涡轮盘榫槽高温复合疲劳试验方案研究

A NEW APPROACH TO COMBINED FATIGUE EXPERIMENT OF TURBINE DISK MORTISES AT ELEVATED TEMPERATURE

针对某型航空发动机二级涡轮盘榫齿高温复合疲劳裂纹故障，采用全尺寸真实涡轮盘作为试验件，设计了一套新型试验方案，着重解决了高低周疲劳载荷的加载并互不干扰、高频感应局部加温（５５０℃恒温）、高周振动振幅控制以及裂纹检测等几大关键技术，载荷谱与加温均模拟外场真实情况。试验完全实现了故障再现，这说明：该试验方案设计合理，易于推广到其它多种构件的复合疲劳试验，在工程应用研究中具有重要意义。

Crack and fracture fault emerged in the mortises of a given aeroengine second-stage turbine disk for a long time and seriously endangered the aircraft′s regular flight.The fractography analysis indicated that the faults were caused by combined fatigue at elevated temperature.So we were engaged in this experiment to study and research a new failure criterion of the disk.A real disk was used as experimental component,we worked out a new failure experimental approach,including key technique to ensure the noninterference between the low cycle loading and high cycle loading,the high frequency induction local heating (550℃ constant temperature),the control of high cycle vibration frequency and amplitude, and crack real-time detection.Experimental load spectrum and temperature field emulated the reality,and the experiment completely reproduced the practical flight fault. The present experimental approach can be applied to the combined fatigue analysis of any components.