Grating intelligent prestressed steel strand and manufacturing method thereof

Abstract

A grating intelligent prestressed steel strand relates to a prestressed steel strand and a manufacturing method thereof, which comprises a center wire, a side wire and an optical fiber sensor, the center wire is provided with a groove in the axial direction, and the optical fiber sensor is embedded in the groove; the optical fiber sensor comprises an outer sleeve, a temperature compensation fiber grating sensor located in the outer sleeve, a fiber grating sensor and a fiber wire; the temperature compensation fiber grating sensor and the fiber grating sensor are connected in series on the fiber wire, and a filler is injected between the outer sleeve and the fiber wire or the temperature compensation fiber grating sensor or the fiber grating sensor; a casting glue is used for pasting between the outer sleeve and the center wire. The method comprises steps S1. manufacturing an optical fiber sensor, S2. manufacturing a grating intelligent prestressed steel strand, and S3. sheathing an exposed outer sleeve. The application can avoid damage to the optical fiber due to folding, can prolong the service life of the sensor, has the characteristics of high strength, high measurement accuracy, and is not easy to occur the phenomenon of wire breakage, and can realize the intelligentization and wisdom of the prestressed steel strand monitoring.

Description

TECHNICAL FIELD

[0001] The present application relates to a kind of prestressed steel strand and its manufacturing method, in particular to a kind of grating wisdom prestressed steel strand and its manufacturing method. BACKGROUND

[0002] As one of the important load-bearing components of cable-stayed bridge, suspension bridge, arch bridge and other bridge systems or other buildings, the health status of prestressed steel strand plays a key role in the service of the entire building. The current detection means for the health status of prestressed steel strand has various deficiencies, such as low precision, poor operability, great influence from external environment, poor stability, poor durability, and inability to monitor the changing state of prestressed steel strand in real time. Using fiber grating sensors to detect prestressed steel strand can better solve the problems of poor operability and inability to monitor the changing state of prestressed steel strand in real time. However, there are still some problems:

[0003] The utility model patent with the authorized announcement number CN213927094 U discloses a kind of for building prestressed concrete structure's slow-bonding wisdom steel strand, the steel strand is in center silk and is carried out groove, fiber grating sensor is pasted in groove, since fiber is relatively soft and easy to fold, poor shear performance, it is directly pasted in groove, easy to fold damage.

[0004] The invention patent application with the application publication number CN104196258 A discloses a post-tensioned prestressed intelligent reinforcement system based on fiber grating sensing technology, which has the following deficiencies: the intelligent steel strand center wire of the system is a fiber grating fiber-reinforced composite sensing bar containing a fiber grating sensor, which has low strength and high flexibility, resulting in low measurement accuracy.

[0005] The invention patent application with the application publication number CN106353016 A discloses a manufacturing method of intelligent steel strand containing a fiber grating sensor, which has the following deficiencies: the steel strand is obtained by embedding fiber, plastic sleeve and filler into a first metal pipe, and replacing the original center wire of the steel strand with the metal pipe center wire, which reduces the strength. SUMMARY

[0006] The technical problem to be solved by the present application is to provide a kind of grating wisdom prestressed steel strand and its manufacturing method to solve the deficiencies of easy to fold damage, low strength and low measurement accuracy in the prior art.

[0007] The technical scheme for solving the above technical problems is: a grating intelligent prestressed steel strand, comprising a center wire, a side wire and a fiber sensor, the center wire is provided with a through-length groove in the axial direction, and the fiber sensor is embedded in the groove; the fiber sensor comprises an outer sleeve, a temperature compensation fiber grating sensor, a fiber grating strain sensor and a fiber wire, the temperature compensation fiber grating sensor and the fiber grating strain sensor are connected in series on the fiber wire, a filler is filled in the gap between the outer sleeve and the fiber wire or the temperature compensation fiber grating sensor or the fiber grating strain sensor, and a casting glue is used to stick between the outer sleeve and the center wire.

[0008] A further technical scheme of the present application is that a steel wire armor layer is arranged on the outer surface of the outer sleeve exposed at both ends of the center wire, and a heat shrink tube is further sleeved outside the steel wire armor layer, the heat shrink tube is tightly adhered to the steel wire armor layer and the outer sleeve by being shrunk through heating.

[0009] A further technical scheme of the present application is that the temperature compensation fiber grating sensor and the fiber grating strain sensor have 1-9 groups, and the 1-9 groups of temperature compensation fiber grating sensors and fiber grating strain sensors are connected in series on the fiber wire.

