Multiaxial high-cycle fatigue life prediction model considering mean shear stress effect under constant and variable amplitude loading

In this paper, load controlled uniaxial, pure torsion, constant and variable amplitude tension-torsion tests on 7075-T651 aluminum alloy tubular specimens were conducted. According to the analysis of the experimental data obtained, a multiaxial high-cycle fatigue life prediction model, based on the critical plane method and considering mean shear stress effect, is proposed. The critical plane is proposed to be determined by a weight average, which is based on the variation of the maximum shear stress. The estimated fatigue lives obtained by applying the proposed model, for the fatigue limits related to 106, 2×106 and 107 cycles, are compared. The results demonstrate that the proposed model shows a good predictive capability.