Estimation for fatigue limit reliability of a metal with inhomogeneities under stress ratio R=-1

In this paper, by using statistical characteristics of hardness in a small region and statistical characteristics of mechanical condition in a small region based on a defect size distribution and a certain stress which is applied to a defect, a quantitative prediction method for fatigue limit reliability of a metal with inhomogeneities is proposed. Also rotating bending and push-pull fatigue tests under R=-1 are carried out on quenched-tempered 0.5% carbon steels, whose average hardness is about HV≃600. Comparing a predicted fatigue limit reliability with experimental data, the applicability of the present proposed method is examined and confirmed.