Fiber bragg grating strain monitoring device for deformed steel bar

Abstract

The utility model discloses a fiber bragg grating strain monitoring device for deformed steel bars, which can flexibly rotate on the deformed steel bars to adjust the distance through the flexible matching of a deformed steel bar locking clamp and a trapezoidal threaded sleeve, and can tightly hold the deformed steel bars; the installation limiting plate is used for fixing the deformed steel bar locking clamps to ensure that the installation plane is consistent with the installation hole position, the through hole is formed in one side of the installation limiting plate, the notch hole is formed in the other side of the installation limiting plate, and the distance between the two deformed steel bar locking clamps can be adjusted through the notch hole without being limited by the shape straightness of deformed steel bars; the deformed steel bar locking clamp and the trapezoidal threaded sleeve are locked through a second bolt; a strain sensor, a strain mounting seat and a strain locking clamp are preliminarily assembled through a plug screw and a third bolt, the strain locking clamp is fixed to a deformed steel bar locking clamp through a fourth bolt, and the monitoring linearity of the strain sensor is ensured by adjusting the torque of the third bolt, eliminating an assembly gap and pre-tightening the strain sensor; when the deformed steel bar is subjected to stress change, the strain can be accurately transmitted to the strain sensor through the strain monitoring device.

Description

Technical Field

[0001] The utility model belongs to the technical field of optical fiber Bragg grating strain monitoring, in particular to an optical fiber Bragg grating strain monitoring device for threaded steel. Background Art

[0002] Rebar is widely used in many fields. In building structures, it is often used to reinforce and connect beams, columns, slabs and other components in reinforced concrete structures, significantly enhancing the stability and load-bearing capacity of the structure, making the building safer and more reliable. In civil engineering projects such as bridges, tunnels and highways, post-anchor rebar is used as a reinforcement and connection material, which not only enhances the stability of the project but also improves its seismic performance. In addition, rebar is also used in railway projects to ensure the fixation and connection of railway tracks and the smooth and safe operation of railway lines. The stress monitoring of rebar directly affects construction safety. By monitoring the strain of rebar, the load changes throughout the construction process can be intuitively reflected, which is conducive to analyzing and optimizing construction plans.

[0003] According to Chinese application number CN112230327A, "An all-glass packaging device and packaging method for fiber Bragg gratings," a new fiber Bragg grating sensor substrate innovatively developed based on this substrate addresses the issues of poor durability and stability of current fiber Bragg grating sensors. Strain sensors developed based on this substrate offer the advantages of stability, durability, and precise monitoring, meeting the requirements for applications in complex environments such as mining and construction. However, rebar stress monitoring is subject to installation requirements. Due to its use and function, rebar cannot be welded on-site to avoid defects such as stress concentration, which affects construction safety. Adhesive strain sensors have disadvantages such as accuracy issues, operational complexity, and environmental sensitivity. Furthermore, the housings of current fiber Bragg grating strain sensors are mostly made of metal. Due to the mechanical properties of the material and installation gaps, the initial range strain transmission is inaccurate, requiring further improvement. Utility Model Content

[0004] The utility model provides a fiber grating strain monitoring device for threaded steel, which can solve the shortcomings of the prior art, such as the inability to weld and install threaded steel, the accuracy problems of adhesive strain sensors, the complexity of operation and environmental sensitivity, and the inaccurate strain transmission of the strain starting range; the inaccurate strain transmission of the strain monitoring preload starting strain sensor, the inability to weld and install surface-mounted strain sensors, the inability of surface-mounted electronic strain gauges to adapt to outdoor operations, the uneven surface of the threaded steel, the inaccurate strain transmission, and the inaccurate strain monitoring starting range.

[0005] In order to solve the above problems, the technical solutions provided by the present invention are as follows:

[0006] The embodiment of the utility model provides a fiber Bragg grating strain monitoring device for threaded steel, comprising a threaded steel (1), a trapezoidal thread sleeve (2), a threaded steel locking clamp (3), a mounting limit plate (4), a strain mounting seat (5), a strain sensor (6), a strain locking clamp (7), a first bolt (8), a second bolt (9), a plug screw (10), a third bolt (11) and a fourth bolt (12);

