Nonlinear Analysis on the Static and Cyclic Behaviors of UHPC Filled Rectangular Steel Tube Columns

In this paper, a fiber-based computational model is developed for the nonlinear analysis on the static and cyclic behaviors of ultra-high performance concrete filled rectangular steel tube (UHPCFST) columns. In the computational framework, a simplified compressive constitutive model of UHPC confined by rectangular steel tubes is firstly proposed based on available experimental data. Then, two approaches are adopted for considering the local buckling of steel tubes. The second-order as well as the material nonlinearity are also taken into account. Finally, comparative analyses between the predicted and experimental results of the UHPCFST columns are undertaken to verify the robustness and reliability of the fiber-based model. It is shown that the developed fiber-based modeling technique can predict the structural performance of UHPCFST columns with good satisfaction.