A Hypothesis of Non-Propagating Fatigue Crack

Abstract

A hypothesis for the mechanism of non-propagating fatigue crack related with the stress amplitude and the critical strength of a material in a region ahead of the fatigue crack tip below notch root was proposed. It was shown that the calculated results based on the hypothesis well explained the experimental results of a rotating bending fatigue test of a round bar specimen with a circumeferential deep hyperbolic notch (i.e.Neuber type notch) in each case of two sample (fine grained steel and coarse grained steel) which had been obtained by the heat-treatment of a mild steel.