On the calculation of fatigue life for notched specimens made of the low-carbon steel SAE 1017

A prerequisite for an exact prediction with the local strain approach is the same evolution of damage during cyclic fatigue both in smooth and notched specimens. Examinations on a low-carbon steel SAE 1017 in fine and coarse grain condition indicate the influence of fatigue Luders bands on the accuracy of such a prediction. As a consequence of cyclic loading, the surface of smooth polished specimens becomes rough while this effect is much less pronounced in the notch root. The reduction of Luders strain in coarse-grained material leads to an improved congruence between predicted and measured lifetime.