Mechanical fault monitoring method for photoelectric composite submarine cable

Abstract

The invention discloses a mechanical fault monitoring method for a photoelectric composite submarine cable, and belongs to the technical field of fault monitoring. According to the method, a 110kV YJQ41x300mm2 type submarine cable is used as a research object; based on ANSYS / LS-DYNA explicit dynamics analysis, a structural dynamics finite element model is established, modeling simulation is carried out on three typical fault conditions such as stretching, twisting and anchoring of the submarine cable, the strain distribution along a submarine cable composite fiber and a corresponding relationship between the strain and stress of a relevant structure in the submarine cable and the fiber strain in the fault development process are obtained, a functional relation between cable core and armorstrains and stress and optical fiber strains in the stretching and twisting states is established, and an evaluation index of the submarine cable damage state and the fiber strains under the anchoring condition is established. According to the mechanical fault monitoring method for the photoelectric composite submarine cable provided by the invention, the possible mechanical fault state types ofthe submarine cable can be identified, and preliminarily judgment is carried out on the development degree of corresponding faults by combining the established functional relation and a damage evaluation index.

Description

technical field [0001] The invention belongs to the technical field of fault monitoring, and in particular relates to a mechanical fault monitoring method of a photoelectric composite submarine cable. Background technique [0002] Photoelectric composite submarine cables are expensive, complex in structure, and operate in harsh environments. Monitoring and fault diagnosis of their operating status is a prerequisite for subsequent fault prevention and maintenance, and is very important to ensure the safe and stable operation of submarine cables. The random and diverse mechanical stresses in the actual installation and operation of submarine cables will pose a great threat to submarine cables. The causes of mechanical failure mainly include external force damage caused by fishing gear and anchors during human activities, damage during laying, and damage caused by the seabed terrain environment. Under the action of external force, the submarine cable will form a bend, and at th...

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Problems solved by technology

[0004] Our research group has successfully realized the online monitoring of a submarine cable somewhere in the East China Sea based on BOTDR technology in 2013, and obtained a large amount of Brillouin frequency shift data that varies with the position and time of the submarine cable. The failure diagnosis of the submarine cable under mechanical stress based on the measurement data cannot be effectively realized, so that the function of the system cannot be fully utilized

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