Fatigue Crack Growth in Austenitic Stainless Steel: Effects of Phase Shifted Loading and Crack Paths

In this study, the cyclic crack growth behavior of biaxially loaded cruciform specimens is investigated and compared with an uniaxially loaded cruciform specimen together with the Paris law to detect differences between uniaxial and multiaxial experiments and to understand the occuring mechanisms. The tests are performed on a planar‐biaxial test system and a stress ratio of R = 0.1. Biaxial loading takes place both in‐phase as well as out‐of‐phase, after an initial technical crack is generated, whereby the phase shift loading leads to a constantly changing biaxial force ratio . The crack path curved after changing from in‐phase to out‐of‐phase loading and subsequently the cracks grow straight again. Both cracks of each specimen have an almost identical crack path indicating a symmetrical stress distribution on the specimen. The calculation of the stress intensity factor range for the curved crack path is done by FE‐calculations.