Experimental Study on Corrosion-Fretting Fatigue Behavior of Bridge Cable Wires

Bridge cables are often subjected to tensile stress variation, interior contact stress, and corrosion environment, resulting in premature failure of wires. This paper experimentally investigates the behavior of bridge wires under the coupled action of corrosion, fretting, and fatigue. A corrosion-fretting fatigue test system was developed, and its working principle and test method were introduced. Corrosion-fretting fatigue tests and comparison tests of cable wires with different test parameters were conducted based on the proposed test system. Damage process, fracture mechanism, friction coefficient, and lifetime of wires were further investigated. It is observed that the failure originated from micro surface cracks at the trailing edges due to morphology irregularity and tear stress. The crack propagation was dependent on the friction angle that affected the stress distribution in the contact area. During corrosion-fretting fatigue tests, corrosion facilitated the wear through damaging the wire surface and inner micro structure, and simultaneously fretting fatigue accelerated corrosion via promoting the contact between corrosive media and wires. Thus, the coupling scar can be even deeper than the sum of the fretting fatigue scar and corrosion pit. Larger friction angle and corrosion current aggravated failure and decreased the lifetime of wires.