Abstract The fatigue limit state (FLS) of High-Voltage Direct Current (HVDC) cable bundles, in a configuration comprising two main conductors and a smaller fiber optic/earth cable, is investigated in this paper. Firstly, the effect of static tension and sag on the natural frequency of a single span with pinned-pinned end conditions is examined following two approaches recommended by DNV-RP-F105 (2017) and Zhu et al. (2023a), respectively. It is found that Zhu’s model outperforms DNV’s model for very long spans. Secondly, the FLS of a cable bundle is assessed for the lead sheath considering the reduction of VIV response amplitudes and the potential increase of damping ratio. Results show that the fatigue damage of a cable bundle can be significantly reduced when proper values of the VIV response reduction and the increase of damping ratio are considered.
Griffiths et al. (Sun,) studied this question.