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

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.