Behavior of CFRP confined circular CFST columns reinforced with internal latticed steel angles under seismic loading

Abstract

This paper investigated the hysteretic behavior of CFRP confined concrete-filled steel tube (CFST) reinforced with internal latticed steel angles. The parameters studied were the diameter-to-thickness ratio, the CFRP wrapping layers and the axial compression ratio. The failure modes, hysteretic curves, skeleton curves, stiffness degradation, ductility and energy dissipation capacity were presented and discussed. Experimental results revealed that the ultimate load and drift capacity increased by 18.8% and 33.5% when the plastic hinge region was confined by CFRP, all specimens failed due to the compression-bending failure in the plastic hinge region. Moreover, the CFRP can significantly improve the energy dissipation capacity under higher axial compression ratios. After testing, the developed finite element model was also used to perform parameter analysis, with a total of 53 specimens analyzed, and based on the parameter analysis results, the design equation for the drift capacity was proposed.