Comparison of fatigue life for T and cruciform welded joints with different combinations of geometrical parameters

Abstract

The fatigue life for T and cruciform welded joints containing different extents of lack of root penetration was calculated for different combinations of geometrical parameters, including thicknesses up to 45 mm, 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 for both types of joints. All the curves show higher fatigue life for T joints than for cruciform joints. These curves were then compared with the S– N curves for failure from either weld toe position or on the weld throat, proposed by Eurocode 3. The maximum tolerable sizes for lack of penetration at which weld toe failures would still rule are reported for each case. Results of experimental tests are in good agreement with the predictions.