Intelligent inhaul cable with central steel wire slotted coupling fiber bragg grating and manufacturing method of intelligent inhaul cable

Abstract

The invention discloses a central steel wire slotted coupling fiber grating intelligent inhaul cable and a manufacturing method, the central steel wire slotted coupling fiber grating intelligent inhaul cable comprises a sealed connecting cylinder, one end of the sealed connecting cylinder is connected with an anchor cup, and a steel wire bundle penetrates from an inlet of one end, far away from the anchor cup, of the sealed connecting cylinder and is separated and dispersed in the anchor cup; the scattered single steel wires are arranged on the inner side of the sealing connecting cylinder in parallel and penetrate out of an outlet in the other end of the anchor cup, the scattered single steel wires penetrate through anchor plate round holes formed in the inner side of the anchor cup, a center steel wire coupled with the fiber bragg grating is arranged in the center of the steel wire bundle, and the center steel wire and other single steel wires are twisted into the steel wire bundle. The system has the functions of long-term prestress monitoring, information transmission and safety early warning. Deviation between actual prestress and designed prestress is found in time, on one hand, the safety state of the inhaul cable is mastered, and overall operation safety of a project is guaranteed; and on the other hand, the technical support is provided for the optimization design of the product by monitoring the change condition of the cable force for a long time.

Description

Technical Field

[0001] The present invention relates to the technical field of cables, and in particular to an intelligent cable with a central steel wire slot coupled to an optical fiber grating and a manufacturing method thereof. Background Art

[0002] Prestressed cables are the most important load-bearing components in large-span spatial structures and bridge structures. Their reliability and durability are directly related to the safety and service life of the structure. Many projects at home and abroad have caused structural collapse accidents due to the breakage of cables, which has caused great social impact. At present, cables used in domestic structures and bridge projects mostly use external sensor equipment to monitor cable force, including vibrating string pressure sensors and magnetic flux sensors. These sensors are separate from the cables and are generally installed at the end of the anchor during construction, such as vibrating string pressure sensors; or inserted into the cable body during production, such as magnetic flux sensors. This structure is not only unsightly in appearance, but also will cause measurement value drift after long-term use, affecting the spatial structure and the accurate judgment of the prestress of the cable. Summary of the invention

[0003] In order to solve the technical problems mentioned in the background technology, the present invention provides a smart cable with a central steel wire slot coupled to a fiber grating and a manufacturing method thereof.

[0004] The present invention adopts the following technical scheme: a smart cable with a central steel wire slot coupled to an optical fiber Bragg grating, comprising a sealed connecting tube; one end of the sealed connecting tube is connected to an anchor cup; a fixing nut is arranged outside the anchor cup; the steel wire bundle penetrates from an entrance at one end of the sealed connecting tube away from the anchor cup, and is separated and spread out in the anchor cup, and the spread single steel wires are arranged in parallel on the inner side of the sealed connecting tube and pass out from the outlet at the other end of the anchor cup; a sealing fixing is arranged at the connection between the steel wire bundle and the entrance of the sealed connecting tube; the anchor cup and the sealed connecting tube are filled with casting material; the spread single steel wire passes through the circular hole of the anchor plate arranged on the inner side of the anchor cup, and the end of the single steel wire is processed into a swaging head; wherein, a central steel wire coupled with an optical fiber Bragg grating is arranged at the center of the steel wire bundle, and the central steel wire is twisted and braided with other single steel wires into a steel wire bundle; the central steel wire is fixedly connected to the central hole of the anchor plate, and the lead wire for connecting the optical fiber Bragg grating passes out from the central hole on the surface of the anchor plate.

[0005] Furthermore, a notch is arranged on the top of the central steel wire; the optical fiber Bragg grating is bonded in the notch; the optical fiber Bragg grating is coated with a heat-resistant protective layer; the lead wire passes through the inside of the optical fiber Bragg grating, and an armor layer is arranged outside the lead wire.

[0006] Furthermore, the depth of the notch is 1-1.2 mm; the width of the notch is 1-1.2 mm.

