This paper proposes a theoretical method for structural analysis of wind farm inter-array cables. By establishing a theoretical model for inter-array cables, the configuration, curvature, bending moment and tension distribution of the cables are obtained, and a parametric analysis is conducted. The entire cable is modeled as a series of continuous segments including buoyancy sections and suspended spans. Subsequently, equilibrium equations are established based on the principle of minimum potential energy. The finite difference method is adopted for spatial discretization, and the Newton-Raphson algorithm is utilized to realize iterative convergence of the nonlinear system. The analysis results are compared with those from OrcaFlex simulations to validate the feasibility and accuracy of the proposed method. Furthermore, a detailed parametric analysis is performed to investigate the effects of buoy length, spatial arrangement, and ocean current velocity on the mechanical properties of the cables. This method contributes to the structural analysis and layout design of inter-array cables in offshore wind farms.

The umbilical cable is a vital component of subsea production systems that provide power, chemical agents, control signals et al., and its requirement for reliability is exceedingly high. However, as the umbilical cable is a composite structure comprising multiple functional units, the reliability analysis of such cables involves numerous parameters that can impact calculation efficiency. In this paper, the reliability analysis of a new kind of umbilical cable with carbon fiber rod under tension is analyzed. The global dynamic analytical model is first established to determine the maximum tension load, then the local analytical model of umbilical cable including each unit are constructed by finite element method (FEM). Based on the mechanical analytical model, the reliability of umbilical cable under tension load is studied using response surface method (RSM) and Monte Carlo method. During the calculation process, a new tangent plane sampling method to calculate the response surface function (RSF) is proposed in this paper, which could make sampling points faster come close to the RSF curve, and it is proved that the calculation efficiency increases about 33% comparing with traditional method.