Multiaxial Fatigue Life Prediction Based on Weight Function Method Under Random Loading

Based on strain parameters, a weight function method is proposed to determine the critical plane under variable amplitude axial-torsion loading. The critical plane is determined by averaging the maximum absolute shear strain plane during the time for one block loading. The averaging process is conducted through a weight function, which is proposed based on the maximum shear strain. Then, combined with the life prediction model and Wang-Brown's cycle counting method, the proposed method is used to predict the fatigue life under variable amplitude loading. The experimental data of En15R steel and 7050-T7451 aluminum alloy are used to verify the proposed method, and a good result is obtained.