STUDY OF CONCRETE-FILLED STEEL COMPOSITE COLUMNS USING COLD-FORMED STEEL SHEET

Concrete-filled steel composite columns using cold-formed steel sheet are studied in this paper. In order to study the structural behaviour of the columns, finite element program LUSAS is used to carry out the nonlinear finite element analyses. Modelling verification is established with the aid of the comparison of the finite element result against the existing experimental result which shows that they agree well with each other. Therefore, the proposed modelling can predict the structural behaviour of the columns with a very good accuracy. Various thicknesses of cold-formed sheet sheets with different number of stiffeners are analysed by the use of nonlinear finite element method. Results of the analyses are indicated in the form of axial load-normalized axial shortening plots. Effects of thickness of cold-formed steel sheet, number of stiffeners, and composite action between steel and concrete on ultimate axial load capacity and ductility of the columns are discussed. Effects of compressive strength f(c) of concrete and yield strength f(yp) of cold-formed steel sheet on ultimate axial load capacity are also examined. It is found that the mentioned parameters affect ultimate axial load capacity and ductility.