Effect of bending on steel wire rope sling breaking load: Modelling and experimental insights

Abstract

Behaviour of steel wire rope slings when they are bent over small diameter rigid bodies, e.g. pins, has been studied to determine the reduction of the slings’ static strength due to bending. For this purpose, the Papailiou model was extended by adding plasticity in the material behaviour and expanding the friction model from a single layer strand to multiple layers and multiple strands. It was shown that in addition to the diameter ratio, the sling bending strength reduction factor depends on the friction between the wires in the rope and the geometry of the rope, namely the lay angle and the number of wires in the rope. The actual breaking load was obtained from experiments on small and full-scale rope slings at rather low ratios of the pin to rope diameter and compared with modelling results and the sling capacity reduction factor associated with bending prescribed by guidelines for lifting operations.