Assessment for the service life of cable wire under corrosion fatigue coupling effect in extreme marine environment

With the widespread application of cable-stayed bridges, the issues of cable failure caused by atmospheric corrosion and vehicle alternating loads have received increasing attention. In the typical tropical marine environment, this failure is especially early to occur. To determine the service time in this condition, a simulation method for evaluating the service life of hot-dip galvanized steel wire and cable is proposed in a broad sense. The full lifecycle is divided into two stages: before crack propagation and after crack propagation. Therefore, the whole model includes model I and model II. The enhancement factor of fatigue on corrosion is obtained based on previous research for the model I. The enhancement factor of corrosion on fatigue is added into the paris formula for the model Ⅱ. Cellular automaton is used to simulate the corrosion developments of single steel and cable, verifying the accuracy of model I. Comparison of load cycle times calculated from model Ⅱ and the corrosion fatigue tests conducted by others before indicate that this model Ⅱ has accuracy over 90%. The novel fatigue life simulation of the cable is also completed by quantifying the progression relationship between corrosion and crack propagation, which has not been involved before.