Nonmetal sensing optical cable for ocean dynamic monitoring

Abstract

The invention relates to the technical field of optical cables, in particular to a nonmetal sensing optical cable for ocean dynamic monitoring, the optical cable comprises a cable core, an optical fiber unit and an outer protection unit, the optical fiber unit is wound on the cable core and extends along the axial direction of the cable core; the outer protection unit sleeves the outer side of the optical fiber unit and is used for fixing the optical fiber unit. The multi-layer composite structure is adopted, the sensitization layer improves the sensitivity to external signal changes, and the high-performance optical fiber assembly achieves accurate data transmission and monitoring functions. The wrapping tape layer and the inner sheath provide basic protection for the optical cable, the aramid fiber enhancement layer significantly improves the tensile strength, and the outer sheath is formed by extruding a TPU material, so that the optical cable is endowed with excellent corrosion resistance and durability, and the optical cable can adapt to a complex marine environment and meet the requirement of long-term dynamic monitoring. The method is suitable for real-time stress monitoring of ocean platform pile foundations and submarine pipelines, micro-deformation early warning of submarine landslides and earthquake activities and distributed sensing scenes of ocean temperature and salt flow fields and ecological environments.

Description

Technical Field

[0001] This application relates to the field of optical cable technology, and in particular to a non-metallic sensing optical cable for marine dynamic monitoring. Background Technology

[0002] A sensing optical cable is a type of optical cable that utilizes the characteristics of optical fibers to sense and measure various physical quantities. Based on the principle of total internal reflection, optical signals are transmitted within the optical fiber. An optical fiber is a thin, long piece of glass or plastic material with a refractive index greater than the surrounding medium. When light enters the fiber from one end, it undergoes repeated total internal reflections within the fiber, thus transmitting along the fiber to the other end, achieving long-distance, high-speed optical signal transmission. Optical fibers are sensitive to external environmental factors such as stress, temperature, electric fields, and magnetic fields. When the external environment changes, the intensity, phase, frequency, polarization state, and other characteristic parameters of the light wave transmitted in the fiber will change accordingly. By detecting these changes in parameters, information about the measured external parameters can be obtained, realizing the sensing function of external physical quantities.

[0003] In the field of marine dynamic monitoring (such as marine engineering structure health monitoring, seabed geological disaster early warning, and marine ecological environment monitoring), traditional sensing optical cables generally suffer from the following technical bottlenecks:

[0004] 1. The single fiber optic monitoring mode results in insufficient data reliability and susceptibility to environmental interference;

[0005] 2. Optical cables have limited structural strength and are unable to withstand dynamic loads such as complex ocean currents and tides;

[0006] 3. Insufficient sensitivity, unable to accurately capture minute changes in the marine environment (such as millimeter-level displacement or temperature fluctuations of around 0.3°C). Therefore, a new type of sensing optical cable with high sensitivity and high mechanical strength needs to be developed. Summary of the Invention

[0007] This application provides a non-metallic sensing optical cable for marine dynamic monitoring, which solves the problems of insufficient data reliability and susceptibility to environmental interference caused by the single optical fiber monitoring mode in the prior art; limited structural strength of the optical cable, making it difficult to withstand dynamic loads such as complex ocean currents and tides; and insufficient sensitivity, making it unable to accurately capture minute changes in the marine environment.

[0008] This application provides a non-metallic sensing optical cable for marine dynamic monitoring, comprising:

[0009] Cable core;

[0010] The optical fiber unit is wound around the cable core and extends along the axial direction of the cable core.

[0011] The outer sheath unit is fitted onto the outside of the fiber optic unit and is used to fix the fiber optic unit.

[0012] In one possible design, the optical fiber unit includes an enhanced optical fiber and a regular optical fiber, which are wound around the surface of the cable core in an equal-pitch spiral manner to form a distributed sensing structure.

[0013] In one possible design, the sensitivity-enhancing fiber consists of two fibers, while the ordinary fiber consists of one fiber.

[0014] In one possible design, a sensitizing layer is provided between the cable core and the optical fiber unit. The sensitizing layer is an elastic material layer that can amplify external stress or strain signals through its own elastic properties.

[0015] In one possible design, the sensitizing layer is made of thermoplastic polyurethane material with a thickness of 5 mm.

[0016] In one possible design, the outer protective unit includes:

[0017] The cladding layer is fitted over the outside of the optical fiber unit;

[0018] Inner sheath, fitted over the outer side of the wrapping layer;

[0019] The outer sheath is fitted over the outer side of the inner sheath.

[0020] In one possible design, the strap layer is made of non-woven fabric wrapped around it.

[0021] In one possible design, the inner and outer sheaths are made of thermoplastic polyurethane elastomers, with the inner sheath being thinner than the outer sheath.

[0022] In one possible design, a reinforcing layer is provided between the inner and outer sheaths, and the reinforcing layer is made of aramid fiber.

[0023] In one possible design, the cable core is made of Kevlar fiber reinforced plastic.