[0010] A further technical scheme of the present application is that the outer sleeve is made of a stainless steel pipe with an outer diameter of 0.5-1 mm and an inner diameter of 0.3-0.8 mm.

[0011] A further technical scheme of the present application is that the filler is glue.

[0012] Another technical scheme of the present application is a manufacturing method of a grating intelligent prestressed steel strand, which comprises the following steps:

[0013] S1. Manufacturing a fiber sensor

[0014] The temperature compensation fiber grating sensor and the fiber grating strain sensor connected in series on the fiber wire are buried in the outer sleeve by using a pulling method, and then the filler is filled into the outer sleeve to obtain the fiber sensor.

[0015] S2. Manufacturing a grating intelligent prestressed steel strand

[0016] The prestressed steel strand is scattered, the center wire is taken and subjected to groove processing, the fiber sensor is arranged in the groove of the center wire, the outer sleeve at both ends is exposed by 2-3 mm, the casting glue is used to stick between the center wire and the outer sleeve, and after the casting glue is completely solidified, the obtained center wire and side wire are twisted into a steel strand to obtain the grating intelligent prestressed steel strand.

[0017] The further technical scheme of the present application is that the step S1 comprises the following specific contents:

[0018] S11. First, the temperature compensation fiber grating sensor and the fiber grating strain sensor are connected in series on the fiber wire;

[0019] S12. The temperature compensation fiber grating sensor is pulled into the outer sleeve using the pulling method;

[0020] S13. The fiber wire and the fiber grating strain sensor are immersed in glue, then taken out and dried, and then the fiber wire and the fiber grating strain sensor are parallelly buried in the outer sleeve using the pulling method;

[0021] S14. Finally, the filler is poured into the outer sleeve to obtain the fiber sensor.

[0022] The further technical scheme of the present application is that after the step S2, there is a step:

[0023] S3. The outer sleeve is exposed

[0024] The steel wire is spirally wound on the outer surface of the outer sleeve exposed at both ends of the central wire to form a steel wire armor layer, and then a heat shrink tube is sleeved outside the steel wire armor layer, and the heat shrink tube is shrunk by heating to tightly adhere to the steel wire armor layer and the outer sleeve.

[0025] Compared with the prior art, the grating intelligent prestressed steel strand and the manufacturing method thereof have the following beneficial effects:

[0026] 1. The fiber can be prevented from being damaged by folding

[0027] The fiber sensor of the present application comprises an outer sleeve, a temperature compensation fiber grating sensor and a fiber grating strain sensor located in the outer sleeve, and a fiber wire; the temperature compensation fiber grating sensor and the fiber grating strain sensor are connected in series on the fiber wire, and a filler is poured into the gap between the outer sleeve and the fiber wire or the temperature compensation fiber grating sensor or the fiber grating strain sensor. Since the present application has an outer sleeve outside the fiber wire, the fiber grating strain sensor can be protected from being damaged by folding, is not affected by the external environment, and the shear resistance of the fiber grating strain sensor is increased.

[0028] 2. The service life of the sensor can be prolonged

[0029] Since the present application has an outer sleeve outside the fiber wire, the fiber grating strain sensor can be protected from being damaged by folding.

[0030] In addition, the present application also provides a steel wire armor layer and a heat shrink tube for protecting the optical fiber wire led out of the fiber grating strain sensor, so that the service life of the fiber grating strain sensor and the temperature compensation fiber grating sensor inside the sheath tube can be further prolonged.

[0031] 3. High strength

[0032] The present application comprises a center wire, a side wire and a fiber sensor, wherein the center wire and the side wire are high-strength steel wires with a strength of 1470-1960 MPa; a through groove is formed in the center wire along the axial direction, and the fiber sensor is embedded in the groove and bonded with the fiber sensor by an adhesive. Therefore, compared with the center wire made of other materials in the prior art, the steel strand made by the present application has higher strength.

[0033] In addition, the fiber sensor of the present application comprises a sheath tube, a temperature compensation fiber grating sensor, a fiber grating strain sensor and an optical fiber wire, and a dense filler is poured into the gap between the sheath tube and the optical fiber wire or the temperature compensation fiber grating sensor or the fiber grating strain sensor; the sheath tube, the optical fiber wire, the temperature compensation fiber grating sensor and the fiber grating strain sensor are integrated by the filler; and the center wire and the fiber sensor are integrated by the adhesive between the center wire and the sheath tube. Therefore, the fiber sensor of the present application has high strength and is not easy to be damaged by folding.

