A portable fiber optic strain sensor calibration device

Abstract

This invention provides a portable fiber Bragg grating strain sensor calibration device, comprising a fiber Bragg grating strain sensor, a clamping module, a tensile / compressive strain module, a demodulation module, a data processing module, and a host computer. The clamping module holds the fiber Bragg grating strain sensor and is connected to the tensile / compressive strain module, which in turn is connected to the fiber Bragg grating strain sensor. The fiber Bragg grating strain sensor is connected to the demodulation module, and both the tensile / compressive strain module and the demodulation module are connected to the data processing module, which is then connected to the host computer. The host computer stores strain and wavelength data, and uses a fitting algorithm to plot a strain-wavelength relationship model and calculate the strain sensitivity coefficient of the fiber Bragg grating strain sensor. The advantages of this invention are that it solves the problems of traditional calibration methods, such as reliance on manual operation, inability to eliminate temperature cross-sensitivity, and strain transfer loss due to adhesives.

Description

Technical Field

[0001] This utility model belongs to the field of fiber optic sensing technology, and in particular relates to a portable fiber optic strain sensor calibration device. Background Technology

[0002] Many mechanical components fail to meet quality standards due to strain generated during the manufacturing process. With continuous improvements in manufacturing processes, strain measurement has become increasingly important. Fiber Bragg grating (FBG) sensors utilize the photosensitivity of the fiber core and its internal grating. When broadband light waves are incident, specific wavelengths are reflected back, while other wavelengths are transmitted. The reflected spectrum peaks at the center wavelength, and FBG strain sensors respond to strain changes based on the drift of this center wavelength. Due to their advantages such as electromagnetic interference resistance and corrosion resistance, FBG strain sensors are widely used in the detection and monitoring of strain in various industries, including intelligent manufacturing, aerospace, marine engineering, water conservancy and hydropower, civil engineering, rail transportation, highway bridges, and petrochemicals. Existing calibration devices often employ hydraulic loading or large tensile machines, which are bulky, complex to operate, and unable to meet on-site calibration needs. Furthermore, commonly used FBG sensor calibration methods rely on adhesives, but due to inconsistent elastic moduli between layers after bonding, strain transmission loss occurs, affecting the strain transmitted from the substrate structure to the sensor and impacting measurement results, leading to inaccurate readings. Utility Model Content

[0003] In view of this, the present invention aims to propose a portable fiber optic strain sensor calibration device to solve the problems of traditional calibration methods relying on manual operation, being unable to eliminate temperature cross-sensitivity, and adhesive strain transfer loss.

[0004] To achieve the above objectives, the technical solution of this utility model is implemented as follows:

[0005] A portable fiber optic strain sensor calibration device includes a fiber optic strain sensor, a clamping module, a tensile / compressive strain module, a demodulation module, a data processing module, and a host computer.

[0006] The clamping module clamps the fiber Bragg grating strain sensor and is connected to the tension / compression strain module. The tension / compression strain module is connected to the fiber Bragg grating strain sensor. The fiber Bragg grating strain sensor is connected to the demodulation module. Both the tension / compression strain module and the demodulation module are connected to the data processing module. The data processing module is connected to the host computer.

[0007] Furthermore, the tension / compression strain module includes an extensometer and a sliding tension / compression module. The extensometer is connected to the data processing module and the clamping module. The sliding tension / compression module is connected to the clamping module. The sliding tension / compression module includes a sliding guide rail and a fixing component.

[0008] Furthermore, the tension-compression strain module includes a bidirectional strain loading module, an upper connecting rod, and a lower connecting rod. One end of the upper connecting rod is connected to the top of the bidirectional strain loading module, and one end of the lower connecting rod is connected to the bottom of the bidirectional strain loading module. The other ends of both the upper and lower connecting rods are connected to a clamping module. The bidirectional strain loading module includes a high-precision differential cylinder, an incremental rotary encoder, and a worm gear mechanism. Both the incremental rotary encoder and the worm gear mechanism are connected to the high-precision differential cylinder.

[0009] Furthermore, the clamping module includes two clamping components, which respectively clamp the upper and lower ends of the fiber optic strain sensor. Each clamping component includes two clamping rods, two positioning nuts, a fastening rod, four fastening nuts, and two clamping support plates. The clamping rods are U-shaped, and the fastening rods extend laterally through the two clamping rods. Both ends of the clamping rods extend through both ends of the clamping support plates, and both ends of the clamping rods are threaded to the fastening nuts. The fastening nuts are pre-tightened to the clamping support plates, and both ends of the fastening rods are threaded to the positioning nuts, which are pre-tightened to the clamping rods.

