A method for analyzing the static response of submerged rope systems based on a finite element method

Abstract

A method is presented for determining the equilibrium configuration and tensions of submerged rope systems in a uniform current based on a non-linear finite element formulation. A standard straight rope element is adopted to model rope segments of the system. Rope stretch is included in the formulation, and a hydrodynamic model is introduced for the rope. The structural and hydrodynamic models are coupled in order to account for the interaction between the structural response and hydrodynamic load acting on the rope itself. The Newton-Raphson method is employed in the formulation, ensuring the global convergence of the iteration to the correct response (and hence to the correct equilibrium configuration and tension of the rope system) from any set of initially estimated responses. Good agreement between this numerical simulation and experimental behavior was revealed in an application of this method to a long-line model.