Analytical Study on Elasto-Plastic Flexural Behavior of Concrete-Filled Circular Steel Tubular Columns

摘要

This paper discusses the applicability of stress-strain relationships for confined concrete and steel have been proposed by the authors and recommended in current design guidelines, to predict the ultimate strength and the elasto-plastic flexural behavior of concrete-filled circular steel tubular columns. Based on the comparison between calculated and experimental results of the bending moment-curvature (M — φ) curves and the axial load-bending moment interaction (M — N) curves, it is concluded that the authors' proposed model can quantitatively evaluate the confining effect of steel tube in the columns and predict the experimental results more appropriately than the other models. Furthermore in order to better understand the elasto-plastic flexural behavior of the columns, the influences of the various axial load levels, the material strength ratio of concrete to steel and the diameter thickness ratio of steel tube as well as the strain hardening of steel are investigated by using the proposed stress-strain model.