[0010] Furthermore, the clamping module includes two parallel clamping assemblies, which respectively clamp the upper and lower ends of the fiber Bragg grating strain sensor. Each parallel clamping assembly includes two clamping support plates, a fixed support, twenty fastening nuts, and ten fastening rods. The two clamping support plates are located at the front and rear, respectively. The fixed support is located at the rear of the two clamping support plates. The fastening rods penetrate the clamping support plates and are threaded to the fastening nuts at both ends. The rear ends of the two fastening rods in the middle penetrate the fixed support at both ends. The sixteen fastening nuts on the left and right are pre-tightened to the clamping support plates. The two fastening nuts at the front of the middle section are pre-tightened to the clamping support plates. The two fastening nuts at the rear of the middle section are pre-tightened to the fixed support.

[0011] Furthermore, the demodulation module is a fiber Bragg grating demodulator, which is connected to a fiber Bragg grating strain sensor and a data processing module.

[0012] Furthermore, the demodulation module includes a stepper motor, a fiber Bragg grating demodulator, and a temperature compensation module. The fiber Bragg grating demodulator is connected to a fiber Bragg grating strain sensor. The stepper motor, fiber Bragg grating demodulator, and temperature compensation module are all connected to the data processing module. The stepper motor drives the bidirectional strain loading module.

[0013] Furthermore, one end of the extensometer is pre-tightly connected to the clamping support plate, and the other end of the extensometer is pre-tightly connected to the fiber optic strain sensor. The fiber optic strain sensor is pre-tightly connected to the sliding tension-compression module. The upper and lower ends of the sliding tension-compression module respectively penetrate the middle of the fastening round rods of the two clamping components. The sliding tension-compression module is located between the two clamping round rods, and the sliding tension-compression module is pre-tightly connected to the clamping round rods on both sides.

[0014] Furthermore, the upper parallel clamping assembly clamps the upper connecting rod through the fixed support and clamping support plate two, and the lower parallel clamping assembly clamps the lower connecting rod through the fixed support and clamping support plate two. The upper parallel clamping assembly clamps the upper ends of eight fiber optic strain sensors through the front and rear clamping support plates two, and the lower parallel clamping assembly clamps the lower ends of eight fiber optic strain sensors through the front and rear clamping support plates two. The eight fiber optic strain sensors are separated by the fastening round rod two.

[0015] Compared with the prior art, the portable fiber optic strain sensor calibration device of this utility model has the following advantages:

[0016] (1) The extensometer can directly clamp and stretch the fiber optic grating sensor, avoiding the bending error and strain transmission loss problems of traditional calibration methods, as well as the aging and creep phenomena of adhesives after long-term use, and the problem of adhesive detachment.

[0017] (2) A temperature compensation module and a multi-sensor parallel calibration structure are set up, which solves the problems of traditional calibration methods such as reliance on manual operation, inability to eliminate temperature cross-sensitivity, and adhesive strain transfer loss. It is suitable for the calibration needs of high-precision fiber optic sensing systems in aerospace, civil engineering and other fields.

[0018] (3) It can improve the long-term stability and reliability of fiber Bragg grating strain sensors, effectively reduce the strain measurement error of fiber Bragg grating sensors, and make the device miniaturized and easy to carry. Attached Figure Description

[0019] The accompanying drawings, which form part of this utility model, are used to provide a further understanding of the utility model. The illustrative embodiments of the utility model and their descriptions are used to explain the utility model and do not constitute an undue limitation of the utility model. In the drawings:

[0020] Figure 1This is a schematic diagram of the overall structure of Embodiment 1 of the present utility model;

[0021] Figure 2 This is a schematic diagram of the clamping module according to Embodiment 1 of this utility model;

[0022] Figure 3 This is a schematic diagram of the overall structure of Embodiment 2 of this utility model;

[0023] Figure 4 This is a schematic diagram of the clamping module of Embodiment 2 of this utility model.

