A detachable encapsulation structure and method for the end optical fiber of an intelligent FRP cable for full-length strain distribution monitoring
The removable encapsulation structure for smart FRP cables addresses issues of reduced anchor efficiency and incomplete monitoring by keeping fibers outside the anchor cup, enhancing survivability and enabling repair, thus ensuring reliable long-term strain monitoring.
Patent Information
- Application Number
- CN202411084286.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-08
- Publication Date
- 2025-07-15
- Estimated Expiration
- 2044-08-08
Smart Images
Figure CN119001962B_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the field of intelligent structure monitoring, and particularly relates to a detachable encapsulation structure and method for an optical fiber at the end of an intelligent FRP cable for monitoring the full-length strain distribution. Background Art
[0002] The cable structure is a core load-bearing component in projects such as bridges and large-span spaces. Fiber Reinforced Polymer (FRP) cables have the advantages of light weight, high strength, corrosion resistance, and fatigue resistance, and can effectively overcome the defects of traditional steel cables such as large self-weight, easy corrosion, and easy fatigue, improving the performance and lifespan of structures under ultra-long spans, large tonnages, and complex environments. FRP cables are made by braiding multiple FRP rods and anchoring them at both ends. FRP rods are prepared by pultrusion of fibers and resins, and common FRP materials include Carbon Fiber Reinforced Polymer (CFRP), Glass Fiber Reinforced Polymer (GFRP), and Basalt Fiber Reinforced Polymer (BFRP), etc. However, FRP materials are highly brittle and may undergo sudden fracture failure; moreover, the shear and compressive properties of FRP materials are poor, and improper anchoring may cause shear or debonding failure of the cable anchoring system. Therefore, long-term health monitoring of FRP cables is required to achieve health assessment and disaster warning of structures.
[0003] Optical fiber monitoring technology can achieve long-term monitoring of strain, temperature, and vibration changes in the surrounding environment through pre-embedded optical fibers, and has advantages such as long lifespan, high stability, large bandwidth, long distance, and small sensors. At the same time, by pultruding optical fiber sensors together with fibers and resins, intelligent FRP rods can be prepared. Intelligent FRP rods have the characteristics of integrated structural functions of load-bearing capacity, environmental monitoring, and damage monitoring of their own FRP materials. Currently, commonly used optical fiber monitoring technologies include Fiber Bragg Grating technology (FBG), weak grating technology (mFRP), Brillouin scattering technology (BOTDA / R), and Rayleigh scattering optical frequency domain reflectometry (OFDR), etc. Especially for the measuring equipment developed based on OFDR technology, it has been able to achieve distributed strain monitoring with a maximum spatial resolution of 1 mm and a maximum strain measurement accuracy of ±1.0 με, and is expected to achieve strain distribution monitoring in areas with short distances but high resolution requirements such as the cable anchorage zone. Therefore, using intelligent FRP rods in FRP cables to prepare intelligent FRP cables can achieve long-term non-destructive monitoring of the full-length strain of the cable including the anchorage zone without reducing the cable's bearing capacity.
[0004] However, in order to protect the fiber optic fusion splice points in the traditional intelligent FRP cable encapsulation process, the fiber optic fusion splice points are usually encapsulated inside the anchor cup of the anchor, and cured with the resin of the grouting material inside the anchor cup. This may lead to the following problems: First, the unloaded fiber optic protective sleeve generated due to fiber optic encapsulation may affect the anchoring efficiency of the cable anchor and reduce the bearing capacity of the cable; Second, there is no FRP layer in the part from the encapsulation point to the end of the anchor. The stress state of this part is significantly different from that of other FRP rods. Therefore, the strain monitored in the anchorage area is incomplete and cannot represent the actual stress state of the cable anchorage area; Third, the encapsulation point inside the anchor may be subjected to the tensile stress at the loading end of the cable, which may cause the fiber optic at the encapsulation point to break, resulting in a low survival rate of the fiber optic and possibly leading to the failure of the cable monitoring function; Fourth, since the encapsulation point is inside the anchor and cured with the resin of the grouting material, once the fiber optic breaks, the encapsulation point cannot be disassembled and reinstalled, and the monitoring function cannot be restored.
[0005] Therefore, there is an urgent need for a solution that does not affect the anchoring efficiency of the cable, can achieve the full-length strain monitoring of the cable including the anchorage area, has a high survival rate of the fiber optic, and can be repaired after the fiber optic is damaged. Summary of the Invention
[0006] In view of this, the present invention aims to propose a detachable encapsulation structure and method for the fiber optic at the end of an intelligent FRP cable for full-length strain distribution monitoring, so as to solve the problems that the existing self-monitoring rod encapsulation structure reduces the anchoring efficiency of the cable, the full-length strain monitoring of the anchorage area is incomplete, and the survival rate of the encapsulated fiber optic is low.
[0007] To achieve the above object, the present invention adopts the following technical solutions. According to one aspect of the present invention, a detachable encapsulation structure for the fiber optic at the end of an intelligent FRP cable for full-length strain distribution monitoring is provided, including:
[0008] A lead area, in which at least one intelligent FRP rod is provided. One end of each intelligent FRP rod passes through the anchor cup and is encapsulated to form a lead area, and a lead fiber optic is formed at the end of the lead area away from the anchor cup;
[0009] A fusion splicing area, in which the joints provided therein are arranged in one-to-one correspondence with the intelligent FRP rods. One end of each joint passes through the end cover at the distal end of the protective cylinder to form a joint fiber optic arranged opposite to the corresponding lead fiber optic. After the lead fiber optic and the joint fiber optic are fusion spliced, they are encapsulated to form a fusion splicing area;
[0010] A protective cylinder area, in which the protective cylinder provided therein is arranged coaxially with the anchor cup, and the proximal end of the protective cylinder is detachably connected to the end wall surface of the lead area of the anchor cup where the lead area passes through.
[0011] Furthermore, the lead fiber optic is fusion spliced with the joint fiber optic formed at the end of the joint fiber optic through the lead fiber core formed at the end.