[0007] Furthermore, the surface of the steel wire bundle is wrapped with a tape and then hot-extruded with a high-density polyethylene protective layer.

[0008] The present invention also provides a method for manufacturing the above-mentioned intelligent cable with a central steel wire slot coupled to a fiber grating, comprising the following steps: The central steel wire is made, the steel wire is pre-tensioned, the top is grooved, the fiber grating is set in the groove by using adhesive coupling, and the steel wire is coated with a heat-resistant protective layer; To make a steel wire bundle, all the steel wires are arranged in order according to the specifications, and the central steel wire is placed in the center of the cable body. All the steel wires are twisted together through a twisting process; the surface of the steel wire bundle is wrapped with a tape and then hot-extruded with high-density polyethylene to make a semi-parallel steel wire bundle cable body; After the steel wire bundle passes through the sealing connection tube, anchor cup and anchor plate in sequence, each steel wire is separated; the central steel wire needs to be inserted into the central hole of the anchor plate, and the fiber optic Bragg grating is protected by a sleeve; the remaining steel wires are headed by a head machine and fixed to the anchor plate; Pouring casting material into the anchor cup and the sealing connection tube, and fixing the anchor plate and the anchor cup; The cable is tensioned on the testing machine so that the central steel wire and the overall cable are subjected to force in coordination, and finally the fitting coefficient between the force value measured by the fiber Bragg grating and the force value of the testing machine is determined.

[0009] Compared with the prior art, the advantages of the present invention are: the intelligent cable with a central steel wire slot coupled with a fiber grating designed by the present invention implants the fiber grating into the interior of the cable body steel wire, and with the help of the anchoring and torsion effect of the end of the steel wire under stress, the central steel wire coupled with the fiber grating is naturally gripped, achieving the effect of coordinated deformation of the fiber grating sensing tendon and the steel wire, thereby enabling the cable to have the functions of long-term prestress monitoring, information transmission, and safety warning without reducing its own mechanical properties.

[0010] When a deviation is found between the actual prestress and the designed prestress, on the one hand, the safety status of the cables can be monitored and timely maintenance suggestions can be provided to managers to ensure the overall operational safety of the project; on the other hand, through long-term monitoring of cable force changes, data can be accumulated for scientific decision-making and spatial structure and bridge structure design, providing technical support for product optimization design and further improving the safety of spatial structures and bridge structures. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 It is a schematic diagram of the overall structure of the intelligent cable with a central steel wire slot coupled to a fiber grating of the present invention; Figure 2 is a schematic cross-sectional view of the center steel wire of the present invention; Figure 3 It is a schematic cross-sectional view of the steel wire bundle of the present invention.

[0012] in: 1-sealed connecting tube, 2-anchor cup, 3-fixing nut, 4-wire bundle, 5-sealed fixing, 6-anchor plate, 7-fiber Bragg grating, 8-center steel wire, 9-lead, 10-high-density polyethylene protective layer, 8-1-Notch. DETAILED DESCRIPTION

[0013] In order to facilitate those skilled in the art to understand the technical solution of the present invention, further description will be given below with reference to the accompanying drawings. It should be understood that these descriptions are only exemplary and are not intended to limit the scope of the present invention.

[0014] In the following detailed description, for ease of explanation, many specific details are set forth to provide a comprehensive understanding of embodiments of the present invention. However, it is apparent that one or more embodiments may be implemented without these specific details. In addition, in the following description, descriptions of known structures and techniques are omitted to avoid unnecessary confusion of concepts of the present invention.