[0024] Explanation of reference numerals in the attached figures:

[0025] 1. Clamping assembly; 11. Clamping rod; 12. Positioning nut; 13. Fastening rod one; 14. Fastening nut one; 15. Clamping support plate one; 2. Parallel clamping assembly; 21. Clamping support plate two; 22. Fixing support; 23. Fastening nut two; 24. Fastening rod two; 3. Extensometer; 4. Sliding tension / compression module; 5. Fiber optic strain sensor; 6. Demodulation module; 7. Bidirectional strain loading module; 8. Upper connecting rod; 9. Lower connecting rod; 10. Data processing module. Detailed Implementation

[0026] It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0027] In the description of this utility model, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this utility model, unless otherwise stated, "a plurality of" means two or more.

[0028] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0029] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0030] like Figures 1 to 4 As shown, a portable fiber Bragg grating strain sensor calibration device includes a fiber Bragg grating strain sensor 5, a clamping module, a tensile / compressive strain module, a demodulation module 6, a data processing module 10, and a host computer. The clamping module clamps the fiber Bragg grating strain sensor 5 and is connected to the tensile / compressive strain module. The tensile / compressive strain module is connected to the fiber Bragg grating strain sensor 5. The fiber Bragg grating strain sensor 5 is connected to the demodulation module 6. Both the tensile / compressive strain module and the demodulation module 6 are connected to the data processing module 10, and the data processing module 10 is connected to the host computer.

[0031] The specific implementation method is as follows:

[0032] In a preferred embodiment of this utility model, such as Figure 1 As shown, the tension / compression strain module includes an extensometer 3 and a sliding tension / compression module 4. The extensometer 3 is connected to the data processing module 10 and also to the clamping module. The sliding tension / compression module 4 is connected to the clamping module and includes a sliding guide rail and a fixing component. The demodulation module 6 is a fiber Bragg grating demodulator, which is connected to the fiber Bragg grating strain sensor 5 and also to the data processing module 10. In this embodiment, the host computer controls the extensometer 3 to measure and record the strain value per unit step of the fiber Bragg grating strain sensor 5 through the data processing module 10. The sliding tension / compression module 4 slides up and down in the fastening rod 13 and is fixed with a positioning nut 12. The host computer controls the extensometer 3 to stretch or compress the fiber Bragg grating strain sensor 5 through the data processing module 10, and the host computer controls the fiber Bragg grating demodulator to demodulate the center wavelength of the fiber Bragg grating strain sensor 5 through the data processing module 10.

[0033] In a preferred embodiment of this utility model, such as Figure 3As shown, the tension / compression strain module includes a bidirectional strain loading module 7, an upper connecting rod 8, and a lower connecting rod 9. One end of the upper connecting rod 8 is connected to the top of the bidirectional strain loading module 7, and one end of the lower connecting rod 9 is connected to the bottom of the bidirectional strain loading module 7. The other ends of both the upper connecting rod 8 and the lower connecting rod 9 are connected to a clamping module. The bidirectional strain loading module 7 includes a high-precision differential cylinder, an incremental rotary encoder, and a worm gear mechanism. The incremental rotary encoder and the worm gear mechanism are both connected to the high-precision differential cylinder. The demodulation module 6 includes a fiber Bragg grating demodulator and a temperature compensation module. Both the fiber Bragg grating demodulator and the temperature compensation module are connected to the fiber Bragg grating strain sensor 5, and both the fiber Bragg grating demodulator and the temperature compensation module are connected to the data processing module 10. In this embodiment, the axial displacement of the precision differential cylinder is converted into the tensile or compressive strain of the fiber Bragg grating strain sensor 5 through a worm gear mechanism. The strain loading range is not less than ±5000με. The host computer controls the bidirectional strain loading module 7 through the data processing module 10 to measure and record the strain value per unit step of the fiber Bragg grating strain sensor 5. The host computer controls the stepper motor through the data processing module 10 to drive the bidirectional strain loading module 7 to stretch or compress the fiber Bragg grating strain sensor 5. The host computer controls the fiber Bragg grating demodulator through the data processing module 10 to demodulate the center wavelength of the fiber Bragg grating strain sensor 5. The temperature compensation module consists of a temperature-sensitive fiber Bragg grating strain sensor 5, which simultaneously demodulates the wavelength and temperature with the fiber Bragg grating strain sensor 5 under test to eliminate strain deviation caused by temperature.

