Experimental study on seismic behavior of prefabricated self-centering concrete-filled square steel tubular frame with slotted energy-dissipating plates
A prefabricated self-centering concrete-filled square steel tubular frame(PSC-CFSTF)with slotted energy-dissipating plates was proposed to address the issue of the conflict between energy-dissipation and self-centering capacity.In the new solution,post-tensioned strands are independently arranged in every span for facilitating construction.Low-cycle loading tests were carried out on 1/2-scale four single-span two-story specimens considering different thicknesses of energy-dissipating plates and loading histories,followed by theoretical analysis considering frame-expansion effects.The results demonstrate that the hysteresis curve of PSC-CFSTF exhibits a typical double flag shape and the residual drift of all specimens is approximately 0.20%after being loaded to 2.0%story drift.Damage is only found in the replaceable energy-dissipating plates while the structural components remain usable.Besides,restoration is confirmed at 2.0%story drift with favorable damage-control ability and resilience.Reducing the width of bars but keeping same section area can increase the recentering ability while maintaining the same strength.Frame expansion leads to larger axial force in the beam and different shear forces of the column bases.Moreover,the proposed mechanical model can well predict the axial force in beams and strands,and errors is less than 10%,which can facilitate structural design.