An experimental investigation into the influence of incorrect root gaps in welded-in transverse stiffeners on fatigue performance

The paper presents a comprehensive set of special experimental fatigue tests designed to determine the fatigue strength sensitivity of steel components, under circumstances where fabrication quality levels deviate from regulatory standards. Precise monitoring of the manufacturing process of test specimens containing internal imperfections facilitates accurate documentation of the phenomena that contribute to the eventual shape of the imperfection. Welded-in stiffeners with incorrect root gaps of varying sizes were subjected to fatigue testing, as such studies have never been carried out in experimental form before, as the background data to EN 1993-1-9 disclosed. The experimental investigation confirms numerical estimations, which predicted that even large root gaps do not result in lower fatigue strength values, when compared to stiffeners that were properly fitted. Moreover, details in welded beams that feature an intersection of three welds at the stiffener exhibit no discernible decrease in fatigue performance compared to rolled sections.