Parallel steel wire inhaul cable with built-in fiber grating sensors and cable-stayed bridge

Abstract

The utility model discloses a parallel steel wire inhaul cable with built-in fiber grating sensors and a cable-stayed bridge. The parallel steel wire inhaul cable with the built-in fiber grating sensors comprises an outer sheath, a first steel wire, grating array sensing optical fibers and a plurality of second steel wires. The first steel wire is arranged in the outer sheath and is arranged along the axial direction of the outer sheath, and a mounting channel with at least one open end is arranged along the axial direction of the first steel wire; the grating array sensing optical fiber comprises a strain grating array sensing optical fiber and a temperature grating array sensing optical fiber, the strain grating array sensing optical fiber and the temperature grating array sensing optical fiber are arranged in the mounting channel, and one end of each of the strain grating array sensing optical fiber and the temperature grating array sensing optical fiber extends out of the opening of the mounting channel; and the plurality of second steel wires are filled in the outer sheath and surround the periphery of the first steel wires. According to the scheme, force measurement and temperature measurement can be carried out at the same time, the influence of the temperature is considered, temperature data near each grating site can be compensated, the influence of the temperature on strain measurement is eliminated, the measurement precision of the cable force value is improved, and the practicability is good.

Description

Technical Field

[0001] The utility model relates to the technical field of cables, in particular to a parallel steel cable with a built-in optical fiber grating sensor and a cable-stayed bridge. Background Art

[0002] A cable-stayed bridge is a type of bridge that uses many cables to pull the main beam directly onto the bridge tower. It relies on its own main beam, tower and cable to form a self-anchored structural system. The cable of a cable-stayed bridge is the main load-bearing component of the bridge, and its stress condition is directly related to whether the bridge is in a safe operating state.

[0003] For example, patent CN219930711U discloses a cable for a cable-stayed bridge, which is provided with a rubber sleeve, which is arranged on the outer surface of the cable so that the sides of the two extension blocks that are close to each other are in contact with each other. At this time, the rubber sleeve can protect the outer surface of the cable body, reduce the direct contact between the cable body and the air, and thus help to slow down the oxidation of the cable body and extend the overall service life of the cable.

[0004] Since cable force is an important parameter for evaluating cable structures, some cable-stayed bridges currently install pressure sensors between the cable anchors and the cable hole pads, and use the strain of the pressure sensor material to measure the cable force. This is too costly and can only measure the tension of the anchor head, so its practicality needs to be improved. Utility Model Content

[0005] The purpose of the utility model is to overcome the above technical deficiencies and propose a parallel steel wire cable and a cable-stayed bridge with a built-in fiber optic grating sensor, so as to solve the technical problem that the existing technology uses the strain of the pressure sensor material to measure the cable force, which can only measure the tension of the anchor head and has a need to improve its practicality.

[0006] In order to achieve the above technical purpose, the utility model adopts the following technical solutions:

[0007] In a first aspect, the utility model provides a parallel steel wire cable with a built-in fiber grating sensor, comprising:

[0008] Outer sheath;

[0009] A first steel wire is arranged in the outer sheath and arranged along the axial direction of the outer sheath, and is provided with a mounting channel with at least one end open along the axial direction;

[0010] Grating array sensing optical fibers, including strain grating array sensing optical fibers and temperature grating array sensing optical fibers, wherein the strain grating array sensing optical fibers and the temperature grating array sensing optical fibers are arranged in the installation channel, and one end of each of the two extends out of the opening of the installation channel; and

[0011] A plurality of second steel wires are filled in the outer sheath and are arranged around the outer periphery of the first steel wire.

[0012] In some embodiments, a connecting groove connected to the outside is formed on the side wall of the installation channel, and the connecting groove extends along the axis of the first steel wire and is connected to the open end of the installation channel.

[0013] In some embodiments, the parallel steel wire cable with built-in fiber grating sensor further includes an inner sheath, and the inner sheath is sleeved outside the first steel wire.

[0014] In some embodiments, the installation channels and the connecting grooves are provided in two groups, the installation channels of the two groups are arranged at intervals along the circumference of the first steel wire, and each connecting groove is provided in the corresponding installation channel;

[0015] The strain grating array sensing optical fiber and the temperature grating array sensing optical fiber are respectively arranged in the two installation channels.

