Vortex-Induced Vibration and Fatigue Characteristics Analysis of Submarine Power Cable Based on Model Similarity Theory

In recent years, there have been numerous failures in submarine power cables caused by seawater erosion. Vortex-induced vibration is the main cause of fatigue damage or breakage in submarine power cables. In this paper, model similarity theory was introduced into finite element modeling of submarine power cable for the first time, which dramatically reduced the amount of model calculation. The resonance frequency, amplitude and corresponding flow rate were determined and the stress distribution was analyzed of submarine power cable with different length-to-diameter ratios by acoustics modal and harmonic response. A relationship equation between fatigue life and length-to-diameter ratio was established. The results show that the resonance frequency ranges from 2.651 to 6.633 Hz and the resonance amplitude was 0.64 times the cable diameter when the 110 kV submarine power cable had a length-to-diameter ratio between 70 and 110. The fatigue life was a power function of different length-to-diameter ratios. This research overcomes the difficulties of conducting physical tests and full-scale modeling of vortex-induced vibration of submarine power cable. It provides a viable method and data support for the characterization and fatigue analysis of vortex-induced vibration of submarine power cable.