On the lawfulness of the application of cumulative damage theory on tension ropes

Technical Meeting SAFETY, ACCEPTANCE AND DISCARD OF WIRE ROPES – Nantes 1991

In two previous papers [1], [2] we reported about the tests on a tension rope : the experimental values of the tests on wires (traction, torsion, bending), of the static breaking Ioad and of the fatigue tests performed on a 12mm rope, when it was new and after ten years of use on skilifts facilities, were compared. The comparison between the results obtained from the tests on the wires indicates no difference in tensile strength, in the number of bendings and in the number of torsions in internal wires, whilst a limited decrease can be observed in the number of torsions of outer wires. The results of traction tests on the rope show no significant difference as regards the fatigue tests, we have found that the endurance of the used rope doesn't show appreciable decrease in comparison with the endurance of the new rope when testing conditions are similar to service conditions. But if the testing conditions are severer, the differences in rope life between the new and the used rope are comprised between 35% and 60%.

Author(s): G. Faraggiana & U. Rossetti