[0024] The beneficial effects of this application are as follows:

[0025] The non-metallic sensing optical cable for marine dynamic monitoring provided in this application adopts a multi-layer composite structure, including a cable core to enhance overall stability, a sensitivity-enhancing layer to improve sensitivity to changes in external signals, and high-performance optical fiber components to achieve precise data transmission and monitoring functions. The wrapping layer and inner sheath provide basic protection for the optical cable, the aramid reinforcement layer significantly improves tensile strength, and the outer sheath, formed by extruding TPU material, gives the optical cable excellent corrosion resistance and durability, enabling it to adapt to complex marine environments and meet the needs of long-term dynamic monitoring. The non-metallic sensing optical cable for marine dynamic monitoring provided in this application is suitable for real-time stress monitoring of marine platform pile foundations and subsea pipelines, early warning of micro-deformation in submarine landslides and seismic activity, and distributed sensing scenarios for marine temperature, salinity, current fields, and the ecological environment. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the specific embodiments of this application or the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0027] Figure 1 A schematic diagram of the structure of a non-metallic sensing optical cable for marine dynamic monitoring provided in this application embodiment. Figure 1 ;

[0028] Figure 2 A schematic diagram of the structure of a non-metallic sensing optical cable for marine dynamic monitoring provided in this application embodiment. Figure 2 .

[0029] Figure label:

[0030] 1. Cable core; 2. Sensitivity-enhancing layer; 31. Sensitivity-enhancing optical fiber; 32. Ordinary optical fiber; 4. Wrapping layer; 5. Inner sheath; 6. Reinforcement layer; 7. Outer sheath. Detailed Implementation

[0031] The technical solutions of this application will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0032] The following is combined with Figures 1-2 This application describes a non-metallic sensing optical cable for marine dynamic monitoring provided in its embodiments.

[0033] Reference Figure 1 , Figure 2As shown in the illustration, an embodiment of this application provides a non-metallic sensing optical cable for marine dynamic monitoring, comprising a cable core 1, an optical fiber unit, and an outer sheath unit. The cable core 1 is located at the center of the entire optical cable, ensuring good tensile and water pressure resistance. The optical fiber unit is spirally wound on the cable core 1, extending along the axial direction of the cable core 1. The optical fiber unit is used to sense stress and strain changes in the marine environment. The outer sheath unit is fitted over the outer side of the optical fiber unit, used to fix the optical fiber unit. It is made of non-metallic material and has properties such as corrosion resistance and wear resistance, enabling it to adapt to harsh marine environments such as high salinity and high pressure.

[0034] Reference Figure 2 As shown, in some embodiments provided in this application, the optical fiber unit includes an enhanced optical fiber 31 and a regular optical fiber 32. The enhanced optical fiber 31 and the regular optical fiber 32 are wound in an equal-pitch spiral manner on the surface of the cable core 1 to form a distributed sensing structure. The enhanced optical fiber 31 is used to sense stress and strain changes in the marine environment. The regular optical fiber 32 serves as a reference channel to eliminate common-mode interference such as temperature, thereby improving data reliability.

[0035] In some specific embodiments, the number of sensitizing optical fibers 31 includes two, and the number of ordinary optical fibers 32 includes one. The two sensitizing optical fibers 31 and the one ordinary optical fiber 32 are spirally wound on the surface of the sensitizing layer 2 with equal pitch. The pitch parameter matches the frequency response characteristics of marine dynamic signals, forming a distributed sensing structure similar to a fiber optic grating.

[0036] Reference Figure 2 As shown, in some embodiments provided in this application, a sensitivity-enhancing layer 2 is disposed between the cable core 1 and the optical fiber unit. The sensitivity-enhancing layer 2 is an elastic material layer that can amplify external stress or strain signals through its own elastic properties. The sensitivity-enhancing layer 2 amplifies external stress / strain signals through the elastic material properties, thereby improving the sensitivity of optical fiber monitoring.

[0037] In some specific embodiments, the sensitizing layer 2 is made of thermoplastic polyurethane material with a thickness of 5 mm. The elastic properties of thermoplastic polyurethane material amplify external stress / strain signals, thereby improving the sensitivity of fiber optic monitoring.

[0038] Reference Figure 2As shown, in some embodiments provided in this application, the outer sheath unit includes a wrapping layer 4, an inner sheath 5, and an outer sheath 7. The wrapping layer 4 is fitted over the outer side of the spiral structure on the surface of the cable core 1, where the sensitive-enhancing optical fiber 31 and the ordinary optical fiber 32 are wound in a spiral manner with equal pitch. The wrapping layer 4 is used to fix the position of the optical fiber, prevent the winding from loosening, and provide initial protection. The inner sheath 5 is fitted over the outer side of the wrapping layer 4. The inner sheath 5 is used to seal the optical fiber assembly, enhance waterproof performance, and buffer external mechanical impacts. The outer sheath 7 is fitted over the outer side of the inner sheath 5. The outer sheath 7 is used to provide an outer layer of physical protection against damage such as seawater corrosion, biological adhesion, and rock friction.

