Fatigue resistance of steel ropes: failure criterion: Background to the verification in prEN 1993‐1‐11:2020

Abstract

Many steel rope systems are subjected to fluctuating tensile loads and therefore can fail due to fatigue. Available fatigue test data indicate that rope diameter, mean stress, socket type, lay angle and rope length influence the fatigue resistance. Most of the tests were terminated before full failure of the ropes. This paper shows that the test termination criterion, such as fracture of the first wire, fracture of 5 % of the wires or full rope fracture, has a large influence on the resulting fatigue resistance. A probabilistic analysis is carried out for a rope system in a bridge, demonstrating that the required structural reliability levels are met when considering full failure as the end‐of‐life criterion for ropes.

S‐N curve for full‐locked coil ropes: Background to the verification in prEN 1993‐1‐11:2020

“…-The tests were terminated after different criteria, namely, a cross-section loss between 1 % and 100 % of the full cross-section. The accompanying paper [3] shows the significance of this parameter.…”

“…Most fatigue evaluations of rope systems are based on tests on spiral strand ropes and stranded ropes [3]. The construction of full-locked coil ropes is different from that of spiral strand ropes and stranded ropes, and this may affect the fatigue resistance.…”

“…An increase in rope diameter appears to result in a decrease in the fatigue resistance [3]. Therefore, the fatigue data collected here cover large diameter ropes only.…”

“…The evaluation of the fatigue resistance in the following is based on fatigue failure of the full rope. The accompanying paper [3] demonstrates that an S-N curve derived for full rope failure satisfies the reliability required by EN 1990 [19]. In order to use the test data in conjunction with the termination criterion for failure of the full rope, a model is applied here to extrapolate the test data.…”

“…The current paper provides background to the fatigue resistance of ropes in [2]. It is closely linked to an accompanying paper [3] describing the termination criterion that fulfils the reliability requirements.…”