Experimental study on the axial compression behavior of circular steel tube short columns under coastal environmental corrosion

This study adopts experimental, numerical, and algorithmic methods to investigate the compressive behavior and failure mode of corroded circular steel tube short columns. The study establishes an equivalent relationship between electrochemical accelerated corrosion and natural coastal corrosion environments. The effects of current intensity, sodium chloride concentration, and energizing time on corrosion equivalent duration and mechanical properties of specimens are analyzed. The results demonstrate that the ultimate bearing capacity and energy absorption capacity of the specimens are significantly reduced with increasing current intensity and energized time. However, the NaCl concentration has minimal effect on the mechanical properties of the specimens. After natural corrosion in a coastal area with medium salinity for 19.2 years, the ultimate bearing capacity, ductility, initial stiffness, and energy absorption capacity of circular steel tube short columns decreased by 49.5%, 63.1%, 48.9%, and 85.6%, respectively. A novel corrosion pit generation algorithm is suggested to accurately simulate the distribution of corrosion pits and determine the ultimate bearing capacity of circular steel tube short columns. This algorithm demonstrates improved accuracy and stability compared to traditional simplified methods. Subsequently, a corrosion pit random generation model is developed using this method, and the accuracy of the finite element model is validated against experimental results. Furthermore, the impact of the diameter thickness ratio on the ultimate bearing capacity of corrosion specimens is thoroughly analyzed.