[0015] like Figure 1 The figure shows the overall structure of the smart cable with a central steel wire slot coupled to a fiber grating of the present invention, which includes a sealed connection tube 1, one end of which is connected to an anchor cup 2, a fixing nut 3 is arranged outside the anchor cup 2, a steel wire bundle 4 is inserted from the entrance of the sealed connection tube 1 away from the anchor cup 2, and is separated and spread in the anchor cup 2, and the spread single steel wires are arranged in parallel on the inner side of the sealed connection tube 1 and pass through the outlet at the other end of the anchor cup 2, and a sealing fixing 5 is arranged at the connection between the steel wire bundle 4 and the entrance of the sealed connection tube 1. The anchor cup 2 and the sealed connection tube 1 are filled with casting material, and the spread single steel wire passes through the circular hole of the anchor plate 6 arranged on the inner side of the anchor cup 2, and the end of the single steel wire is processed into a swaging head to enhance the anchoring performance. Among them, a central steel wire 8 coupled with a fiber Bragg grating 7 is arranged at the center of the steel wire bundle 4, the central steel wire 8 is twisted and braided with other single-strand steel wires to form a steel wire bundle 4, the central steel wire 8 is fixedly connected to the central hole of the anchor plate 6, and a lead wire 9 for connecting the fiber Bragg grating 7 passes through the central hole of the anchor plate 6. This embodiment uses a fiber Bragg grating as a light conduction sensor, which is not interfered by electromagnetic signals during transmission, is corrosion-resistant, has stable chemical properties, and is suitable for long-term monitoring.

[0016] like Figure 2 As shown, it is a schematic cross-sectional view of the central steel wire of the present invention. A notch 8-1 is set at the top of the central steel wire 8, and the optical fiber grating 7 is bonded in the notch 8-1. In specific implementation, the depth of the notch 8-1 is 1-1.2 mm; the width of the notch 8-1 is 1-1.2 mm. The optical fiber grating 7 is coated with a heat-resistant protective layer, and the lead wire 9 passes through the inside of the optical fiber grating 7. An armor layer is set outside the lead wire 9. The lead wire part adopts armoring or other packaging processes to enhance the bending resistance and ensure its survival rate.

[0017] like Figure 3As shown, in a specific implementation, the surface of the steel wire bundle 4 is wrapped with a tape and then a high-density polyethylene protective layer 10 is hot-extruded.

[0018] The present invention also provides a method for manufacturing the above-mentioned intelligent cable with a central steel wire slot coupled to a fiber grating, which specifically comprises the following steps: A central steel wire 8 is made, the steel wire is pre-tensioned, a groove is made on the top, a fiber Bragg grating is arranged in the groove 8-1 by using an adhesive for coupling, and a heat-resistant protective layer is coated on the outside of the steel wire; To make a steel wire bundle 4, all the steel wires are arranged in order according to the specifications, wherein the central steel wire is placed in the center of the cable body, and all the steel wires are twisted together through a twisting process; the surface of the steel wire bundle is wrapped with a tape and then hot-extruded with high-density polyethylene to make a semi-parallel steel wire bundle cable body; After the steel wire bundle 4 passes through the sealing connection tube 1, the anchor cup 2 and the anchor plate 6 in sequence, each steel wire is separated; the central steel wire 8 needs to be inserted into the central hole of the anchor plate 6, and the fiber optic grating 7 is protected by a sleeve; the remaining steel wires are headed by a head machine and fixed to the anchor plate; Pour the casting material into the anchor cup 2 and the sealing connection tube 1, and fix the anchor plate 6 to the anchor cup 2; The cable is tensioned on the testing machine so that the central steel wire 8 and the whole cable are subjected to force in coordination, and finally the fitting coefficient between the force value measured by the fiber grating and the force value of the testing machine is determined.

[0019] In summary, the intelligent cable with a central steel wire slot coupled with a fiber grating designed by the present invention implants the fiber grating into the steel wire of the cable body, and with the help of the anchoring and torsion effect of the end of the steel wire under stress, the central steel wire coupled with the fiber grating is naturally gripped, achieving the effect of coordinated deformation of the fiber grating sensing tendons and the steel wire, thereby enabling the cable to have the functions of long-term prestress monitoring, information transmission, and safety warning without reducing its own mechanical properties. When it is found that there is a deviation between the actual prestress and the designed prestress, on the one hand, the safety status of the cable can be mastered, and timely maintenance suggestions can be provided to managers to ensure the overall operational safety of the project; on the other hand, by long-term monitoring of the changes in cable force, data can be accumulated for scientific decision-making and spatial structure and bridge structure design, providing technical support for the optimal design of products, and further improving the safety of spatial structures and bridge structures.

