A fiber extraction structure and stripping method for optical fibers at the end of an optical fiber composite carbon fiber core rod.

Abstract

This invention discloses a fiber lead-out structure and stripping method for the end of an optical fiber composite carbon fiber core rod, belonging to the field of intelligent power transmission line technology. The invention features a peelable sleeve assembly on the outer side of the fiber lead-out section at the end of the carbon fiber composite core rod. The sleeve, from the inside out, consists of a release layer, a reinforcing armor layer, and an adhesive coupling layer. The release layer forms a low-adhesion interface with the optical fiber, the reinforcing armor layer protects the optical fiber from external forces, and the adhesive coupling layer is chemically bonded to the core rod resin. During stripping, the end of the core rod is first circumferentially cut to the surface of the reinforcing armor layer, then the sleeve assembly is axially pulled out to bring out the optical fiber, and finally the sleeve is removed to complete the fiber lead-out. This invention only features a peelable structure at the end, without affecting the performance of the core rod sensing section; the stripping process involves no cutting damage, resulting in extremely low additional fiber loss; and it requires no chemical reagents or high-temperature equipment. The process is simple and convenient to construct, and it can be widely applied to the on-site construction and maintenance of optical fiber composite carbon fiber core rods in intelligent power transmission lines.

Description

Technical Field

[0001] This invention belongs to the field of intelligent power transmission line technology, specifically relating to a fiber lead-out structure and stripping method for the end of an optical fiber composite carbon fiber core rod. Background Technology

[0002] Fiber-optic composite carbon fiber conductors are a new generation of smart conductors. They achieve fully distributed real-time monitoring of the carbon fiber composite core and the conductor's temperature, strain, and other conditions by embedding sensing optical fibers inside the carbon fiber composite core. The current mainstream one-step molding manufacturing technology involves introducing optical fibers online into the center of the fiber bundle during the pultrusion process of impregnating carbon fiber bundles with resin. Subsequently, they are cured together through a heated mold to form an integrated core rod structure in which the optical fibers are fully wrapped in resin and solidified in the center of the core rod.

[0003] However, this integrated structure faces a significant challenge in practical engineering applications: the lossless extraction of the optical fiber ends is extremely difficult. Because the optical fiber is tightly encapsulated and cured into a single unit by a high-strength epoxy resin matrix, on-site construction requires stripping the optical fibers from both ends to connect to the demodulation equipment. Current methods typically involve using mechanical cutters to directly cut and peel off the resin layer at the core rod ends. However, due to the inability to precisely control the cutting depth and position, this easily damages the internal quartz optical fiber, leading to breakage or micro-cracks, making on-site implementation difficult.

[0004] Existing technologies involve coating optical fibers with soluble or thermally decomposable materials to achieve fiber stripping via chemical or heating methods. However, these methods have shortcomings: (1) The presence of the coating may weaken the interfacial bonding between the optical fiber and the resin matrix in the normal sensing section, leading to a decrease in strain transfer efficiency and affecting sensing accuracy. (2) Chemical solvents or high-temperature treatment may cause potential damage to the high-temperature resistant coating of the optical fiber itself, and the process is complex and not suitable for rapid operation in engineering sites.

[0005] Therefore, a special structure and method are needed that can ensure a firm and integrated connection between the sensing fiber and the core rod, and enable the non-destructive, rapid, and reliable extraction of the end fiber. Summary of the Invention

[0006] The purpose of this section is to outline some aspects of embodiments of the present invention and to briefly describe some preferred embodiments. Simplifications or omissions may be made in this section, as well as in the abstract and title of this application, to avoid obscuring the purpose of these documents; however, such simplifications or omissions should not be construed as limiting the scope of the invention.

[0007] In view of the problems existing in the above and / or prior art, the present invention is proposed.

[0008] Therefore, the purpose of this invention is to overcome the shortcomings of the prior art and provide a fiber lead-out structure for the end of an optical fiber composite carbon fiber core rod.