[0016] In some embodiments, the parallel steel wire cable with built-in fiber grating sensor further includes structural adhesive, and the structural adhesive is bonded to the strain grating array sensing optical fiber and the inner wall of the corresponding installation channel.

[0017] In some embodiments, the parallel steel wire rope with built-in fiber grating sensor also includes a round tube, which is sleeved outside the temperature grating array sensing optical fiber and placed in an installation channel corresponding to the temperature grating array sensing optical fiber.

[0018] In some embodiments, each of the second steel wires is arranged along the axial direction of the outer sheath, and a polyester fiber belt is wound around the plurality of second steel wires, and the polyester fiber belt is located on the inner side of the outer sheath.

[0019] In some embodiments, the outer sheath is a high density polyethylene outer sheath.

[0020] In some embodiments, the parallel steel wire cable with built-in fiber grating sensor further comprises a connecting tube, an anchor cup and an anchor ring connected in sequence, the connecting tube is connected to the first steel wire, the outer sheath and the plurality of the second steel wires, and is located at one end of the installation channel with an opening;

[0021] Wherein, the ends of the strain grating array sensing optical fiber and the temperature grating array sensing optical fiber extending out of the open opening of the installation channel are sequentially passed through the connecting tube, the anchor cup and the anchor ring.

[0022] In a second aspect, the utility model further provides a cable-stayed bridge, which includes parallel steel cables with built-in fiber grating sensors as described in any one of the above items.

[0023] Compared with the prior art, in the parallel steel wire cable with built-in fiber grating sensor provided by the utility model, an installation channel is provided on the first steel wire in the middle, and the strain grating array sensing fiber and the temperature grating array sensing fiber are placed in the installation channel of the first steel wire, and then a plurality of second steel wires are arranged around the periphery of the first steel wire, so that the physical strength of the strain grating array sensing fiber and the temperature grating array sensing fiber are guaranteed by means of the first steel wire and the second steel wire, solving the problem that the traditional measurement method is easily interfered by external factors. And with the help of the strain grating array sensing fiber and the temperature grating array sensing fiber, force and temperature can be measured at the same time, and considering the influence of temperature, the temperature data near each grating site can be compensated, the influence of temperature on the measurement of strain can be eliminated, and the measurement accuracy of the cable force value can be improved, and the practicality is good. At the same time, the optical fiber can transmit a wide range of light wave frequencies, with low transmission loss, high linear response and low noise level, and can achieve a balance between accuracy and sensitivity within a large measurement range, solving the problem of cost and portability, and the large-scale and distributed nature of the fiber grating array greatly improves the measurement accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a cross-sectional schematic diagram of a parallel steel wire cable with a built-in fiber grating sensor provided by an embodiment of the utility model;

[0025] Figure 2 yes Figure 1 A schematic diagram of the structure of the first steel wire and the grating array sensing optical fiber;

[0026] Figure 3 yes Figure 2 Schematic diagram of the structure of the first steel wire

[0027] Figure 4 yes Figure 1 Schematic diagram of parallel steel wire cables with built-in fiber grating sensors.

[0028] Description of reference numerals:

[0029] 1. Outer sheath; 2. First steel wire; 2a. Installation channel; 2b. Connecting groove; 3. Strain grating array sensing optical fiber; 4. Temperature grating array sensing optical fiber; 5. Second steel wire; 6. Inner sheath; 7. Structural adhesive; 8. Round tube; 9. Polyester fiber belt; 10. Connecting tube; 11. Anchor cup; 12. Anchor ring; 13. Optical fiber pigtail; 14. Optical fiber flange. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical solution and advantages of the utility model more clear, the utility model is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the utility model and are not used to limit the utility model.

[0031] In order to solve the technical problems in the prior art of measuring cable tension by using the strain of pressure sensor materials, which is too costly, can only measure the tension of the anchor head, and has a need to improve its practicality, the utility model provides a parallel steel wire cable with a built-in fiber optic grating sensor, which can measure force and temperature at the same time, eliminates the influence of temperature on the measurement of strain, improves the measurement accuracy of the cable force value, has good practicality, and solves the problems of cost and portability.

[0032] It should be noted that the parallel steel wire cables with built-in fiber grating sensors described in the utility model are used for but not limited to cable-stayed bridges, etc. For the convenience of explanation, in the utility model, only the application of parallel steel wire cables with built-in fiber grating sensors in cable-stayed bridges is used as an example for explanation, and the principle of applying parallel steel wire cables with built-in fiber grating sensors to other types of equipment is essentially the same as the principle applied to cable-stayed bridges, which will not be repeated here.

