Effect of mean strain level on the cyclic stress–strain behavior of AISI 316 stainless steel

This paper presents a modified expression that describes/predicts the cyclic stress/strain curve under an applied mean strain. The Smith, Watson and Topper criterion [14] be extracted from the modified cyclic stress–strain curve (CSSC) expression and used in the prediction of fatigue life. Furthermore, the paper examines the effects of mean strain level on the CSSC. The CSSC expression obtained from completely reversed fatigue test is shown to be identical to the usual description. In addition, based on the two hypotheses given in this study, a simple approach is derived for the determination of the stable mean stress that occurs in strain-controlled cyclic loading with an applied mean strain. The analytical expressions obtained based on the modified endochronic constitutive theory by Valanic. These are used to simulate the stable hysteresis loop under an applied mean strain level. Subsequently the paper presents the results obtained from a series of fatigue experiments performed on AISI 316 stainless steel to confirm the validity of the proposed methods. The experimental results show the data generated by the proposed methods are in qualitative agreement with the experimental data.