Simulation Methodologies for Fatigue Damage Estimation in Subsea Power Cable Conductors: A Comparative Study

Abstract

The deployment of floating offshore wind systems in deeper waters introduces additional challenges for subsea power cables due to complex mechanical, environmental and operational factors. Among these, ensuring the longevity of cables requires a reliable fatigue damage assessment, which this study addresses by applying a wave fatigue methodology that integrates global and local analyses. Central to this methodology is the Adaptive Hysteresis Model, which transforms global loads into local strain. To evaluate its effectiveness, the methodology is applied to a 400 kV direct current subsea power cable design. Strain parameters from a detailed local analysis are used to transform global loads into local strain, followed by a rainflow counting method to extract the ranges. The identified strain ranges are then evaluated against a fatigue curve to determine the number of cycles to failure and the cumulative damage is calculated using the Miner–Palmgren summation. The study demonstrates the efficiency of the Adaptive Hysteresis Model and highlights the differences between higher-order hysteresis-based and simplified strain transfer methodologies when predicting strain ranges and fatigue damage in higher-order helically laid elements.