics of bladed disk

在参数化建模、求解的基础上重点研究了叶盘结构盘片耦合振动频率转向特性、由结构参数随机失谐引起的振动局部化特性对结构设计参数变化的敏感性.对盘片耦合振动频率转向特性的研究发现,随着轮盘扇区间耦合刚度或叶片刚度的变化,频率转向间隙曲线的改变具有碗状形式;对振动局部化特性的研究表明,以轮盘扇区间耦合刚度和结构参数失谐强度为自变量的失谐响应放大因子曲面呈类马鞍形;响应放大阈值现象存在与否,与轮盘扇区间耦合刚度的大小直接相关.若选择位于鞍部的轮盘扇区间耦合刚度-失谐强度组合参数设计,失谐响应放大因子最多能够被减小37.5%.

Based on parametric modeling and solution of bladed disk, the parametric sensitivity for coupling vibration characteristics of bladed disk were studied, of which the frequency veering and modal localization caused by random mistuning of structure parameters were mainly focused on. The study on coupling vibration characteristics of frequency veering of bladed disk uncovers that the loci of the gap of frequency veering is a bowl-style-curve while the inter-sector stiffness or bladed stiffness varies within a certain range. And the study on localization vibration characteristics finds that there exists a quasi-saddle-surface while the amplification factor is related to inter-sector stiffness and mistuning strength. The latter reveals that the existence of threshold of amplification factor against mistuning strength depends on the strength of inter-sector stiffness. It is also found that a proper choice of inter-sector stiffness and mistuning strength in saddle could lead to a suppression of amplification factor of 37.5 %.