Strain Energy Partitioning Approach and Its Application to Low Cycle Fatigue Life Prediction for Some Heat-Resistant Alloys

An improved life prediction approach of time-dependent fatigue, strain energy partitioning (SEP), was verified with three alloys of different strengths. SEP synthesizes the energy concept of the Ostergren model and the thought of inelastic strain partition of the SRP model, and, thus, the partitioned strain energy component (U i j ) is the single independent variable in SEP. The results show that the life predictability of SEP to all three alloys appears to be the most promising in comparison with those of strainrange partitioning (SRP) and frequency separation (FS) methods. It seems that the higher the strength level of the tested material, the better the predictability of SEP over that of SRP and FS.