Estimation of Endurance Limits of Welded Joints by the Criterion of Non-propagating Cracks

The results of the suggested model have been checked on carbon and ferrite-pearlite steels. The authors have manage to obtain the fluctuating stresses values on the criteria of non-propagating cracks depending on the size of the defect and based on the endurance limit criterion. The sizes of non-propagating cracks appearing in the area of stress concentration action and depending on the diameter of the circular hole in the plate have been calculated. Comparing to the model mentioned in G.M. Charzynski's monograph, the suggested methodology gives an asymptotic approximation endurance limit to the value σ−1/3 macro concentrators with increasing stress as a hole. The model has been built for an infinite plate and does not consider changes in the stress field due to the limited size effects.