A damage model based on the critical plane to estimate fatigue life under multi-axial random loading

A multi-axial random vibration fatigue damage parameter was proposed based on a critical plane damage parameter for multi-axial high cycle fatigue, which is an equivalent stress power spectral density (PSD). The fatigue life calculation under multi-axial random loading could be conducted based on the equivalent stress PSD, combined with the spectral method under uniaxial random loading. The multi-axial random vibration fatigue experiment was conducted on the thin-walled circular tube with slots on the side. The fatigue life results obtained from the experiment were compared with the ones calculated from the proposed model, which indicated that the proposed parameter did a good job in predicting the multi-axial random vibration fatigue life.