Confinement effectiveness of circular concrete-filled steel tubular columns under axial compression

In this paper, a large database of 491 test results of circular concrete-filled steel tube (CFT) columns under axial compression was collected from the available literature. The collected results were employed to investigate the effects of loading conditions, diameter-to-thickness ratio, concrete type and compressive strength on the load-carrying capacity of CFT columns, from which models for the hoop stress of steel tubes are obtained through nonlinear regression analyses. Based on the von Mises yield criterion together with the proposed hoop stress models, a model for predicting the load-carrying capacity of CFT columns was developed. The performances of the proposed model and the existing models were evaluated using the database. Due to the rationality of the model development process, the proposed model offers a more reasonable and accurate prediction of load-carrying capacity for CFT columns under various loading conditions.