Abstract:
In order to study the seismic performance of corroded box-shaped steel frame columns, accelerated corrosion and a quasi-static test were carried out on nine specimens of box steel columns. The influences of the corrosion degree, axial compression ratio and width-to-thickness ratio on the seismic performance of the columns were analyzed. The parametric analysis was carried out using numerical simulation to study the plastic development of the bottom section of the columns, and the calculation formula for the remaining ultimate moment-carrying capacity of the corroded steel column was obtained by regression. The results show that the failure mode of all specimens is mainly local buckling at the bottom of the column. However, the increase in corrosion, excessive axial compression ratio and reduction in plate thickness will accelerate the local buckling of the plate at the bottom of the column and limit the plastic development and plastic deformation capacity of the column bottom, which may result in the deterioration of the bearing capacity, deformation capacity and energy-consuming capacity. The prediction results obtained by using the formulae for the calculation of the residual ultimate moment bearing capacity of the corroded columns proposed through regression analysis and the results of the experimental and numerical analyses are in high agreement.