[0009] To solve the above technical problems, the present invention provides the following technical solution: an optical fiber lead-out structure at the end of an optical fiber composite carbon fiber core rod, characterized in that: the lead-out structure includes a carbon fiber composite core rod body and an optical fiber disposed at the center of the core rod body, wherein the optical fiber consists of an optical fiber core 21, an optical fiber cladding 22 and an optical fiber coating layer 23 from the inside out. The fiber lead-out sections at both ends of the core rod body have a peelable sleeve assembly pre-placed between the fiber coating layer 23 and the resin matrix 11 of the core rod body. The peelable sleeve assembly includes, from the inside to the outside in the radial direction, a release layer 31, a reinforcing armor layer 32, and an adhesive coupling layer 33; The release layer 31 is closely attached to the outer surface of the optical fiber coating layer 23, forming a low-adhesion separation interface; The reinforced armor layer 32 covers the outside of the release layer 31 and is used to bear the external forces of circumcision and extraction and to protect the internal optical fibers. The adhesive coupling layer 33 covers the outside of the reinforcing armor layer 32, and its outer surface is chemically bonded to the resin matrix 11.

[0010] As a preferred embodiment of the lead-out structure of the present invention, the release layer 31 is a polytetrafluoroethylene thin-walled tube, a fluorinated ethylene propylene copolymer thin-walled tube, or a silicone oil coating; the surface energy of the release layer 31 material is 18~22mN / m, the temperature resistance is not lower than 200℃, and the coefficient of friction is 0.04~0.10.

[0011] As a preferred embodiment of the lead-out structure of the present invention, the reinforcing armor layer 32 is a stainless steel spiral tube or an aramid fiber braided tube. When stainless steel spiral pipes are used, the material is 304 or 316L stainless steel, the strip thickness is 0.08~0.15mm, the strip width is 0.5~1.5mm, the inner diameter of the pipe is 0.5~1.0mm, the outer diameter of the pipe is 1.0~2.0mm, and the pitch is 0.8~1.5mm. When using aramid fiber braided tubing, the material is Kevlar49 aramid fiber, the number of braiding spindles is 24 or 32, the braiding angle is 45°±5°, the tube wall thickness is 0.2~0.3mm, and the tube outer diameter is 1.5~2.5mm.

[0012] As a preferred embodiment of the lead-out structure of the present invention, the adhesive coupling layer 33 adopts a bisphenol A epoxy resin system that is homogeneous with the resin matrix 11, or adopts a cyanate ester resin system; when the reinforcing armor layer 32 is a stainless steel spiral tube, the outer surface of the stainless steel spiral tube is modified by a silane coupling agent.

[0013] As a preferred embodiment of the lead-out structure of the present invention, the peelable sleeve assembly is only provided at the optical fiber lead-out sections at both ends of the core rod, and the optical fiber coating layer 23 of the sensing section in the middle of the core rod is directly and tightly bonded to the resin matrix 11; the axial length of the peelable sleeve assembly is 1~3m.

[0014] Another objective of this invention is to overcome the shortcomings of the prior art and provide a method for stripping optical fibers from an extraction structure, characterized by comprising the following steps: A ring cutting tool is used to perform a circumferential ring cut at the end of the mandrel corresponding to the peelable sleeve assembly. The cutting depth penetrates the resin matrix 11 and the adhesive coupling layer 33 until the cutting edge touches the outer surface of the reinforcing armor layer 32 and then the cutting stops. Clamping tool is used to clamp the exposed end of the reinforcing armor layer 32 and pull it outward at a uniform speed along the core rod axis, so that the release layer 31 and the optical fiber coating layer 23 are separated along the low adhesion interface, and the peelable sleeve assembly together with the optical fiber segment inside it is pulled out from the core rod body. The reinforcing armor layer 32 and release layer 31 of the extracted section are removed in sequence to expose the complete optical fiber coating layer 23, thus completing the fiber end lead-out.

