Research on three-parameter power function equivalent energy method for high temperature strain fatigue

Researched on Manson-Coffin equation, the tensile hysteresis energy damage function method, walker strain life prediction model, the three-parameter power function formula and the three-parameter power function energy method, a three-parameter power function equivalent energy method is put forward, specific algorithm and the solution process are given. The method is validated by the low-cycle fatigue test data of GH4133 material under the strain ratio of −1 and 0.44 at 250°C. Through the analysis of life dispersion coefficient and standard deviation, the method has higher calculation accuracy and does not require an average strain or stress amendment It is able to fit fatigue test data with different strain ratio at the same time.