松装叶片燕尾型叶根干摩擦力模型及振动响应分析

Dry Friction Force Model and Dynamic Response Analysis of Blades with Loosely Assembled Dovetail Attachment

建立了叶片燕尾型叶根与轮缘接触面干摩擦力宏滑移迟滞模型,推导出了干摩擦力的数学表达式.采用一阶谐波平衡法和集中质量弹簧模型对燕尾型叶根叶片系统进行了强迫振动响应分析.计算结果表明:随着离心力增大,燕尾型叶根的等效刚度单调地增大,存在一个渐近值;等效阻尼先增后减,存在最大值;叶片系统的共振频率随离心力增大而增大,存在最优的离心力使叶片系统阻尼效果最佳.所提出的干摩擦力模型可应用于燕尾型叶根叶片振动响应分析.

A macroslip model to determine the dry friction force on the contact interlace between the blade dovetail attachment and the disk dovetail groove is presented, and then the mathematical expression of the dry friction force is obtained. The dynamic response of blades with loosely assembled dovetail attachment is analyzed using the lumped mass and spring model via the oneterm harmonic balance method. The results show that the equivalent stiffness of loosely assembled dovetail attachment increases with the blade centrifugal force and then reaches a maximum value gradually. The equivalent damping increases at the beginning and then decreases with the increase of blade centrifugal force, and thus there exists a maximum value. The resonance frequency of the blade system rises with the blade centrifugal force and there exists an optimal centrifugal force at which the optimal effect of the dry friction damping can be achieved for the blade system.