Plastic Strain Energy in Fatigue Failure

In this paper the cyclic plastic strain energy of the A-516 Gr. 70 carbon low-alloy steel during fully reversed constant strain or stress-controlled cycles is discussed. A relationship is proposed which can be used to determine the plastic strain energy per cycle for a non-Masing material for various stress ranges during the entire life cycle. Predictions of the proposed method are in good agreement with the experimental data. The variation of the plastic strain energy per cycle and cyclic creep during the life of fully reversed stress-controlled tests is also presented. It is shown that the cyclic creep strain affects the fatigue crack initiation period and consequently the amount of the total absorbed plastic strain energy to failure.