Adjustable sensitive fiber bragg grating pipeline strain sensing device

Abstract

The utility model relates to the technical field of optical sensors, in particular to an adjustable sensitive fiber bragg grating pipeline strain sensing device which comprises an upper sliding assembly, upper sliding rails, a double-sliding-block assembly and an annular strain fixing hoop, the annular strain fixing hoop comprises a pipeline clamping hoop and lower sliding rails, the corresponding upper sliding rails are arranged above the lower sliding rails in parallel, and the double-sliding-block assembly is arranged above the pipeline clamping hoop. The upper sliding rail and the lower sliding rail at the two ends are fixedly connected through a double-sliding-block assembly respectively, an upper sliding assembly is fixedly installed at the top of the upper sliding rail, and the two ends of the fiber grating sensor are fixedly arranged between the upper sliding assembly at the two ends and the upper sliding rail respectively. The device is simple in installation process, small in size and resistant to electromagnetic interference, the sensitivity of the fiber grating sensor can be effectively improved, the geometric configuration of the device can be flexibly adjusted according to the thermal expansion coefficient of an object to be measured so as to achieve sensibilization or desensitization, meanwhile, the combination of the upper sliding rail and the upper sliding assembly can further achieve pre-tensioning of the fiber grating sensor, and the sensitivity of the fiber grating sensor is improved. The method can be widely applied to pipeline strain monitoring.

Description

Technical Field

[0001] This utility model relates to the field of optical sensor technology, specifically to an adjustable fiber optic grating strain sensing device for pipelines. Background Technology

[0002] As critical infrastructure in industrial sectors such as oil and gas transportation and urban pipe networks, pipeline structural health monitoring is of paramount importance for preventing leaks and ensuring operational safety. However, traditional pipeline monitoring technologies mainly rely on resistance strain gauges or piezoelectric sensors, which have many inherent limitations in practical applications.

[0003] First, resistance strain gauges and piezoelectric sensors are susceptible to electromagnetic interference, which is particularly pronounced in complex industrial environments, potentially leading to inaccurate or distorted measurement data. Second, these sensors exhibit poor long-term stability and are easily affected by environmental factors such as temperature and humidity, thus impacting their measurement accuracy and reliability. Furthermore, due to limitations in sensor deployment density, traditional technologies struggle to achieve comprehensive monitoring of the entire pipeline area, resulting in monitoring blind spots.

[0004] In recent years, fiber Bragg grating (FBG) sensors have gradually become a research hotspot in pipeline monitoring due to their significant advantages such as resistance to electromagnetic interference, corrosion resistance, and the ability to achieve quasi-distributed measurement. FBG sensors reflect pipeline strain by sensing changes in the wavelength of the fiber Bragg grating, exhibiting high precision, high sensitivity, and good long-term stability. However, current technologies typically employ directly packaged FBG strain sensors, rigidly coupling the fiber Bragg grating to the pipeline surface using adhesives. While this approach achieves strain transfer, it reveals significant technical bottlenecks in practical engineering applications.

[0005] On the one hand, the strain transfer efficiency of conventional packaging structures is limited by the elastic modulus of the substrate, significantly reducing their ability to detect minute circumferential strains in pipelines and making it difficult to meet the needs of early warning for high-risk pipeline sections. On the other hand, high-sensitivity designs often lead to limited measurement ranges, and under abnormal deformation conditions in high-pressure pipelines, chirping or even grid region breakage can easily occur, affecting the sensor's lifespan and measurement accuracy.

[0006] More importantly, a single packaging structure is insufficient to meet the diverse sensitivity requirements of sensors for different pipe materials and operating conditions. In practical engineering, pipes of different materials have different coefficients of thermal expansion and mechanical properties, resulting in varying sensitivity requirements for sensors. Therefore, customized sensor models are often necessary, which not only significantly increases engineering costs but also extends project cycles.

[0007] Therefore, maintaining the good stability and high accuracy of fiber Bragg grating sensors while meeting the sensitivity requirements under different operating conditions has become a pressing technical challenge for fiber optic sensing technology in pipeline monitoring. This invention addresses this challenge by proposing an adjustable-sensitivity fiber Bragg grating pipeline strain sensing device. The aim is to achieve free adjustment of sensor sensitivity through flexible adjustment of the device's geometric configuration, thereby adapting to the monitoring needs of different pipe materials and service conditions. Utility Model Content

[0008] To address the aforementioned issues, this invention provides an adjustable fiber Bragg grating strain sensing device for pipelines. This device features a simple installation process, small size, and resistance to electromagnetic interference. It effectively improves the sensitivity of the fiber Bragg grating sensor and allows for flexible adjustment of the device's geometry based on the thermal expansion coefficient of the measured object to enhance or reduce sensitivity. Furthermore, the combination of the upper slide rail and the upper sliding assembly enables pre-tensioning of the fiber Bragg grating sensor, making it widely applicable for pipeline strain monitoring.

[0009] The technical solution of this utility model is as follows:

[0010] An adjustable fiber Bragg grating pipe strain sensing device includes an upper sliding assembly, an upper slide rail, a dual slider assembly, and a circumferential strain fixing clamp. The circumferential strain fixing clamp includes a pipe clamp and a lower slide rail. The pipe clamp is an annular strip structure with an open notch. Opposite lower slide rails are respectively provided at the two ends of the notch. Corresponding upper slide rails are respectively arranged parallel above the lower slide rails. The upper slide rails and lower slide rails at both ends are fixedly connected by the dual slider assembly. When not tightened, the dual slider assembly can be adjusted along the length direction of the upper or lower slide rail. An upper sliding assembly is fixedly installed on the top of the upper slide rail. When not tightened, the upper sliding assembly can be adjusted along the length direction of the upper slide rail. The two ends of the fiber Bragg grating sensor are respectively fixedly disposed between the upper sliding assembly and the upper slide rail at both ends.

