CN214224006U - Surface type fiber grating strain sensor - Google Patents

Abstract

The utility model relates to a strain transducer's field especially relates to a surface type fiber grating strain transducer, including two mount pads, be fixed in the first encapsulation joint on one of them mount pad, be fixed in the second encapsulation joint on another mount pad, install the encapsulation pipe on first encapsulation joint and second encapsulation joint respectively, be fixed in the encapsulation pipe and both ends respectively by the fiber grating that first encapsulation joint and second encapsulation joint were drawn forth, and the outside section of thick bamboo that protects of two encapsulation pipes is located to the cover simultaneously, protect the one end and the first encapsulation joint fixed coordination of a section of thick bamboo, the other end and the cooperation of sliding of second encapsulation joint, and protect and be equipped with the limit structure who restricts both strokes of sliding between a section of thick bamboo and the second encapsulation joint. The fiber grating breaking device has the effect of reducing the possibility of fiber grating breaking.

Description

Surface type fiber grating strain sensor

Technical Field

The application relates to the field of strain sensors, in particular to a surface type fiber grating strain sensor.

Background

The fiber Bragg grating sensor is one of fiber optic sensors, mainly obtains sensing information by modulating fiber Bragg wavelength by external physical parameters, and is widely applied to measurement of data such as displacement, vibration, strain and the like because the fiber Bragg grating sensor has the advantages of no electromagnetic interference, large signal bandwidth, high sensitivity, high temperature resistance, corrosion resistance and the like.

At present, the fiber bragg grating strain sensor comprises two installation seats and a sensor body fixed between the two installation seats, the sensor body at least comprises two packaging parts and a fiber bragg grating fixed on the two packaging parts, the two packaging parts are respectively installed on the two installation seats, the installation seats are fixed on the surface of a structure in a bolt or electric welding mode, and specific reference can be made to a Chinese patent with an authorization publication number of CN 109631745A.

When the structure surface is deformed, the fiber grating in the sensor body is deformed, and the signal is transmitted to the demodulator, and the measured parameter is obtained after demodulation.

In view of the above-mentioned related art, the inventor found that when the deformation generated on the structure surface is large, the fiber grating is prone to wire breakage, resulting in damage to the strain sensor.

SUMMERY OF THE UTILITY MODEL

In order to reduce the possibility of fiber grating wire breakage, the application provides a surface type fiber grating strain sensor.

The application provides a surface type fiber grating strain sensor adopts following technical scheme:

a surface type fiber grating strain sensor comprises two mounting seats, a first packaging joint fixed on one of the mounting seats, a second packaging joint fixed on the other mounting seat, packaging pipes respectively installed on the first packaging joint and the second packaging joint, a fiber grating fixed in the packaging pipes and with two ends led out by the first packaging joint and the second packaging joint respectively, and a protective barrel sleeved outside the two packaging pipes, wherein one end of the protective barrel is fixedly matched with the first packaging joint, the other end of the protective barrel is matched with the second packaging joint in a sliding manner, and a limiting structure for limiting the sliding stroke of the protective barrel and the second packaging joint is arranged between the protective barrel and the second packaging joint.

Through adopting above-mentioned technical scheme, during the construction, be fixed in the component surface that awaits measuring with fiber grating strain transducer through two mount pads, when the component surface that awaits measuring produces great deformation, limit structure can restrict and protect the stroke that slides between a and the second encapsulation connects to protect fiber grating, reduce fiber grating and take place the possibility of disconnected silk in the testing process.

Preferably, first encapsulation connects including fixing first locating piece and the first sleeve of a body coupling in first locating piece one end on the mount pad, and the inside of first locating piece and first sleeve is equipped with and communicates with the external world in order to supply the logical chamber that the encapsulation pipe stretched into, and processing has the V-arrangement annular on the outer wall of first sleeve, and the position processing that the corresponding V-arrangement annular of the casing has the fixed part of embedding V-arrangement annular in order to fix on first sleeve.

By adopting the technical scheme, the protective cylinder is sleeved on the first sleeve during installation, and force is applied to the protective cylinder through a tool according to a pre-drawn marking line, so that the position of the protective cylinder corresponding to the V-shaped annular groove is embedded into the V-shaped annular groove, and the fixed connection between the protective cylinder and the V-shaped annular groove is realized.

