Shear flow capacity of stiffened flanges in steel box girders

Abstract

The purpose of this paper is to model the shear flow capacity of stiffened flange in a steel box girder. The present study uses an energy-based variational approach to analyze the steel box girder. A new parameter is introduced that is strongly correlated to the shear lag response of stiffeners to flanges. This parameter is named as shear flow parameter. The shear flow parameter decreases with increasing stiffener area to flange area ratio. Along with increasing the stiffness of the flange, stiffeners also reduce the shear flow capacity of the flange plate. It is observed that the reduced shear flow capacity causes more shear lag in the flange, increasing the stress at the web-flange junction. As a result of a high percentage of longitudinal stiffeners, steel box girders have a small effective width ratio, high negative shear lag effect, and significant deflection. This approach is in close agreement with experimental results, finite element results and theoretical results.