Effect of degradation and impaired quality on wire rope bending over sheave fatigue endurance

This paper reports the outcome of a series of teats undertaken on six stran d and multi-strand ropes to investigate the effects of degradation and impa ired quality on the repels Bending-over-Sheave (BoS) fatigue endurance. The stimulated degradation and quality impairment investigated were: wire brea ks (internal and external); plastic wear, abrasive weal, corrosion, slack s trands, slack wires and torsional imbalance. Theoretical predictions of rop e fatigue endurance have been made to compare with the experimental values, using Feyrer's equation. The investigation indicates that the bending over sheave fatigue endurance of rope is little influenced by degradation and i mpaired quality, which is primarily dependent on the rope construction and the diameter ratio of sheave to rope. The study establishes methodologies f or assessment of the residual BoS fatigue endurance of degraded or impaired rope, which can inform the practical operation, inspection and discard of wire rope thereby enhancing safety. (C) 2001 Elsevier Science Ltd. All righ ts reserved.