[0007] The threaded steel (1) is a rod-shaped structure, and its cross-section is elliptical, and an oblique rib structure is distributed at a tangent position of the elliptical long axis; the trapezoidal thread sleeve (2) is a stepped cylindrical structure, and the trapezoidal thread sleeve (2) is provided with a first trapezoidal thread (201-01), a second trapezoidal thread (202-01) and a third trapezoidal thread (203-01) with the center line of the cylinder as the axis, and the trapezoidal thread sleeve (2) is provided with a trapezoidal thread sleeve 1 (201), a trapezoidal thread sleeve 2 (202) and a trapezoidal thread sleeve 3 (203) at intervals, and the stepped bottom layers of the trapezoidal thread sleeve 1 (201), the trapezoidal thread sleeve 2 (202) and the trapezoidal thread sleeve 3 (203) are polygonal platform 1 (201-02), polygonal platform 2 (202-02) and polygonal platform 3 (203-02) respectively;

[0008] The threaded steel locking card (3) includes a limit locking card (301) and an installation locking card (302), wherein the limit locking card (301) is a rectangular parallelepiped structure, and a first semicircular through hole (301-01) is provided on the bottom surface of the limit locking card (301), and the axis position of the first semicircular through hole (301-01) is outside the bottom surface; four first through holes (301-02) are provided on the top of the limit locking card (301), and the four first through holes (301-02) do not intersect with the first semicircular through holes (301-01); the installation locking card (302) has the same shape as the limit locking card (301), and a second semicircular through hole (302-01) is provided on the bottom surface of the installation locking card (302). The first semicircular through hole (301-01) and the second semicircular through hole (302-01) are of the same shape and are coaxially arranged; the top surface of the mounting locking card (302) is provided with four first threaded holes (302-02) and four second threaded holes (302-03); the first threaded holes (302-02) and the first through hole (301-02) are distributed at the same position and are coaxially arranged, and the second threaded holes (302-03) are distributed within the first threaded hole (302-02); the four second threaded holes (302-03) and the four fifth through holes (7-05) of the strain locking card (7) are distributed at the same position and are coaxially arranged;

[0009] Eight first bolts (8) are used to pass through the first circular hole (4-01) and the first slot hole (4-02) of the installation limit plate (4) and to tightly connect the two installation locking clamps (302) to the installation limit plate (4) through the first threaded hole (302-02), and the top surface of the installation locking clamp (302) is set in abutment with the installation limit plate (4); the two sets of the trapezoidal thread sleeves (2) are assembled in a thread connection sequence, and the truncated cones of the trapezoidal thread sleeves (2) are adjacently sleeved on the threaded steel (1) and screwed to a preset position, and the polygonal platform one (201-02), polygonal platform two (202-02) and polygonal platform three (202-02) of the trapezoidal thread sleeve (2) are outside the first semicircular through hole (301-01) and the second semicircular through hole (302-01); the trapezoidal thread sleeves (2) are assembled in a thread connection sequence, and the truncated cones of the trapezoidal thread sleeves (2) are adjacently sleeved on the threaded steel (1) and screwed to a preset position, and the polygonal platform one (201-02), polygonal platform two (202-02) and polygonal platform three (202-02) of the trapezoidal thread sleeves ... The threaded sleeve (2) can be squeezed by the second semicircular through hole (302-01) of the installation locking card (302), and the second bolt (9) is used to pass through the first through hole (301-02) and the limit locking card (301) respectively, and then loosely engage with the first threaded hole (302-02) of the installation locking card (302), and continue to screw the trapezoidal threaded sleeve (2) so that the polygonal platform one (201-02), the polygonal platform two (202-02), and the polygonal platform three (202-02) are tightly fitted with the limit locking card (301) and the installation locking card (302), and the second bolt (9) is locked to ensure that the threaded steel locking card (3) is tightly held; the first bolt (8) is used to fix the limit locking card (301) and the installation locking card (302);

