Tensile capacity degradation of randomly corroded strands based on a refined numerical model

Abstract

In this study, we develop a sophisticated numerical model to analyze the axial tension behavior of seven-wire steel strands subjected to corrosion by employing the ANSYS finite element software. The axial tensile performance of steel strands subjected to random corrosion is examined, and the model's accuracy is validated by comparing it with experimental results. The corrosion degree in the steel strands is quantified by the mass loss rate χ, which denotes the ratio of the mass lost due to corrosion to the total mass. The reduction factor θ is employed to characterize the diminished axial tensile performance of the steel strands following corrosion. Two corrosion modes under random corrosion in steel strands were proposed, with lower bound formulas for the θ-χ distribution derived for each. In Mode I, the largest corrosion depth is prespecified. Mode II is characterized by destructive cross-sectional corrosion. As the corrosion intensifies, the corrosion pits can expand indefinitely across the wire's cross-section, potentially leading to significant loss or complete corrosion of a section of the steel strand. The finite element analysis indicates that the wire diameter and the corrosion pit depth affect θ-χ. The element size, steel strand length, and lay length have minimal impact.