CN105423939A - Coupling fiber grating wide-range intelligent carbon fiber rib and manufacturing method thereof - Google Patents

Abstract

The present application provides a large-scale intelligent carbon fiber tendon coupled with a fiber grating, on which at least one spiral groove is arranged, and an optical fiber line and an optical fiber protective layer for covering the optical fiber line are placed in the spiral groove, A plurality of strain gratings and temperature gratings are engraved on the optical fiber line. The present application also provides a method for manufacturing a large-range intelligent carbon fiber rib coupled with a fiber grating. The application can solve the problem that the measuring range is limited during the stress and strain monitoring of the existing fiber grating to the carbon fiber rib during use.

Description

Large-scale intelligent carbon fiber rib coupled with fiber grating and its manufacturing method

technical field

The application belongs to the technical field of monitoring, and in particular relates to a large-scale intelligent carbon fiber bar coupled with a fiber grating and a manufacturing method thereof.

Background technique

Various structures such as building structures, bridge structures, underground structures, marine structures, etc. are coupled by various effects of the environment and loads during their service period, inevitably causing damage and accumulation, and they need to be repaired when necessary and reinforcement. Prestressed carbon fiber reinforcement is widely used in the maintenance and reinforcement of various structures and components because of its advantages of high strength, light weight, good durability, and easy construction. It is of great significance to monitor the stress and deformation state during the reinforcement process. . Fiber Bragg grating technology perceives small changes in external physical quantities such as stress, strain, temperature, and concentration through the change and movement of the grating reflection wavelength, and the measurement has a high degree of linear fitting and good stability. Fiber Bragg Grating has the advantages of strong anti-electromagnetic interference ability, small sensor size, simple wiring, and convenient long-distance data transmission. It can perform high-precision, absolute, and quasi-distributed digital measurement of the strain energy of structural members, and is suitable for high-strength carbon fiber Monitoring of stress and deformation of tendons.

The material of fiber Bragg grating is brittle, and the tensile strain it receives during use is limited, and generally cannot exceed 5000 microstrain, so the measuring range of fiber Bragg grating is small. In order to improve the strength utilization rate, the strain of carbon fiber tendons used for maintenance and reinforcement is often high when under stress. The stress and strain value of carbon fiber tendons without prestress is close to 6000 microstrain, and the strain value of carbon fiber tendons with prestressed stress for a long time reaches Even more than 9000 microstrain. In addition, since the fiber grating is an extremely small and brittle wire with a diameter of only about 0.05 mm, the laying process is difficult. Improper laying may lead to insufficient bonding between the fiber grating and the component. The detected strain and the actual strain It may not match; in addition, in the complex construction process, the fiber grating may not be properly protected, and its service life cannot be guaranteed to meet the monitoring of the entire service life of the component.

Contents of the invention

In view of this, the technical problem to be solved in this application is to solve the problem that the measurement range is limited when the existing fiber grating monitors the stress and strain of carbon fiber bars during use.

In order to solve the above technical problems, the present application provides a large-scale smart carbon fiber tendon coupled with a fiber grating, on which at least one spiral groove is arranged, and an optical fiber line is placed in the spiral groove and is used to cover the optical fiber An optical fiber protective layer of a wire on which a plurality of strain gratings and temperature gratings are engraved.

Further, the cross-section of the spiral groove is arc-shaped, and its radius is greater than or equal to 0.1 mm and less than or equal to 0.5 mm.

Further, the optical fiber wire and the optical fiber protective layer fill the spiral groove.

Further, the number of the spiral grooves is 1 to 4.

Further, the helix angle of the helical groove is greater than 0° and less than or equal to 90°.

Further, the large-range smart carbon fiber rib coupled with the fiber grating is a reinforced carbon fiber rib.

The present application also provides a method for manufacturing a large-scale intelligent carbon fiber rib coupled with a fiber grating, including the following steps:

Create a spiral groove on the carbon fiber rib;

Stretching the carbon fiber tendons, the tensile stress is greater than or equal to 10MPa and less than or equal to 2400MPa;

Applying an optical fiber adhesive in the spiral groove, and pasting the optical fiber wire engraved with a plurality of strain gratings and temperature gratings in the spiral groove;

An optical fiber protection layer for covering the optical fiber wire is placed in the spiral groove.

Further, the cross-section of the spiral groove is arc-shaped, and its radius is greater than or equal to 0.1 mm and less than or equal to 0.5 mm.

Further, the number of the spiral grooves is 1 to 4.

Further, the helix angle of the helical groove is greater than 0° and less than or equal to 90°.

