Fatigue strength evaluation of load-carrying cruciform fillet-welded joints made with mild steel plates of different thickness

This study examined the fatigue behavior of load-carrying cruciform fillet-welded joints made with mild steel plates of different thickness. Fatigue tests were carried out on four types of welded joint, made from two 6-, 9-, 14-, or 25-mm thick main plates and one 6- or 14-mm thick cross plate. The fatigue strength was also analyzed using linear elastic fracture mechanics on 34 parametric models simulating welded joints with different plate thicknesses. From the experimental and analytical results, the effects of the thickness ratio of the main plates and the change in cross plate thickness on fatigue strength were evaluated.