Behaviour of Beam with Slender Flanges

Compression members buckle globally or locally, depending on the overall section slenderness and the local plate element slenderness. If plate elements buckle at a stress lower than the stress which would cause the section to buckle globally, the local buckling of the plate will control the overall section strength. When this occurs, the section is said to be composed of slender elements. There is extensive research on buckling of slender web, but hardly any research regarding behaviour of slender flanges have been undertaken. Therefore, to study the behaviour of beam with slender flanges, a group of I-sections were selected with varying flange width to thickness ratios ranging from slender to highly slender sections, different unbraced span lengths and end support conditions. The I-sections were modelled on ANSYS workbench with the aforementioned parameters and loading condition of uniformly distributed pressure over flange. The buckling load behaviour due to slender flanges w.r.t the changes in width, thickness, unbraced span lengths and end support conditions were obtained. Indian and American standard codes, IS 800–2007, IS 801 1975 and AISC 360–16 were referred.