Fatigue Life Prediction of Fan Blade Using Nominal Stress Method and Cumulative Fatigue Damage Theory

Abstract

Abstract Fan blade is one of the key parts used in aircraft engine and its failure is mainly caused by fatigue fracture. This paper aims to predict fatigue life of fan blade during its service operation. First, the effective load and stress of fan blade are obtained by using finite element analysis and simulation. Second, the fatigue notch factor of fan blade is determined by using the nominal stress method. Then, the material properties of fan blade are used to correct and obtain the <m:math xmlns:m="http://www.w3.org/1998/Math/MathML"> <m:mi>S</m:mi> <m:mo>−</m:mo> <m:mi>N</m:mi> </m:math> $S - N$ curve of fan blade. Finally, according to the actual load spectrum of three working loading cycles in 900h, the Miner’s damage accumulation rule is employed to predict the fatigue life of fan blade.