[0033] See also Figures 1 to 3 , Figures 1 to 3 The present invention is a schematic structural diagram of a parallel steel wire cable with a built-in fiber grating sensor in one embodiment of the utility model. The parallel steel wire cable with a built-in fiber grating sensor comprises an outer sheath 1, a first steel wire 2, a grating array sensing optical fiber and a plurality of second steel wires 5; the first steel wire 2 is arranged in the outer sheath 1 and arranged along the axial direction of the outer sheath 1, and an installation channel 2a with at least one end open is provided along its axial direction; the grating array sensing optical fiber comprises a strain grating array sensing optical fiber 3 and a temperature grating array sensing optical fiber 4, the strain grating array sensing optical fiber 3 and the temperature grating array sensing optical fiber 4 are arranged in the installation channel 2a, and one end of each of the strain grating array sensing optical fiber 3 and the temperature grating array sensing optical fiber 4 extends out of the opening of the installation channel 2a; a plurality of second steel wires 5 are filled in the outer sheath 1 and arranged around the outer periphery of the first steel wire 2.

[0034] In the parallel steel wire cable with built-in fiber grating sensor provided by the utility model, an installation channel 2a is provided on the middle first steel wire 2, and the strain grating array sensing fiber 3 and the temperature grating array sensing fiber 4 are placed in the installation channel 2a of the first steel wire 2, and then a plurality of second steel wires 5 are arranged around the periphery of the first steel wire 2, so that the physical strength of the strain grating array sensing fiber 3 and the temperature grating array sensing fiber 4 is ensured by means of the first steel wire 2 and the second steel wire 5, and the problem that the traditional measurement method is easily disturbed by external factors is solved. And with the help of the strain grating array sensing fiber 3 and the temperature grating array sensing fiber 4, force and temperature can be measured at the same time, and considering the influence of temperature, the temperature data near each grating site can be compensated, the influence of temperature on the measurement of strain is eliminated, and the measurement accuracy of the cable force value is improved, and the practicality is good. At the same time, optical fibers can transmit light waves with a wide frequency range, low transmission loss, high linear response and low noise level. They can achieve a balance between accuracy and sensitivity within a larger measurement range, solving the problems of cost and portability. The large scale and distribution of fiber grating arrays greatly improve measurement accuracy.

[0035] It should be understood that, in this embodiment, the strain grating array sensing fiber 3 is an optical fiber with multiple strain fiber Bragg grating sensors distributed thereon, and is used for sensitive strain sensing. The temperature grating array sensing fiber 4 is an optical fiber with multiple temperature fiber Bragg grating sensors distributed thereon, and is used for sensitive temperature sensing and temperature compensation for strain sensing.

[0036] In addition, in one embodiment, a first steel wire 2 and 84 second steel wires 5 are arranged inside the cable, and the internal fiber grating uses a weak grating with a refractive index ≥0.1‰ to ensure that the sheath and the interior are not damaged after the mechanical properties experiment. The temperature sensing range of the utility model can reach -20℃~80℃, and the temperature measurement accuracy is ≤±1.0℃; the strain measurement range can reach 0με~5000με, and the strain measurement accuracy is ≤±5%FS.

[0037] In one embodiment, see Figure 2 and Figure 3 A connecting groove 2b connected to the outside is formed on the side wall of the installation channel 2a. The connecting groove 2b extends along the axis of the first steel wire 2 and is connected to the open end of the installation channel 2a.

[0038] In this embodiment, a connecting groove 2b is opened on the side wall of the installation channel 2a, and the connecting groove 2b and the installation channel 2a constitute an installation channel, so that the staff can put the strain grating array sensing optical fiber 3 and the temperature grating array sensing optical fiber 4 from the groove of the connecting groove 2b into the installation channel 2a, thereby improving the convenience of assembly.

[0039] In one embodiment, the parallel steel wire cable with built-in fiber grating sensor further includes an inner sheath 6 , which is sleeved on the outside of the first steel wire 2 .

[0040] In this embodiment, an inner sheath 6 is provided on the outer periphery of the first steel wire 2 to protect the strain grating array sensing optical fiber 3 and the temperature grating array sensing optical fiber 4. Specifically, in this solution, the inner sheath 6 is a high-density polyethylene (HDPE) inner sheath.