[0020] The above embodiments are merely descriptions of preferred implementation modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A smart cable with a central steel wire slot coupled to a fiber grating, characterized in that: The invention comprises a sealing connection tube (1); one end of the sealing connection tube (1) is connected to an anchor cup (2); a fixing nut (3) is arranged on the outer surface of the anchor cup (2); a steel wire bundle (4) penetrates from an entrance at one end of the sealing connection tube (1) away from the anchor cup (2), and is spread out in the anchor cup (2); the spread single steel wires are arranged in parallel on the inner side of the sealing connection tube (1) and pass out from an exit at the other end of the anchor cup (2); a sealing fixing piece (5) is arranged at the connection between the steel wire bundle (4) and the entrance of the sealing connection tube (1); the anchor cup (2) and a sealing connection tube (1) filled with casting material; the scattered single steel wires pass through the circular hole of the anchor plate (6) arranged on the inner side of the anchor cup (2), and the ends of the single steel wires are processed into swaged heads; wherein a central steel wire (8) coupled with an optical fiber Bragg grating (7) is arranged at the center of the steel wire bundle (4), and the central steel wire (8) and other single steel wires are twisted and braided into a steel wire bundle (4); the central steel wire (8) is fixedly connected to the central hole on the surface of the anchor plate (6), and a lead wire (9) for connecting the optical fiber Bragg grating (7) passes through the central hole of the anchor plate (6).

2. The intelligent cable with a central steel wire slot coupled to a fiber grating according to claim 1, characterized in that: A notch (8-1) is provided at the top of the central steel wire (8); a fiber grating (7) is bonded inside the notch (8-1); the outside of the fiber grating (7) is coated with a heat-resistant protective layer; a lead wire (9) passes through the inside of the fiber grating (7), and an armor layer is provided outside the lead wire (9).

3. The intelligent cable with a central steel wire slot coupled to a fiber grating according to claim 2, characterized in that: The depth of the notch (8-1) is 1-1.2 mm; The width of the notch (8-1) is 1-1.2 mm.

4. The intelligent cable with a central steel wire slot coupled to a fiber grating according to claim 3, characterized in that: The surface of the steel wire bundle (4) is wrapped with a tape and then hot-extruded with a high-density polyethylene protective layer (10).

5. A method for manufacturing a smart cable with a central steel wire slot coupled to a fiber grating as claimed in any one of claims 1 to 4, characterized in that: The steps include: A central steel wire (8) is manufactured, the steel wire is pre-tensioned, a groove is cut on the top, a fiber grating is arranged in the groove (8-1) by using an adhesive for coupling, and a heat-resistant protective layer is coated on the outside of the steel wire; Making a steel wire bundle (4), arranging all the steel wires in order according to specifications, wherein the central steel wire is placed at the center of the cable body, and twisting all the steel wires together through a twisting process; wrapping the surface of the steel wire bundle with a tape and then hot-extrude high-density polyethylene to make a semi-parallel steel wire bundle cable body; After the steel wire bundle (4) passes through the sealing connection tube (1), the anchor cup (2) and the anchor plate (6) in sequence, each steel wire is separated; the central steel wire (8) needs to be inserted into the central hole of the anchor plate (6), and the optical fiber Bragg grating (7) is protected by a sleeve; the remaining steel wires are headed by a head-heading machine and fixed to the anchor plate; Pouring the casting material into the anchor cup (2) and the sealing connection tube (1), and fixing the anchor plate (6) to the anchor cup (2); The cable is tensioned on a testing machine so that the central steel wire (8) and the whole cable are subjected to force in coordination, and finally a fitting coefficient between the force value measured by the fiber grating and the force value of the testing machine is determined.

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