Abstract:
This paper presents a finite element investigation to investigate the axial capacity of CFS channels, connected back-to-back with a gap. A finite element model was firstly developed and verified against test results, currently conducted on CFS built-up gapped columns by the authors. Initial imperfections and material properties of the test specimens were included in the FE model. The column strengths, buckling modes, load verses displacement and load verses strain relationships were predicted from the FEA and compared against the test results. The verified FE was used for an extensive parametric study, comprising 84 models to investigate the effect of the gap between the back-to-back channels, link channel spacing, different column lengths and cross-sectional geometries. The FE results together with the test results were compared against the design strength, calculated in accordance with the AISI and AS/NZ Standard, which showed that the design standards can be conservative by only 5% when non-dimensional slenderness that considers the gap, is used to calculate the design strength of such columns.
