Identification of damage development in the core of steel cord belts with the diagnostic system

Belt conveyors are used for transporting bulk materials over distances. The core of the belt, by transferring the longitudinal stresses and ensuring proper frictional coupling of the belt, enables belt movement and transportation of materials on its surface. As the belt cover and edges are used, the belt becomes abraded, and the core is subject to fatigue. The result is the development of cracks in rubber covers across the belt, which leads to the development of damage not only along the cables (the natural direction of water migration and corrosion) but also in the direction transverse to the belt axis. Conducting a series of scans of the St-type belt operating in one of the underground copper ore mines in Poland allowed identifying the number of failures as well as their size and changes over time. These data were in turn used to determine the measures defining the condition of the belt such as the density of defects (the number of defects per 1 m of the belt), the density of the area of damage (the area of damage per 1 m of the belt) and the change in the average area of a single defect over time. By determining the regression of these measures in time and the rate of damage development in both directions (along the axis of the belt and across the belt), it was possible to forecast future states of the belt, as well as to evaluate the costs of different belt replacement strategies and the economic rationalization of the decision to replace them. This research has become possible owing to the development of the DiagBelt system for two-dimensional imaging of the damage to the core of steel-cord belts with resolution sufficiently high to allow tracking the development of single core defects.