Sequence Effects on Stochastic Fatigue of Welded Joints

Abstract

The influence of small stress ranges on a recently proposed sequencedependent fatigue damage model is examined. The damage model is capable of including sequence effects by taking into account the interaction of neighboring cycles in predicting the fatigue damage accumulation. The parameters necessary for use of the damage model are obtained using a combined experimental and empirical approach. The model is modified here to ignore stress cycles below a truncation level that is consistent with the endurance limit of the specimens under constant amplitude loads. It is shown that with this modification, the damage model gives fatigue life predictions that compare very well with experimental results for a wide variety of stochastic loads. Additional experimental investigation with different specimen geometry and material is needed to further examine the validity of the proposed damage model and the extent to which the parameters needed to use this model are geometry‐ and material‐dependent.