Overview on the fatigue strength of single-sided transverse and longitudinal fillet weld joints

Abstract

In the present study, an overview on the fatigue performance of single-sided fillet welds is carried out. Both longitudinal load-carrying joints, for instance existing in beam structures and welded hollow sections, and transverse joints are considered in this work. Experimental data of such joints made of mild and ultra-high-strength steel (UHSS) is extracted from existing studies to evaluate the fatigue strength properties. The main characteristics affecting fatigue strength properties of these joints are discussed. Furthermore, the paper evaluates the fatigue strength of single-sided fillet weld joints in comparison with the joints with double-sided welds. The experimental results indicate that in the transverse welds, an increase in material’s yield strength shows a slight decrease in fatigue strength compared to mild steels, while in the longitudinal load-carrying seams, in the case of continuous weld root geometry, high fatigue strength can be achieved with UHSS materials. The double-sided welds provide one FAT class higher fatigue strength for transverse non-load-carrying joints, obtained in terms of mean fatigue strengths. In addition, in transverse joint configurations, intermediate welding was found to have no detrimental effect on the fatigue performance compared to the joints with continuous welds. In longitudinal load-carrying joints, double-sided welds do not provide any additional benefit unless full penetration and, thus, continuous longitudinal weld root shape is achieved with such weld preparation.