[0010] The main structure (6-01) of the strain sensor (6) is a long plate-shaped structure, with signal cables (6-02) connected to its two ends; a plurality of the plug screws (10) pass through a plurality of second through holes (6-03) opened at both ends of the strain sensor (6) and engage with the plug screw holes (5-01) of the two strain mounting seats (5), so that the strain sensor (6) and the strain mounting seat (5) are tightly fitted; the signal cable (6-02) passes through the third through hole (7-01) of the strain locking card (7), and the third bolt (11) passes through the fourth through hole (7-02) of the strain locking card (7) and engages with the fourth through hole (7-01) of the strain mounting seat (5). The third threaded hole (5-02) is engaged; the strain mounting seat (5) is embedded in the first square groove (7-03) and the second square groove (7-04) of the strain locking card (7); the height of the first square groove (7-03) is slightly higher than the height of the strain mounting seat (5); the fourth bolt (12) passes through the fifth through hole (7-05) of the strain locking card (7) to fix the strain mounting seat (5), the strain sensor (6) and the strain locking card (7) on the mounting locking card (302), and the fourth bolt (12) is engaged with the first threaded hole (302-02); the third bolt (11) can preset a pre-tightening force to adjust the measurement starting point of the strain sensor (6).

[0011] In an optional embodiment of the present invention, the strain mounting seat (5) is a rectangular parallelepiped structure, and a plurality of the plug screw holes (5-01) are provided on a plane in the length and width directions thereof, the plug screw holes (5-01) are distributed in the same manner as the second through holes (6-03), and are coaxially arranged; the upper portion of the plug screw hole (5-01) is a circular hole, which is connected to the threaded hole; and a third threaded hole (5-02) is provided on the side surface in the high direction of the strain mounting seat (5).

[0012] In an optional embodiment of the present invention, the installation limit plate (4) is a rectangular plate-shaped structure, and the installation limit plate (4) is respectively provided with four first circular holes (4-01) and four first notch holes (4-02) at positions corresponding to the distribution of the first threaded holes (302-02) and the first through holes (301-02).

[0013] In an optional embodiment of the present invention, the strain locking card (7) is a rectangular parallelepiped structure, the bottom and side surfaces of which are both provided with the first square groove (7-03), the second square groove (7-04) is provided in the first square groove (7-03), the side surfaces of the first square groove (7-03) and the second square groove (7-04) are provided with a third through hole (7-01) and a fourth through hole (7-02); and the top of the strain locking card (7) is provided with four fifth through holes (7-05).

[0014] Compared with the prior art, the present invention provides a fiber Bragg grating strain monitoring device for threaded steel, which has the following beneficial effects:

[0015] (1) The utility model does not adopt welding method, has no influence on the mechanical properties of threaded steel, does not adopt gluing method, is simple to operate, and has strong environmental adaptability.

[0016] (2) The strain sensor is matched with the screw holes of the strain mounting base through multiple plug screws, which can minimize the installation gap of the strain sensor. The trapezoidal thread sleeve and threaded steel locking card are tightened by the principle of tension to ensure that it fits tightly with the threaded steel. The irregular deformation of the threaded steel does not affect the tight fit. The installation limit plate has a round hole on one side and a slotted through hole on the other side. There is no need to pull out the threaded steel and the device can be directly assembled. It can ensure the consistency of the installation plane, ensure the installation quality, reduce the installation technical requirements, and can be flexibly adjusted. The strain transmission is precise in practice and is suitable for the actual project site.

[0017] (3) The strain monitoring device further controls the problem of inaccurate initial strain transmission caused by factors such as the installation gap of the strain locking card, strain sensor, and strain mounting seat and material mechanics by adjusting the torque of the third bolt.

[0018] (4) The strain sensor is a special glass solid-state package, and the fiber Bragg grating is tightly integrated with the main body. It has the advantages of long life, anti-oxidation, anti-fatigue, and not easy to disengage. It is a replaceable module.

[0019] (5) The utility model is applicable to strain monitoring of various types of threaded steel. The main components are all made of metal. No electric energy is used in the monitoring process. The sensor is an intrinsically safe sensor with strong anti-electromagnetic interference performance, can be used for a long time in harsh environments and is not easily damaged. The measurement distance is long, and it can meet current monitoring requirements in terms of continuity, real-time performance and measurement sensitivity.

[0020] (6) The strain monitoring device is detachable and reusable. By installing a limit plate, the monitoring cost is reduced and the loss to resources and the environment is reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the embodiments or prior art, the following briefly introduces the drawings required for use in the embodiments or prior art descriptions. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0022] Figure 1 This is a schematic diagram of an exploded view of a fiber Bragg grating strain monitoring device for threaded steel provided in an embodiment of the present application.

[0023] Figure 2 This is a schematic structural diagram of a fiber Bragg grating strain monitoring device for threaded steel provided in an embodiment of the present application.