[0015] In a preferred embodiment of the optical fiber stripping method of the present invention, the circumferential cutting position is 5-15 mm away from the end face of the core rod; the inner diameter of the circumferential cutting blade is 0.2 mm larger than the outer diameter of the reinforcing armor layer 32, and the blade angle is 30°-45°.

[0016] In a preferred embodiment of the fiber stripping method of the present invention, the extraction speed is 10~30mm / s, the extraction force is controlled at 10~30N, and the axial deviation is kept constant during the extraction process.

[0017] As a preferred embodiment of the fiber stripping method described in this invention, after stripping, the fiber is detected by an optical time domain reflectometer, and the additional loss increment of the fiber is less than 0.01 dB / km.

[0018] Another objective of this invention is to overcome the shortcomings of the prior art and provide an application of the lead-out structure in the lead-out of the fiber end of the fiber composite carbon fiber core rod in intelligent power transmission lines.

[0019] Beneficial effects of this invention: (1) The stripping process is achieved through separation at the release layer interface. The optical fiber itself is not subjected to any cutting force or tension (the tension is borne by the reinforcing armor layer), the optical fiber coating is intact, and the fiber performance attenuation is reduced.

[0020] (2) The mechanical extraction method is highly controllable, simple to operate, and has a high success rate of end extraction.

[0021] (3) The peelable structure is limited to the end length. The optical fiber in the sensing section in the middle of the core rod is still firmly integrated with the resin matrix, and the optical fiber temperature strain transmission efficiency is not affected.

[0022] (4) The stripping operation only requires a simple ring cutter and clamping pliers, without the need for chemical reagents or heating equipment, making it suitable for rapid operation at the construction site of power transmission lines. Attached Figure Description

[0023] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Wherein: Figure 1 This is a schematic diagram of the radial cross-sectional structure of the fiber-optic composite carbon fiber core rod end lead-out structure. Detailed Implementation

[0024] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the examples in the specification.

[0025] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0026] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it a single or selective embodiment that is mutually exclusive with other embodiments.

[0027] Unless otherwise specified, all materials used in the embodiments of this invention are commercially available.

[0028] Example 1 This embodiment provides a fiber lead-out structure and stripping method for the end fiber of an optical fiber composite carbon fiber core rod. The lead-out structure includes a carbon fiber composite core rod body and an optical fiber disposed at the center of the core rod body. The optical fiber consists of an optical fiber core 21, an optical fiber cladding 22 and an optical fiber coating layer 23 from the inside out. The fiber lead-out sections at both ends of the core rod body have a peelable sleeve assembly pre-placed between the fiber coating layer 23 and the resin matrix 11 of the core rod body. The peelable sleeve assembly includes, from the inside to the outside in the radial direction, a release layer 31, a reinforcing armor layer 32, and an adhesive coupling layer 33; The release layer 31 is closely attached to the outer surface of the optical fiber coating layer 23, forming a low-adhesion separation interface; The reinforced armor layer 32 covers the outside of the release layer 31 and is used to bear the external forces of circumcision and extraction and to protect the internal optical fibers. The adhesive coupling layer 33 covers the outside of the reinforcing armor layer 32, and its outer surface is chemically bonded to the resin matrix 11.

[0029] Specifically: (1) Release layer: The outer surface of the coating layer that is in close contact with the optical fiber is made of a polymer material with extremely low surface energy and is used to provide a low adhesive force separation interface with the optical fiber coating layer; The release layer serves to create a low-adhesion separation interface between the fiber coating and the peelable sleeve, ensuring that the fiber can be smoothly and without damage from the sleeve during the pull-out operation. The release layer material is selected from polytetrafluoroethylene (PTFE, surface energy 18~20 mN / m, temperature resistance -190℃~260℃), fluorinated ethylene propylene copolymer (FEP, surface energy 18~22 mN / m, temperature resistance 200℃), and silicone oil coating (surface energy 20 mN / m, temperature resistance 200~250℃).

