Effect of fatigue load on the bending tribo-corrosion-fatigue behaviors between the main cable wires

The main cable bent around the saddle of the suspension bridge is subjected to the wind,the vehicle,the bridge’s own weight and the corrosive media.The coupling of the three loads and the environments causes the friction,the corrosion,and the fatigue(tribo-corrosion-fatigue)among the wires inside the main cable.In this paper,a wire bending tribo-corrosion-fatigue test rig was designed and developed.The effect of fatigue load on the bending friction behaviors between the cable wires in ultrapure water and 3.5%NaCl solution was explored.The tribological properties and electrochemical corrosion behaviors under different fatigue loading ranges were investigated.The tribo-corrosion-fatigue interaction between the cable wires was quantitatively characterized,and the mechanism of the interaction was analyzed.The results demonstrate that the increasing fatigue load exacerbates the coupling damage of the cable wires attributed to the enhanced interaction.The findings carry theoretical importance when assessing the main cable’s deterioration and the load-bearing safety of a suspension bridge.

Tribo-corrosion interaction of the parallel steel wires in the suspension bridges

The effect of contact load and relative displacement on tribo-corrosion interaction of parallel steel wires of main cable in the suspension bridge was investigated in this study.A self-made tribo-corrosion test bench was employed to conduct tribo-corrosion tests of parallel steel wires in 3.5%(wt%)NaCl solution and deionized water under different contact loads and different relative displacements.The friction coefficient and wear coefficient of wires were presented.Electrochemical corrosion behavior(Tafel polarization curves,Nyquist diagram,and equivalent circuit diagram)was characterized by electrochemical analyzer.Wear morphology was observed by scanning electron microscope.Wear volume loss and corrosion‒wear interaction were quantitatively demonstrated by high-precision weighing balance.The results show that the electrochemical corrosion ability of the steel wires increases with the increase of the contact load or relative displacement.The increased contact load or relative displacement increases the volume loss of corrosion‒wear and pure wear,but decreases the wear coefficient.The wear mechanisms in 3.5%NaCl solution are adhesive wear,abrasive wear,and corrosive wear as compared to adhesive wear and abrasive wear in deionized water under different contact loads.The wear mechanisms of parallel steel wires are slightly different under different relative displacements.But the main wear mechanisms are similar to that under different contact loads.The interaction effects of corrosion and wear produced by the contact load and relative displacement are all the synergistic effects.