Local Buckling And Inelastic Interactive Buckling Between Local And Global Buckling Of Tee Beams

Owing to the monosymmetric nature, tee beams are highly susceptible to failure in the flexural-torsional buckling mode when subjected to bending moments. Although many studies have been performed on local and lateral buckling of monosymmetric I-beams, few studies have been made on the buckling of tee beams. This paper investigates the elastic and inelastic local and global flexural-torsional buckling of simply supported tee beams.The buckling coefficient of the rectangular plate is obtained via using the Rayleigh-Ritz energy approach. Based on the understanding of the local budding of the rectangular plate, research into the buckling of simply supported tee beams has been developed. The Galerkin energy approach is presented to determine the elastic critical moments of simply supported tee beams, assuming a special sine series for the buckled shapes. And the general FEA program ANSYS is also used to testify the result. Some approximate formulae for the buckling coefficient of tee beams under moment gradient are proposed.The inelastic buckling of tee beam is studied through the FEA program ANSYS with the Shell181 element. The solution process considers the initial curvature and residual stress ,including the material plasticity. It is found that the buckling capacity and bucked mode shapes depend on the parameter h/t-w and λ_p . When the loading producescompression in the free edge of the stem, interactive buckling produces a critical moment, which is lower than the local buckling moment.