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

Abstract

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.

Investigation of Concrete-Filled Steel Composite (Cfsc) Stub Columns With Bar Stiffeners

“…These comparisons showed that Eurocode 4 (2004) and equations of Baig et al (2006) and Bahrami et al (2011b), respectively, predicted the ultimate axial load capacities with 4.4% underestimation (a COVof 0.031), 3.8% overestimation (a COV of 0.034), and 0.1% underestimation (a COV of 0.032). Therefore, the proposed equation by Bahrami et al (2011b) could predict the ultimate axial load capacities of the columns with a very good accuracy.…”

“…The ultimate axial load capacity of a square or rectangular CFSC stub column can be predicted from Eqns (13), (14) and (15), respectively, based on Eurocode 4 (2004), Baig et al (2006) and Bahrami et al (2011b): (14)…”

“…In addition, the ultimate axial load capacities of the columns were predicted based on Eurocode 4 (2004) and the equations recommended by Baig et al (2006) and Bahrami et al (2011b), and also compared with those obtained values from the non-linear analyses. These comparisons showed that Eurocode 4 (2004) and equations of Baig et al (2006) and Bahrami et al (2011b), respectively, predicted the ultimate axial load capacities with 4.4% underestimation (a COVof 0.031), 3.8% overestimation (a COV of 0.034), and 0.1% underestimation (a COV of 0.032). Therefore, the proposed equation by Bahrami et al (2011b) could predict the ultimate axial load capacities of the columns with a very good accuracy.…”

“…Also, effects of different diameters of the bar stiffeners, concrete compressive strengths and steel yield stresses on the ultimate axial load capacity of the columns are assessed. The obtained ultimate axial load capacities from the non-linear finite element analyses are compared with the predicted capacities by the design code Eurocode 4 (2004) and recommended equations by Baig et al (2006) and Bahrami et al (2011b).…”

Fire Resistance of Concrete-Filled Box Columns Fabricated with Different Welding Methods

“…In particular, concrete-filled box columns (CFBCs) possess excellent structural behavior. (1)(2)(3) They offer a practical solution for providing fire protection to hollow structural steel columns without any external protection. Therefore, steel-reinforced concrete columns have been used in various building projects to great advantage throughout the world in the last decade.…”