[0041] In one embodiment, two groups of mounting channels 2a and connecting grooves 2b are provided, the two groups of mounting channels 2a are arranged at intervals along the circumference of the first steel wire 2, and each connecting groove 2b is provided in the corresponding mounting channel 2a; the strain grating array sensing optical fiber 3 and the temperature grating array sensing optical fiber 4 are respectively provided in the two mounting channels 2a.

[0042] In this embodiment, the strain grating array sensing optical fiber 3 and the temperature grating array sensing optical fiber 4 are respectively placed in two installation channels 2a to avoid interference between the strain grating array sensing optical fiber 3 and the temperature grating array sensing optical fiber 4, thereby ensuring measurement accuracy. Specifically, in this solution, the two installation channels 2a are located on opposite sides of the first steel wire 2, and the connecting groove 2b is located on the side of the installation channel 2a away from the other installation channel 2a.

[0043] In one embodiment, the parallel steel wire cable with built-in fiber grating sensor further includes structural adhesive 7, and the structural adhesive 7 is bonded to the strain grating array sensing optical fiber 3 and the inner wall of the corresponding installation channel 2a.

[0044] In this embodiment, the strain grating array sensing optical fiber 3 is fixed on the first steel wire 2 by the structural adhesive 7, so as to ensure that the strain grating array sensing optical fiber 3 and the first steel wire 2 are stretched synchronously, thereby ensuring the measurement accuracy. In addition, the structural adhesive 7 can withstand a large load, and is resistant to aging, fatigue, and corrosion, and has stable performance within the expected service life, thereby improving the connection stability between the strain grating array sensing optical fiber 3 and the first steel wire 2.

[0045] In one embodiment, the parallel steel wire rope with built-in fiber grating sensor also includes a round tube, which is sleeved outside the temperature grating array sensing optical fiber 4 and placed in the installation channel 2a corresponding to the temperature grating array sensing optical fiber 4.

[0046] In this embodiment, the temperature grating array sensing optical fiber 4 is built into a round tube to prevent the temperature grating array sensing optical fiber 4 from being squeezed by the first steel wire 2 through the round tube, thereby ensuring the measurement accuracy of the temperature grating array sensing optical fiber 4.

[0047] In one embodiment, each second steel wire 5 is arranged along the axial direction of the outer sheath 1, and a polyester fiber belt 9 is wound around the second steel wires 5, and the polyester fiber belt 9 is located on the inner side of the outer sheath 1. The outer sheath 1 is a high-density polyethylene outer sheath.

[0048] In this embodiment, a polyester fiber belt 9 and a high-density polyethylene outer sheath 1 are sequentially arranged on the periphery of a plurality of steel wires to improve the wear resistance of the cable while preventing external water vapor from directly contacting the steel wires, preventing the steel wires from being corroded by water vapor, and extending the service life of the cable.

[0049] In one embodiment, see Figure 4 The parallel steel wire rope with built-in fiber grating sensor also includes a connecting tube 10, an anchor cup 11 and an anchor ring 12 connected in sequence. The connecting tube 10 is connected to the first steel wire 2, the outer sheath 1 and the plurality of second steel wires 5, and is located at an end of the installation channel 2a with an opening; wherein the ends of the strain grating array sensing optical fiber 3 and the temperature grating array sensing optical fiber 4 extending out of the opening of the installation channel 2a are sequentially passed through the connecting tube 10, the anchor cup 11 and the anchor ring 12.

[0050] In this embodiment, the ends of the strain grating array sensing optical fiber 3 and the temperature grating array sensing optical fiber 4 extending outside the installation channel 2a are respectively connected to the optical fiber flange 14 and the fixing plate through the optical fiber pigtail 13, and the anchor ring 12, the anchor cup 11 and the connecting tube 10 are the structure of the anchor cable, which are used to maintain the strength, fix and protect the built-in optical path structure.

[0051] In addition, the utility model also provides a cable-stayed bridge, which includes a parallel steel wire cable with a built-in fiber grating sensor as described in any one of the above items. It should be noted that the detailed structure of the parallel steel wire cable with a built-in fiber grating sensor of the cable-stayed bridge can refer to the embodiment of the parallel steel wire cable with a built-in fiber grating sensor, which will not be repeated here; since the parallel steel wire cable with a built-in fiber grating sensor is used in the cable-stayed bridge of the utility model, the embodiment of the cable-stayed bridge of the utility model includes all technical solutions of all embodiments of the parallel steel wire cable with a built-in fiber grating sensor, and the technical effects achieved are also exactly the same, which will not be repeated here.