[0039] In some specific embodiments, the wrapping layer 4 is made of non-woven fabric and is used to fix the optical fiber position, prevent tangling and loosening, and provide initial protection. The inner sheath 5 and the outer sheath 7 are both made of thermoplastic polyurethane elastomer, with the inner sheath 5 being thinner than the outer sheath 7. Specifically, the inner sheath 5 is a 2mm thick TPU sheath used to seal the optical fiber assembly, enhance waterproof performance, and buffer against external mechanical impacts. The outer sheath 7 is a 2.5mm thick TPU sheath used to provide an outer layer of physical protection against damage such as seawater corrosion, biofouling, and rock friction.

[0040] Reference Figure 2 As shown, in some embodiments provided in this application, a reinforcing layer 6 is provided between the inner sheath 5 and the outer sheath 7, and the reinforcing layer 6 is woven from aramid fibers.

[0041] In one possible design, the cable core 1 is made of Kevlar fiber reinforced plastic. In some specific embodiments, the reinforcing layer 6 is made of 9480 aramid fiber, with 48 strands braided together to form the reinforcing layer 6; by setting the aramid reinforcing layer 6, the tensile and shear strength of the optical cable can be significantly improved, making it adaptable to dynamic load environments such as ocean currents and towing.

[0042] The performance testing results of a non-metallic sensing optical cable for marine dynamic monitoring according to an embodiment of this application are shown in the table below:

[0043]

[0044]

[0045] The fabrication process of a non-metallic sensing optical cable for marine dynamic monitoring according to an embodiment of this application is as follows:

[0046] Cable core 1: Cable core 1 adopts a KFRP central reinforcement and is composed of a KFRP rod;

[0047] Sensitizing layer 2: Sensitizing layer 2 is formed by extruding TPU material to wrap the central steel strand through an extrusion process;

[0048] Fiber winding: Sensitizing fiber 31 and ordinary fiber 32 are synchronously wound on the surface of sensitizing layer 2 in an equal pitch spiral manner. The pitch is determined by marine dynamics simulation optimization.

[0049] Forming of the inner sheath 5: After the non-woven fabric is wrapped around and fixed to the optical fiber, the TPU inner sheath 5 is extruded.

[0050] Aramid braiding: 48 aramid 9480 fibers are used to form a reinforcing layer 6 through a braiding process;

[0051] Outer sheath 7 extrusion: Finally, the TPU outer sheath 7 is extruded to complete the optical cable forming.

[0052] An embodiment of this application provides a non-metallic sensing optical cable for marine dynamic monitoring that can be laid underwater for real-time stress monitoring of marine platform pile foundations and subsea pipelines, early warning of micro-deformation of submarine landslides and seismic activity, and distributed sensing of marine temperature, salinity and current fields and ecological environment.

[0053] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0054] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0055] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between components; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0056] In this application, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0057] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. A non-metallic sensing optical cable for marine dynamic monitoring, characterized in that, include: Cable core; An optical fiber unit is wound around the cable core and extends along the axial direction of the cable core; An outer protective unit is fitted onto the outside of the optical fiber unit to fix the optical fiber unit.

2. The non-metallic sensing optical cable for marine dynamic monitoring according to claim 1, characterized in that: The optical fiber unit includes an enhanced optical fiber and a regular optical fiber. The enhanced optical fiber and the regular optical fiber are wound around the surface of the cable core in an equal-pitch spiral manner to form a distributed sensing structure.

3. The non-metallic sensing optical cable for marine dynamic monitoring according to claim 2, characterized in that: The enhanced optical fiber comprises two fibers, while the ordinary optical fiber comprises one fiber.

4. The non-metallic sensing optical cable for marine dynamic monitoring according to any one of claims 1-3, characterized in that: A sensitivity-enhancing layer is provided between the cable core and the optical fiber unit. The sensitivity-enhancing layer is an elastic material layer that can amplify external stress or strain signals through its own elastic properties.

5. The non-metallic sensing optical cable for marine dynamic monitoring according to claim 4, characterized in that: The sensitizing layer is made of thermoplastic polyurethane material with a thickness of 5 mm.

6. The non-metallic sensing optical cable for marine dynamic monitoring according to claim 1, characterized in that, The outer protective unit includes: A wrapping layer is fitted onto the outside of the optical fiber unit; Inner sheath, fitted over the outside of the wrapping layer; An outer sheath is fitted over the outer side of the inner sheath.

7. The non-metallic sensing optical cable for marine dynamic monitoring according to claim 6, characterized in that: The wrapping layer is made of non-woven fabric material.

8. The non-metallic sensing optical cable for marine dynamic monitoring according to claim 6, characterized in that: The inner sheath and the outer sheath are both made of thermoplastic polyurethane elastomer, and the thickness of the inner sheath is less than the thickness of the outer sheath.

9. The non-metallic sensing optical cable for marine dynamic monitoring according to claim 6, characterized in that: A reinforcing layer is provided between the inner sheath and the outer sheath, and the reinforcing layer is woven from aramid fibers.

10. The non-metallic sensing optical cable for marine dynamic monitoring according to claim 1, characterized in that: The cable core is made of Kevlar fiber reinforced plastic.

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