Perea, Leon, Hajjar, and Denavit 2013
CFT columns have been proven to have superior stiffness, strength, toughness, and deformation properties when compared to steel columns. Applications of specific CFT usages include efficient construction practices, reduced loads on foundations, and lower maintenance costs.
Experimental Study, Results & Discussion
CFT columns have been proven to have superior stiffness, strength, toughness, and deformation properties when compared to steel columns. Applications of specific CFT usages include efficient construction practices, reduced loads on foundations, and lower maintenance costs. However, slender CFT columns have not received adequate testing to ensure that the structural system response factors and comprehensive design equations are accurate. Axial behavior of slender CFT columns without internal reinforcement or shear connectors was investigated to correctly measure the column’s buckling load. This paper addresses disparities between experimental data and AISC 360 equations, due to uncertainties such as specimen imperfections, and testing system compliance. For the testing itself, specimens were selected by slenderness, length, and concrete strength. Additionally, thick endplates were welded with complete joint penetration, and tubes were fabricated onto the endplates. The parameters for this axial test include (but are not limited to) buckling critical load, slenderness, and effective flexural stiffness. The AISC design equations generated for this experiment provided a conservative and accurate prediction of the CFT column’s stiffness and strength properties. Also, a general agreement between nonlinear fiber analysis and experimental data, as it was able to predict confinement, residual stress, and local buckling of slender CFT members was determined.
Analytical Study
Design equations and computational models were calibrated to improve the ability to predict confinement, residual stress, and local buckling responses of slender CFT columns. A nonlinear fiber analysis model and experimental loading response were contrasted, resulting in general agreement for residual stress and local buckling in the steel and confinement effects in the concrete component.
Reference
Perea, T., Leon, R., Hajjar, J., and Denavit, M. (2013): “Full-Scale Tests of Slender Concrete-Filled Tubes: Interaction Behavior” Journal of Structural Engineering Vol. 140, Issue 9. doi: https://doi.org/10.1061/(ASCE)ST.1943-541X.0000949