A Three-Dimensional Nonlinear Large-Deflection Model for Dynamic Behavior of Risers, Pipelines, and Cables

Abstract

A comprehensive nonlinear model for the dynamic behavior of marine risers, cables, and pipelines has been developed. Large three-dimensional lateral oscillations are modeled in the local principal, osculating and rectifying planes. Longitudinal extensional oscillations in the local tangential direction are also taken into account. The derived model shows the significance of three-dimensional bending effects and the contribution of the nonlinear terms. Lateral and longitudinal oscillations are coupled due to the curvature and geometric torsion of the centerline of the structure. The model also shows the effects of the external hydrostatic and the internal mud static pressure forces—which are integrated exactly along the structure—on the structure's tensile and bending rigidity.