An Efficient Approach for Modelling Dynamic Torsional Behavior of a Complex Marine Power Cable

Abstract

Dynamic power cables (DPC) are a common, yet complex component used in offshore renewable energy systems such as floating offshore wind farms/turbines. However, their dynamic torsional behavior has not yet been contemplated. Hence, this paper develops an effective numerical approach using a simplified, scaled-down finite element (FE) model to predict the dynamic torsional behavior of a 24 kV dynamic power cable, thus addressing the scarcity of torsion-focused FE studies. This work is the first study to develop a FE model for this specific type of innovative cable design introduced by Nordiske Kabel og Traadfabriker (NKT). Exclusive torsion and traction data are acquired in this work to validate and calibrate the numerical model. These datasets can also serve as references for cable designers and engineers to validate, benchmark, or develop their own FE models. The objective of the study is determine the torsional stiffness of the cable, a critical mechanical property required during the early design stage. The FE model was developed in ABAQUS software and calibrated through experimental traction and torsion testing performed at Université Gustave Eiffel in France. The numerical domain was reduced to a representative section of the cable, enabling efficient modelling while preserving the dominant mechanical interactions and physics. To ensure validity of the developed model, its results were compared with both experimental data and analytical stress calculations which revealed good agreement across all approaches. The study demonstrates that accurate contact modelling is crucial and that a simplified FE approach can be employed in the initial stages as a cost and time-efficient alternative to experimental testing for prediction of torsional characteristics of DPCs. Methodologies for further reduction of the computational domain is currently under investigation.