Research Of Submarine Cable Bending Properties Based On Optical Fiber Strain

With frequent marine development activities in China,the single-core optical fiber composite submarine power cable with communication and transmission is widely used in many islands and offshore platforms,and the importance research of submarine cable also increasingly prominent.The current research of the submarine cable is mainly confined to the electrical properties research,rarely involving the study of mechanical properties of submarine cable.Bending as one of the mechanical failure,it is likely to causes an electrical fault.Therefore,it is significant to study the bending properties of submarine cable.In this paper,the finite element software ANSYS is used to study the mechanical bending failure of submarine cable.By simulating the mechanical bending of submarine cable,the stress data of each structure and the strain data of optical fiber are obtained providing the theoretical basis for the research of submarine cable mechanical failure.In this paper,finite element method is the main theoretical basis,the submarine cable bending causes are divided into two categories,one is caused by winding and laying and the other is hooks.In the first category,submarine cable is constructed according to the material parameters,the construction standards and the CIGRE conference documents.The suitable materials and unit types are selected to establish the finite element model of submarine cables.The contact condition of each structure is determined by the surface automatic contact algorithm,and the boundary conditions of the model are set up according to the characteristics of each structure.The bending environment is abstracted and the loads with different bending speeds and different bending radius are applied,simulating the bending of the submarine cable during winding and laying.In the second category,the submarine cable model is simplified according to the contact type,and the anchorage is simplified under the premise of not affecting the contact area with the anchor.The process of anchoring the submarine cable is abstracted and the speed load was applied to the anchor to simulate the process of the anchor hooks the submarine cable.Based on the simulations,the stress and strain data of submarine cables under different bending factors are obtained and drawn out the time-stress curves,time-strain curves and stress-strain curves and studied the changes of the structures during the bending process.Finally,a relational function is established,in which the strain of the optical element is the independent variable and the structural stress is the dependent variable.In this paper,the stress and strain variation of submarine cables in the process of bending are discussed in detail,which provides a theoretical basis for future study about the bending state and bending properties of submarine cable.