Research on improved power exponent function for life prediction method

On the base of researching on Manson-coffin function, walker strain life prediction model, the method based on the three parameter power formulation and power function model for low cycle life prediction, an improved power exponent function model is proposed and a specific solving process is given. The improved method is validated in low cycle fatigue test with GH4133 material under strain ratio of −1 and 0.44 at 250°C. Through the analysis of life dispersion coefficient, standard deviation and comparing with other life prediction methods, the improved method has a higher calculation accuracy and does not require an average strain or stress amendment. Fatigue test data with different strain ratio are fit together at the same time.