Article,
Free Bending Fatigue Prediction of Steel Cables with the Effect of lnterwire Fretting Taken into Account
(1994)
Abstract
The importance of design against free bending fatigue at the points of fixity to
steel cables used in various applications is emphasized. It is suggested that there is a pressing
need for re-examination of the traditional extreme fibre stress (or strain) approaches.
Based on the newly proposed theoretical model, the present paper reports the final formulations
from an extensive series of theoretical parameteric studies on a number of realistic strand
constructions with widely different cable (and wire) diameters and lay angles.
A straightforward method for design against free bending fatigue, aimed at practising engineers,
which takes interwire/interlayer fretting fully into account, is presented. The proposed
design method is amenable to hand calculations using a pocket calculator.
The significant shortcomings of certain previously reported twin-wire fretting experiments
aimed at predicting and/or improving steel cable fatigue life is discussed. It is suggested that
realistic fretting fatigue tests on single or twin wires should be carried out under the modes of
deformation representing those operative inside the cables.