[0034] 4. High measurement accuracy

[0035] The information collected by the fiber sensor plays a key role in the construction and service of the prestressed steel strand member; the fiber sensor of the present application comprises a sheath tube, a temperature compensation fiber grating sensor, a fiber grating strain sensor and an optical fiber wire located in the sheath tube, and a filler is poured into the gap between the sheath tube and the optical fiber wire or the temperature compensation fiber grating sensor or the fiber grating strain sensor. The sheath tube, the optical fiber wire, the temperature compensation fiber grating sensor and the fiber grating strain sensor are integrated by the filler; the center wire and the fiber sensor are integrated by the casting adhesive between the center wire and the sheath tube of the fiber sensor; so that the fiber sensor and the center wire can deform and bear force together, and the measurement accuracy can be greatly improved; and the present application can directly obtain the strain, cable force and measured frictional force of the prestressed steel strand, and can most directly obtain the temperature inside the prestressed steel strand, especially in harsh environments, which can better reflect the advantages of the fiber grating intelligent prestressed steel strand.

[0036] 5. Coordinated deformation under stress, not easy to occur wire breakage

[0037] The application is provided with a sleeve pipe outside the optical fiber wire, the sleeve pipe is made of stainless steel metal pipe, has good mechanical property, simple production, better yield, better shear resistance, and small difference of elastic modulus and thermal expansion coefficient with the steel strand, can coordinate stress deformation in use, and is not easy to cause wire breakage.

[0038] 6. Intelligent and smart monitoring of prestressed steel strand

[0039] The application can guarantee that the fiber grating strain sensor remotely monitors the cable force, strain and temperature of the prestressed steel strand in real time, realizes intelligent and smart monitoring of the prestressed steel strand, and is convenient for mastering the stress condition of the prestressed steel strand component during construction and service.

[0040] 7. Anti-electromagnetic interference, good electrical insulation performance, large transmission capacity, corrosion resistance and strong stability

[0041] The temperature compensation fiber grating sensor and the fiber grating strain sensor used in the application acquire the prestressed steel strand information by the modulation of the external physical parameter to the fiber Bragg wavelength, realize direct measurement of temperature and strain, and have many advantages such as anti-electromagnetic interference, good electrical insulation performance, large transmission capacity, corrosion resistance and strong stability.

[0042] Next, the technical features of the grating smart prestressed steel strand and the manufacturing method thereof of the application are further described in combination with the drawings and embodiments. BRIEF DESCRIPTION OF DRAWINGS

[0043] Figure 1 Fig. 1 is a structure schematic view of the grating smart prestressed steel strand of the application in embodiment one,

[0044] Figure 2 Fig. 2 is an exploded view of the grating smart prestressed steel strand of the application in embodiment one,

[0045] Figure 3 Fig. 3 is a structure schematic view of the fiber sensor in embodiment one,

[0046] Figure 4 Fig. 4 is an exploded view of the fiber sensor in embodiment one;

[0047] In the above drawings, the respective drawing reference signs are described as follows:

[0048] 1 - center wire, 101 - groove,

[0049] 2 - edge wire,

[0050] 3 - fiber sensor, 301 - sleeve pipe, 302 - temperature compensation fiber grating sensor, 303 - fiber grating strain sensor,

[0051] 304-heat shrink tube, 305-steel wire armor layer, 306-optical fiber wire. Embodiment Example One

[0052] A grating intelligent pre-stressed steel strand, comprising a center wire 1, a side wire 2, and an optical fiber sensor 3, the center wire and the side wire are high-strength steel wires with a strength of 1470-1960 MPa; wherein:

[0053] The center wire 1 has a through-length groove 101 opened in an axial direction on one side;

[0054] The side wire 2 has six wires, and the six side wires 2 are twisted into a regular hexagon with the center line of the center wire 1 as the axis;

[0055] The optical fiber sensor 3 is embedded in the groove 101 of the center wire 1; the optical fiber sensor 3 comprises an outer sleeve 301, a temperature compensation fiber grating sensor 302 and a fiber grating strain sensor 303 located in the outer sleeve 301, and an optical fiber wire 306; the temperature compensation fiber grating sensor 302 and the fiber grating strain sensor 303 are connected in series on the optical fiber wire 306, a filler is poured in the gap between the outer sleeve 301 and the optical fiber wire 306 or the temperature compensation fiber grating sensor 302 or the fiber grating strain sensor 303, the filler is glue, and a casting glue is pasted between the outer sleeve 301 and the groove 101 of the center wire 1. By pouring glue, the gap between the outer sleeve 301 and the optical fiber wire 306, the temperature compensation fiber grating sensor 302, and the fiber grating strain sensor 303 can be filled densely; by pasting the casting glue between the outer sleeve 301 and the center wire 1, the outer sleeve 301 and the center wire 1 can be filled densely, so that the deformation of the center wire 1 can be completely transmitted to the optical fiber sensor 3.

