On the dynamics of taut mooring systems

The dynamics of vertical tauttethers for compliant offshore platforms are assessed using three types of dynamic analysis and the resulting models are compared. An analytic linear model is derived as a basis for comparison with a linear modal analysis as well as with both linear and nonlinear finite element models. It is shown that the linear finite element analysis can predict the behaviour of the continuous tether with adequate accuracy over the frequency range of interest. The finite element model is subsequently used to study the effect of spatial variation of tether tension due to self-weight and square law damping. The validity of equivalent energy dissipative linearization is investigated.