Inelastic Local Buckling and Rotation Capacity of Steel I-Beams Strengthened with Bonded FRP Sheets: Fid-Bau Portal

Inelastic Local Buckling and Rotation Capacity of Steel I-Beams Strengthened with Bonded FRP Sheets

Ragheb, Wael F

AbstractThis paper presents an analytical investigation of the inelastic local buckling of steel I-section beams strengthened with bonded fiber-reinforced polymer (FRP) sheets. Attention is focused on the ability of the FRP sheets to increase the beam rotations before onset of local buckling takes place. An inelastic stability analysis technique is presented that models the beam as a group of connected plates. The behavior of the steel beyond the elastic limit was modeled using the deformation theory of plasticity. The model results were verified through comparison with the results of a finite-element model and some reported experimental data. The developed model was used to conduct a parametric study to investigate the effect of each of the parameters of the problem focusing on FRP type and strengthening configurations. The study results showed that FRP materials with high longitudinal elastic modulus do not necessarily result in higher increases in the inelastic local buckling capacity. The FRP in-plane shear modulus is found to be more influential when buckling is controlled by the flange, while the transverse modulus becomes more effective when buckling is controlled by the web.