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

ln two previous papers (Faraggiana. & Rossetti 1989 & 1990) we reported the results of tests on a tension rope. The experimental results of tests on wires (traction, torsion, bending), of static breaking load tests, and of fatigue tests performed on a 12 mm rope, both when it was new and after ten years of use on
ski lifts facilities, were compared. The comparison between the results obtained from the tests on the wires indicated no difference in tensile strength, in the number of bending cycles to failure, or in the torsional ductility of internal wires, though a limited decrease could be observed in the torsional ductility of outer wires. The results of tensile tests on the rope showed no significant difference. As regards the fatigue tests , we found that the endurance of the used rope did not show any appreciable decrease by comparison with the endurance of the new rope when the testing conditions were similar to the service conditions. But if the testing conditions were more severe, then the differences in rope life between the new and the used rope were between 35% and 60%.

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