[0034] In a preferred embodiment of this utility model, such as Figure 2As shown, the clamping module includes two clamping components 1, which respectively clamp the upper and lower ends of the fiber Bragg grating strain sensor 5. Each clamping component 1 includes two clamping rods 11, two positioning nuts 12, a fastening rod 13, four fastening nuts 14, and two clamping support plates 15. The clamping rods 11 are U-shaped. The fastening rod 13 extends laterally through the two clamping rods 11. Both ends of the clamping rods 11 extend through both ends of the clamping support plates 15, and both ends of the clamping rods 11 are threadedly connected to the fastening nuts 14. The fastening nuts 14 are connected to the clamping support plates 15. 5. Pre-tightening connection: Both ends of the fastening round rod 13 are threadedly connected to the positioning nut 12, and the positioning nut 12 is pre-tightened connected to the clamping round rod 11; One end of the extensometer 3 is pre-tightened connected to the clamping support plate 15, and the other end of the extensometer 3 is pre-tightened connected to the fiber optic strain sensor 5, and the fiber optic strain sensor 5 is pre-tightened connected to the sliding tension-compression module 4. The upper and lower ends of the sliding tension-compression module 4 pass through the middle of the fastening round rods 13 of the two clamping components 1, and the sliding tension-compression module 4 is located between the two clamping round rods 11, and the sliding tension-compression module 4 is pre-tightened connected to the clamping round rods 11 on both sides. In this embodiment, the positioning nut 12 provides an adjustable preload for the two clamping rods 11 to clamp the fiber Bragg grating strain sensor 5, and the fastening nut 14 provides an adjustable preload for the clamping support plate 15 and the clamping rods 11 to clamp the fiber Bragg grating strain sensor 5. The clamping rods 11, the fastening rod 13, and the clamping support plate 15 together fix the position of the fiber Bragg grating strain sensor 5.

[0035] In a preferred embodiment of this utility model, such as Figure 4As shown, the clamping module includes two parallel clamping components 2, which respectively clamp the upper and lower ends of the fiber optic strain sensor 5. Each parallel clamping component 2 includes two clamping support plates 21, a fixing support 22, twenty fastening nuts 23, and ten fastening rods 24. The two clamping support plates 21 are located at the front and rear, respectively. The fixing support 22 is located at the rear of the two clamping support plates 21. The fastening rods 24 penetrate the clamping support plates 21, and both ends of the fastening rods 24 are threadedly connected to the fastening nuts 23. The rear ends of the two fastening rods 24 in the middle penetrate both ends of the fixing support 22. The sixteen fastening nuts 23 on the left and right sides are all connected to the clamping support plates 21. The support plate 21 is pre-tightened, and the two fastening nuts 23 at the front end of the middle section are pre-tightened to the clamping support plate 21. The two fastening nuts 23 at the rear end of the middle section are pre-tightened to the fixed support member 22. The upper parallel clamping assembly 2 clamps the upper connecting rod 8 through the fixed support member 22 and the clamping support plate 21. The lower parallel clamping assembly 2 clamps the lower connecting rod 9 through the fixed support member 22 and the clamping support plate 21. The upper parallel clamping assembly 2 clamps the upper ends of eight fiber optic strain sensors 5 through the clamping support plates 21 at the front and rear. The lower parallel clamping assembly 2 clamps the lower ends of eight fiber optic strain sensors 5 through the clamping support plates 21 at the front and rear. The eight fiber optic strain sensors 5 are separated by the fastening round rod 24. In this embodiment, the parallel clamping assembly 2 is used for the synchronous calibration of multiple fiber Bragg grating strain sensors 5. It adopts a parallel design and supports the synchronous calibration of eight-channel sensors. The fastening nut 23 provides an adjustable preload for the clamping support plate 21 at the front and rear to clamp the fiber Bragg grating strain sensor 5. At the same time, it provides an adjustable preload for the clamping support 22 and the upper connecting rod 8 and the lower connecting rod 9 by the fixed support 22 and the clamping support plate 21 at the rear.

[0036] Test procedure for a portable fiber optic strain sensor calibration device:

[0037] Under constant temperature conditions, connect and start the calibration device, clamp the fiber optic strain sensor, zero the signal display on the host computer, adjust the tension and compression strain module to the relaxed state, and record the initial wavelength output by the demodulation module.

[0038] The host computer controls the tension and compression strain module to stretch or compress the fiber optic strain sensor in step size through the data processing module, and simultaneously records the strain value per unit step size and the corresponding output wavelength of the demodulation module until the maximum range is reached.