[0012] Further, both the lead area and the welding area are arranged inside the casing sleeve, and the casing sleeve is coaxially arranged inside the casing and is sleeved with the front support plate and the rear support plate at both ends of the casing respectively.
[0013] Further, the front support plate is located at the tail end of the anchor cup, and the rear support plate is located at the tail end of the casing and penetrates into a screw arranged at the tail end of the casing; the casing sleeve penetrates through the front support plate and the rear support plate and is sealed by a sealing ring between the support plate and the sealing plate.
[0014] Further, the encapsulation structure further includes: a connection component, which is arranged between the sealing ring and the sealing plate and the joint passes through the connection component, and is used for transmitting the force of the joint to the sealing plate.
[0015] Further, the connection component is a resin mold and presents a stepped shape, with one end being a cylinder and the other end being a square prism. The cylinder end is arranged between the sealing ring and the sealing plate, and the square prism end passes through a through hole on the sealing plate with a cross section consistent with that of the square prism and is sealed by a sealing cap. Resin is arranged inside and after curing, the resin molds the joint. Thus, the resin mold, the internal resin, and the joint armor sheath can be restricted through the sealing plate to prevent the fiber optic joint from being pulled to the lead area and the welding area during the force application process, improving the fiber optic survival rate; and since the resin mold is not directly bonded to the through hole of the sealing plate, the detachable and reinstallable functions of the casing area and the welding area can be realized.
[0016] Further, the lead area further includes a lead armor sheath, lead resin, a lead sleeve, and a lead heat shrink sleeve. The lead armor sheath is sleeved on the lead optical fiber, the lead sleeve is sleeved on the outer wall of the intelligent FRP rod and houses part of the lead armor sheath inside, lead resin is arranged between the lead sleeve and the lead armor sheath, and a lead heat shrink sleeve is arranged at the distal end of the lead sleeve to cooperate with the lead armor sheath to encapsulate the resin.
[0017] Further, the welding area further includes a joint armor sheath, a welding heat shrink tube, welding resin, a welding sleeve, and a joint heat shrink tube. The two ends of the welding heat shrink tube are respectively sleeved on the lead armor sheath and the joint armor sheath of the joint and encapsulate the lead optical fiber and the joint optical fiber inside. The welding sleeve is sleeved outside the welding heat shrink tube and is connected to the lead armor sheath and the joint armor sheath on the corresponding side through a joint heat shrink tube at both ends respectively. The welding resin is arranged in a cavity formed by the outer wall of the lead armor sheath, the outer wall of the joint armor sheath, the inner wall of the welding sleeve, and the inner wall of the joint heat shrink tube.
[0018] According to another aspect of the present invention, there is provided a method for encapsulating a lead area, including the following steps:
[0019] S11, stripping the lead optical fiber from the intelligent FRP rod;
[0020] S12, slip the lead sleeve onto the outside of the FRP rod and press against the end of the original grout inside the anchor cup;
[0021] S13, slip the lead armored sheath over the outer layer of the lead optical fiber;
[0022] S14, pour the lead resin into the lead sleeve, and after slipping the lead heat shrinkable sleeve onto the end of the lead sleeve, heat it to achieve heat shrinkage sealing of the end of the lead sleeve.
[0023] According to another aspect of the present invention, there is provided a method for encapsulating a fusion splicing area, including the following steps:
[0024] S21, strip the coating resins on the surfaces of the lead optical fiber and the splice optical fiber to obtain the lead fiber core and the splice fiber core respectively;
[0025] S22, fuse the lead fiber core and the splice fiber core to form an optical fiber fusion splice point;
[0026] S23, slip the fusion heat shrinkable tube over the outside of the optical fiber fusion splice point, the lead armored sheath and the splice armored sheath, and then heat it to achieve heat shrinkage encapsulation of the optical fiber fusion splice point;
[0027] S24, slip the fusion sleeve over the outer layer of the fusion heat shrinkable tube;
[0028] S25, slip the splice heat shrinkable tube onto one end of the fusion sleeve, heat the splice heat shrinkable tube to achieve heat shrinkage sealing of one end of the fusion sleeve, then pour the fusion resin into the fusion sleeve, and after slipping the splice heat shrinkable tube onto the other end of the fusion sleeve, heat this end of the splice heat shrinkable tube to achieve heat shrinkage sealing of the other end of the fusion sleeve.
[0029] According to another aspect of the present invention, there is provided a method for encapsulating a casing area, including the following steps:
[0030] S31, slip the casing sleeve over the outside of the lead area and the fusion splicing area, ensuring that the optical fiber in the casing area is in an axial straight state;
[0031] S32, slip the front support plate onto the outside of the casing sleeve and press tightly against the end of the anchor cup;
[0032] S33, slip the casing over the outside of the lead area and the fusion splicing area, and achieve a tight connection with the anchor cup through bolts;
[0033] S34, slip the rear support plate onto the outer layer of the splice casing sleeve and pass through the casing screw;
[0034] S35, slip the sealing ring onto the outside of the splice armored sheath and press tightly against the rear support plate;
[0035] S36, slip the resin mold onto the outside of the splice armored sheath and press tightly against the sealing ring;
[0036] S37. Insert the sealing plate into the outer layer of the joint armored sheath, and pass the resin mold through the sealing plate;
[0037] S38. Tighten the bolts. After locking the sealing plate, the sealing plate squeezes the casing sleeve and the sealing ring to achieve the sealing and restraint of the structure;
[0038] S39. Inject resin into the resin mold, then put the sealing cap on the resin mold to achieve the end sealing of the resin mold, and wait for the resin to fully cure, and the encapsulation is completed.
