Stress Concentration of Simply Supported Box Girder with Longitudinal Stiffeners Including Shear Lag Effect

摘要

This study is focused on stress concentration of longitudinally stiffenedrnbox girder accounting for shear lag effect by three-dimensional finite elementrnanalysis. For the practical design of steel box girders, longitudinal stiffeners arernincorporated to add buckling strength of the girders. There were a few studies onrnshear lag effect of stiffened box girder reported in the past literatures. In the presentrnstudy, the longitudinal stiffeners are added to the top and bottom flange plates ofrnsimply-supported box girder in order to examine the shear lag of flange plates. Thernsize and number of stiffeners are designed according to AASHTO code. The loadingrnconditions consist of concentrated loads at mid span and uniformly distributed loadsrnalong the girder length. The parametric studies on geometry of box girder arernperformed. The finite element mesh is paid attention through the use of multi-meshrnextrapolation method to improve the solution accuracy. Based on the numericalrnresults, stress concentration factors of box girders with stiffeners including the effectrnof shear lag are discussed. The empirical formulas are proposed to evaluate the stressrnconcentration including effect of shear lag.