Fatigue behaviour of butt-lap friction stir welded joints used with aluminum bridge decks. (May 2023)

• Record Type: Journal Article
• Authors: Trimech, Mahmoud; Annan, Charles Darwin; Walbridge, Scott; Maljaars, Johan
• Is Part Of: Structures. Volume 51(2023)
• Page Start: 1795
• Page End: 1805
• Publication Date: 2023-05
• Subjects: Aluminum bridge deck extrusions -- Friction stir welding -- Butt-lap joint -- Fatigue behaviour -- Effective notch stress; Structural engineering -- Periodicals; 624.1
• DOI: 10.1016/j.istruc.2023.03.151
• Languages: English
• ISSNs: 2352-0124

Abstract

Highlights: Fatigue testing of large-scale butt-lap FSW specimens extracted from roadway aluminium bridge deck application. Fatigue failure mechanism of butt-lap FSW joints depends on the FS welding orientation. The ENS approach was applied for the fatigue assessment of the butt-lap FSW joints. Abstract: This paper presents the results of experimental tests and a numerical investigation of the fatigue behavior of butt-lap friction stir welded (FSW) joints used in highway bridge decks made from aluminum extrusions. A large-scale fatigue experiment was designed to initiate fatigue failure in the butt-lap FS welds joining two full-scale aluminum extrusions used for highway bridge decks. Ten fatigue tests were carried out on an MTS servo-hydraulic press. Test results were used to analyze the fatigue failure mode of this unique joint type and to derive the S-N curve useful for the characterization and design of fatigue-sensitive details. The fatigue data was assessed using the effective notch stress (ENS) approach as recommended by the International Institute of Welding (IIW). Results show that the IIW design ENS IIW FAT-71 curve derived from fatigue tests on fusion-welded joints is conservative in assessing the fatigue behavior of butt-lap friction stir welded (FSW) joints, especially in the high cycle regime.