航空发动机涡轮叶片疲劳—蠕变寿命试验技术研究

Research on Experimental Technique for Fatigue-Creep Life of the Turbine Blade in Aeroengine

涡轮叶片是航空发动机工作环境最恶劣 ,结构最复杂的零件之一 ,也是发动机断裂故障多发件之一。由于发动机工作时涡轮叶片始终在高温下承受复合载荷的作用 ,因此在涡轮叶片定寿中 ,不能将叶片的蠕变和疲劳寿命割裂开 ,而必须充分考虑疲劳—蠕变交互作用的影响。目前理论上对结构疲劳—蠕变寿命的预测方法还很不完善 ,故对涡轮叶片开展疲劳—蠕变寿命试验研究是叶片设计和定寿工作中的重要环节。本文对涡轮叶片疲劳—蠕变试验技术进行了综合论述。文中特别强调了试验载荷谱确定和叶片模拟试验件设计的关键技术环节 ,同时还介绍了一种专门适用于叶片疲劳—蠕变试验的基于机电伺服加载系统的疲劳蠕变综合试验器。

Turbine blades of aeroengine are one kind of component parts working in the most severe conditions.They have the most complex structure,and are apt to fracture.The turbine blades endure the compound loads at high temperature all the time when the engine is working.Therefore,to determine the working life of the blade,the creep and fatigue life cannot be separately considered.On the contrary,the mutual effects of fatigue and creep must be fully considered.At present the method for predicting the fatigue-creep life of structure is imperfect in theory,so experimental research for the fatigue-creep life of the turbine blade is an important procedure in the design and life determination of the blade.This paper has a general discussion on the technique of fatigue-creep experiment of turbine blade.The determination of the experimental load spectrum and the key technical procedure of designing the testing blade sample are emphasized.This paper also introduces a synthetical testbed,whose loading system is based on the electric-mechanical servo device and which is especially suitable for blade fatigue-creep experiment.