[0024] Figure 3 This is a front view of a fiber Bragg grating strain monitoring device for threaded steel provided in an embodiment of the present application.

[0025] Figure 4 This is a left view of a fiber Bragg grating strain monitoring device for threaded steel provided in an embodiment of the present application.

[0026] Figure 5 for Figure 4 Schematic diagram of the cross-sectional structure of A1-A2.

[0027] Figure 6 This is a partial structural diagram of a fiber Bragg grating strain monitoring device for threaded steel provided in an embodiment of the present application.

[0028] Figure 7 This is a front view of a partial structure of a fiber Bragg grating strain monitoring device for threaded steel provided in an embodiment of the present application.

[0029] Figure 8 This is a schematic diagram of the structure of a threaded steel locking card of a fiber Bragg grating strain monitoring device for threaded steel provided in an embodiment of the present application.

[0030] Figure 9 A front view of a threaded steel locking clip provided in an embodiment of the present application.

[0031] Figure 10 A top view of a threaded steel locking clip provided in an embodiment of the present application.

[0032] Figure 11 for Figure 10 Schematic diagram of the cross-sectional structure of B1-B2.

[0033] Figure 12 A schematic diagram of the structure of a strain mounting base of a fiber Bragg grating strain monitoring device for threaded steel provided in an embodiment of the present application.

[0034] Figure 13 A front view of a strain mount provided in an embodiment of the present application.

[0035] Figure 14 for Figure 13 Schematic diagram of the cross-sectional structure of C1-C2.

[0036] Figure 15 This is a schematic diagram of the structure of a strain locking card of a fiber Bragg grating strain monitoring device for threaded steel provided in an embodiment of the present application.

[0037] Figure 16 A top view of a strain locking card provided in an embodiment of the present application.

[0038] Figure 17 A front view of a strain locking card provided in an embodiment of the present application.

[0039] Figure 18 for Figure 17 Schematic diagram of the cross-sectional structure of D1-D2. DETAILED DESCRIPTION

[0040] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the embodiments described are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without making creative efforts are within the scope of protection of this application.

[0041] like Figures 1 to 18 As shown, an embodiment of the utility model provides a fiber optic Bragg grating strain monitoring device for threaded steel, including a threaded steel 1, a trapezoidal thread sleeve 2, a threaded steel locking card 3, an installation limit plate 4, a strain mounting seat 5, a strain sensor 6, a strain locking card 7, a first bolt 8, a second bolt 9, a plug screw 10, a third bolt 11 and a fourth bolt 12.

[0042] The threaded steel bar 1 is a rod-shaped structure with an elliptical cross-section and an oblique rib structure distributed at the tangent position of the elliptical long axis; the trapezoidal thread sleeve 2 is a stepped cylindrical structure, and the trapezoidal thread sleeve 2 is provided with a first trapezoidal thread 201-01, a second trapezoidal thread 202-01 and a third trapezoidal thread 203-01 with the center line of the cylinder as the axis. The trapezoidal thread sleeve 2 is provided with a trapezoidal thread sleeve 1 201, a trapezoidal thread sleeve 2 202 and a trapezoidal thread sleeve 3 203 at intervals. The bottom layers of the trapezoidal thread sleeve 1 201, the trapezoidal thread sleeve 2 202 and the trapezoidal thread sleeve 3 203 are polygonal platform 1 201-02, polygonal platform 202-02 and polygonal platform 3 203-02 respectively.

[0043] The threaded steel locking card 3 includes a limit locking card 301 and an installation locking card 302. The limit locking card 301 is a rectangular parallelepiped structure. The bottom surface of the limit locking card 301 is provided with a first semicircular through hole 301-01, and the axis position of the first semicircular through hole 301-01 is outside its bottom surface; the top of the limit locking card 301 is provided with 4 first through holes 301-02, and they do not intersect with the first semicircular through hole 301-01; the installation locking card 302 has the same shape as the limit locking card 301, and the bottom surface of the installation locking card 302 is provided with a second semicircular through hole 302-01, the first The semicircular through hole 301-01 and the second semicircular through hole 302-01 have the same shape and are coaxially arranged; the top surface of the mounting locking card 302 is provided with four first threaded holes 302-02 and four second threaded holes 302-03, the first threaded holes 302-02 and the first through holes 301-02 are distributed at the same position and are coaxially arranged, and the second threaded holes 302-03 are distributed within the first threaded holes 302-02; the four second threaded holes 302-03 and the four fifth through holes 7-05 of the strain locking card 7 are distributed at the same position and are coaxially arranged.