[0039] According to another aspect of the present invention, there is provided a detachable and reinstallable method for the above-mentioned casing area, including the following steps:
[0040] S41. Loosen the bolts and remove the sealing plate from the casing;
[0041] S42. Remove the rear support plate from the casing sleeve;
[0042] S43. Remove the casing from the front support plate;
[0043] S44. Remove the front support plate from the casing sleeve;
[0044] S45. Remove the casing sleeve from the lead area and the welding area;
[0045] S46. Cut off the welding area to facilitate reinstallation;
[0046] S47. Operate according to the steps of S21 - S25 to reinstall the welding area;
[0047] S48. Operate according to the steps of S31 - S39 to reinstall the casing area.
[0048] Compared with the prior art, the beneficial effects of the present invention are:
[0049] 1. The present encapsulation structure can realize the full - length strain monitoring of the anchorage area without affecting the cable - anchoring efficiency: By adding a casing at the tail end of the anchor cup, the lead area and the welding area of the intelligent FRP rod are both arranged at the outer end of the anchor cup, so as to prevent the reduction of the cable - anchoring efficiency and the incomplete full - length strain monitoring of the anchorage area caused by being encapsulated in the anchor cup.
[0050] 2. The present encapsulation structure can improve the survival rate of the encapsulated optical fiber: The optical fiber is encapsulated at the rear end of the anchor cup, not inside the anchor cup, so the optical fiber is not affected by the load at the loading end of the cable; at the same time, by setting the lead area and the welding area, the two vulnerable transition points of the optical fiber at the stripping point and the welding point are protected; in addition, by setting the lead sleeve in the casing area, it is ensured that the optical fiber in the casing area is in an axial straight state, and by setting the resin mold and pouring the resin, it is prevented that the optical fiber joint is pulled to the lead area and the welding area during the stress process, further improving the survival rate of the optical fiber.
[0051] 3. This encapsulation structure can achieve the disassembly and renovation repair of the encapsulation structure: By setting the sealing plate, bolts, and resin molds in the casing area, the direct resin bonding between the optical fiber and the casing and the anchor cup is prevented, thereby realizing the detachable of the casing area and the reinstalled fusion splicing of the fusion splicing area to meet the repair requirements after the optical fiber in the fusion splicing area breaks in actual projects. BRIEF DESCRIPTION OF THE DRAWINGS
[0052] The drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:
[0053] Figure 1 is a cross-sectional view of a detachable encapsulation structure for the end optical fiber of an intelligent FRP cable for full-length strain distribution monitoring according to the present invention;
[0054] Figure 2 is a schematic three-dimensional structure diagram of a detachable encapsulation structure for the end optical fiber of an intelligent FRP cable for full-length strain distribution monitoring according to the present invention;
[0055] Figure 3 is a cross-sectional view of the lead area according to the present invention;
[0056] Figure 4 is a cross-sectional view of the fusion splicing area according to the present invention;
[0057] Figure 5 is a cross-sectional view of the casing area according to the present invention;
[0058] Figure 6 is a partial enlarged view of the connection component according to the present invention;
[0059] Figure 7 is a schematic diagram of the steps of the encapsulation method for the lead area according to the present invention;
[0060] Figure 8 is a schematic diagram of the steps of the encapsulation method for the fusion splicing area according to the present invention;
[0061] Figure 9 is a schematic diagram of the steps of the encapsulation method for the casing area according to the present invention.
[0062] Lead area 1; lead optical fiber 101; intelligent FRP rod 102; lead armored sheath 103; lead resin 104; lead sleeve 105; lead heat shrinkable sleeve 106; lead fiber core 107; fusion splicing area 2; joint fiber core 201; joint optical fiber 202; joint armored sheath 203; fusion splicing heat shrinkable tube 204; fusion splicing resin 205; fusion splicing sleeve 206; joint heat shrinkable tube 207; casing area 3; casing sleeve 301; front support plate 302; casing 303; rear support plate 304; sealing ring 305; resin mold 306; sealing plate 307; bolt 308; sealing cap 309; anchor cup 4; joint 5. Detailed implementation mode
[0063] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. It should be noted that, without conflict, the embodiments and features in the embodiments of the present invention can be combined with each other. The described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments.
[0064] It should be noted that the descriptions of directions such as "left", "right", "left side", "right side", "upper part", "lower part", "top", "bottom", etc. in the present invention are all defined based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the described structure must be constructed and operated in a specific orientation. Therefore, it cannot be understood as a limitation to the present invention. In the description of the present invention, the meaning of "a plurality" is more than two, unless otherwise specifically defined.
[0065] In the description of the present invention, unless otherwise clearly defined and limited, the terms "installation", "connection", and "connection" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected, or indirectly connected through an intermediate medium, and it can be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations. Detailed implementation mode one:
[0067] Refer to the accompanying drawings to illustrate this implementation mode. According to one aspect of the present invention, a detachable encapsulation structure for the optical fiber at the tail end of an intelligent FRP cable for full-length strain distribution monitoring is provided, including:
[0068] The lead area 1 is provided with at least one intelligent FRP rod 102 therein. One end of each intelligent FRP rod 102 passes through the anchor cup 4 and is encapsulated to form the lead area 1, and a lead optical fiber 101 is formed at one end of the lead area 1 away from the anchor cup 4; an optical fiber is wrapped inside the intelligent FRP rod 102. The lead area 1 is specifically located at the tail end of the intelligent FRP rod 102. Through the encapsulation of the lead sleeve 105, the lead armored sheath 103, and the lead resin 104, the transition area protection between the intelligent FRP rod 102 and the lead optical fiber 101 is realized, and at the same time, the encapsulation structure is located outside the anchor cup 4 to avoid adverse effects on the anchoring efficiency of the anchor cup 4.
[0069] The splicing area 2 is provided with joints 5 therein, which are arranged in one-to-one correspondence with the intelligent FRP rods 102. One end of each joint 5 passes through the end cover at the distal end of the casing 303 and forms a joint optical fiber 202 arranged opposite to the corresponding lead optical fiber 101. After the lead optical fiber 101 and the joint optical fiber 202 are spliced, they are encapsulated to form the splicing area 2. The splicing area 2 is specifically located at the tail end of the lead optical fiber 101. Through the encapsulation of the splicing heat shrinkable tube 204, the splicing resin 205, and the splicing sleeve 206, the protection of the splicing transition point between the lead optical fiber 101 and the joint optical fiber 202 is realized.
