Analysis of multiaxial low cycle fatigue of notched specimens for type 316L stainless steel under non-proportional loading

•Multiaxial fatigue test of 316LSS notched specimen under non-proportional loading are presented.•Crack initiation site corresponds to the location where maximum strain occurs.•A new Kt′ is defined considering the stress occurring at the maximum strain site.•Itoh-Sakane’s model is modified to take into account the maximum strain site.•The modified IS’s model permits to obtain a narrower fatigue scatter band. The paper analyzes multiaxial low cycle fatigue tests of notched specimens under proportional and non-proportional loading conditions. Strain controlled multiaxial low cycle fatigue tests were carried out using circumferentially notched round-bar specimens of type 316L stainless steel, with different stress concentration factors. The experimental results show that the crack initiation site is shifted from the notch tip. Based on this finding, a new model for life evaluation is proposed by taking into account the strain gradient in the proximity of the notch tip and the effective maximum strain range. The new model allows evaluating the fatigue life in a narrow scatter band.