Performance degradations of the vibration-worn wire ropes under different service states in mines

[Display omitted] •The evolutions of mechanical properties of the vibration-worn wire rope were obtained through experiments.•The fracture failure mechanisms of the vibration-worn wire ropes under different stress states were revealed.•The mineral dust has little effect on the mechanical properties of the wire rope in the state of full lubrication.•The fracture mechanism of the steel wire at the action of tensile load is microporous aggregation fracture. The service environment of multilayer winding wire rope in mine hoists is complex and harsh, and working conditions such as poor lubrication and mineral dust pollution are inevitable. The harsh environment promotes the friction damage of the winding wire rope, coupled with the vibration effect, and eventually causes the rapid degradation of its mechanical properties. The relationships between the vibration conditions, lubricating state and mineral dust environment and the performance degradation of vibration-worn wire ropes were explored experimentally, and the fracture failure mechanisms under different stress states were revealed. It was found that the wire rope mainly undergoes the stages of structural deformation, elastic deformation, plastic deformation, localized necking plastic deformation and fracture under tensile loading, necking appears in the stage of localized necking plastic deformation, and the fracture of the steel wire has the cup-cone shape. Additionally, the bending fatigue fracture of steel wires is a process of cumulative deterioration. The evolution of the high-risk region of bending fatigue broken wires for the vibration-worn wire rope in the state of dry friction is initially concentrated in the wear region, and then dispersed in the strand-strand bending extrusion region and the region subjected to relatively large tensile-bending coupling stress. The breaking force decreases by 6.03 % and the number of bends when the wire rope reaches the scrap standard decreases by 11.29%, as the lubricating state of the wire rope changes from full lubrication to dry friction. Mineral dust has little influence on the service performance of wire rope in the state of full lubrication. Furthermore, the microporous aggregation fracture occurs for the steel wire under tensile loading, whereas the bending fatigue fracture mechanism of the steel wire is brittle fracture, the fatigue source zone is transferred to the wear surface or subsurface, and crack propagation is accelerated for the worn steel wire