[0030] (2) Reinforced armor layer: Covering the release layer, it is made of metal spiral tube or fiber braided tube to provide compressive strength and shear strength, and to protect the internal optical fiber from being pulled apart during stripping and pulling.

[0031] The function of the reinforced armor layer is to withstand the cutting resistance during circumferential cutting, provide tensile and compressive strength during extraction, and protect the internal optical fibers from external damage during stripping.

[0032] The reinforcing armor layer is a stainless steel spiral tube or an aramid fiber braided tube. The stainless steel spiral armor tube is made of 304 or 316L stainless steel, with a strip thickness of 0.08~0.15 mm, a strip width of 0.5~1.5 mm, an inner diameter of 0.5~1.0 mm, an outer diameter of 1.0~2.0 mm, and a pitch of 0.8~1.5 mm.

[0033] The stainless steel spiral tube provides tactile and acoustic feedback to the cutting edge. When the annular cutting blade cuts through the resin layer and touches the stainless steel surface, the cutting resistance suddenly increases, producing a metallic friction sound. The operator can judge the cutting point by touch and stop the cutting. The metal hardness of the spiral tube is much higher than that of epoxy resin, so the cutting edge will not accidentally cut into the armor layer and damage the optical fiber.

[0034] The material for aramid fiber braided tubing can be aramid fiber (Kevlar49), which has the characteristics of high strength, high temperature resistance, and non-conductivity. The number of braiding spindles is 24 or 32, the braiding angle is 45°±5°, the wall thickness of the braided tubing is 0.2~0.3mm, and the outer diameter of the braided tubing is 1.5~2.5mm.

[0035] (3) Adhesive coupling layer: Covering the reinforcing armor layer, its outer surface is firmly bonded to the resin matrix of the carbon fiber composite mandrel body by chemical bonding.

[0036] The adhesive coupling layer is the bridge connecting the peelable sleeve and the resin matrix of the mandrel. It is required to form a strong chemical bond with the epoxy resin matrix of the mandrel to ensure that the peelable sleeve becomes a structural integral with the mandrel after the mandrel is cured, without affecting the macroscopic mechanical properties of the end mandrel.

[0037] The bonding coupling layer uses a high-temperature resistant epoxy resin system (bisphenol A epoxy resin + aromatic amine curing agent) that is homogeneous with the pultruded epoxy resin matrix. During the high-temperature curing stage of pultrusion molding, the epoxy groups in the bonding coupling layer resin and the epoxy groups in the mandrel matrix resin undergo a copolymerization and crosslinking reaction under the action of the same aromatic amine curing agent. A covalent crosslinked network is formed between the two resin layers, rather than a physical interface.

[0038] After curing, the adhesive coupling layer and the core rod matrix are integrated at the molecular level, with no macroscopic interface, achieving a bonding strength of 20 MPa.

[0039] To enhance the bonding force between the adhesive coupling layer resin and the outer surface of the stainless steel armor layer, the outer surface of the stainless steel spiral tube is treated with a silane coupling agent. After hydrolysis at one end of the silane coupling agent, it forms a Si-O-Me covalent bond with the hydroxyl groups on the metal surface, while the amino group at the other end reacts with the epoxy groups of the epoxy resin to form a chemical bridge, achieving a bonding strength of 5 MPa.

[0040] The above interface design ensures that the peelable sleeve is firmly integrated with the mandrel during normal use, while it can be easily separated from the inner layer during peeling operations.

[0041] The end fiber stripping method based on the above structure includes the following steps: (1) Circumferential cutting: Using a ring-shaped cutting tool, a shallow groove is cut radially in the region of the mandrel end where the peelable sleeve assembly is located, with the cutting depth just penetrating the resin layer of the mandrel body and the adhesive coupling layer, until the outer surface of the reinforcing armor layer is exposed.

