Suggested new element reference frame for dynamic analysis of marine cables

Abstract

The dynamics of marine cables are efficiently expressed using the lumped-mass model, which divides the cable into finite elements, on each of which a reference frame is fixed in order to convert loads acting on the element. This paper proposes a new element reference frame that is formulated by the vectors of the element orientation and relative velocity of the fluid. This frame satisfactorily addresses situations wherein singularities are generated by the Frenet frame and Euler angles. Additionally, it expresses the hydrodynamic drag force in a concise formulation. The advantages of the proposed frame are demonstrated by comparing the established cable modeling with that established by the Frenet frame and Euler angles in several examples. Simulation results reveal that the proposed frame is more suitable for dynamic analysis of marine cables compared with the Frenet frame and Euler angles.