Dynamic modeling of a radially multilayered tether cable for a remotely-operated underwater vehicle (ROV) based on the absolute nodal coordinate formulation (ANCF)

Abstract

This research is aimed at the accurate modeling of an ROV's tether cable with a radially multilayered circular cross-section. In the coupled motion analysis of an ROV-tether system, dynamic modeling of a numerical tether continuum, which can accurately reproduce the nonlinear motion behavior of a flexible cable, is crucial since the tether motion greatly affects the ROV's stability. To this end, a new tether cable element based on the multilayered modeling approach is developed. To deal with the inconsistency of the tether's cross-section, the integration domain on the cross-section is divided into subdomains to account for different material properties in each layer and an accurate representation of the tether's cross-section. A Kelvin-Voigt model is employed to account for the viscoelastic behavior of the inner matrix, while nearly incompressible Mooney-Rivlin model is applied for the outer sheath. Structural weakening parameters are applied to modify the beam's strain energy. A new approach for analytical determination of dissipation factors for dilatational and deviatoric responses is proposed. Through validations against the numerical studies and experiment, the effectiveness of the proposed tether cable element is verified.