Compared with the prior art, the present application can obtain the following technical effects:

1) By directly coupling multiple strain gratings inside the carbon fiber reinforcement, the degree of structural bonding is improved, and it is consistent with the deformation of the component, so that the strain measured by the strain grating is consistent with the actual strain of the component;

2) By setting a spiral groove on the carbon fiber rib, according to the strain range of the component, the size of the helix angle of the groove is changed, that is, the pitch of the groove is changed, and the measurement range of the strain grating is expanded, which avoids the glass brittleness of the grating material itself. Unfavorable factors that limit its measurement range;

3) By setting the temperature grating and strain grating inside the carbon fiber reinforcement, it is basically not affected in a complex construction environment, avoiding the adverse effects of construction factors on the temperature grating and strain grating, and ensuring the use of temperature grating and strain grating Lifespan meets the purpose of long-term monitoring;

4) Multiple spiral grooves are opened through carbon fiber ribs, so that multiple groups of optical fibers can work at the same time, and multiple data comparisons can be performed, which greatly improves the accuracy and persuasiveness of the monitoring results;

Of course, implementing any product of the present application does not necessarily need to achieve all the technical effects described above at the same time.

Description of drawings

The drawings described here are used to provide a further understanding of the application and constitute a part of the application. The schematic embodiments and descriptions of the application are used to explain the application and do not constitute an improper limitation to the application. In the attached picture:

1 is a schematic diagram of a large-range smart carbon fiber rib coupled with a fiber grating according to an embodiment of the present application;

Fig. 2 is a partially enlarged schematic diagram of a large-range smart carbon fiber rib coupled with a fiber grating according to an embodiment of the present application;

Fig. 3 is a schematic cross-sectional view of a large-range smart carbon fiber rib coupled with a fiber grating according to an embodiment of the present application;

Fig. 4 is another schematic diagram of the cross-section of the large-range smart carbon fiber rib coupled with the fiber Bragg grating according to the embodiment of the present application;

Fig. 5 is a schematic diagram of the mathematical relationship between the temperature grating and the axial deformation of the carbon fiber rib according to the embodiment of the present application.

detailed description

The implementation of the present application will be described in detail below with reference to the accompanying drawings and examples, so as to fully understand and implement the implementation process of how the present application uses technical means to solve technical problems and achieve technical effects.

As shown in Figures 1 to 5, this embodiment provides a large-range smart carbon fiber bar (hereinafter referred to as "carbon fiber bar") 10 coupled with a fiber grating, which is provided with at least one spiral groove 101, and the spiral groove An optical fiber 102 and an optical fiber protective layer 103 for covering the optical fiber 102 are placed in the groove 101 , and a plurality of strain gratings and temperature gratings are engraved on the optical fiber 102 .

Specifically, the carbon fiber reinforcement 10 is a reinforced carbon fiber reinforcement, and its size and specifications can be cut or processed according to actual needs. The cross section of the spiral groove 101 is arc-shaped, and its radius is greater than or equal to 0.1 mm and less than or equal to 0.5 mm. The optical fiber wire 102 and the optical fiber protection layer 103 fill the spiral groove 101 . The number of the spiral grooves is 1 to 4. The helix angle of the helical groove is greater than 0° and less than or equal to 90°.

As shown in FIG. 5 , the helix angle θ of the spiral groove 101 may be greater than 0° and less than or equal to 90°. In this embodiment, the helix angle θ of the groove 2 is 45°.

In this embodiment, the effect of the helix angle θ of the spiral groove 101 on the measuring range of the optical fiber 102 is as follows:

When the carbon fiber rib 10 produces micro-strain, due to the large gap between the strain and the size of the carbon fiber rib 10, the angle change is negligible. In Fig. 5, the helix angle θ is 45°, L1 is the length of the optical fiber line 102, L2 is the pitch, and Q1 is the carbon fiber rib 10 axial strain, Q2 is the strain of the optical fiber line 102, the ratio of the strain Q2 of the optical fiber line 102 coupled on the carbon fiber tendon 10 to the axial strain Q1 of the carbon fiber tendon 10 is sin45°, that is, the helix angle θ of the spiral groove 101 When it is 45 degrees, the strain of the optical fiber line 102 is only 0.707 times of the axial strain of the carbon fiber rib 10, so at this time the measuring range of the optical fiber line 102 becomes 1.414 times of that when it is arranged directly along the axial direction of the carbon fiber rib 10. When the temperature grating and the strain grating are spirally arranged at different angles, their effects on increasing the measuring range are different. Therefore, the purpose of using different measurement ranges according to the needs of different buildings can be realized by changing the helix angle.