[0070] The casing area 3 is provided with a casing 303 therein, which is coaxially arranged with the anchor cup 4. The proximal end of the casing 303 is detachably connected to the end wall surface of the lead area 1 passing through the anchor cup 4 by bolts; the setting of the casing area 3 enables the casing area 3 body and the anchor cup 4 to cooperate to form a load-bearing component, so that the lead area 1 and the splicing area 2 can be protected inside the casing area 3 from external loads. At the same time, due to the detachable structure of the casing area 3, the splicing area 2 can be repeatedly installed, avoiding the disadvantages of being unable to perform secondary operations, disassemble and repair after being encapsulated in the anchor cup 4. At the same time, this can improve the efficiency of disassembly, modification and installation and shorten the construction period. The casing area protects the lead area 1 and the splicing area 2 through the casing sleeve 301, the front support plate 302, the casing 303, and the rear support plate 304, and at the same time realizes the detachable function of the structural casing area 3 and the renovation and repair of the splicing area 2 through the resin mold 306, the sealing plate 307, and the bolts 308.
[0071] In this embodiment, the lead optical fiber 101 is spliced with the joint optical fiber 201 formed at the end of the joint optical fiber 202 through a lead fiber core 107 formed at the end.
[0072] In this embodiment, both the lead area 1 and the splicing area 2 are arranged inside the casing sleeve 301. The casing sleeve 301 is coaxially arranged inside the casing 303 and is sleeved with the front support plate 302 and the rear support plate 304 at both ends respectively. Specifically, the front support plate 302 is used to provide support for the casing sleeve 301. The front support plate 302 specifically abuts against the grouting material in the anchor cup 4, and then the front support plate 302 is clamped after connecting the casing 303 to the anchor cup 4 through bolts.
[0073] In this embodiment, the front support plate 302 is located at the tail end of the anchor cup 4, and the rear support plate 304 is located at the tail end of the casing 303 and penetrates into the screw of the casing 303; the casing sleeve 301 passes through the front support plate 302 and the rear support plate 304 and is sealed by a sealing ring 305 between the support plate 304 and the sealing plate 307.
[0074] In this embodiment, the encapsulation structure further includes: a connection component, which is arranged between the sealing ring 305 and the sealing plate 307 and the joint 5 passes through the connection component, and is used to transmit the force of the joint 5 to the sealing plate 307. Thereby preventing external loads from acting on the lead area 1 and the fusion area 2, avoiding the stress on the optical fiber, and prolonging the service life of the optical fiber. The sealing ring 305 plays a role in isolating the casing sleeve 301, and the casing sleeve 301 can ensure that the lead area 1 and the fusion area 2 remain in a straight state within the casing area 3, ensuring a good usage state. The lead sleeve 105, the fusion sleeve 206, and the casing sleeve 301 are all thin-walled metal tubes.
[0075] In this embodiment, the connection component is a resin mold 306 and presents a stepped shape, with one end being a cylinder and the other end being a square prism. The cylindrical end is arranged between the sealing ring 305 and the sealing plate 307. The square prism end passes through a through hole on the sealing plate 307 with a cross-section consistent with that of the square prism and is blocked by a sealing cap 309. After the resin is cured inside, the resin mold 306 is bonded to the joint 5. Thereby, the resin mold 306, the internal resin, and the joint armor sheath 203 can be restricted through the sealing plate 307 to prevent the optical fiber joint from being pulled into the lead area 1 and the fusion area 2 during the stress process, improving the survival rate of the optical fiber; and since the resin mold 306 is not directly bonded to the through hole of the sealing plate 307, the detachable and reinstallable functions of the casing area 3 and the fusion area 2 can be realized.
[0076] In this embodiment, the lead area 1 includes a lead armor sheath 103, lead resin 104, a lead sleeve 105, and a lead heat shrink sleeve 106. The lead armor sheath 103 is sleeved on the lead optical fiber 101. The lead sleeve 105 is sleeved on the outer wall of the intelligent FRP rod 102 and accommodates a part of the lead armor sheath 103 inside. After the lead resin 104 is arranged between the lead sleeve 105 and the lead armor sheath 103, a lead heat shrink sleeve 106 is arranged at the distal end of the lead sleeve 105 to cooperate with the lead armor sheath 103 to encapsulate the resin. The lead heat shrink sleeve 106 is a heat shrinkable material, and the heat shrinkable tubes involved in this application can all use commercially available existing heat shrinkable tubes. The inner diameter of the lead armor sheath 103 needs to be larger than the outer diameter of the lead optical fiber 101 and smaller than the outer diameter of the FRP rod 102. The inner diameter of the lead sleeve 105 is larger than the outer diameter of the FRP rod 102, and the length needs to be greater than 40 mm. After heat shrinking, the lead heat shrink sleeve 106 tightly wraps and seals the lead sleeve 105 and the lead armor sheath 103.
[0077] In this embodiment, the welding zone 2 includes a joint armored sheath 203, a welding heat shrinkable tube 204, welding resin 205, a welding sleeve 206, and a joint heat shrinkable tube 207. Both ends of the welding heat shrinkable tube 204 are respectively sleeved on the lead armored sheath 103 and the joint armored sheath 203 of the joint 5, and the lead optical fiber 101 and the joint optical fiber 202 are encapsulated therein. The welding sleeve 206 is sleeved outside the welding heat shrinkable tube 204, and both ends are respectively connected to the corresponding lead armored sheath 103 and the joint armored sheath 203 through a joint heat shrinkable tube 207. The welding resin 205 is disposed in a cavity formed by the outer wall of the lead armored sheath 103, the outer wall of the joint armored sheath 203, the inner wall of the welding sleeve 206, and the inner wall of the joint heat shrinkable tube 207. The inner diameter of the welding heat shrinkable tube 204 needs to be greater than the outer diameter of the armored sheath, and at the same time, both ends of the armored sheath need to be wrapped therein. The inner diameter of the welding sleeve 206 needs to be greater than the outer diameter of the heat-shrunk welding heat shrinkable tube 204, and the length needs to be greater than 40 mm. After heat shrinkage, the joint heat shrinkable tube 207 tightly wraps the welding sleeve 206 and the armored sheath.