[0044] Use 8 first bolts 8 to pass through the first circular hole 4-01 and the first slot hole 4-02 of the mounting limit plate 4 and connect the two mounting locking cards 302 to the mounting limit plate 4 tightly through the first threaded hole 302-02, and the top surface of the mounting locking card 302 is set in conflict with the mounting limit plate 4; assemble the two sets of trapezoidal thread sleeves 2 in the order of thread connection, and the trapezoidal thread sleeve 2 cones are adjacently mounted on the threaded steel 1 and screwed to the preset position, and the polygonal platform 1 201-02, polygonal platform 2 202-02 and polygonal platform 3 202-02 of the trapezoidal thread sleeve 2 are outside the first semicircular through hole 301-01 and the second semicircular through hole 302-01 ; The trapezoidal thread sleeve 2 can be squeezed by the second semicircular through hole 302-01 of the installation locking card 302, and the second bolt 9 is used to pass through the first through hole 301-02 and the limit locking card 301 respectively, and loosely engage with the first threaded hole 302-02 of the installation locking card 302, and continue to spiral the trapezoidal thread sleeve 2, so that the polygonal platform 1 201-02, polygonal platform 202-02, and polygonal platform 3 202-02 are tightly fitted with the limit locking card 301 and the installation locking card 302, and the second bolt 9 is locked to ensure that the threaded steel locking card 3 is tightly held; the first bolt 8 is used to fix the limit locking card 301 and the installation locking card 302.

[0045] The main structure 6-01 of the strain sensor 6 is a long plate-like structure, with signal cables 6-02 connected to its two ends; multiple plug screws 10 pass through multiple second through holes 6-03 opened at both ends of the strain sensor 6 and engage with the plug screw holes 5-01 of the two strain mounting bases 5, so that the strain sensor 6 and the strain mounting base 5 are tightly fitted; the signal cable 6-02 passes through the third through hole 7-01 of the strain locking card 7, and the third bolt 11 passes through the fourth through hole 7-02 of the strain locking card 7 and the third screw hole 5-01 of the strain mounting base 5. The grooved hole 5-02 is engaged; the strain mounting seat 5 is embedded in the first square groove 7-03 and the second square groove 7-04 of the strain locking card 7; the height of the first square groove 7-03 is slightly higher than the height of the strain mounting seat 5; the fourth bolt 12 passes through the fifth through hole 7-05 of the strain locking card 7 to fix the strain mounting seat 5, the strain sensor 6 and the strain locking card 7 on the mounting locking card 302, and the fourth bolt 12 is engaged with the first threaded hole 302-02; the third bolt 11 can preset the preload force to adjust the measurement starting point of the strain sensor 6.

[0046] like Figure 12 、 Figure 13 and Figure 14 As shown, the strain mounting seat 5 is a rectangular structure, and a plurality of plug screw holes 5-01 are provided on the plane in the length and width directions. The plug screw holes 5-01 are distributed in the same manner as the second through holes 6-03 and are coaxially arranged; the upper portion of the plug screw hole 5-01 is a circular hole, which is connected to the threaded hole; a third threaded hole 5-02 is provided on the side in the high direction of the strain mounting seat 5.

[0047] like Figure 1 As shown, the installation limit plate 4 is a rectangular plate structure, and the installation limit plate 4 is respectively provided with four first circular holes 4-01 and four first notch holes 4-02 at the distribution positions corresponding to the first threaded holes (302-02) and the first through holes 301-02.

[0048] like Figure 15 、 Figure 16 、 Figure 17 and Figure 18 As shown, the strain locking card 7 is a rectangular parallelepiped structure, with a first square groove 7-03 provided on the bottom and side surfaces, a second square groove 7-04 provided in the first square groove 7-03, a third through hole 7-01 and a fourth through hole 7-02 provided on the sides of the first square groove 7-03 and the second square groove 7-04; four fifth through holes 7-05 are provided on the top of the strain locking card 7.