[0052] In order to better understand the present invention, the following Figures 1 to 4 The technical solution of the utility model is described in detail:

[0053] When the cable is strained due to external factors, the stress will be transmitted along the cable to various parts of the cable strand; connected to the external demodulation system through the optical fiber flange 14, the distributed optical fiber Bragg gratings on the strain grating array sensing fiber 3 can accurately and sensitively sense the strain field data on a cable; if the influence of temperature is considered, the temperature data near each grating site on the strain grating array sensing fiber 3 can be compensated through the temperature grating array sensing fiber 4 to eliminate the influence of temperature on the measurement of strain.

[0054] The specific implementation methods of the utility model described above do not constitute a limitation on the protection scope of the utility model. Any other corresponding changes and modifications made according to the technical concept of the utility model should be included in the protection scope of the claims of the utility model.

Claims

1. A parallel steel wire cable with a built-in fiber grating sensor, characterized in that: include: Outer sheath; A first steel wire is arranged in the outer sheath and arranged along the axial direction of the outer sheath, and is provided with a mounting channel with at least one end open along the axial direction; Grating array sensing optical fiber, including a strain grating array sensing optical fiber and a temperature grating array sensing optical fiber, wherein the strain grating array sensing optical fiber and the temperature grating array sensing optical fiber are arranged in the installation channel, and one end of each of the two extends out of the opening of the installation channel; and A plurality of second steel wires are filled in the outer sheath and are arranged around the outer periphery of the first steel wire.

2. The parallel steel wire cable with built-in fiber grating sensor according to claim 1, characterized in that: A connecting groove connected to the outside is formed on the side wall of the installation channel. The connecting groove extends along the axis of the first steel wire and is connected to the open end of the installation channel.

3. The parallel steel wire cable with built-in fiber grating sensor according to claim 2, characterized in that: The parallel steel wire cable with built-in fiber grating sensor also includes an inner sheath, which is sleeved outside the first steel wire.

4. The parallel steel wire cable with built-in fiber grating sensor according to claim 2, characterized in that: The installation channels and the connecting grooves are provided in two groups, the installation channels of the two groups are arranged at intervals along the circumference of the first steel wire, and each connecting groove is provided in the corresponding installation channel; The strain grating array sensing optical fiber and the temperature grating array sensing optical fiber are respectively arranged in the two installation channels.

5. The parallel steel wire cable with built-in fiber grating sensor according to claim 4, characterized in that: The parallel steel wire cable with built-in fiber grating sensor also includes structural adhesive, and the structural adhesive is bonded to the strain grating array sensing optical fiber and the inner wall of the corresponding installation channel.

6. The parallel steel wire cable with built-in fiber grating sensor according to claim 4, characterized in that: The parallel steel wire cable with built-in optical fiber grating sensor also includes a round tube, which is sleeved outside the temperature grating array sensing optical fiber and placed in an installation channel corresponding to the temperature grating array sensing optical fiber.

7. The parallel steel wire cable with built-in fiber grating sensor according to claim 1, characterized in that: Each of the second steel wires is arranged along the axial direction of the outer sheath, and a polyester fiber belt is wound around the plurality of second steel wires, and the polyester fiber belt is located on the inner side of the outer sheath.

8. The parallel steel wire cable with built-in fiber grating sensor according to claim 1, characterized in that: The outer sheath is a high-density polyethylene outer sheath.

9. The parallel steel wire cable with built-in fiber grating sensor according to claim 1, characterized in that: The parallel steel wire cable with built-in fiber grating sensor also includes a connecting tube, an anchor cup and an anchor ring connected in sequence, the connecting tube is connected to the first steel wire, the outer sheath and the plurality of the second steel wires, and is located at one end of the installation channel with an opening; Wherein, the ends of the strain grating array sensing optical fiber and the temperature grating array sensing optical fiber extending out of the open opening of the installation channel are sequentially passed through the connecting tube, the anchor cup and the anchor ring.

10. A cable-stayed bridge, characterized in that: A parallel steel wire cable with a built-in fiber optic grating sensor comprising any one of claims 1-9.

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