[0056] The outer sleeve 301 is made of a stainless steel metal pipe with an outer diameter of 0.5-1 mm and an inner diameter of 0.3-0.8 mm. The stainless steel metal pipe has good mechanical properties, and the elastic modulus and the thermal expansion coefficient are similar to those of the steel strand, so that the deformation under stress can be coordinated and the wire breakage phenomenon is less likely to occur.

[0057] The 1-9 groups of temperature compensation fiber grating sensors 302 and fiber grating strain sensors 303 are connected in series on the fiber wire 306; the temperature compensation fiber grating sensor 302 and the fiber grating strain sensor 303 are used to obtain prestressed steel strand information by modulating the fiber Bragg wavelength through external physical parameters, to realize direct measurement of temperature and strain, and have many advantages such as anti-electromagnetic interference, good electrical insulation performance, large transmission capacity, corrosion resistance, and strong stability. The temperature compensation fiber grating sensor 302 is used to make the fiber freely stretchable by full-length fiber bonding, and the fiber grating strain sensor 303 is used to make the fiber wire and the center wire 1 deform synchronously.

[0058] The outer sleeve 301 is exposed by 2-3 mm at both ends from the groove of the center wire 1, and a steel wire armor layer 305 is arranged on the outer surface of the exposed outer sleeve 301, so that the fiber wire 306 can freely stretch, and a heat shrink tube 304 is further sleeved outside the steel wire armor layer 305, the heat shrink tube 304 is tightly bonded with the steel wire armor layer 305 and the outer sleeve 301 by heating and shrinking, and the heat shrink tube 304 plays a role in protecting the fiber wire from the influence of rainwater, water vapor and the like. Example Two

[0059] A method for manufacturing a grating intelligent prestressed steel strand, which is the method for manufacturing a grating intelligent prestressed steel strand described in Example One, comprising the following steps:

[0060] S1. Manufacturing a fiber sensor

[0061] The temperature compensation fiber grating sensor 302 and the fiber grating strain sensor 303 connected in series on the fiber wire 306 are pulled together and parallelly buried in the outer sleeve by using a pulling method, and then the filler is poured into the outer sleeve 301 to obtain the fiber sensor 3.

[0062] This step S1 includes the following specific contents:

[0063] S11. The temperature compensation fiber grating sensor 302 and the fiber grating strain sensor 303 are connected in series on the fiber wire 306 respectively;

[0064] S12. The temperature compensation fiber grating sensor 302 is pulled into the outer sleeve 301 by using a pulling method;

[0065] S13. The fiber wire 306 and the fiber grating strain sensor 303 are immersed in glue, then taken out and dried, and then the fiber wire 306 and the fiber grating strain sensor 303 are parallelly buried in the outer sleeve 301 by using a pulling method;

[0066] S14. Finally, the filler is filled into the outer sleeve 301 to obtain the optical fiber sensor 3.

[0067] S2. Making the grating intelligent prestressed steel strand

[0068] The prestressed steel strand is scattered, the center wire 1 is taken and is subjected to the slotting treatment, the optical fiber sensor 3 is arranged into the groove of the center wire 1, and the outer sleeve at two ends is exposed by 2-3 mm, the gap between the center wire and the outer sleeve is pasted by the foundry glue, after the foundry glue is completely solidified, the obtained center wire 1 and the side wire 2 are twisted into the steel strand again, and the grating intelligent prestressed steel strand is obtained.

[0069] S3. Armoring the exposed outer sleeve

[0070] The steel wire garter layer 305 is formed by spirally winding the steel wire on the outer surface of the outer sleeve 301 exposed at two ends of the center wire 1, then the heat shrink tube 304 is sleeved outside the steel wire garter layer 305, and the heat shrink tube 304 is tightly pasted with the steel wire garter layer 305 and the outer sleeve 301 by heating and blowing with the hot air gun.

