UHPC-Filled Rectangular Steel Tubular Beam–Column: Numerical Study and Design

Abstract

This paper presents a numerical study on the nonlinear behaviors of UHPC-filled square steel tubular (UHPCFST) columns under complex actions. A novel fiber model was developed considering the local buckling effects of steel tubes. The reliability and robustness of the model were validated by a large amount of experimental data in the reported literature. Then, the current design codes were evaluated and discussed on the basis of the collected experimental data, and a practical calculation method was finally proposed to predict the bending moment capacities of UHPCFST beam–columns. The results indicate that the proposed fiber model can accurately predict the nonlinear behaviors of UHPCFST beam–columns, including axial compression, eccentric compression, pure bending, and hysteretic behaviors. Compared with current design codes, the practical calculation method presents high precision and can accurately predict the bending moment capacities of UHPCFST beam–columns.