TWI Industrial Member Report Summary 93/1979
By G S Booth and S J Maddox
Background
This report presents the results of fatigue tests'carried out on steel plates with fillet-welded attachments.
It has been shown that the fatigue strength of a longitudinal attachment is increased as both the length and the thickness of the attachment are decreased. Attempts have been made to increase the fatigue strength of a longitudinal attachment by separating the ends of the fillet weld from the ends of the attachment. Extending the weld beyond the ends of the attachment, however, did not significantly increase the fatigue strength, except when the weld and the end of a chamfered attachment were blended into the plate by grinding. Stopping the weld short of the ends of the attachment resulted in only a small increase in fatigue strength.
The fatigue strength of a fillet-welded attachment has been shown to increase as the orientation df the attachment is rotated from the direction transverse to the applied load, provided that failure does not occur at the ends of the attachment.
No significant differences in fatigue strength have been observed between transverse joints fabricated using manual metal arc (MMA) welding, submerged arc welding and MIG (CO2) welding in the flat position.