[0078] In this embodiment, in the casing zone 3, a front support plate 302, a casing 303, a rear support plate 304, and a sealing plate 307 are sequentially arranged from the proximal end to the distal end of the anchor cup 4. The front support plate 302 is clamped on the anchor cup 4 and limited by the casing 303. The casing 303 is installed on the anchor cup 4 by bolts. A stud is integrally provided at the distal end of the casing 303. Openings for the stud to pass through are provided on both the rear support plate 304 and the sealing plate 307. After the stud passes through the openings, bolts 308 are screwed onto each stud to complete the fixation. To improve stability, the number of studs is set to be multiple. In this application, four studs evenly distributed in a circumferential manner provide a stable connection form. By filling resin through a resin mold 306, the force on the joint 5 can be transmitted to the sealing plate 307 through the resin and the resin mold 306, which can prevent the force from being transmitted to the lead zone 1 and the welding zone 2 and extend the service life. The inner diameter of the casing sleeve 301 needs to be greater than the outer diameters of the lead zone 1 and the welding zone 2, and the length needs to be greater than 150 mm to facilitate secondary welding during optical fiber welding and disassembly and reinstallation.
[0079] According to another aspect of the present invention, a method for encapsulating the lead zone 1 is provided, including the following steps:
[0080] S11, stripping the lead optical fiber 101 from the intelligent FRP rod 102;
[0081] S12, sleeving the lead sleeve 105 outside the FRP rod 102 and pressing against the tail end of the original grouting material in the anchor cup 4, and then clamping the lead sleeve 105 and the FRP rod 102 with pliers;
[0082] S13, sleeving the lead armored sheath 103 on the outer layer of the lead optical fiber 101;
[0083] S14. Pour the lead resin 104 into the lead sleeve 105, slip the lead heat shrink sleeve 106 over the end of the lead sleeve 105, and heat the lead heat shrink sleeve 106 with a flame to achieve heat shrinkage sealing of the end of the lead sleeve 105.
[0084] According to one aspect of the present invention, there is provided a method for encapsulating the fusion zone 2, including the following steps:
[0085] S21. Strip the coating resins on the surfaces of the lead optical fiber 101 and the joint optical fiber 202 to obtain the lead fiber core 107 and the joint fiber core 201 respectively;
[0086] S22. Splice the lead fiber core 107 and the joint fiber core 201 by an optical fiber fusion splicer;
[0087] S23. Slip the fusion heat shrink tube 204 over the optical fiber fusion splice point and heat it by an optical fiber fusion splicer to achieve heat shrinkage encapsulation of the optical fiber fusion splice point;
[0088] S24. Slip the fusion sleeve 206 over the outer layer of the fusion heat shrink tube 204;
[0089] S25. Slip the joint heat shrink tube 207 over one end of the fusion sleeve 206 and heat the joint heat shrink tube 207 with a flame to achieve heat shrinkage sealing of one end of the fusion sleeve 206; after pouring the fusion resin 205 into the fusion sleeve 206, slip the joint heat shrink tube 207 over the other end of the fusion sleeve 206 and heat the joint heat shrink tube 207 with a flame to achieve heat shrinkage sealing of the other end of the fusion sleeve 206.
[0090] According to another aspect of the present invention, there is provided a method for encapsulating the casing zone 3, including the following steps:
[0091] S31. Slip the casing sleeve 301 over the outer sides of the lead zone 1 and the fusion zone 2 to ensure that the optical fiber in the casing zone 3 is in an axial straight state;
[0092] S32. Slip the front support plate 302 over the outer side of the casing sleeve 301 and press it tightly against the end of the anchor cup 4;
[0093] S33. Slip the casing 303 over the outer sides of the lead zone 1 and the fusion zone 2 and achieve a tight connection with the anchor cup 4 through bolts 308;
[0094] S34. Slip the rear support plate 304 over the outer layer of the joint casing sleeve 301 and pass it through the screw of the casing 303;
[0095] S35. Slip the sealing ring 305 over the outer side of the joint armored sheath 203 and press it tightly against the rear support plate 304;
[0096] S36. Slip the resin mold 306 over the outer side of the joint armored sheath 203 and press it tightly against the sealing ring 305;
[0097] S37. Insert the sealing plate 307 over the outer layer of the joint armored sheath 203, so that the square prism of the resin mold 306 is inserted into the sealing plate 307.
[0098] S38. Tighten the bolt 308 so that the sealing plate 307 presses against the casing sleeve 301 and the sealing ring 305 to achieve the sealing and restraint of the structure.
[0099] S39. After injecting resin into the resin mold 306, put the sealing cap 309 on the resin mold 306 to seal the tail end of the resin mold 306, and wait for the resin to fully cure, then the encapsulation is completed.
[0100] According to another aspect of the invention, there is provided a method for disassembling and reinstalling a detachable encapsulation structure for the end optical fiber of an intelligent FRP cable for full-length strain distribution monitoring, including the following steps:
[0101] S41. Loosen the bolt 308 and remove the sealing plate 307 from the casing 303.
[0102] S42. Remove the rear support plate 304 from the casing sleeve 301.
[0103] S43. Remove the casing 303 from the front support plate 302.
[0104] S44. Remove the front support plate 302 from the casing sleeve 301.
[0105] S45. Remove the casing sleeve 301 from the lead area 1 and the fusion area 2.
[0106] S46. Cut off the fusion area 2 to facilitate reinstallation.
[0107] S47. Operate according to steps S21 - S25 to reinstall the fusion area 2.
