Predictive model for fatigue life in parallel-wire stay cables considering corrosion variability

This study quantitatively assessed the influence of corrosion and its variability on the stay cable fatigue life. The corrosion-life inverse equal rank assumption is proposed to identify the order of wire failures, with the wires with the largest level of corrosion failing first. Recursion formulas of stay cable fatigue life are established based on models of the evolution of fatigue damage for multi-step loading, assuming the loading redistribution after the failure of each wire. The bounds for the cumulative distribution function for stay cable fatigue life are estimated using order statistics, and Monte Carlo simulation is conducted to simulate the stay cable fatigue failure. As the variability in the corrosion of the wires increases, the variability in the fatigue life of the wires and stay cables increases, resulting in a decrease in the stay cable fatigue life. The stay cable fatigue life decreases sharply with the increase in the corrosion degree of the wires, with the effect being more pronounced for larger corrosion variability. Moreover, the effect of the corrosion variability on the stay cable fatigue life is much significant for larger corrosion levels and under lower stress ranges.