一种叶片缘板阻尼器二维耦合振动的分析方法

采用带滑动触点的并联弹簧来模拟二维平面运动时叶片-阻尼器间的干摩擦接触,建立一种二维局部滑动摩擦接触模型.在叶片缘板处附加两个相互垂直的弹簧阻尼单元来模拟叶片振动时的二维干摩擦力建立B-G(blade-ground)型叶片-缘板阻尼器有限元模型.结合两个模型提出二维耦合振动时叶片缘板阻尼器减振特性的分析方法.算例分析表明在工作频率附近,存在一个正压力的范围使得二维耦合振动时叶片稳态幅值减振效果最好,频率对稳态幅值减振特性无明显影响.分析方法适用于各种复杂平面摩擦接触时叶片缘板阻尼器耦合振动的分析. 

Method for analyzing two-dimensional coupled vibration of turbine blade with dry friction platform damper

A two-dimensional micro slip model was presented by introducing parallel springs with sliding contact to simulate two-dimensional friction force in in-plane motion.Two coupling spring-damper elements were used to mimic the damping effect and the finite element model of the B-G (blade-ground) platform damper was set up.From the friction model and finite element model,the reducing vibration characteristic of blade at or near operating frequency is studied.The results show that there is a range of normal load,during which the steady amplitude of blade can be controlled to a minimum value,and that exciting frequency has no effect on reducing vibration characteristic of blade.The two-dimensional micro model can be developed to analyze blade with platform damper as contacting motion is in complicated in-plane.