Preferably, the second packaging connector comprises a second positioning block fixed on the mounting seat and a second sleeve integrally connected to one end of the second positioning block, and a through cavity communicated with the outside and used for the packaging tube to extend into is formed in the second positioning block and the second sleeve;

the limiting structure comprises an annular sleeve coaxially arranged at one end of the protective sleeve and sleeved on the second sleeve, and a connecting plate used for connecting the annular sleeve and the protective sleeve, wherein a limiting groove axially extending along the outer wall of the second sleeve is processed on the outer wall of the second sleeve, part of the side wall of the annular sleeve is attached to the groove bottom of the limiting groove in a sliding manner, and the length of the limiting groove is greater than that of the annular sleeve.

By adopting the technical scheme, when the deformation of the component to be tested is larger than the sliding stroke between the protective sleeve and the second packaging joint, the groove wall of the limiting groove limits the annular sleeve, so that the fiber bragg grating is protected; meanwhile, according to the requirement, the worker can adjust the position of the annular sleeve in the limiting groove in the assembling process to measure the positive and negative strain quantities.

Preferably, the inner wall of the casing is matched with the outer walls of the first sleeve and the second sleeve.

Through adopting above-mentioned technical scheme, guarantee to protect the leakproofness between section of thick bamboo and first sleeve and the second sleeve.

Preferably, the outer walls of the first sleeve and the second sleeve are provided with annular grooves, and O-shaped sealing rings tightly abutted to the inner wall of the protective cylinder are installed in the annular grooves.

By adopting the technical scheme, the sealing performance is further improved, and the fiber bragg grating in the protective cylinder is protected.

Preferably, one end, far away from the second locating piece, of the second sleeve is coaxially and fixedly connected with a lengthened cylinder with the diameter smaller than that of the second sleeve, an annular groove is formed in the outer wall of the lengthened cylinder, and a damping ring is installed in the annular groove.

Through adopting above-mentioned technical scheme, damping ring's setting mainly is used for preventing that the in-process that protects a section of thick bamboo and second encapsulation and connect relative slip from appearing blocking.

Preferably, the mount pad includes bottom plate and an organic whole and connects in the same one side of bottom plate and two risers that are parallel to each other, forms the standing groove that supplies first locating piece or second locating piece installation between two risers and the bottom plate, and threaded connection has the positioning bolt who passes riser to the standing groove in respectively on two risers.

By adopting the technical scheme, during installation, the positioning bolt is rotated to penetrate through the vertical plate and tightly abut and fix the first packaging connector or the second packaging connector.

Preferably, the side walls of the first positioning block and the second positioning block are both in threaded connection with jackscrews extending into the first positioning block or the second positioning block.

By adopting the technical scheme, after the packaging pipe is in place, a worker can fix the packaging pipe through the top thread.

Preferably, the device also comprises two groups of wire pressing assemblies, wherein each group of wire pressing assemblies at least comprises an external thread sleeve fixedly connected to one end of the first positioning block far away from the first sleeve or one end of the second positioning block far away from the second sleeve, a fastening nut in threaded connection with the external thread sleeve, a gasket fixedly connected to an opening at one side of the fastening nut, and a deformation sleeve arranged in the external thread sleeve and the fastening nut;

the inner wall of the external thread sleeve from the free end to the inside is processed with an inner conical wall with the diameter gradually reduced, the deformation sleeve is processed with an outer conical wall, and the taper of the inner conical wall is smaller than that of the outer conical wall;

the gasket is provided with a threading hole for the fiber grating to pass through.

Through adopting above-mentioned technical scheme, the setting of line ball subassembly, mainly used fixes by the fiber grating that first encapsulation connects and the joint is drawn forth to the second encapsulation, avoids strain sensor because the rocking of external protection pipe and the fiber grating that drives inside rocks, guarantees the accuracy of detection data.

Preferably, one side of each of the two packaging tubes is provided with an abdicating notch with the same length as the packaging tube.

By adopting the technical scheme, during packaging, the fiber bragg grating can be placed in the two packaging pipes through the abdicating notch without threading, so that the packaging difficulty is greatly reduced.

