Experimental and numerical investigations on residual axial compressive behavior of circular CFST columns with corrosion defects after lateral impact

Offshore and water-crossing concrete-filled steel tubular (CFST) structures regularly encounter environmental corrosion and mechanical impact risks over their service life. However, the residual load-carrying performance of CFST structures under the combined action of corrosion and impact has been rarely investigated. In response, the present study experimentally examines the residual axial compressive behaviour of corrosion defects circular CFST members following lateral impact. Moreover, a detailed finite element (FE) model is developed to incorporate the lateral impact and random distribution of corrosion defects. The effect of key parameters, such as the corrosion ratio and impact residual deflection, on the residual axial load-carrying performance and deformation behaviour of corrosion defects circular CFST columns following lateral impact is comprehensively examined. The typical failure modes and damage evolution are clarified. Furthermore, a computational approach for predicting the residual axial load-carrying performance of circular CFST columns with corrosion defects following lateral impact is developed. The results reveal that the existence and escalation of corrosion defects markedly magnify the lateral deformation and extent of deterioration in circular CFST columns under identical lateral impact energy, thereby diminishing their residual axial compressive resistance. The findings of this research are anticipated to offer a theoretical foundation for evaluating the residual load-bearing capability of CFST structures with corrosion defects following lateral impact.