New energy model for fatigue life determination under multiaxial loading with different mean values

• Good results for fatigue life calculation for a new variant of stress strain parameter.
• Proposed variant takes into account the shear and normal mean stress.
• Proposed variant comprises three material coefficients of the mean stress sensitivity.

The paper proposes a new variant of the stress–strain parameter used to estimate the fatigue life in the multiaxial stress states with the influence of mean stress. The results of the fatigue life calculated according to the proposed variant have been compared to the results of fatigue tests of specimens made of 2017A-T4 aluminum alloy and S355J0 and 30NCD16 alloy steel in conditions of constant amplitude bending and torsion stress, as well as proportionate combinations of bending and torsion, while taking into account the mean stress. The experimental results have been compared to the results of calculations using models by Goodman, Gerber, Morrow, Findley, Dang Van, McDiarmid, Papadopoulos and Smith–Watson–Topper. Statistical analysis have been carried out for the results of calculations, involving the calculation of a scatter band for results of the comparison of experimental data with calculations.