Numerical simulation and specification provisions for buckling characteristics of a built-up steel column section subjected to axial loading

Abstract

The demand for lightweight materials in construction has become very popular due to its flexibility and economical importance. Cold-formed steel beams and columns are used for provision of lightweight, durable and cost-efficient structures, and its usage also helps to optimize the construction time. Cold-formed steel section exhibits post-buckling strength, in which hot rolled section is deficient. However, more theoretical background on design and behavior of cold form section is still required, especially when it is subjected to axial loading. Thus, this paper presents numerical and theoretical behavior of pin -jointed cold-formed steel (CFS) column section (built-up battened Lip channel) under axial loading. The numerical modeling was done by using ABAQUS 6.10 software. Based on American Iron and Steel Institute (AISI) specifications, two types of sections were selected for single lipped channel, and it was ensured that the selected chord spacing permits both moment of inertia about the major axis and minor axis are equal. The numerical and theoretical study were done using a varying batten number and section slenderness ratio. The ultimate loads were obtained under the two approaches, for the lipped channel built-up columns, and were compared for the effective section proposed. From the results, the prediction of buckling mode and the failure load of the column were found to be stable and approximately relevant to the FEM results from slenderness ratio ranging from 20 to 60. Also, flexural buckling of all column sections occurred about the axis parallel to the webs, where there is an opportunity for composite action.