Experimental fatigue curves to perform the fatigue assessment of aluminium-to-steel thin welded joints

Welding of different materials, especially aluminium alloys to steel, has always been a challenge because of the significant differences in their mechanical, thermo-physical and metallurgical properties that result in the formation of hard and brittle intermetallic phases in the welding region. In this context, this paper experimentally investigates the fatigue behaviour of aluminium-to-steel thin welded joints. The purpose of this investigation is to verify the accuracy of the nominal stress approach in estimating the fatigue life of aluminium-to-steel welded joints. EWM coldArc® welding technology was used to make the welded samples used for this validation exercise. The results of this experimental/theoretical study show that the nominal stress approach can be used to evaluate the fatigue of thin aluminium-to-steel welded joints, provided that the appropriate reference/calibration fatigue curves are used.