Fatigue assessment of cruciform joints welded in different positions

Welded structures are frequently used in today's metal industry. Since fatigue is still one major reason of failures, investigation in this field is of interest to engineers. In this study both numerical and experimental methods are employed to perform a fatigue evaluation concerning local weld geometry. The emphasis was on quantifying the weld toe radius as a feature in quantification of weld quality. Three different welding positions which have been led to different toe radii were analyzed. Each batch contained 12 specimens manufactured in cruciform joint and has been tested in non-load carrying status. Finally, the results of tests were compiled in Wöhler (S-N) curve and compared to reference curves introduced by IIW (International Institute of Welding). Results of this study show that local weld geometry has remarkable influence on strength of welded structures. It can be concluded that specimens with larger toe radii had more fatigue strength - as it was expected from the theory.