Fatigue Performance of Pre-Corroded Bridge Wires

Abstract

<p>Corroded high-strength bridge wires on three corrosion levels were produced from the accelerated corrosion experiment. The uniform corrosion depth was calculated and the zinc coating was totally consumed for all the specimens. Three-dimensional (3D) profile measurements of the wires without destruction were conducted after the corrosion products were removed by the chemical cleaning. Based on the 3D coordinates of the points on the surface, it was found that the pitting depth followed the normal distribution. The corrosion depth contours and the maximum pitting depth of each specimen were also obtained from the data.</p> <p>Fatigue tests were conducted to investigate the fatigue properties of the corroded wire specimens and significant decrease in fatigue life of corroded wires was observed. A modified fatigue crack growth model considering the fatigue threshold was used for fatigue life prediction of the wire specimens. The material constants used in the model were fitted according to the most relevant tests. The results showed that fatigue lives predicted by the model were compared well against the experimental results as the largest error of the life predictions is within 36% of the experimental lives. The life prediction method based on the model and 3D profile is a valuable tool for assessing remaining fatigue life of corroded bridge wires without destruction and expensive fatigue tests.</p>