Research On Mechanical And Thermal Properties Of Submarine Cable Based On Optical Fiber Sensing

With the development of China's offshore oil and gas,the construction of coastal urban industrial and agricultural,as well as the continuous development of offshore wind power technology,the application of fiber composite submarine cable is more and more extensive.In order to make three-core optical fiber composite submarine cable work long time without fault,it is necessary to use distributed optical fiber sensing to monitor the strain and temperature change of the optical fiber at any time,obtaining the healthy state of the submarine cable to ensure its long-term and reliable operation.The text makes a research on the three-core optical fiber composite submarine cable.Firstly,the basic knowledge about the research of the submarine cable is introduced.Then,the finite element model of tensile machine is established according to the laying and running environment of submarine cable and the mechanical properties in the process of stretching,and the simulation data of stress,strain and plastic strain of submarine cable under different tensile speed is obtained.According to the data analysis,the relationship between the stress of the t three-core optical fiber composite submarine cable and the strain of fiber is established,which provides a basis for obtaining the stress of the submarine cable through the strain of optical unit.In addition,the paper calculate the loss of the three-core optical fiber composite submarine cable' layers according to the IEC standard,converting them to heat generation rate as the load of the finite element model,and the steady state thermodynamic model of three-core optical fiber composite submarine cables with different specifications are established.With analyzing the influence of soil thermal resistance coefficient and ambient temperature on the temperature of fiber and copper conductor in steady state,the paper obtain the temperature relationship between the fiber and copper conductor,which is applicable to different conditions and different specifications of submarine cables.It provides the basis of obtaining the cable core temperature of the submarine cable through the fiber temperature.The research results of this paper provide a convenient way to calculate the stress and temperature of the submarine cable by using the optical fiber strain and temperature distribution data of the three-core optical fiber composite submarine cable,providing a certain reference value for the research on the condition monitoring of the three-core submarine cable.