STEEL WIRE ROPE SLING BREAKING LOAD REDUCTION DUE TO BENDING

Summary

A study has been performed to understand the behaviour of steel wire rope slings bent over small radii pins. The actual breaking load was obtained from tests on small and full-scale rope slings at rather low 𝐷/𝑑 ratios and compared with the sling capacity reduction factors prescribed by the guidelines in codes and regulations for lifting operations. Furthermore, the driving factors for the reduction of the sling strength due to forced bending have been studied with an analytical model. 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 the sling strength reduction factor depends, in addition to the 𝐷/𝑑 ratio, 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.

Author(s): H.I. Ivanov, N.S. Ermolaeva, J. Breukels, B.C. de Jong, P.A. de Vries and P.C. Meijers