Elastic web bend-buckling analysis of longitudinally stiffened I-section girders

Abstract

The linear elastic web bend-buckling behavior of I-section girders with a longitudinal stiffener is investigated by a threedimensional finite element analysis in which the web, top and bottom flanges, and transverse and longitudinal stiffeners are modeled as thin shell elements. After obtaining the bend-buckling moment for an I-section girder by finite element analysis, the buckling stress and subsequently the buckling coefficient of a rectangular web panel with a longitudinal stiffener are calculated and compared with those obtained by AASHTO LRFD and Eurocode 3. To observe the effect of various parameters on the buckling behavior of an I-section girder under pure bending, the following aspects are considered: the non-symmetry of the cross-section, the location of the longitudinal stiffener, the boundary conditions along the transverse and longitudinal stiffeners and flanges, the flexural rigidity of the longitudinal stiffener, the spacing of the transverse web stiffeners, and the slenderness of the web. Based on the numerical results, new design equations for the bend-buckling coefficient of a longitudinally stiffened I-girder are proposed.