For a single mooring cable, the effect of current and seabed friction on mooring-cable tension and energy dissipation are studied in both the time domain and the frequency domain. In the time domain, all nonlinearities can be taken into account. In the frequency domain, the nonlinear drag forces can be linearized either by a direct integration method or by statistical linearization techniques; for sea-floor effects, a simple lumped stiffness model and the statistical linearization method based on friction-controlled slip are combined. Two example structures, one flexible riser and one deep water mooring, are analysed. The time-domain and frequency-domain results compare well. The findings of the effects of current and friction on mooring-cable responses are discussed, they show that the linearized frequency-domain solution can produce satisfactory results. (C) 1997 Elsevier Science Ltd.