[0108] S48. Operate according to steps S31 - S39 to reinstall the casing area 3. Specific Embodiment 2:
[0110] The encapsulation and reinstallation operation steps for the polyimide distributed optical fiber intelligent CFRP cable are as follows:
[0111] I. Encapsulation of the lead segment:
[0112] S11. Strip the polyimide lead optical fiber from the intelligent CFRP rod by burning, and the length of the optical fiber is 150 mm.
[0113] S12. Put the lead sleeve 105 on the outside of the CFRP rod and press against the tail end of the original grouting material in the anchor cup.
[0114] S13. Sheath the lead armored sheath 103 over the outer layer of the lead optical fiber.
[0115] S14. Pour the lead resin 104 into the lead sleeve 105, and slip the lead heat shrink sleeve 106 over the end of the lead sleeve 105. Heat the lead heat shrink sleeve 106 with a flame to achieve heat shrinkage sealing at the end of the lead sleeve 105.
[0116] II. Encapsulation of the fusion section:
[0117] S21. Strip the coating resins on the surfaces of the lead optical fiber 101 and the joint optical fiber to obtain the lead core 107 and the joint core 201 respectively.
[0118] S22. Fusion splice the lead core 107 and the joint core 201 using an optical fiber fusion splicer.
[0119] S23. Slip the fusion heat shrink tube 204 over the optical fiber fusion point and heat it with an optical fiber fusion splicer to achieve heat shrinkage encapsulation of the optical fiber fusion point.
[0120] S24. Slip the fusion sleeve 206 over the outer layer of the fusion heat shrink tube.
[0121] S25. Slip the joint heat shrink tube 207 over one end of the fusion sleeve 206 and heat the joint heat shrink tube 207 with a flame to achieve heat shrinkage sealing at one end of the fusion sleeve 206. After pouring the fusion resin 205 into the fusion sleeve 206, slip the joint heat shrink tube 207 over the other end of the fusion sleeve 206 and heat the joint heat shrink tube 207 with a flame to achieve heat shrinkage sealing at the other end of the fusion sleeve 206.
[0122] III. Encapsulation of the sheath area:
[0123] S31. Slip the sheath sleeve 301 over the outside of the lead area 1 and the fusion area 2, ensuring that the optical fiber in the sheath area 3 is in an axial straight state.
[0124] S32. Slip the front support plate 302 over the outside of the sheath sleeve 301 and press it tightly against the end of the anchor cup 4.
[0125] S33. Slip the sheath 303 over the outside of the lead area 1 and the fusion area 1 and achieve a tight connection with the anchor cup 4 through the bolt 308.
[0126] S34. Slip the rear support plate 304 over the outer layer of the sheath sleeve 301 and pass it through the sheath screw.
[0127] S35. Slip the sealing ring 305 over the outside of the joint armored sheath 203 and press it tightly against the rear support plate 304.
[0128] S36. Slip the resin mold 306 over the outside of the joint armored sheath 203 and press it tightly against the sealing ring 305.
[0129] S37. Insert the sealing plate 307 over the outer layer of the joint armored sheath 203, so that the square prism of the resin mold is inserted into the opening of the sealing plate 307.
[0130] S38. Tighten the bolt 308. After locking the sealing plate 307, the sealing plate 307 presses the casing sleeve 301 and the sealing ring 305 to achieve the sealing and restraint of the structure.
[0131] S39. Inject resin into the resin mold 306, then put the sealing cap 309 on the resin mold 306 to seal the tail end of the resin mold 306, and wait for the resin to fully cure, then the encapsulation is completed.
[0132] IV. Structure disassembly and reassembly:
[0133] S41. Loosen the bolt 308 and remove the sealing plate 307 from the casing 303.
[0134] S42. Remove the rear support plate 304 from the casing sleeve 301.
[0135] S43. Remove the casing from the front support plate 302.
[0136] S44. Remove the front support plate 302 from the casing sleeve 301.
[0137] S45. Remove the casing sleeve 301 from the lead area 1 and the welding area 2.
[0138] S46. Cut off the welding area 2 to facilitate reassembly.
[0139] S47. Operate according to the steps of S21 - S25 to reassemble the welding area 2.
[0140] S48. Operate according to the steps of S31 - S39 to reassemble the casing area 3. Specific Embodiment 3:
[0142] The operating steps for encapsulating and reassembling the Teflon tightly wrapped distributed fiber optic intelligent GFRP cable are as follows:
[0143] I. Encapsulation of the lead segment:
[0144] S11. Strip the Teflon tightly wrapped lead fiber optic from the intelligent GFRP rod by means of sheath stripping, and the length of the fiber optic is 200 mm.
[0145] S12. Put the lead sleeve 105 on the outside of the GFRP rod and press against the tail end of the original grouting material in the anchor cup 4.
[0146] S13. Put the lead armored sheath 103 on the outer layer of the lead fiber optic 101.
[0147] S14. Pour the lead resin 104 into the lead sleeve 105, put a lead heat shrink sleeve 106 on the end of the lead sleeve 105, and heat the lead heat shrink sleeve 106 with a flame to achieve heat shrinkage sealing at the end of the lead sleeve 105.
[0148] II. Encapsulation of the fusion section:
[0149] S21. Strip the coating resins on the surface of the lead optical fiber 101 and the connector optical fiber to obtain a lead core 107 and a connector core 201 respectively.
[0150] S22. Splice the lead core 107 and the connector core 201 with an optical fiber fusion splicer.
[0151] S23. Put a fusion heat shrink tube 204 over the optical fiber fusion splice point and heat it with an optical fiber fusion splicer to achieve heat shrinkage encapsulation of the optical fiber fusion splice point.
[0152] S24. Put a fusion sleeve 206 over the outer layer of the fusion heat shrink tube.
