Research on dynamic characteristics analysis and configuration optimisation of underwater umbilical cable based on OrcaFlex

The subsea configuration of umbilical cables critically governs structural integrity and operational economy, being significantly influenced by intrinsic kinematic properties and complex marine environmental loading. To select the appropriate configuration, an investigation employing OrcaFlex's nonlinear finite-element solver is conducted to analyse dynamic responses and stress states of the umbilical cable discretised with 3D catenary beam elements. To reasonably account for environmental impacts, the Morison hydrodynamic model and seabed contact friction algorithms are integrated into the finite element calculations. Analysis reveals that at 1750m water depth over soft clay seabed conditions, a lazy wave configuration delivers superior performance for 260 mm composite umbilicals with 300 kN pre-tension. This significantly reduces fatigue damage risk and enhances economic benefit. The conclusion provides a rigorous theoretical basis for umbilical design, selection criteria, and integrity management protocols.