COMPUTATIONAL STUDY ON BUCKLING CAPACITY OF LIPPED-CHANNEL BEAMS INFILLED WITH CONCRETE

Abstract

This paper presents the computational study employing finite element analysis (FEA) to evaluate the buckling capacity of lipped channel beams infilled with concrete. Locally available lipped channel sections with overall depths ranging from 100 mm to 250 mm were used in the computational study. The length of the beams varies between 3 m and 7.5 m. Two sets of beams were modeled: control beams consisting 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 under a four-point bending test. The results revealed 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. Longer span beams, being slenderer, demonstrated reduced buckling capacities. The buckling capacity of lipped channel beams increased significantly with concrete infill compared to plain-lipped channel beams. 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.