[0153] S25. Put a connector heat shrink tube 207 on one end of the fusion sleeve 206 and heat the connector heat shrink tube 207 with a flame to achieve heat shrinkage sealing at one end of the fusion sleeve 206; after pouring the fusion resin 205 into the fusion sleeve 206, put a connector heat shrink tube 207 on the other end of the fusion sleeve 206 and heat the connector heat shrink tube 207 with a flame to achieve heat shrinkage sealing at the other end of the fusion sleeve 206.
[0154] III. Encapsulation of the sheath area:
[0155] S31. Put a sheath sleeve 301 over the outside of the lead area 1 and the fusion area 2 to ensure that the optical fiber in the sheath area 3 is in an axial straight state.
[0156] S32. Put a front support plate 302 over the outside of the sheath sleeve 301 and close to the end of the anchor cup 4.
[0157] S33. Put a sheath 303 over the outside of the lead area 1 and the fusion area 1 and tightly connect it to the anchor cup 4 through bolts 308.
[0158] S34. Put a rear support plate 304 over the outer layer of the sheath sleeve 301 and pass it through the sheath screw.
[0159] S35. Put a sealing ring 305 over the outside of the connector armored sheath 203 and close to the rear support plate 304.
[0160] S36. Put a resin mold 306 over the outside of the connector armored sheath 203 and close to the sealing ring 305.
[0161] S37. Put a sealing plate 307 over the outer layer of the connector armored sheath 203 so that the square prism of the resin mold is inserted into the opening of the sealing plate 307.
[0162] S38. Tighten the bolt 308. After locking the sealing plate 307, the sealing plate 307 presses the casing 301 of the casing and the sealing ring 305 to achieve the sealing and restraint of the structure.
[0163] S39. Inject resin into the resin mold 306, then put the sealing cap 309 on the resin mold 306 to seal the tail end of the resin mold 306, and wait for the resin to fully cure, and the encapsulation is completed.
[0164] IV. Structure disassembly and reinstallation:
[0165] S41. Loosen the bolt 308 and remove the sealing plate 307 from the casing 303.
[0166] S42. Remove the rear support plate 304 from the casing 301 of the casing.
[0167] S43. Remove the casing from the front support plate 302.
[0168] S44. Remove the front support plate 302 from the casing 301 of the casing.
[0169] S45. Remove the casing 301 from the lead area 1 and the welding area 2.
[0170] S46. Cut off the welding area 2 to facilitate reinstallation.
[0171] S47. Operate according to the steps of S21 - S25 to reinstall the welding area 2.
[0172] S48. Operate according to the steps of S31 - S39 to reinstall the casing area 3.
[0173] The embodiments of the present invention disclosed above are only used to help illustrate the present invention. The embodiments do not describe all the details in detail, nor do they limit the invention to the specific embodiments described. According to the content of this specification, many modifications and changes can be made. These embodiments are selected and specifically described in this specification to better explain the principle and practical application of the present invention, so that those skilled in the art can understand and utilize the present invention well.
Claims
1. A detachable encapsulation structure for the end optical fiber of an intelligent FRP cable for full-length strain distribution monitoring, characterized in that, Comprising: A lead area (1) in which at least one intelligent FRP rod (102) is provided. One end of each said intelligent FRP rod (102) penetrates through the anchor cup (4) and is encapsulated to form the lead area (1), and a lead optical fiber (101) is formed at the end of the lead area (1) away from the anchor cup (4); A fusion splicing area (2) in which the connectors (5) provided therein are arranged in one-to-one correspondence with the intelligent FRP rods (102). One end of each said connector (5) forms a connector optical fiber (202) arranged opposite to the corresponding lead optical fiber (101) after passing through the end cover at the distal end of the casing (303). The lead optical fiber (101) and the connector optical fiber (202) are fusion spliced and encapsulated to form the fusion splicing area (2); A casing area (3) in which the casing (303) provided therein is coaxially arranged with the anchor cup (4), and the proximal end of the casing (303) is detachably connected to the wall surface of the lead area (1) penetrating end of the anchor cup (4); Both the lead area (1) and the fusion splicing area (2) are arranged within the casing sleeve (301). The casing sleeve (301) is coaxially arranged within the casing (303) and is sleeved with the front support plate (302) and the rear support plate (304) of the casing (303) at both ends respectively; The front support plate (302) is located at the tail end of the anchor cup (4), and the rear support plate (304) is located at the tail end of the casing (303) and penetrates into a screw provided at the tail end of the casing (303). The casing sleeve (301) passes through the front support plate (302) and the rear support plate (304), and is sealed by a sealing ring (305) between the rear support plate (304) and the sealing plate (307); The encapsulation structure further includes a connection assembly provided between the sealing ring (305) and the sealing plate (307), and the connector (5) passes through the connection assembly, for transmitting the force of the connector (5) to the sealing plate (307); The connection assembly is a resin mold (306) and presents a stepped shape, with one end being a cylinder and the other end being a square prism. The cylinder end is arranged between the sealing ring (305) and the sealing plate (307), and the square prism end passes through a through hole provided on the sealing plate (307) with a cross section consistent with that of the square prism and is blocked by a sealing cap (309). Resin is provided inside, and after curing, the resin bonds the resin mold (306) and the connector (5), so that the resin mold (306), the internal resin, and the connector armored sheath (203) can be constrained by the sealing plate (307), to prevent the optical fiber connector from pulling the lead area (1) and the fusion splicing area (2) during the force application process, and improve the survival rate of the optical fiber; and since the resin mold (306) is not directly bonded to the through hole of the sealing plate (307), the detachable and reinstallable functions of the casing area (3) and the fusion splicing area (2) can be realized.
2. The detachable encapsulation structure of the intelligent FRP cable end optical fiber for full-length strain distribution monitoring according to claim 1, wherein: The lead optical fiber (101) is fusion spliced with the connector optical fiber (201) formed at the end of the connector optical fiber (202) through a lead fiber core (107) formed at the end.
