Abstract Summary
Submarine power cables are considered lifelines in wind farm engineering, playing a key role in transporting electric current produced by wind turbines or wave converter. Cables inevitably confront combined loadings in deep-sea areas, affecting the integrity and safety during their installation and application. Helical wires have been used in flexible structures like flexible pipes, umbilicals and submarine power cables for a long history. The cross section of a helical wire could differ from round to rectangular, which affects the mechanical behaviour of the wire itself, influences the behaviour of the helical layer, and finally causes a different overall response of a flexible structure. This paper represents a model based on periodic boundary conditions in order to investigate this phenomenon. This model makes as less assumptions as possible, capturing the contact and stick-slip behaviour among each component more efficiently than a full finite element model. It also considers the mechanical behaviour of the other layers under tension and bending, including their plasticity. The results from the model are verified with a few analytical models considering different wire cross section. Finally, a series of sensitivity studies are given to investigate the influence of winding angle, pith length and wire radius through the proposed model. The research results will benefit the cable/umbilical/flexible pipe designers.