In summary, the present application includes at least one of the following beneficial technical effects:

1. during construction, the fiber bragg grating strain sensor is fixed on the surface of a component to be detected through the two mounting seats, and when the surface of the component to be detected is greatly deformed, the limiting structure can limit the sliding stroke between the protective cylinder and the second packaging joint, so that the fiber bragg grating is protected, and the possibility of wire breakage of the fiber bragg grating in the detection process is reduced;

2. the O-shaped sealing ring is mainly used for improving the sealing performance and protecting the fiber bragg grating in the protective cylinder;

3. the damping ring is arranged and mainly used for preventing the clamping in the relative sliding process of the protective cylinder and the second packaging joint;

4. the setting of line ball subassembly, mainly used fixes the fiber grating who is drawn forth by first encapsulation joint and second encapsulation joint, avoids strain sensor to lead to inside fiber grating because rocking of external protection pipe and rocks, guarantees the accuracy of detected data.

Drawings

FIG. 1 is a schematic diagram of the overall structure of a surface-type fiber grating strain sensor in the present application;

FIG. 2 is a schematic structural diagram showing a mating relationship between a first package connector, a second package connector, and a package tube;

FIG. 3 is a schematic view showing a specific structure of a mounting base;

FIG. 4 is a schematic diagram showing a concrete structure of a grouted mount;

FIG. 5 is a schematic diagram showing a specific structure of a welding type mounting seat;

FIG. 6 is a schematic view of a first encapsulated joint embodiment and the mating relationship between the first sleeve and the casing;

FIG. 7 is a diagram illustrating a second package connector embodiment;

FIG. 8 is a schematic view of a specific structure of the packaging tube;

FIG. 9 is an exploded view showing the fitting relationship between the second sleeve and the sheath and the specific structure of the wire pressing assembly;

fig. 10 is a schematic view showing a specific structure of the stopper structure.

Description of reference numerals: 1. a mounting seat; 11. a base plate; 12. a vertical plate; 13. mounting holes; 14. positioning the bolt; 2. a first package connector; 21. a first positioning block; 22. a first sleeve; 23. a V-shaped ring groove; 3. a second package connector; 31. a second positioning block; 32. a second sleeve; 33. lengthening the barrel; 34. a damping ring; 35. a limiting groove; 4. packaging the tube; 41. a abdication gap; 42. injecting glue groove; 5. a wire pressing assembly; 51. an external thread sleeve; 52. fastening a nut; 53. a gasket; 54. a deformation sleeve; 55. ejecting the head; 551. a conical head; 552. a push ring; 6. protecting the cylinder; 61. a fixed part; 7. a limiting structure; 71. a ring-shaped sleeve member; 72. a connector tile; 73. cutting into straight sections; 74. cutting into straight section; 8. an O-shaped sealing ring; 9. and (5) jacking the screw.

Detailed Description

The present application is described in further detail below with reference to figures 1-10.

The embodiment of the application discloses a surface type fiber grating strain sensor. Referring to fig. 1 and 2, the surface fiber grating strain sensor includes two symmetrically arranged mounting bases 1, a first package connector 2 fixed on one of the mounting bases 1, and a second package connector 3 fixed on the other mounting base 1; the first packaging joint 2 and the second packaging joint 3 are both provided with a packaging tube 4, a fiber grating (not shown in the figure) is fixed in the two packaging tubes 4, two ends of the fiber grating are respectively led out from the first packaging joint 2 and the second packaging joint 3, and a grid area for detecting strain is arranged on the fiber grating between the two packaging tubes 4.

It should be noted that, the outer cladding of the fiber grating that is drawn forth by first encapsulation joint 2 and second encapsulation joint 3 has the protection tube, for avoiding strain sensor because the rocking of protection tube and driving fiber grating rock, and then influence the detected data, set up a set of line ball subassembly 5 respectively on first encapsulation joint 2 and second encapsulation joint 3 for fix the fiber grating who draws forth.

The outside cover of two encapsulation pipes 4 is equipped with one and protects a section of thick bamboo 6, the one end and the first encapsulation of protecting a section of thick bamboo 6 connect 2 fixed coordination, protect the 6 other end of a section of thick bamboo and the cooperation of sliding of second encapsulation joint 3, be equipped with limit structure 7 between protecting a section of thick bamboo 6 and second encapsulation joint 3, when the surface of the component that awaits measuring produces great deformation, limit structure 7 can restrict and protect the stroke of sliding between a section of thick bamboo 6 and the second encapsulation joint 3, thereby protect fiber grating, reduce fiber grating and take place the possibility of disconnected silk in the testing process.

