Lateral Torsional Buckling of Steel I-Section Cellular Beams

ABSTRACT: Cellular beams are usually desirable in places where there are services below the ceiling and the openings allow services to pass through without increasing the floor height or building height. Architects also prefer this type of members due to their aesthetic look. After the cutting, shifting and welding of these members, there will be changes to their cross sectional slenderness since due to the heat, they experience through the cutting and welding process hence they may be subjected to different types of failure modes. In this study the lateral torsional buckling (LTB) failure mode of steel cellular beams is investigated. The LTB can cause partial failure or whole failure in the structure. An experimental steel section was verified using finite element software (Abaqus). The shell element for finite element (FE) modeling was used. FE analysis results showed a good agreement with the experimental test results. Based on the verified section, more members were modeled to study their behaviors against LTB. Some modifications were introduced to these sections in order to decrease the risks of LTB failure mode. The aim of this study, is to find ways of reducing the risks of lateral torsional buckling on perforated sections. Instead of the usual beam stiffeners, T-shaped stiffeners were used as a substitute for the beam. This kind of stiffener is a very good way of simulating the secondary to main beam connection in real life. Furthermore, the stiffener thicknesses of different values were used to see their effects on displacements. It was found that the use of T-shaped stiffeners with the increase in the thickness of stiffeners, significantly reduce the lateral displacements as well as the occurrence of lateral torsional buckling. Keywords: Finite element, Cellular beams, Lateral torsional buckling, Stiffeners. …………………………………………………………………………………………………………………………