Fatigue life evaluation of high-strength steel wires with multiple corrosion pits based on the TCD

摘要

The stay cable composed of high-strength steel wires is susceptible to external corrosion during service, and multiple pitting damage will occur on the surface of steel wires. For the sake of simplifying the pitting morphology, this paper used artificial notches to simulate corrosion pits, and the fatigue properties of highstrength steel wires with multiple notches were systematically studied. First, fatigue tests of steel wires with multiple pits were performed, and the finite element models were established by ABAQUS software. The fitting equations related to stress concentration factor (SCF) and corrosion pit parameters were obtained. Subsequently, the fatigue life of corroded high-strength steel wires was predicted by the Point method (PM) and the Line method (LM) originated from the Theory of Critical Distances (TCD). Finally, the prediction results compared with the experimental results. The results show that the fatigue life of steel wires with a single pit is mainly related to the pit depth-to-length ratio. The fatigue life of steel wires with double pits located on the same side mainly depends on deeper pits, but it slightly decreases as the increase of the depth of shallow pits. The effect of the spacing of double pits is very small. The fatigue life of steel wires with double pits in the circumferential direction decreases as the angle between the double pits increases. The reliability of the TCD for fatigue evaluation of multi-notch components is verified.