A selective review of high-cycle fatigue criteria with applications in out-of-phase bending and torsion

摘要

The aim of this contribution is to provide a concise assessment of some multiaxial high-cycle fatigue criteria and to check their predictive capabilities against synchronous sinusoidal out-of-phase bending and torsion experimental results. This bending4orsion stress system does not closely represent real load conditions undergone by a machine part. However, it is complex enough to differentiate the various fatigue criteria and to permit an initial classification of the approaches examined, according to the accuracy of their predictions. A fatigue criterion recently formulated with the help of the mesoscopic approach, by the first of the authors, is also included in this comparative study. According to this criterion, the phase difference in out-of-phase bending and torsion does not affect the fatigue strength corresponding to a very high (theoretically infinite) fatigue life. It is pointed out that this theoretical finding is valid for the category of hard metals for which the ratio of the fully reversed torsion fatigue limit over the fully reversed bending fatigue limit, lies in the interval from 0.6 to 0.8 approximately. Experimental results collected from the relevant literature, concerning precisely hard metal specimens submitted to out-of-phase bending and torsion, fully support this theoretical finding.