Stress singularity field and fatigue strength assessment of V-notch plates and welded joints under combined tension-bending loads

In order to simplify the calculation of notch stress field and N-SIF for V-notched structures, the concept of equivalent intensity factor was introduced and the simplified semi-analytical formula was deduced and fitted for calculating the notch stress and N-SIF of V-shaped notch. By establishing a large number of multi-parameter models, the equivalent intensity factor and simple formula of notch stress field under complex tension-bending load were quantitatively described and fitted. Furthermore, equivalent intensity factor as was used to solve dimensionless N-SIF. Numerical results show that the semi-analytical method proposed in this paper has high prediction accuracy. For the convenience of engineering application, the relationship between welded geometry and V-notch model parameters is established on the premise that the equivalent singular intensity factors are equal. The simple formula is extended to the prediction of notch stress field and N-SIF of typically welded joints, and the convenience and reliability of the simple formula are further verified by fatigue strength evaluation.