Behaviour of stiffened concrete-filled steel composite (CFSC) stub columns

this paper investigates the behaviour of axially loaded stiffened concrete-filled steel composite (cfsc) stub columns using the finite element software lusas. modelling accuracy is established by comparing results of the nonlinear analysis and the experimental test. the cfsc stub columns are extensively developed using different special arrangements, number, spacing, and diameters of bar stiffeners with various steel wall thicknesses, concrete compressive strengths, and steel yield stresses. their effects on the columns behaviour are examined. failure modes of the columns are also illustrated. it is concluded that the parameters have considerable effects on the behaviour of the columns. an equation is proposed based on the obtained results to predict the ultimate load capacity of the columns. results are compared with predicted values by the design code ec4, suggested equation of other researchers, and proposed equation of this study which is concluded that the proposed equation can give closer predictions than the others.