Some studies on bending response of the stranded cable under free bending and constrained bending

Abstract

Helically wound strands have numerous engineering applications. newlineEach strand of a wire rope consists of a central core as a straight wire newlinesurrounded by a number of wires wound helically in a single layer or newlinemultilayer. In practical applications, stranded cables often impose some newlinetransverse loading or curvature loading such as when ropes run over a sheave newlineor a drum, wind-induced transverse vibration of conductors etc. Such newlinetransversely loaded cables are classified as free bending and constrained newlinebending. Vibration of slack cables comes under the category of free bending newlineand cables running over a drum or bent on a pulley come under the category of constrained bending. Owing to their construction in layers, the bending newlinestiffness of the cable varies according to the tension, deformation, curvature newlineand loading. The need and hence the interest for the prediction of bending newlineresponse of helical wire strands and cable continue, while the prediction itself newlineposes a great challenge. In order to understand the behaviour of such cable newlineassemblies, several factors have to be considered such as the constructional newlinearrangements of the wires, their winding pattern, material combinations, the newlinenature of the contacts at the wire interfaces and the interwire movements or newlineslip at the interfaces. Prediction of cable behavior under bending loads has been newlineattempted using several analytical models. However consideration of all the newlinefactors mentioned earlier makes the problem highly complex. In some newlineinstances, the effect of some of the factors, although locally significant, becomes very negligible in the overall system performance and hence have newlinenot been considered by some researchers. The studies made to predict newlineresponse of cables to bending, are very few. In the literature available, several newlineassumptions have been made to make the predictions simpler. The present newlinework aims at predicting the response of stranded cables subjected to free newlinebending and constrained bending. newline