Numerical and experimental investigations into the mechanical behaviour of compacted stranded copper conductors used in dynamic subsea power cables

• Novel periodic mesh generation method proposed for compacted cable geometry. • The layer-by-layer compaction process is simulated in 3D for comparison with the periodic model. • DIC used to validate FE surface strain prediction. • Multiscale method successfully used to predict the compacted conductor behaviour in a 3-point bending test. This paper proposes a repeated unit cell (RUC) FE modelling strategy for multilayered compacted copper conductors, specifically those used in dynamic subsea power cables, subject to tensile loading and bending with an initial tensile load. A novel periodic compacted conductor mesh creation strategy is presented, utilising 2D compaction models, to allow periodic boundary conditions to be applied to the periodic RUC model. In a separate model the compaction process is directly simulated in 3D to provide validation to the generated periodic compacted conductor model. Both tensile tests and bending tests with an initial tensile load were carried out, where surface strains were measured in the tensile test using both DIC and strain gauges. Both models showed good agreement with the test results in both the elastic and plastic regions of the tensile test and were able to predict the strain measured by the strain gauges. A multiscale modelling approach is proposed whereby the moment-curvature response from the periodic FE model is programmed into a beam element. The periodic FE model is then further validated against bending tests with initial tension showing very good agreement.