[0049] The working principle of this utility model is as follows: the spacing can be flexibly adjusted by combining the trapezoidal thread sleeve and the threaded steel locking clamp to ensure a tight fit. The installation of the limit plate and the tapered nut ensures that the installation plane and the installation hole position are consistent. The installation limit plate has a through hole on one side and a slot on the other side. The slot can adjust the distance between the two threaded steel locking clamps, which is not affected by the straightness of the threaded steel. After the second bolt locks the threaded steel locking clamp, the installation limit plate is removed. The strain sensor, strain mounting base, and strain locking clamp are initially assembled using the fourth bolt. By adjusting the torque of the second bolt, the assembly gap is eliminated and the strain sensor is pre-tightened to ensure its monitoring linearity. When the threaded steel is subjected to stress changes, the stress is transmitted to the strain locking card through the trapezoidal thread sleeve and the threaded steel locking card, and then to the strain locking card to the strain mounting seat, and then to the strain mounting seat to the strain sensor. The strain sensor body stretches, and the center wavelength of the fiber Bragg grating changes. The fiber Bragg grating interrogator is connected to the optical fiber, and the interrogator can distinguish the change in the center wavelength of the fiber Bragg grating, and then calculate the wavelength change of the fiber Bragg grating sensitive element and eliminate the influence of temperature on the sensitive element. The fiber Bragg grating strain sensor body and the fiber Bragg grating are encapsulated in a dedicated glass solid state. The fiber Bragg grating and the strain sensor body are tightly combined, with the advantages of long life, anti-oxidation, anti-fatigue, and not easy to disengage. They are all replaceable modules and can distinguish tiny deformations at the pm level.

[0050] The assembly connection grating detection involved in the present invention is a common method used by those skilled in the art, which can be obtained through limited experiments and belongs to common knowledge. The components not described in detail in the present invention are prior art.

[0051] In summary, although the specific embodiments of the present invention have been described in detail, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by ordinary technicians in this field, various changes can be made without departing from the purpose of the present invention. Modifications or deformations that do not involve creative work are still within the scope of protection of the present invention.

