Seismic Behavior of UHPC-Filled Rectangular Steel Tube Columns Incorporating Local Buckling

This paper presents a numerical study on the static behavior and cyclic of UHPC-filled steel tube (UHPCFST) columns. A novel fiber element model is developed based effective distribution width method to consider influence local buckling. The parameters descending branch stress–strain curve constrained concrete have been modified proposed according existing experimental results. Thereafter, impact parameter analysis seismic performance UHPCFST columns under pseudo load conducted, strength UHPC, width–thickness ratio, length–diameter ratio axial compression are considered. results indicate that can accurately predict nonlinear behaviors bearing capacity post-peak ductility be overestimated, such as neglecting buckling tube, which will lead insecurity structures.