Local Instability of Horizontally Curved Members

An analytical study of the elastic buckling behavior of the flanges of horizontally curved I-shaped girders is presented. The prebuckling flange stresses in the longitudinal and radial directions due to bending and nonuniform torsion are determined using an elasticity approach. The magnitudes of these stresses are compared with those resulting from a strength of materials approach. Using these stresses and the finite difference method, buckling coefficients, k, are obtained by treating the flanges of the girder as elastically restrained curved plates. The influence of curvature and the ratio of bending stress to warping normal stress on these buckling coefficients is evaluated. The buckling coefficients are compared with those for rectangular plates. Width to thickness requirements based on preventing local buckling in the elastic range are also obtained.