Inelastic Flange Buckling of Curved Plate Girders

Local buckling of the flanges of horizontally curved plate girders is studied analytically. Buckling in both the elastic and inelastic range is considered. The mathematical model consists of the small deflection plate equations for an isotropic media in the elastic range and an orthotropic media in the inelastic range. Prebuckling stresses due to bending and nonuniform torsion and residual stresses due to the fabrication process are included in the mathematical model. The influence of the stress distribution and yielding of portions of the curved plate on the buckling coefficients is studied. Plate buckling curves relating the internal forces in curved beams to the flange dimensions, width-to-thickness ratio, required to prevent buckling are also presented.