[0042] The parameters for circumferential cutting include: The circumferential cut position is 5~15 mm away from the end face of the mandrel, leaving sufficient clamping length for the armored tube; The circumferential cutting depth is precisely cut to the outer surface of the armor layer, which can be judged by tactile feedback and the sound of metal friction. The cutting tool used is a ring-shaped cutting blade (the inner diameter is slightly larger than the outer diameter of the armored tube by 0.2 mm), with a cutting angle of 30°~45°.

[0043] (2) Withdrawal: Use a clamping tool to clamp the exposed reinforcing armor layer and the ends of its internal components, and pull it outward along the mandrel axis.

[0044] Under the action of the pulling force, the low adhesion interface between the release layer and the optical fiber coating layer separates, and the peelable sleeve assembly, together with the optical fiber segment inside it, is pulled out from the core body.

[0045] The parameters for the pull-out operation include: Pulling should be done along the axial direction of the mandrel, without deviation or bending. Pull out slowly and uniformly at a speed of 10~30 mm / s to avoid the impact force causing the optical fiber to break. The extraction force should be 10~30 N. If the extraction force is too large (greater than 50 N), check for abnormalities in the process.

[0046] (3) Peeling: After removing the outer reinforcing armor layer and release layer of the extracted section, the intact fiber coating layer inside is exposed, allowing subsequent fusion splicing or connector termination operations to proceed.

[0047] After stripping, use an OTDR to remeasure the fiber attenuation; the additional loss increment should be less than 0.01 dB / km.

[0048] Example 2 This embodiment provides a fiber extraction structure and stripping method for the end fiber of an optical fiber composite carbon fiber core rod. The structural parameters are as follows: The axial length of the peelable sleeve assembly is 1.5m; The release layer is made of polytetrafluoroethylene (PTFE) thin-walled tube with an inner diameter of 0.30 mm and a wall thickness of 0.05 mm. The reinforcing armor layer is made of 304 stainless steel spiral tube with an inner diameter of 0.50 mm, an outer diameter of 1.2 mm, a strip thickness of 0.10 mm, and a pitch of 1.0 mm. The bonding coupling layer is made of bisphenol A epoxy resin of the same material as the core rod matrix, with a thickness of 0.2 mm. The outer surface of the stainless steel spiral tube is treated with silane coupling agent.

[0049] Preparation and pre-setting processes: Before optical fiber pultrusion, a PTFE release layer, a stainless steel spiral armor layer, and an epoxy resin bonding coupling layer are sequentially threaded through the outer side of the 1.5 m length of the optical fiber at the end, and a temporary clamp is used to fix the position of the sleeve assembly. The optical fiber is then fed into a pultrusion device. After the carbon fiber bundle is impregnated with epoxy resin, it is bundled with the optical fiber and then put into a heating mold. It is cured and formed at 180~220℃. The bonding coupling layer and the core rod resin are copolymerized and cross-linked into one.

[0050] On-site stripping steps: Circumferential cutting: Use a ring-shaped cutting blade with an inner diameter of 1.4 mm and a cutting edge angle of 35° to make circumferential cuts at a distance of 10 mm from the end face of the mandrel. Stop cutting when the blade contacts the stainless steel spiral tube and produces a metallic friction sound and a sudden change in resistance.

[0051] Pulling out: Use special clamps to clamp the exposed stainless steel armor layer and pull it out at a uniform speed of 20 mm / s along the axial direction. The actual pulling force is 15~25N. The sleeve assembly and the internal optical fiber are pulled out as a whole.

[0052] Stripping: Use wire strippers to cut open the stainless steel spiral tube, remove the PTFE release layer, and expose the complete optical fiber.

[0053] Performance testing: OTDR was used to test the fiber loss. The additional loss increment of the fiber was less than 0.005dB / km, and there were no cracks or breaks in the fiber.

