Fatigue Criterion Based on the Novoshilov Criterion for Non-proportional Loadings

In the present paper the fatigue limit has been calculated under non-proportional loads, proposing a modification of the Huber-von Mises-Hencky criterion, i. e. the Novoshilov interpretation of that criterion was applied. As an effective amplitude, the maximum value of shear stress in the non-proportional load cycle was assumed. There has also been proposed the weight function showing preference of the directions of easy slip in the network A2. Subsequently, verification calculations were performed for respective literature data. The data included experimental fatigue limits reported under biaxial loads which are sinusoidally variable from the phase shift. The present results are compared with the Huber-von Mises-Hencky criterion. The analysis showed that the proposed solutions demonstrate greater accuracy, especially under loadings with a high degree of non-proportional loads.