Dynamic response of buoy-assisted shared-mooring spar arrays with correlation-based synchronization analysis

Shared mooring systems can reduce anchor demand in floating wind arrays, but their interconnected dynamics may produce platform-dependent motions and line loads. This study investigates a 3×3 spar array with catenary and taut shared-mooring configurations and buoy-assisted catenary lines with float attachment intervals of 10–100 m. OrcaFlex simulations evaluated platform motions, fairlead tensions, power spectral densities, and lagged cross-correlation. Model consistency was checked through free-decay, transient-load, and numerical-sensitivity analyses. The taut configuration reduced the mean surge-offset magnitudes of Spar5 and Spar6 but increased the inward offset of Spar4, while increasing mean fairlead tensions by 19–39% in anchor lines and 30–38% in shared lines. The 10 m interval provided the greatest reduction in mean and 1-h finite-record maximum tensions, but increased shared-line dynamic variability. Taut mooring generally increased the peak lagged-correlation coefficient and reduced the magnitude of the corresponding peak time lag, whereas float-interval effects remained platform-pair dependent. Under the investigated normal-operation condition, the results indicate that shared-mooring assessment should consider platform-specific offsets, line loads, dynamic variability, and pairwise response transmission.