[0039] Repeat the previous step to perform three or more measurements;

[0040] Strain and wavelength data are stored in the host computer. A strain-wavelength relationship model is plotted using a fitting algorithm, and the strain sensitivity coefficient of the fiber optic strain sensor is calculated.

[0041] Example 1:

[0042] Under constant temperature conditions, correctly connect and start all parts of the calibration device. Fix the fiber optic strain sensor 5 to be tested onto the extensometer 3 using clamping rod 11, fastening rod 13, and clamping support plate 15, and tighten the positioning nut 12 and fastening nut 14 to ensure it is in a stable state. Zero the signal display of the extensometer 3, adjust the sliding tension / compression module 4 to the relaxed state, and record the initial wavelength output by the demodulator of the fiber optic strain sensor 5. Secure the lower part of the sliding tension / compression module 4 tightly to the fiber optic strain sensor 5 and the extensometer 3 using clamping rod 11, fastening rod 13, and clamping support plate 15, and tighten the positioning nut 12 and fastening nut 14 to ensure it is in a fixed state. The upper part of the tension or compression sliding module 4 is stretched or compressed to generate strain, which in turn causes the fiber Bragg grating strain sensor 5 to generate tensile or compressive strain. The degree of stretching (or compression) is adjusted according to the planned step size, and the strain value of the extensometer 3 and the corresponding demodulator output wavelength are recorded synchronously at each step until the extensometer 3 reaches its maximum range. This measurement is repeated 3 times or more. The strain and wavelength data are stored in the host computer, and a strain-wavelength relationship model is plotted using a fitting algorithm to calculate the strain sensitivity coefficient of the fiber Bragg grating strain sensor 5.

[0043] Example 2:

[0044] Under constant temperature conditions, correctly connect and start all parts of the calibration device. Connect the bidirectional strain loading module 7 and the multi-fiber grating strain sensor 5 to the parallel calibration module via clamping support plate 21, fixing support 22, fastening nut 23, and fastening rod 24. Fix the fiber grating strain sensor 5 to be tested using clamping support plate 21, fastening nut 23, and fastening rod 24. Zero the signal display in the host computer software and adjust the bidirectional strain loading module 7 to the relaxed state. Record the initial wavelength output by the demodulator for the fiber grating strain sensor 5. Adjust the high-precision differential knob of the bidirectional strain loading module 7 to move the connected upper link 8 up or down, directly causing the parallel clamping assembly 2 fixed to the upper link 8 to be stretched upward or compressed downward, thus stretching or compressing the fiber grating strain sensor 5. Automatically adjust the stretching (or compression) degree according to the planned step size, and synchronously record the strain value and corresponding demodulator output wavelength at each step until the maximum range is reached. Perform 3 or more measurements. Strain, wavelength, and temperature data are stored in the host computer. A strain-wavelength relationship model is plotted using a fitting algorithm, and the strain sensitivity coefficient of the fiber optic strain sensor 5 is calculated.

[0045] It should be noted that this application does not improve the control program, and the control program and electrical components involved are all prior art.

[0046] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A portable fiber optic strain sensor calibration device, characterized in that: It includes a fiber optic strain sensor (5), a clamping module, a tensile and compressive strain module, a demodulation module (6), a data processing module (10), and a host computer; The clamping module clamps the fiber Bragg grating strain sensor (5), and the clamping module is connected to the tension and compression strain module. The tension and compression strain module is connected to the fiber Bragg grating strain sensor (5). The fiber Bragg grating strain sensor (5) is connected to the demodulation module (6). The tension and compression strain module and the demodulation module (6) are both connected to the data processing module (10). The data processing module (10) is connected to the host computer.

2. The portable fiber optic strain sensor calibration device according to claim 1, characterized in that: The tension-compression strain module includes an extensometer (3) and a sliding tension-compression module (4). The extensometer (3) is connected to the data processing module (10) and the extensometer (3) is connected to the clamping module. The sliding tension-compression module (4) is connected to the clamping module. The sliding tension-compression module (4) includes a sliding guide rail and a fixing component.

