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 10(6), 2 x 10(6) and 10(7) cycles, are compared. The results demonstrate that the proposed model shows a good predictive capability.