Tribo-corrosion-fatigue Behaviors of Suspension Bridge Cable Wires in Contact with the Saddle Material

The coupling effect of dead load, vehicle load, wind load and corrosive environment causes the tribo-corrosion-fatigue behaviors between the main cable wires and the saddle material on both sides of main saddle of long-span multi-tower suspension bridge. The tribo-corrosion-fatigue behaviors lead to the gradual deterioration of the load-bearing strength of the wire, which seriously affects the load-bearing safety of the main cable. Therefore, it is very important to study the tribo-corrosion-fatigue behavior between main cable wire and saddle material. The wear profile, wear mechanism, wear coefficient and cross-sectional failure area characteristics of the main cable wire are investigated by ultra-depth electron microscope and scanning electron microscope. The evolution model of wire damage degree and the deterioration model of wire bearing strength are established through the universal testing machine combined with the theory of damage mechanics and finite element method. The results show that the friction coefficient presents a rapid increase - decrease - increase - stabilization trend, decreases with the increasing contact load and increases with the increasing fatigue load. The wire wear profile increases approximately linearly with the fatigue cycles, the failure area increases approximately parabolically with the fatigue cycles, both of them increase with the increase of the contact load and the fatigue load. The wear coefficient decreases in the stable wear period and increases slightly with the increasing fatigue cycles. The wear mechanisms are mainly adhesive wear, abrasive wear, fatigue wear and corrosion wear. There is a good quadratic function relationship between the wire damage degree and the fatigue cycles. The increasing contact load and fatigue load increase the wire damage and decrease the load-bearing strength. The results have theoretical significance for the evaluation of main cable damage and load-bearing safety performance of suspension bridge. © 2023 Editorial Office of Chinese Journal of Mechanical Engineering. All rights reserved.