[0071] After the grating intelligent prestressed steel strand is obtained, the two ends of the optical fiber wire are drawn out, and the drawn-out optical fiber wire joint is connected with the external collection equipment such as the Brillouin measuring instrument, the optical fiber grating demodulator and the like, so that the data can be measured, and the temperature, the strain and the cable force of the prestressed steel strand can be obtained.

Claims

1. A grating intelligent prestressed steel strand, comprising a center wire (1), side wires (2), and an optical fiber sensor (3), wherein the center wire (1) is provided with a continuous groove (101) along the axial direction, and the optical fiber sensor (3) is embedded in the groove (101); characterized in that: The optical fiber sensor (3) comprises an outer sleeve (301), a temperature-compensated optical fiber Bragg grating sensor (302) located in the outer sleeve (301), an optical fiber Bragg grating strain sensor (303), and an optical fiber conductor (306); the temperature-compensated optical fiber Bragg grating sensor (302) and the optical fiber Bragg grating strain sensor (303) are connected in series to the optical fiber conductor (306), and a gap between the outer sleeve (301) and the optical fiber conductor (306) or the temperature-compensated optical fiber Bragg grating sensor (302) or the optical fiber Bragg grating strain sensor (303) is filled with The outer sleeve (301) is provided with a filler, and the gap between the outer sleeve and the center wire is glued with cast glue; a steel wire armor layer (305) is provided on the outer surface of the outer sleeve (301) exposed at both ends of the center wire (1), and a heat shrink tube (304) is also provided outside the steel wire armor layer (305), and the heat shrink tube (304) is tightly glued together with the steel wire armor layer (305) and the outer sleeve (301) by heat shrinkage; the outer sleeve (301) is made of a stainless steel metal tube with an outer diameter of 0.5mm to 1mm and an inner diameter of 0.3mm to 0.8mm.

2. The grating intelligent prestressed steel strand according to claim 1, characterized in that: There are 1 to 9 groups of the temperature-compensated fiber Bragg grating sensors (302) and the fiber Bragg grating strain sensors (303), and the 1 to 9 groups of the temperature-compensated fiber Bragg grating sensors (302) and the fiber Bragg grating strain sensors (303) are sequentially connected in series on the optical fiber conductor (306).

3. The grating intelligent prestressed steel strand according to claim 1, characterized in that: The filler is glue.

4. A method for manufacturing a grating intelligent prestressed steel strand, the method being the method for manufacturing a grating intelligent prestressed steel strand as claimed in claim 1, characterized in that: The method comprises the following steps: S1. Fabrication of fiber optic sensors A temperature compensation fiber Bragg grating sensor (302) and a fiber Bragg grating strain sensor (303) connected in series on an optical fiber conductor (306) are embedded in an outer sleeve by a dragging method, and then a filler is poured into the outer sleeve (301) to obtain an optical fiber sensor (3); S2. Manufacturing grating intelligent prestressed steel strands The prestressed steel strand is broken up, the center wire 1 is taken and slotted, the optical fiber sensor (3) is arranged in the groove of the center wire (1), and the outer sleeves at both ends are exposed 2 to 3 mm, and the gap between the center wire and the outer sleeve is glued with casting glue. After the casting glue is completely solidified, the obtained center wire (1) and the side wire (2) are twisted into a steel strand again to make a grating intelligent prestressed steel strand; S3. Armored exposed outer sleeve A steel wire armor layer (305) is formed by spirally winding a steel wire on the outer surface of the outer sleeve (301) exposed at both ends of the central wire (1), and then a heat shrink tube (304) is sleeved on the outside of the steel wire armor layer (305). The heat shrink tube (304) is shrunk by heating to be tightly adhered to the steel wire armor layer (305) and the outer sleeve (301).

5. The method for manufacturing a grating intelligent prestressed steel strand according to claim 4, characterized in that: The step S1 includes the following specific contents: S11. First, the temperature-compensated fiber Bragg grating sensor (302) and the fiber Bragg grating strain sensor (303) are connected in series to the optical fiber conductor (306); S12. Using the dragging method, the temperature-compensated fiber Bragg grating sensor (302) is first dragged into the outer sleeve (301); S13. Immerse the optical fiber conductor (306) and the fiber Bragg grating strain sensor (303) in glue, then take them out and dry them, and then use the dragging method to bury the optical fiber conductor (306) and the fiber Bragg grating strain sensor (303) in parallel into the outer sleeve (301); S14. Finally, the filler is poured into the outer sleeve (301) to obtain the optical fiber sensor (3).

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