A variational approach for three-dimensional model of extensible marine cables with specified top tension

This paper presents a variational model formulation that can be used for analyzing the three-dimensional steady-state behavior of an extensible marine cable. The virtual work-energy functional, which involves virtual strain energy due to a cable stretching, and virtual works done by the gravitational, inertial and external drag forces, is formulated. Euler-Lagrange's equations, obtained by considering the first variation of the functional, are identical to those obtained by equilibrating forces on a cable infinitesimal segment. Two mathematical simulations, namely, the finite element method and the shooting-optimization technique, are employed to solve and evaluate the problems. The numerical investigations are carried out for the case of a specified end tension, whereas the specified cable unstrained length case can be applied in the algorithm procedure. The validity of the present model and the influence of various geometrical parameters on the cable equilibrium configuration are demonstrated. The effects of cable extensibility and the omnidirectionality of current actions are presented and discussed. (C) 2003 Elsevier Inc. All rights reserved.