含摩擦与间隙的失谐叶盘系统振动局部化研究

 针对叶片榫头与轮盘榫槽连接处间隙及摩擦,基于叶盘结构典型集中参数模型,建立含干摩擦、间隙的非线性动力学方程,研究失谐叶盘系统振动局部化。在叶身刚度随机失谐下分析叶盘系统对不同耦合刚度的固有特性及共振响应。结果表明,非线性谐调叶盘系统亦出现振动局部化现象。利用振幅放大系数对线性、非线性失谐叶盘系统振动响应局部化研究,振幅放大系数呈失谐阈值现象，且非线性干摩擦、间隙作用会降低失谐系统振动响应局部化程度。而谐调叶盘系统非线性振动，随气流激励力频率变化,系统呈非简谐单周期运动、多周期谐波运动、混沌运动等多种动力学行为。失谐因素存在会使非线性失谐叶盘系统动力学行为更复杂。

Vibration localization of a mistuned bladed disk system with friction and gap

Based on the lumped parameter model of a bladed disk, vibration localization of the mistuned bladed disk has been investigated as a function of nonlinear parameters such as dry friction and gap in the connection between blade tenton and mortise. For different coupling stiffness systems, the natural frequencies and resonance response are discussed under random mistuning of the blades stiffness. The results show that vibration localization appears in the tuned system with nonlinear factors. Using amplitude magnification factor (AMF), vibration response localization of the linear and nonlinear mistuned bladed disk has been explored, which uncovers the existence of AMF’s threshold. And the degree of vibration response localization of the mistuned system reduces because of nonlinear dry friction and gap. The analysis of nonlinear tuned system turns out that, with different excitation frequencies, nonlinear dynamics behaviors such as non-harmonic periodic-one motion, multi-period harmonic motion and chaotic motion have been revealed. Besides, as mistuning factor exists, the behavior of nonlinear mistuned disk system becomes more complex.