Computational Study on Buckling Capacity of Lipped Channel Beams Infilled with Concrete

Abstract

This paper presents a computational study employing finite element analysis (FEA) to evaluate the buckling capacity of lipped channel beams infilled with concrete. Lipped channel sections with overall depths ranging from 100 mm to 250 mm, commonly available in the local construction industry, were analysed with beam lengths varying between 3.0 m and 7.5 m. Two sets of beam configurations were modelled: control beams consisted of a plain lipped channel section and another set infilled with concrete. The analysis was conducted under two types of boundary conditions: simply supported (pinned-roller) and pinned-pinned supports. Buckling analysis was performed using LUSAS FEA software, applying a four-point bending test to simulate realistic loading conditions. The results reveal that larger-lipped channel sections exhibited higher buckling capacities for both plain and concrete-infilled configurations. Additionally, concrete-infilled lipped channel beams with pinned-pinned support achieved greater capacities compared to their simply supported counterparts. However, longer span beams, being slenderer, demonstrated reduced buckling capacity. The buckling capacity of lipped channel beams increased significantly with concrete infill compared to plain-lipped channel beams. Overall, this study highlights concrete infill as an effective method to enhance the structural capacity of open steel sections, providing a viable solution for improving their buckling performance.