Referring to fig. 2 and 3, the mounting base 1 includes a bottom plate 11 and two vertical plates 12 integrally connected to the same side of the bottom plate 11 and parallel to each other, and mounting holes 13 are respectively processed on a plate body of the bottom plate 11 located on the opposite side of the two vertical plates 12, and are used for fixing the mounting base 1 on the surface of a component to be tested. A placing groove for installing the first packaging connector 2 or the second packaging connector 3 is formed between the two vertical plates 12 and the bottom plate 11, the two vertical plates 12 are respectively in threaded connection with a positioning bolt 14, and when the positioning bolt 14 is rotated, the positioning bolt 14 can pass through the vertical plates 12 to the placing groove and tightly fix the first packaging connector 2 or the second packaging connector 3.

Referring to fig. 3 and 4, the mounting base 1 may also be configured to be grouting type or welding type according to actual needs, so as to adapt to different application environments and improve the universality of the surface fiber grating strain sensor.

Referring to fig. 6 and 7, the first packing terminal 2 includes a first positioning block 21 and a first sleeve 22 integrally connected to one end of the first positioning block 21; the second encapsulation connector 3 comprises a second positioning block 31, a second sleeve 32 integrally connected to one end of the second positioning block 31, and an elongated sleeve 33 coaxially and fixedly connected to the second sleeve 32 and far away from one end of the second positioning block 31, wherein the diameter of the elongated sleeve 33 is smaller than that of the second sleeve 32, an annular groove is formed in the outer wall of the elongated sleeve 33, a damping ring 34 made of nylon is installed in the annular groove, the outer wall of the damping ring 34 is matched with the inner wall of the protection sleeve 6, and the damping ring 34 is arranged and mainly used for preventing the protection sleeve 6 from being blocked in the relative sliding process of the second encapsulation connector 3.

Cutting surfaces which can be attached to the two vertical plates 12 are processed on two opposite sides of the first positioning block 21 and two opposite sides of the second positioning block 31, and the cutting surfaces are mainly used for preventing the first packaging connector 2 and the second packaging connector 3 from rotating in the installation process.

Annular grooves are formed in the outer walls of the first sleeve 22 and the second sleeve 32, and O-shaped sealing rings 8 which are tightly abutted to the inner wall of the protection cylinder 6 are installed in the annular grooves and are mainly used for sealing, so that fiber gratings in the protection cylinder 6 are protected.

Referring to fig. 6 and 7, the interiors of the first positioning block 21 and the first sleeve 22 and the interiors of the second positioning block 31 and the second sleeve 32 are respectively provided with a through cavity extending along the axial direction and communicated with the outside, one end of the packaging tube 4 extends into the through cavity, threaded holes communicated with the inside of the through cavity are processed in the side walls of the first positioning block 21 and the second positioning block 31, and the packaging tube 4 is fixedly connected with a jackscrew 9 in a threaded manner.

Referring to fig. 8, the inside of the packaging tube 4 is hollow, two ends of the packaging tube 4 are open, a yield notch 41 with the same length as the packaging tube 4 is processed on one side of the packaging tube 4, two glue injection grooves 42 are processed on the position of each packaging tube 4 corresponding to the yield notch 41, during packaging, only the fiber grating needs to be placed in the two packaging tubes 4 through the yield notches 41, then the fiber grating is fixed in the glue injection grooves 42 in a glue dispensing manner, the packaging difficulty is greatly reduced, and the fiber grating between the two glue injection grooves 42 forms a temperature compensation area.

During installation, the packaging tube 4 is only required to be correspondingly placed inside the first sleeve 22 and the second sleeve 32 and then fixed through the jackscrew 9, and the fiber bragg grating at the grid region is pre-tensioned in the fixing process.

Referring to fig. 6, the inner wall of the casing 6 is fitted with the outer walls of the first sleeve 22 and the second sleeve 32, a V-shaped ring groove 23 is formed on the outer wall of the first sleeve 22, and a fixing portion 61 which is embedded in the V-shaped ring groove 23 to be fixed on the first sleeve 22 is formed at a position of the casing 6 corresponding to the V-shaped ring groove 23.

