The three-dimensional coupled behavior during the interaction of buoys
with their mooring systems is numerically analyzed. A time-domain mod
el was developed to predict the response of a tethered buoy subject to
hydrodynamic loadings. External loadings include hydrodynamic forces,
tethers tensions, wind loadings and weight. System nonlinearities inc
lude large rotational and translational motions, and non-conservative
fluid loadings. The mooring problem is formulated as a combined nonlin
ear initial-value and two-point-boundary-value problem which is direct
ly integrated both in time and space. Buoy equations of motion are der
ived using small Eulerian angles. Coupling between rotational and tran
slational degrees of freedom is included and coupling between the buoy
and cable is effected by adopting the buoy equations of motion as bou
ndary conditions at one end for the mooring problem. Numerical example
s are provided to validate the formulation and solution technique; pre
dicted responses of three types of buoy (sphere, spar, and disc) are c
ompared with experimental results. Copyright (C) 1997 Elsevier Science
Ltd.