Claims

1. A fiber Bragg grating strain monitoring device for threaded steel, characterized in that: It comprises a threaded steel bar (1), a trapezoidal thread sleeve (2), a threaded steel locking clamp (3), a mounting limit plate (4), a strain mounting seat (5), a strain sensor (6), a strain locking clamp (7), a first bolt (8), a second bolt (9), a plug screw (10), a third bolt (11) and a fourth bolt (12); The threaded steel (1) is a rod-shaped structure, and its cross-section is elliptical, and an oblique rib structure is distributed at a tangent position of the elliptical long axis; the trapezoidal thread sleeve (2) is a stepped cylindrical structure, and the trapezoidal thread sleeve (2) is provided with a first trapezoidal thread (201-01), a second trapezoidal thread (202-01) and a third trapezoidal thread (203-01) with the center line of the cylinder as the axis, and the trapezoidal thread sleeve (2) is provided with a trapezoidal thread sleeve 1 (201), a trapezoidal thread sleeve 2 (202) and a trapezoidal thread sleeve 3 (203) at intervals, and the stepped bottom layers of the trapezoidal thread sleeve 1 (201), the trapezoidal thread sleeve 2 (202) and the trapezoidal thread sleeve 3 (203) are polygonal platform 1 (201-02), polygonal platform 2 (202-02) and polygonal platform 3 (203-02) respectively; The threaded steel locking card (3) includes a limit locking card (301) and an installation locking card (302), wherein the limit locking card (301) is a rectangular parallelepiped structure, and a first semicircular through hole (301-01) is provided on the bottom surface of the limit locking card (301), and the axis position of the first semicircular through hole (301-01) is outside the bottom surface; four first through holes (301-02) are provided on the top of the limit locking card (301), and the four first through holes (301-02) do not intersect with the first semicircular through holes (301-01); the installation locking card (302) has the same shape as the limit locking card (301), and a second semicircular through hole (302-01) is provided on the bottom surface of the installation locking card (302). The first semicircular through hole (301-01) and the second semicircular through hole (302-01) are of the same shape and are coaxially arranged; the top surface of the mounting locking card (302) is provided with four first threaded holes (302-02) and four second threaded holes (302-03); the first threaded holes (302-02) and the first through hole (301-02) are distributed at the same position and are coaxially arranged, and the second threaded holes (302-03) are distributed within the first threaded hole (302-02); the four second threaded holes (302-03) and the four fifth through holes (7-05) of the strain locking card (7) are distributed at the same position and are coaxially arranged; Eight first bolts (8) are used to pass through the first circular hole (4-01) and the first slot hole (4-02) of the installation limit plate (4) and to tightly connect the two installation locking clamps (302) to the installation limit plate (4) through the first threaded hole (302-02), and the top surface of the installation locking clamp (302) is set in abutment with the installation limit plate (4); the two sets of the trapezoidal thread sleeves (2) are assembled in a thread connection sequence, and the truncated cones of the trapezoidal thread sleeves (2) are adjacently sleeved on the threaded steel (1) and screwed to a preset position, and the polygonal platform one (201-02), polygonal platform two (202-02) and polygonal platform three (203-02) of the trapezoidal thread sleeve (2) are outside the first semicircular through hole (301-01) and the second semicircular through hole (302-01); the trapezoidal thread sleeves (2) are assembled in a thread connection sequence, and the truncated cones of the trapezoidal thread sleeves (2) are adjacently sleeved on the threaded steel (1) and screwed to a preset position, and the polygonal platform one (201-02), polygonal platform two (202-02) and polygonal platform three (203-02) of the trapezoidal thread sleeves ... The threaded sleeve (2) can be squeezed by the second semicircular through hole (302-01) of the installation locking card (302), and the second bolt (9) is used to pass through the first through hole (301-02) and the limit locking card (301) respectively, and then loosely engage with the first threaded hole (302-02) of the installation locking card (302), and continue to screw the trapezoidal threaded sleeve (2) so that the polygonal platform one (201-02), the polygonal platform two (202-02), and the polygonal platform three (203-02) are tightly fitted with the limit locking card (301) and the installation locking card (302), and the second bolt (9) is locked to ensure that the threaded steel locking card (3) is tightly held; the first bolt (8) is used to fix the limit locking card (301) and the installation locking card (302); The main structure (6-01) of the strain sensor (6) is a long plate-shaped structure, with signal cables (6-02) connected to its two ends; a plurality of the plug screws (10) pass through a plurality of second through holes (6-03) opened at both ends of the strain sensor (6) and engage with the plug screw holes (5-01) of the two strain mounting seats (5), so as to fit the strain sensor (6) and the strain mounting seat (5) tightly; the signal cable (6-02) passes through the third through hole (7-01) of the strain locking card (7), and the third bolt (11) passes through the fourth through hole (7-02) of the strain locking card (7) and engages with the first through hole (7-01) of the strain mounting seat (5). The three threaded holes (5-02) are engaged; the strain mounting seat (5) is embedded in the first square groove (7-03) and the second square groove (7-04) of the strain locking card (7); the height of the first square groove (7-03) is slightly higher than the height of the strain mounting seat (5); the fourth bolt (12) passes through the fifth through hole (7-05) of the strain locking card (7) to fix the strain mounting seat (5), the strain sensor (6) and the strain locking card (7) on the mounting locking card (302), and the fourth bolt (12) is engaged with the first threaded hole (302-02); the third bolt (11) can preset a pre-tightening force to adjust the measurement starting point of the strain sensor (6).

2. The fiber Bragg grating strain monitoring device for threaded steel according to claim 1, characterized in that: The strain mounting seat (5) is a rectangular parallelepiped structure, and a plurality of plug screw holes (5-01) are provided on a plane in the length and width directions thereof. The plug screw holes (5-01) are distributed in the same manner as the second through holes (6-03) and are coaxially arranged. The upper portion of the plug screw hole (5-01) is a circular hole, which is connected to the threaded hole. A third threaded hole (5-02) is provided on the side surface in the height direction of the strain mounting seat (5).

3. The fiber Bragg grating strain monitoring device for threaded steel according to claim 1, characterized in that: The installation limiting plate (4) is a rectangular plate-shaped structure, and is provided with four first circular holes (4-01) and four first notched holes (4-02) at positions corresponding to the first threaded holes (302-02) and the first through holes (301-02).

4. The fiber Bragg grating strain monitoring device for threaded steel according to claim 1, characterized in that: The strain locking card (7) is a rectangular parallelepiped structure, with the first square groove (7-03) being provided on its bottom and side surfaces, a second square groove (7-04) being provided in the first square groove (7-03), and a third through hole (7-01) and a fourth through hole (7-02) being provided on the side surfaces of the first square groove (7-03) and the second square groove (7-04); and four fifth through holes (7-05) being provided on the top of the strain locking card (7).

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