Residual life prediction and design correction method of corroded circular steel tubes based on time-varying reliability

Current research on the effects of corrosion on the safety of steel members is primarily focused on the degradation of the ultimate bearing capacity, and there is a lack of research on the reliability-based service life assessment. In this paper, a modified reliability function and an uncertainty model for each parameter considering the effects of corrosion are established based on the reliability analysis method of the GB5 0068-201 8 design specification. The effects of the corrosive environment category, wall thickness, and slenderness ratio on the time-varying reliability of axially compressed round tubes are analyzed. The results indicate that an increase in the corrosion duration and the environmental category can cause a decrease in the reliability index of the component, and the smaller the wall thickness, the faster the corrosion-related degradation of the reliability index. However, with the increase of the slenderness ratio, the corrosion-related degradation of the reliability index gradually decreases. In the end, a residual life prediction method and a design correction method for corroded components based on the reliability index are proposed. Moreover, the values of the corrosion life and corrosion coefficient of circular steel tubes for different environmental categories, slenderness ratios, and thicknesses are determined. This paper provides a technical reference for the residual life prediction and full life design of round steel tubes considering local corrosion. Copyright (c) 2024 by The Hong Kong Institute of Steel Construction. All rights reserved.