Ultimate resistance of longitudinally stiffened webs subjected to patch loading

Longitudinal stiffening increases the ultimate resistance of slender girder webs subjected to patch loading when the stiffener is placed rather close to the loaded flange. In the past, some attempts have been made to quantify this influence, however none of these formulae have been successfully implemented due to poor correlation between predictions and experimental results. This paper describes a methodology to determine the ultimate resistance of longitudinally stiffened girder webs subjected to patch loading. The methodology accounts for the influence of: (a) the relative position of the stiffener, (b) the ratio of flange-to-web thickness, and (c) the ratio between the yield strength of the flange and the web. Finally, theoretical predictions show good agreement with experimental results.