Referring to fig. 9 and 10, the limiting structure 7 includes an annular sleeve 71 coaxially disposed at one end of the casing 6 and sleeved on the second sleeve 32, and two connecting plates 72 symmetrically disposed on end surfaces of the annular sleeve 71 and the casing 6, the annular sleeve 71 and the connecting plates 72 are integrally processed, an inner straight tangent plane 73 extending along the axial direction of the casing 71 is processed on an inner wall of the annular sleeve 71, and an outer straight tangent plane 74 is processed on an outer wall of the annular sleeve 71 and the inner straight tangent plane 73 at the same position; the outer wall of the second sleeve 32 is provided with a limiting groove 35 extending along the axial direction, the length of the limiting groove 35 is greater than that of the annular sleeve 71, and the inner straight cutting surface 73 of the annular sleeve 71 is attached to the bottom of the limiting groove 35 in a sliding manner.

When the deformation of the component to be tested is larger than the sliding stroke between the protective sleeve 6 and the second packaging joint 3, the groove wall of the limiting groove 35 limits the annular sleeve 71, so as to protect the fiber bragg grating; meanwhile, according to the requirement, the worker can also adjust the position of the annular sleeve 71 in the limiting groove 35 in the assembling process to measure the positive and negative strain quantities.

Referring to fig. 9, the above-mentioned wire pressing assembly 5 includes an external thread sleeve 51, a fastening nut 52, a spacer 53, a deformation sleeve 54 and a plug 55; the external thread sleeve 51 is fixedly connected to one end of the first positioning block 21 far away from the first sleeve 22 or one end of the second positioning block 31 far away from the second sleeve 32, and an inner conical wall with the diameter gradually reduced is processed on the inner wall of the external thread sleeve 51 from the free end to the inside; the gasket 53 is fixedly connected to an opening at one side of the fastening nut 52, and a threading hole for the fiber bragg grating to pass through is formed in the gasket 53; the deformation sleeve 54 is provided with an outer conical wall, and the taper of the inner conical wall is smaller than that of the outer conical wall; the plug 55 includes a conical head 551 and a push ring 552 formed integrally, the conical head 551 being extendable into the deformable sleeve 54.

During installation, the plug 55 and the deformation sleeve 54 are sequentially assembled and placed in the fastening nut 52, then the fastening nut 52 is screwed on the external thread sleeve 51, and in the screwing process, the deformation sleeve 54 is subjected to destructive deformation under the extrusion effect, and the protection tube of the fiber grating is clamped, so that fixation is realized.

The implementation principle of the embodiment of the application is as follows:

the first step is as follows: respectively placing the first packaging joint 2 and the second packaging joint 3 on the two mounting seats 1 and fixing the two mounting seats through positioning bolts 14;

the second step is that: the fiber bragg grating passes through the two packaging tubes 4 and is fixed on the two packaging tubes 4;

the third step: sequentially penetrating one of the packaging tubes 4 through the first packaging joint 2 or the second packaging joint 3 and the protective cylinder 6 into the second packaging joint 3 or the first packaging joint 2, adjusting the two packaging tubes 4 in place, fixing the two packaging tubes 4 through the jackscrew 9, and assisting in the operation process by drawing marks on the protection tube of the fiber grating;

the fourth step: sleeving the protective sleeve 6 on the first sleeve 22 and the second sleeve 32, and applying force to the protective sleeve 6 through a tool according to a pre-drawn marking line to enable the position, corresponding to the V-shaped ring groove 23, of the protective sleeve 6 to be embedded into the V-shaped ring groove 23, so that the pressed part of the annular sleeve 71 forms a flat structure and is attached to the bottom of the limiting groove 35 of the second sleeve 32;

the fifth step: the two mounting bases 1 are respectively fixed on the surface of the component to be measured.

The above embodiments are preferred embodiments of the present application, and the protection scope of the present application is not limited by the above embodiments, so: all equivalent changes made according to the structure, shape and principle of the present application shall be covered by the protection scope of the present application.

Claims (10)

1. A surface type fiber grating strain sensor is characterized in that: the optical fiber grating packaging device comprises two mounting seats (1), a first packaging joint (2) fixed on one mounting seat (1), a second packaging joint (3) fixed on the other mounting seat (1), packaging tubes (4) respectively installed on the first packaging joint (2) and the second packaging joint (3), an optical fiber grating fixed in the packaging tubes (4) and respectively led out of the first packaging joint (2) and the second packaging joint (3) at two ends, and a protection tube (6) sleeved outside the two packaging tubes (4) at the same time, wherein one end of the protection tube (6) is fixedly matched with the first packaging joint (2), the other end of the protection tube is matched with the second packaging joint (3) in a sliding manner, and a limiting structure (7) for limiting the sliding stroke of the protection tube (6) and the second packaging joint (3) is arranged between the protection tube (6) and the second packaging joint (3).