3. The portable fiber optic strain sensor calibration device according to claim 1, characterized in that: The tension-compression strain module includes a bidirectional strain loading module (7), an upper connecting rod (8), and a lower connecting rod (9). One end of the upper connecting rod (8) is connected to the top of the bidirectional strain loading module (7), and one end of the lower connecting rod (9) is connected to the bottom of the bidirectional strain loading module (7). The other ends of the upper connecting rod (8) and the lower connecting rod (9) are both connected to the clamping module. The bidirectional strain loading module (7) includes a high-precision differential cylinder, an incremental rotary encoder, and a worm gear mechanism. The incremental rotary encoder and the worm gear mechanism are both connected to the high-precision differential cylinder.

4. The portable fiber optic strain sensor calibration device according to claim 2, characterized in that: The clamping module includes two clamping components (1), which clamp the upper and lower ends of the fiber optic strain sensor (5) respectively. Each clamping component (1) includes two clamping rods (11), two positioning nuts (12), a fastening rod (13), four fastening nuts (14), and two clamping support plates (15). The clamping rods (11) are U-shaped. The fastening rods (13) pass through the two clamping rods (11) laterally. Both ends of the clamping rods (11) pass through both ends of the clamping support plates (15) respectively. Both ends of the clamping rods (11) are threaded to the fastening nuts (14). The fastening nuts (14) are pre-tightly connected to the clamping support plates (15). Both ends of the fastening rods (13) are threaded to the positioning nuts (12). The positioning nuts (12) are pre-tightly connected to the clamping rods (11).

5. The portable fiber optic strain sensor calibration device according to claim 1, characterized in that: The clamping module includes two parallel clamping components (2), which clamp the upper and lower ends of the fiber optic strain sensor (5) respectively. Each parallel clamping component (2) includes two clamping support plates (21), a fixing support (22), twenty fastening nuts (23), and ten fastening rods (24). The two clamping support plates (21) are located at the front and rear, respectively, and the fixing support (22) is located at the rear of the two clamping support plates (21). The fastening rods (24) pass through... The clamping support plate 2 (21) is inserted, and both ends of the fastening round rod 2 (24) are threadedly connected to the fastening nut 2 (23). The rear ends of the two fastening round rods 2 (24) in the middle pass through both ends of the fixed support member (22). The sixteen fastening nuts 2 (23) on the left and right are pre-tightly connected to the clamping support plate 2 (21). The two fastening nuts 2 (23) at the front end of the middle are pre-tightly connected to the clamping support plate 2 (21). The two fastening nuts 2 (23) at the rear end of the middle are pre-tightly connected to the fixed support member (22).

6. The portable fiber optic strain sensor calibration device according to claim 1, characterized in that: The demodulation module (6) is a fiber Bragg grating demodulator, which is connected to the fiber Bragg grating strain sensor (5) and the fiber Bragg grating demodulator is connected to the data processing module (10).

7. A portable fiber optic strain sensor calibration device according to claim 1 or 3, characterized in that: The demodulation module (6) includes a stepper motor, a fiber optic demodulator and a temperature compensation module. The fiber optic demodulator is connected to the fiber optic strain sensor (5). The stepper motor, the fiber optic demodulator and the temperature compensation module are all connected to the data processing module (10). The stepper motor drives the bidirectional strain loading module (7).

8. The portable fiber optic strain sensor calibration device according to claim 4, characterized in that: One end of the extensometer (3) is pre-tightly connected to the clamping support plate (15), and the other end of the extensometer (3) is pre-tightly connected to the fiber optic strain sensor (5). The fiber optic strain sensor (5) is pre-tightly connected to the sliding tension-compression module (4). The upper and lower ends of the sliding tension-compression module (4) pass through the middle of the fastening round rods (13) of the two clamping components (1). The sliding tension-compression module (4) is located between the two clamping round rods (11), and the sliding tension-compression module (4) is pre-tightly connected to the clamping round rods (11) on both sides.

9. A portable fiber optic strain sensor calibration device according to claim 3 or 5, characterized in that: The upper parallel clamping assembly (2) clamps the upper connecting rod (8) through the fixed support (22) and the clamping support plate two (21). The lower parallel clamping assembly (2) clamps the lower connecting rod (9) through the fixed support (22) and the clamping support plate two (21). The upper parallel clamping assembly (2) clamps the upper ends of eight fiber optic strain sensors (5) through the clamping support plates two (21) at the front and rear. The lower parallel clamping assembly (2) clamps the lower ends of eight fiber optic strain sensors (5) through the clamping support plates two (21) at the front and rear. The eight fiber optic strain sensors (5) are separated by the fastening round rod two (24).

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