This embodiment provides a method for manufacturing a large-range smart carbon fiber bar coupled with a fiber grating, including the following steps:

Step 1: Open a spiral groove 101 on the carbon fiber rib 10;

Step 2: Stretching the carbon fiber tendons 10, the tensile stress is greater than or equal to 10MPa and less than or equal to 2400MPa;

Step 3: apply an optical fiber adhesive in the spiral groove 101, and stick the optical fiber 102 engraved with a plurality of temperature gratings and strain gratings in the spiral groove 101;

Step 4: placing an optical fiber protection layer for covering the optical fiber line 102 in the spiral groove 101 .

In this embodiment, the carbon fiber rib 10 is a reinforced carbon fiber rib, and its size and specifications can be cut or processed according to actual needs. The cross section of the spiral groove 101 is arc-shaped, and its radius is greater than or equal to 0.1 mm and less than or equal to 0.5 mm. The optical fiber wire 102 and the optical fiber protection layer 103 fill the spiral groove 101 . The number of the spiral grooves is 1 to 4. The helix angle of the helical groove is greater than 0° and less than or equal to 90°.

The present application directly couples the optical fiber line 102 inside the carbon fiber rib 10, which improves the degree of structural bonding, and keeps consistent with the deformation of the component, so that the strain measured by the strain grating matches the actual strain of the component; The size of the helix angle θ of the groove 101 expands the measurement range of the temperature grating and the strain grating, avoiding the unfavorable factors that limit the measurement range due to the brittleness of the glass of the optical fiber 102 itself; , basically unaffected in a complex construction environment, avoiding the adverse effects of construction factors on the temperature grating and strain grating, ensuring that the service life of the optical fiber line 102 meets the purpose of long-term monitoring; Multiple helical notches 101 enable multiple groups of optical fiber lines 102 to work simultaneously, and multiple data comparisons can be performed, which greatly improves the accuracy and persuasiveness of the monitoring results.

The above description shows and describes several preferred embodiments of the present application, but as mentioned above, it should be understood that the present application is not limited to the form disclosed herein, and should not be regarded as excluding other embodiments, but can be used in various Various other combinations, modifications, and environments can be made within the scope of the inventive concept described herein, by the above teachings or by skill or knowledge in the relevant field. However, modifications and changes made by those skilled in the art do not depart from the spirit and scope of the present application, and should all be within the protection scope of the appended claims of the present application.

Claims (10)

1. the wide range intelligence carbon fibre bar of a coupled fiber grating; it is characterized in that; be provided with at least one spiral groove; being placed with optical fiber cable and the fiber optic protection layer for covering described optical fiber cable in described spiral groove, described optical fiber cable being carved with multiple strain grating and temperature grating.

2. the wide range intelligence carbon fibre bar of coupled fiber grating according to claim 1, it is characterized in that, the xsect of described spiral groove is circular arc, and its radius is more than or equal to 0.1 millimeter, and is less than or equal to 0.5 millimeter.

3. the wide range intelligence carbon fibre bar of coupled fiber grating according to claim 1, it is characterized in that, described optical fiber cable and described fiber optic protection layer fill full described spiral groove.

4. the wide range intelligence carbon fibre bar of coupled fiber grating according to claim 1, it is characterized in that, described spiral groove number is 1 to 4.

5. the wide range intelligence carbon fibre bar of coupled fiber grating according to claim 1, it is characterized in that, the helix angle of described spiral groove is greater than 0 °, and is less than or equal to 90 °.

6., according to the wide range intelligence carbon fibre bar of the coupled fiber grating described in any one of claim 1-5, it is characterized in that, be reinforcement type carbon fibre bar.

7. a method for making for the wide range intelligence carbon fibre bar of coupled fiber grating, is characterized in that, comprise the steps:

Carbon fibre bar is offered spiral groove;

Stretch to described carbon fibre bar, drawing stress is more than or equal to 10MPa, and is less than or equal to 2400MPa;

In described spiral groove, smear optical fiber cable adhesive, and the optical fiber cable being carved with multiple strain grating and temperature grating is pasted onto in described spiral groove;

The fiber optic protection layer for covering described optical fiber cable is placed in described spiral groove.

8. method for making according to claim 7, is characterized in that, the xsect of described spiral groove is circular arc, and its radius is more than or equal to 0.1 millimeter, and is less than or equal to 0.5 millimeter.

9. method for making according to claim 7, is characterized in that, described spiral groove number is 1 to 4.

10. method for making according to claim 7, is characterized in that, the helix angle of described spiral groove is greater than 0 °, and is less than or equal to 90 °.