Numerical Analysis and Finite Element Simulation of Axial Stiffness of Overhead Transmission Line Conductor

Cables, overhead electrical conductors, and ropes are flexible structural assemblies made out of a central core and number of wires which are twisted together to form a complex helical structure. In the majority, cables are subjected to axial loading primarily, followed by the associated twisting. Depending upon the application, they are additionally loaded in bending also. The mechanical behavior of the cables can be predicted by various mathematical models reported in the literature. The mathematical model can predict the overall global behavior of the cable well. However, the local behavior of the cable must be included to have intricate realistic studies. In this paper, an attempt is made to predict the response of the cable considering all the local effects under axial loading. A core with a single layer of six wires is modelled using the helical rod concept and its mechanical behavior is investigated by means of Finite Element Analysis (FEA). The effect of axial loading on the cable is proposed to be studied as a function of various cable axial strains. The core-wire and the wire-wire contact mode of the cable assembly have been considered with due consideration of the contact forces and the associated frictional effects. The reduction in cable stiffness has been studied under various slip modes. The analytical and FEA results are validated with experimental tests on a single-layered transmission line conductor.