Effect of welded residual stresses on the fatigue life of structural components in two-dimensional state

The problem of low-cycle fatigue is investigated by using the local stress-strain approach. The modified rainflow counting method is adopted to obtain the loading and unloading paths as well as rainflow counting. The local stress-strain approach is extended successfull y to the two-dimensional cases by using the first principal stress and strain and the Mises equivalent stress and strain. Three models are established to investigate the effect of residual stresses on the fatigue life in two-dimensional conditions. The effect of residual stresses is treated as that of the mean stress. The fatigue life of a large-scale digging machine is predicted by using the method proposed, and the results agree well with the real fatigue life.