涡轮叶片双层干摩擦阻尼器减振特性研究

Vibration reduction characteristics of double-layer dry friction damper for turbine blade

研究了某型燃气轮机双层干摩擦阻尼结构对涡轮叶片减振效果的影响。首先,将干摩擦阻尼接触局部滑动模型进行拓展,建立整体-局部统一滑动模型;其次,对摩擦力-位移曲线进行仿真,得到不同滑动阶段的迟滞回曲线,并利用等效线性化方法和一次谐波平衡法计算得到阻尼装置等效刚度和阻尼;最后,建立涡轮叶片双层阻尼结构有限元模型,分析阻尼结构关键参数对叶片振动响应的影响。结果表明,双层阻尼结构减振效果比单层阻尼结构更具优势,双层阻尼结构使得系统在更小的正压力下达到更好的减振效果,且外激励在较大变化范围内叶片响应峰值维持在较低的水平。

Here,effects of a gas turbine double-layer dry friction damping structure on vibration reduction effect of turbine blades were studied.Firstly,the local sliding model of dry friction damping contact was extended to establish a global-local unified sliding model.Secondly,the friction force-displacement curve was simulated,and hysteresis curves in different sliding stages were obtained.The equivalent stiffness and damping of the damping device were calculated by using the equivalent linearization method and the first order harmonic balance method.Finally,the finite element model of double-layer damping structure of turbine blade was established to analyze effects of key parameters of damping structure on vibration response of turbine blade.The results showed that the vibration reduction effect of double-layer damping structure is better than that of single-layer damping structure;double-layer damping structure makes the system achieve better vibration reduction effect under smaller positive pressure;peak value of blade vibration response keeps at a lower level when external excitation changes within a larger range.