Fatigue life comparison for T and cruciform welded joints

The fatigue life for T and cruciform welded joints containing different extents of lack of root penetration (L.O.P) was calculated for different combinations of geometrical parameters, by integration of the Paris law and use of stress intensity factor solutions calculated previously. The effect of attachment and main plate thickness, weld leg length and initial lack of penetration size on fatigue life was studied. For T welded joints, the effect of different support span has also been investigated. The results are reported as fatigue life curves againts the lack of penetration size. All the curves show higher fatigue life for T joints than for cruciform joints. Based on these results, a parametric formulae is found to show the correlation between the fatigue life of the cruciform and T welded joints.