On the prediction of fatigue life subjected to variable loading sequence

Miner's rule is one of the most widely used cumulative damage equations for evaluating useful fatigue life. However, it often yields unsatisfactory predictions due to its linearity of the damage accumulation. In this paper, a new nonlinear fatigue damage accumulation model is developed that treats loading sequence effect and, also, enables one to predict the rate of damage by introducing a loading sequence parameter. This parameter is defined using the loading sequence ratio, which depends on material properties. Applicability of the proposed model is validated using the results of nine sets of independent experimental measurements of fatigue life under multiple loading sequences. It is shown that the predictions are in agreement with measured results and that the model provides a reliable estimation of fatigue life.

Automated summary

A new nonlinear fatigue damage accumulation model is developed in this paper, which considers the loading sequence effect and predicts the rate of damage by introducing a loading sequence parameter. The applicability of the proposed model is validated using nine sets of independent experimental measurements of fatigue life under multiple loading sequences, showing that the predictions are in agreement with the measured results and providing a reliable estimation of fatigue life.