Local Buckling of Curved I-Girder Flanges

Abstract

Two analytical approaches are used to investigate the effect of curvature on the elastic local buckling behavior of horizontally curved I-girder compression flanges. First, a governing differential equation for the isolated curved flange plate elements under various loading and boundary conditions is derived in polar coordinates and the equation is solved using the finite-difference technique. Numerical results for various curvatures and aspect ratios are generated. Second, the finite-element method using MSC/NASTRAN is used where the entire cross section of the curved I-girder is modeled. A comparison of the results from the two approaches is made and differences are explained. The effect of curvature on the elastic buckling of the flange plates is observed and a simple but conservative formulation representing this effect is derived for design use.