[0054] Example 3 The structure of this embodiment is basically the same as that of embodiment 2, except that: The release layer uses a 5 μm thick silicone oil coating, which is directly coated onto the surface of the optical fiber coating layer. The reinforcing armor layer is made of Kevlar49 aramid fiber braided tubing, 32 spindles braided, with a braiding angle of 45°, a wall thickness of 0.25 mm, and an outer diameter of 2.0 mm; The adhesive coupling layer is made of cyanate ester resin; The axial length of the peelable sleeve assembly is 3 m.

[0055] Stripping operation parameters: The circumferential cutting position is 12 mm from the end face, the inner diameter of the circumferential cutting blade is 2.2 mm, and the cutting edge angle is 30°; Pulling speed 15 mm / s, pulling force 20~35 N.

[0056] Test results: The increase in additional fiber loss is less than 0.008 dB / km, the fiber is intact, and the structure has better flexibility, making it suitable for long-distance fiber optic cable routing.

[0057] Example 4 The structure of this embodiment is basically the same as that of Embodiment 2, except that: The release layer is made of fluorinated ethylene propylene copolymer (FEP) thin-walled tube with an inner diameter of 0.30 mm and a wall thickness of 0.05 mm; The reinforcing armor layer is made of 304 stainless steel unwound spiral tube with an outer diameter of 1.0 mm and a pitch of 1.5 mm. The axial length of the peelable sleeve assembly is 1m.

[0058] Stripping operation parameters: The circumferential cutting position is 8 mm from the end face, the extraction speed is 25 mm / s, and the extraction force is 10~20 N.

[0059] Test results: The increase in additional fiber loss is less than 0.005 dB / km; FEP temperature-resistant and adaptable to low-temperature curing resin system; and the use of loosely wound spiral tubes can reduce material costs.

[0060] Comparative Example 1 Select fiber composite carbon fiber core rods of the same specification and use traditional hand tools to directly cut the resin at the ends to strip the fiber.

[0061] Twenty core rods were randomly selected for testing. Twelve of the optical fibers were damaged by cutting, with microcracks or breaks, resulting in a damage rate of 60%. The qualified optical fibers were tested by OTDR and found to have an average additional loss greater than 0.1 dB / km.

[0062] To address the problems of difficulty in peeling the fiber from the end of existing one-piece molded fiber composite carbon fiber core rods, easy damage to the fiber by mechanical cutting, and the impact of soluble or thermally decomposable coating schemes on the fiber interface bonding force, this invention provides a lead-out structure and method that targets only the end, has a high peeling success rate, and does not damage the fiber.

[0063] The core technology of this invention, which proposes a pre-installed peelable armor sleeve at the end of the pultrusion molding stage and a corresponding peeling method, lies in the following: a multi-layered peelable sleeve is pre-installed on the outside of the optical fiber only within a limited length where the optical fiber needs to be led out at both ends of the core rod. The outer layer of this sleeve is firmly bonded to the core rod resin, while the inner layer forms a low-adhesion release interface with the optical fiber coating. After curing, the inner section of the sleeve, along with the internal optical fiber, is extracted without damage by circumferential cutting and pulling.

[0064] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the present invention.

Claims

1. A fiber lead-out structure at the end of an optical fiber composite carbon fiber core rod, characterized in that: The lead-out structure includes a carbon fiber composite core rod body and an optical fiber located at the center of the core rod body. The optical fiber consists of an optical fiber core (21), an optical fiber cladding (22), and an optical fiber coating layer (23) from the inside out. The fiber lead-out sections at both ends of the core rod body are provided with a peelable sleeve assembly between the fiber coating layer (23) and the resin matrix (11) of the core rod body. The peelable sleeve assembly includes, in radial order from the inside out, a release layer (31), a reinforcing armor layer (32), and an adhesive coupling layer (33). The release layer (31) is closely attached to the outer surface of the optical fiber coating layer (23), forming a low-adhesion separation interface; The reinforced armor layer (32) covers the outside of the release layer (31) and is used to bear the external force of circumcision and extraction and to protect the internal optical fiber; The adhesive coupling layer (33) covers the outside of the reinforcing armor layer (32), and its outer surface is chemically bonded to the resin matrix (11).

