RESIDUAL VIBRATION FATIGUE LIFE OF COMPRESSOR BLADE DAMAGED BY FOREIGN OBJECT

The residual vibration fatigue life of TC4 plate blade subjected to Foreign Object Damaged (FOD) is investigated by means of eddy current excited vibration fatigue tests.The results show that the extent of FOD depends on both impact energy E and geometric scale S.There exists a critical damage for a given blades.Repairing of the damaged parts and lowering of the vibration stress in the blade are effective measures to improve the resistance of the blade to FOD.Moreover,the comparison of the titanium and steel blades indicates that the excssive fatigue strength of the steel blade is more than that of the titanium one,because the designed stress is usually based on the tension strength of the blades.