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In the present study, a local stress based concept for the fatigue assessment of weld ends in thin sheet structures under combined normal and shear loading is introduced. The notch stresses were calculated using the finite element method and submodel technique. An idealised weld end model was used in order to determine the stress state for such loading situations. Moreover, a numerical method was used to consider size effects, which combines both the geometrical and statistical size effects, to an integrated approach. Therewith and in connection with the cycles-to-failure from fatigue test results, a standardised S-N curve was derived. [ABSTRACT FROM AUTHOR]

ABSTRACT Welding processes often lead to pronounced weld termination points (start/end), which are prone to fatigue events such as crack initiation. The fatigue of weld ends under shear loading, especially in thin sheet structures, is not sufficiently explored yet. In the present investigation, the real geometry of welds was obtained by scanning the three-dimensional surface, especially of weld ends. Cryogenic breaking of the weld opened the view to the weld root geometry and especially to the critical location, where the weld root migrates to a weld toe at the weld end. In the experimental part of this research, fatigue testing of thin sheet plane and cylindrical specimens as well as large components containing weld ends was performed. Based on the data, weld end life curves have been obtained. The notch stress concept and a fracture mechanics based approach were applied for describing the results of fatigue tests providing sufficient accuracy. [ABSTRACT FROM AUTHOR]