2. A surface-mounted fiber grating strain sensor as recited in claim 1, wherein: first encapsulation connects (2) including fixing first locating piece (21) and the first sleeve (22) of a body coupling in first locating piece (21) one end on mount pad (1), the inside of first locating piece (21) and first sleeve (22) is equipped with and communicates with the external world and stretches into in order to supply encapsulation pipe (4) logical chamber, processing has V-arrangement annular (23) on the outer wall of first sleeve (22), it has embedding V-arrangement annular (23) to process in order to fix fixed part (61) on first sleeve (22) to protect the position processing that a section of thick bamboo (6) correspond V-arrangement annular (23).

3. A surface-mounted fiber grating strain sensor as recited in claim 2, wherein: the second packaging connector (3) comprises a second positioning block (31) fixed on the mounting seat (1) and a second sleeve (32) integrally connected to one end of the second positioning block (31), and a through cavity communicated with the outside and used for the packaging pipe (4) to extend into is formed in the second positioning block (31) and the second sleeve (32);

the limiting structure (7) comprises an annular sleeve member (71) which is coaxially arranged at one end of the pile casing (6) and sleeved on the second sleeve (32), and a connecting plate (72) used for connecting the annular sleeve member (71) and the pile casing (6), wherein a limiting groove (35) extending along the axial direction of the limiting groove is processed on the outer wall of the second sleeve (32), part of the side wall of the annular sleeve member (71) is attached to the groove bottom of the limiting groove (35) in a sliding mode, and the length of the limiting groove (35) is larger than that of the annular sleeve member (71).

4. A surface-mounted fiber grating strain sensor as claimed in claim 3, wherein: the inner wall of the protective sleeve (6) is matched with the outer walls of the first sleeve (22) and the second sleeve (32).

5. A surface-mounted fiber grating strain sensor as claimed in claim 3, wherein: annular grooves are formed in the outer walls of the first sleeve (22) and the second sleeve (32), and O-shaped sealing rings (8) which are tightly abutted to the inner wall of the protective cylinder (6) are installed in the annular grooves.

6. A surface-mounted fiber grating strain sensor as claimed in claim 3, wherein: one end, far away from the second positioning block (31), of the second sleeve (32) is coaxially and fixedly connected with a lengthening cylinder (33) with the diameter smaller than that of the second sleeve (32), the outer wall of the lengthening cylinder (33) is provided with a ring groove, and a damping ring (34) is installed in the ring groove.

7. A surface-mounted fiber grating strain sensor as claimed in claim 3, wherein: the mounting seat (1) comprises a bottom plate (11) and two vertical plates (12) which are integrally connected to the same side of the bottom plate (11) and are parallel to each other, a placing groove for mounting a first positioning block (21) or a second positioning block (31) is formed between the two vertical plates (12) and the bottom plate (11), and the two vertical plates (12) are respectively in threaded connection with positioning bolts (14) penetrating through the vertical plates (12) to the placing groove.

8. A surface-mounted fiber grating strain sensor as claimed in claim 3, wherein: the side walls of the first positioning block (21) and the second positioning block (31) are both in threaded connection with jackscrews (9) extending into the first positioning block (21) or the second positioning block (31).

9. A surface-mounted fiber grating strain sensor as recited in claim 1, wherein: the wire pressing device is characterized by further comprising two groups of wire pressing assemblies (5), wherein each group of wire pressing assemblies (5) at least comprises an external thread sleeve (51) fixedly connected to one end, far away from the first sleeve (22), of the first positioning block (21) or one end, far away from the second sleeve (32), of the second positioning block (31), a fastening nut (52) in threaded connection with the external thread sleeve (51), a gasket (53) fixedly connected to an opening on one side of the fastening nut (52), and a deformation sleeve (54) arranged in the external thread sleeve (51) and the fastening nut (52);

an inner conical wall (511) with the diameter gradually reduced is processed on the inner wall of the external thread sleeve (51) from the free end to the inside, an outer conical wall (541) is processed on the deformation sleeve (54), and the taper of the inner conical wall (511) is smaller than that of the outer conical wall (541);

the gasket (53) is provided with a threading hole for the fiber grating to pass through.

10. A surface-mounted fiber grating strain sensor as recited in claim 1, wherein: and one side of each of the two packaging tubes (4) is provided with a yielding notch (41) with the same length as the packaging tube.

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