Seismic behaviour and modelling of reinforced concrete-filled galvanized corrugated steel tubes

Reinforced concrete-filled galvanized corrugated steel tube, named reinforced CFCST, is an innovative composite member commonly used in seismically active regions and corrosive environments. The seismic behaviour of reinforced CFCST under quasi-static tests had been performed in the past. However, a robust numerical model to simulate the seismic behaviour of reinforced CFCST has not been conducted. This paper proposes a finite element (FE) model capable of simulating the seismic behaviour of reinforced CFCST. The responses of the FE model, in terms of failure modes, hysteretic curves, and local strain distributions, are compared with the corresponding experimental results. Based on the validated FE model, detailed parametric studies have been conducted to investigate the effects of axial compression ratio, length-to-diameter ratio, diameter-to-thickness ratio, steel bar ratio, and material strengths. Finally, simplified design equations capable of predicting the nominal hoop stresses of the corrugated steel tube (CST) and the compression-bending strength of reinforced CFCST are proposed.