Evaluation Methods and Sensitivity Analysis of Corrosion Parameters for Eccentrically Loaded Angle Steel Members

Transmission towers are continuously exposed to corrosive environments, and corrosion of their structural members can significantly reduce the overall load-carrying capacity and stability. In this study, four locally corroded angle steel specimens with single-side connections were fabricated using an electrochemical method. Eccentric compression tests were conducted on these four corroded specimens together with two uncorroded reference specimens. The failure modes, load–displacement curves, and load–strain responses of the corroded specimens were systematically analyzed. It was observed that the strain in the compression leg exceeded that in the free leg. A finite element model, validated against experimental results, was employed for a parametric study to investigate the effects of the spacing between two corrosion regions, their respective relative corrosion depths, and corrosion areas on the degradation rate of load-carrying capacity. Based on the observed influence patterns of these corrosion parameters, an assessment method for capacity degradation under a “dual corrosion region” configuration was developed, accounting for three scenarios: corrosion on the compression leg, the free leg, or both sides simultaneously. This method comprehensively captures realistic corrosion characteristics and demonstrates improved rationality and accuracy. Finally, a sensitivity analysis was performed using the proposed assessment approach, examining key parameters including section corrosion ratio, corrosion area, corrosion location, and slenderness ratio. The results indicate that, under the dual corrosion region condition, the section corrosion ratio is the most dominant factor influencing the capacity degradation rate.