Large Displacement Mooring Dynamics

Abstract

Dynamic analysis procedures are presented for predicting the behaviour of cable moored systems used to restrain floating or submerged structures where the excitation is such that the motions are large and the response non-linear. The mathematical models used incorporate discrete parameter representation and numerical solution methods. Both a linear and non-linear dynamic analysis procedure is demonstrated through application to a trapezoidal moor, containing a large cylindrical inclusion. Results are developed through an integrated use of static, non-linear, and linear dynamic analysis procedures which the discrete parameter representation makes possible; and a procedure discussed for determining the necessity of using a full dynamic vs. quasi-dynamic analysis when the mooring excitation is due to a slowly varying cause as results from changing ocean currents.