Three-dimensional representative modelling for fretting wear and fatigue of submarine power cable conductors

Submarine power cables (SPCs) for floating offshore wind turbines (FOWT) have received relatively little attention compared to the structural design of wind turbines. This is particularly true for the assessment of fretting-related damage in multi-strand copper wire conductors, due to the complexity of the contact interactions and potentially severe dynamic loading. In this paper, a three-dimensional representative crossed cylinder methodology is introduced to identify potential inter-wire fretting damage. The approach is based on a global–local methodology for FOWTs. Fretting wear testing of crossed cylinder copper specimens are used to characterise the friction and wear behaviour and validate the local fretting wear simulation. A multiaxial wear-fatigue methodology is implemented in conjunction with the global–local methodology for prediction of effects of normal operating and extreme floating wind SPC design load cases. It is shown that gross slip wear has a beneficial effect on predicted fatigue life by about two to three orders of magnitude. The work demonstrates a global–local modelling methodology for design of SPC conductors in floating wind applications.