2. The lead-out structure as described in claim 1, characterized in that: The release layer (31) is a polytetrafluoroethylene thin-walled tube, a fluorinated ethylene propylene copolymer thin-walled tube, or a silicone oil coating; the surface energy of the release layer (31) material is 18~22mN / m, the temperature resistance is not lower than 200℃, and the friction coefficient is 0.04~0.

10.

3. The lead-out structure as described in claim 1, characterized in that: The reinforcing armor layer (32) is a stainless steel spiral tube or an aramid fiber braided tube; When stainless steel spiral pipes are used, the material is 304 or 316L stainless steel, the strip thickness is 0.08~0.15mm, the strip width is 0.5~1.5mm, the inner diameter of the pipe is 0.5~1.0mm, the outer diameter of the pipe is 1.0~2.0mm, and the pitch is 0.8~1.5mm. When using aramid fiber braided tubing, the material is Kevlar49 aramid fiber, the number of braiding spindles is 24 or 32, the braiding angle is 45°±5°, the tube wall thickness is 0.2~0.3mm, and the tube outer diameter is 1.5~2.5mm.

4. The lead-out structure as described in claim 1, characterized in that: The adhesive coupling layer (33) is made of bisphenol A epoxy resin system that is homogeneous with the resin matrix (11), or a cyanate ester resin system; when the reinforcing armor layer (32) is a stainless steel spiral tube, the outer surface of the stainless steel spiral tube is modified by a silane coupling agent.

5. The lead-out structure as described in claim 1, characterized in that: The peelable sleeve assembly is only provided at the fiber lead-out sections at both ends of the core rod, and the fiber coating layer (23) of the sensing section in the middle of the core rod is directly and tightly bonded to the resin matrix (11); the axial length of the peelable sleeve assembly is 1~3m.

6. A method for stripping optical fibers based on the lead-out structure according to any one of claims 1 to 5, characterized in that, Includes the following steps: A ring cutting tool is used to perform a circumferential ring cut at the end of the mandrel corresponding to the peelable sleeve assembly. The cutting depth penetrates the resin matrix (11) and the adhesive coupling layer (33) until the cutting edge touches the outer surface of the reinforcing armor layer (32) and then the cutting stops. Clamping tool is used to clamp the exposed end of the reinforcing armor layer (32), and the core rod is pulled outward at a constant speed along the axis of the core rod to separate the release layer (31) and the optical fiber coating layer (23) along the low adhesion interface, and the peelable sleeve assembly together with the optical fiber segment inside it is pulled out from the core rod body. The reinforcing armor layer (32) and release layer (31) of the extraction section are removed in sequence to expose the complete optical fiber coating layer (23) and complete the fiber end lead-out.

7. The optical fiber stripping method as described in claim 6, characterized in that: The circumferential cutting position is 5-15mm away from the end face of the mandrel; the inner diameter of the circumferential cutting blade is 0.2mm larger than the outer diameter of the reinforcing armor layer (32), and the blade angle is 30°-45°.

8. The optical fiber stripping method as described in claim 6, characterized in that: The extraction speed is 10~30mm / s, the extraction force is controlled at 10~30N, and the axial deviation is kept constant during the extraction process.

9. The optical fiber stripping method as described in claim 6, characterized in that: After stripping, the optical fiber was tested using an optical time domain reflectometer, and the increase in additional fiber loss was less than 0.01 dB / km.

10. The application of the lead-out structure as described in any one of claims 1 to 5 in the lead-out of the fiber end of the fiber composite carbon fiber core rod in intelligent power transmission lines.

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