3. The detachable encapsulation structure of the intelligent FRP cable end optical fiber for full-length strain distribution monitoring according to claim 1, characterized in that: The lead area (1) further includes a lead armored sheath (103), lead resin (104), a lead sleeve (105), and a lead heat shrinkable sleeve (106). The lead armored sheath (103) is sleeved on the lead optical fiber (101). The lead sleeve (105) is sleeved on the outer wall of the intelligent FRP rod (102) and accommodates a part of the lead armored sheath (103) inside. After the lead resin (104) is arranged between the lead sleeve (105) and the lead armored sheath (103), a lead heat shrinkable sleeve (106) is arranged at the distal end of the lead sleeve (105) to cooperate with the lead armored sheath (103) to encapsulate the resin.
4. The detachable encapsulation structure of the intelligent FRP cable end optical fiber for full-length strain distribution monitoring according to claim 3, wherein: The splicing area (2) further includes a joint armored sheath (203), a splicing heat shrinkable tube (204), splicing resin (205), a splicing sleeve (206), and a joint heat shrinkable tube (207). The two ends of the splicing heat shrinkable tube (204) are respectively sleeved on the lead armored sheath (103) and the joint armored sheath (203) of the joint (5) and encapsulate the lead optical fiber (101) and the joint optical fiber (202) inside. The splicing sleeve (206) is sleeved outside the splicing heat shrinkable tube (204), and the two ends are respectively connected to the corresponding lead armored sheath (103) and joint armored sheath (203) through a joint heat shrinkable tube (207). The splicing resin (205) is arranged in the cavity formed by the outer wall of the lead armored sheath (103), the outer wall of the joint armored sheath (203), the inner wall of the splicing sleeve (206), and the inner wall of the joint heat shrinkable tube (207).
5. A packaging method for a detachable packaging structure of an intelligent FRP cable end optical fiber for full-length strain distribution monitoring according to claim 1, characterized in that, The encapsulation method of the lead area includes the following steps: S11, stripping the lead optical fiber (101) from the intelligent FRP rod (102); S12, sleeving the lead sleeve (105) outside the intelligent FRP rod (102) and pressing against the tail end of the original grouting material in the anchor cup (4); S13, sleeving the lead armored sheath (103) on the outer layer of the lead optical fiber (101); S14, pouring the lead resin (104) into the lead sleeve (105), and after sleeving the lead heat shrinkable sleeve (106) on the end of the lead sleeve (105), heating to realize the heat shrinkage sealing of the end of the lead sleeve (105).
6. A packaging method for a detachable packaging structure of an intelligent FRP cable end optical fiber for full-length strain distribution monitoring according to claim 1, characterized in that, The encapsulation method of the splicing area includes the following steps: S21, stripping the coating resin on the surfaces of the lead optical fiber (101) and the joint optical fiber (202) to respectively obtain a lead fiber core (107) and a joint fiber core (201); S22, splicing the lead fiber core (107) and the joint fiber core (201) to form an optical fiber splice point; S23, sleeving the splicing heat shrinkable tube (204) outside the optical fiber splice point, the lead armored sheath (103), and the joint armored sheath (203) and then heating to realize the heat shrinkage encapsulation of the optical fiber splice point; S24, sleeving the splicing sleeve (206) on the outer layer of the splicing heat shrinkable tube (204); S25. Slip a joint heat-shrinkable tube (207) over one end of the fusion sleeve (206). After heating the joint heat-shrinkable tube (207) to achieve heat-shrink sealing at one end of the fusion sleeve (206), pour the fusion resin (205) into the fusion sleeve (206). Then, slip a joint heat-shrinkable tube (207) over the other end of the fusion sleeve (206) and heat this end of the joint heat-shrinkable tube (207) to achieve heat-shrink sealing at the other end of the fusion sleeve (206).
7. A packaging method for a detachable packaging structure of an intelligent FRP cable end optical fiber for full-length strain distribution monitoring according to claim 1, characterized in that, The encapsulation method for the grommet area includes the following steps: S31. Slip the grommet sleeve (301) over the outside of the lead area (1) and the fusion area (2), ensuring that the optical fiber in the grommet area (3) is in an axial straight state; S32. Slip the front support plate (302) over the outside of the grommet sleeve (301) and press it tightly against the tail end of the anchor cup (4); S33. Slip the grommet (303) over the outside of the lead area (1) and the fusion area (2), and achieve a tight connection with the anchor cup (4) through bolts (308); S34. Slip the rear support plate (304) over the outer layer of the joint grommet sleeve (301) and pass it through the screw of the grommet (303); S35. Slip the sealing ring (305) over the outside of the joint armored sheath (203) and press it tightly against the rear support plate (304); S37. Slip the resin mold (306) over the outside of the joint armored sheath (203) and press it tightly against the sealing ring (305); S38. Slip the sealing plate (307) over the outer layer of the joint armored sheath (203), and make the resin mold (306) pass through the sealing plate (307); S39. Tighten the bolts (308). After locking the sealing plate (307), make the sealing plate (307) squeeze the grommet sleeve (301) and the sealing ring (305) to achieve the sealing and restraint of the structure; S40. Inject resin into the resin mold (306), then slip the sealing cap (309) over the resin mold (306) to achieve the end sealing of the resin mold (306), and wait for the resin to fully cure, and the encapsulation is completed.
8. A detachable and reinstallable method for a detachable encapsulation structure of an intelligent FRP cable end optical fiber for full-length strain distribution monitoring according to claim 1, characterized in that, The detachable and reinstallable method for the grommet area includes the following steps: S41. Loosen the bolts (308) and remove the sealing plate (307) from the grommet (303); S42. Remove the rear support plate (304) from the grommet sleeve (301); S43. Remove the grommet (303) from the front support plate (302); S44. Remove the front support plate (302) from the grommet sleeve (301); S45. Remove the grommet sleeve (301) from the lead area (1) and the fusion area (2); S46. Cut off the fusion area (2) to facilitate reinstallation; S47. Operate according to the steps of S21 - S25 to reinstall the fusion area (2); S48. Operate according to the steps of S31 - S39 to reinstall the grommet area (3).