Pressure at the Interface of Inner Conductor and Dielectric of Armorless Ocean Cable

Abstract

Pressure at the interface of the inner conductor and the dielectric of the armorless ocean cable is experimentally determined for plane stress boundary conditions. Polyethylene outer and steel inner concentric cylinders are considered as a mechanical model of the ocean cable. Equations are derived to give the pressure at the interface for plane stress and plane strain conditions. It is found that the theoretical values of the pressure calculated from equations of elasticity are in good agreement with experimental values, even when one of the materials is polyethylene, which has a nonlinear stress-strain relationship in simple tension or compression. From previously measured values of bulk and Young's moduli, it is shown that, for an elastic analysis, Poisson's ratio for polyethylene is very nearly 0.5. An experimental verification of the plane stress solution given in this paper confirms the foregoing value.