微滑移阻尼叶片最优正压力的影响因素分析

Influence of Structural Parameters on Optimal Normal Load of Microslip Damped Blades

为了研究阻尼结构参数对阻尼叶片最优正压力的影响，基于微滑移模型，推导出了阻尼器非线性干摩擦阻尼力的计算公式．建立了带阻尼结构叶片的有限元非线性动力学方程，采用谐波平衡法对系统动力响应进行了计算．计算结果表明：系统的共振频率随正压力的增大而增大；叶尖响应随正压力的增大先减小后增大；存在一个最优正压力，使阻尼器的减振效果最好，这个最优正压力随阻尼器接近叶尖而减小，随阻尼器截面抗拉刚度的增大而减小，这个最优正压力对激振力幅值改变不敏感．

In order to study the influence of structural parameters on the optimal normal load, a microslip model was used to formulate the nonlinear dry friction force. The nonlinear equations of motion for damping blades were established using the finite element method, and the dynamic response of damped blades were sloved using the harmonic balance method. The results show that the resonance frequency of the blade increases with the increase of normal load. There exists an optimal normal load on which the response is the minimum. The optimal normal load decreases as the damper closes to the blade tip or the cross-section stiffness of the damper optimal normal load is insensitive to the amplitude change of excitation force.