[0011] An optical fiber positioning groove is provided between the bottom of the upper sliding assembly and the top of the upper slide rail, and the two ends of the fiber optic grating sensor are set in the optical fiber positioning groove.

[0012] The fiber optic positioning slot is composed of fiber optic positioning slot A located at the bottom of the upper sliding assembly and fiber optic positioning slot B located at the top of the upper slide rail.

[0013] The dual slider assembly consists of a left clamping block and a right clamping block that are fixedly connected. Slide grooves that cooperate with the upper slide rail and the lower slide rail are respectively provided on the upper and lower positions of the inner sides of the left clamping block and the right clamping block.

[0014] The left clamping block and the right clamping block are fixedly connected by fastening bolt B and matching nut.

[0015] The upper sliding assembly is fastened to the upper slide rail by fastening bolt A.

[0016] The side of the upper slide rail that mates with the upper sliding assembly or the double slider assembly is provided with anti-slip texture A.

[0017] The side of the lower slide rail that mates with the dual slider assembly is provided with anti-slip texture B.

[0018] The material of the circumferential strain gauge clamp is the same as that of the pipe to be tested.

[0019] The upper sliding assembly, upper slide rail, and double slider assembly are made of aluminum alloy.

[0020] The beneficial effects of this utility model are as follows:

[0021] 1. This utility model discloses an adjustable fiber optic grating strain sensing device for pipelines. The sensitivity of this adjustable fiber optic grating strain sensing device is adjustable: by freely dragging the upper sliding component, the upper slide rail and the double slider component laterally, the geometric configuration of the device can be flexibly changed, thereby achieving the effect of increasing or decreasing sensitivity. This design allows the device to freely adjust the sensitivity coefficient according to the thermal expansion coefficient of the object to be measured, adapting to different engineering requirements, especially meeting the needs of early warning for high-risk pipeline sections.

[0022] 2. The present invention discloses an adjustable fiber optic grating strain sensing device for pipelines. The adjustable fiber optic grating strain sensing device for pipelines has a simple installation process and small size: the structural design of the device makes the installation process simple and the overall size is small, which makes it easy to install and deploy on pipelines, thereby improving the efficiency and convenience of project implementation.

[0023] 3. The present invention discloses an adjustable fiber optic grating strain sensing device for pipelines. This adjustable fiber optic grating strain sensing device is resistant to electromagnetic interference: it uses a fiber optic grating sensor as the core component and uses optical fiber to transmit signals, which has excellent anti-electromagnetic interference performance, ensuring stable operation in complex electromagnetic environments and improving the accuracy and reliability of measurement data.

[0024] 4. The present invention discloses an adjustable fiber optic grating strain sensing device for pipelines. This adjustable fiber optic grating strain sensing device has a pre-tensioning function: the combined design of the upper slide rail and the upper sliding component enables the fiber optic grating sensor to achieve pre-tensioning, which not only helps to improve the initial sensitivity of the sensor, but also allows for more accurate capture of minute changes when the pipeline is strained, further improving the monitoring accuracy.

[0025] 5. The present invention discloses an adjustable fiber optic grating strain sensing device for pipelines. The adjustable fiber optic grating strain sensing device has accurate fiber positioning: by setting fiber positioning slots A and B at the bottom of the upper sliding component and the top of the upper slide rail, it is ensured that both ends of the fiber optic grating sensor can be accurately and firmly fixed in the device, avoiding displacement or loosening during the monitoring process and ensuring the accuracy of the measurement data.

[0026] 6. This utility model discloses an adjustable fiber Bragg grating pipe strain sensing device. The adjustable fiber Bragg grating pipe strain sensing device has a stable structure: the dual slider assembly is fixedly connected to the left clamping block and the right clamping block by fastening bolt B and matching nuts to ensure structural stability; at the same time, the side of the upper slide rail that cooperates with the upper sliding assembly or the dual slider assembly is provided with anti-slip texture A, and the side of the lower slide rail that cooperates with the dual slider assembly is provided with anti-slip texture B. These designs increase the friction between the components and further improve the stability and reliability of the device.

[0027] 7. The present invention discloses an adjustable fiber Bragg grating pipe strain sensing device. The adjustable fiber Bragg grating pipe strain sensing device has reasonable material selection: the upper sliding component, upper slide rail and double slider component are made of aluminum alloy, which not only ensures the strength and corrosion resistance of the device, but also reduces the overall weight; the material of the circumferential strain fixing hoop is the same as that of the pipe to be tested, which reduces the measurement error caused by the mismatch of the thermal expansion coefficients of the materials and improves the adaptability and measurement accuracy of the device under different working conditions. Attached Figure Description

[0028] The advantages and features of this application will become clear to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of this invention.

[0029] In the attached diagram:

[0030] Figure 1 This is a schematic diagram of the structure of an adjustable fiber optic grating strain sensing device for pipelines according to an embodiment of the present invention.

[0031] Figure 2 This is a partial front view schematic diagram of an adjustable fiber optic grating strain sensing device for pipelines according to an embodiment of the present invention.

[0032] Figure 3 for Figure 2 Sectional view of AA;

[0033] Figure 4 This is a partial three-dimensional structural diagram of an adjustable fiber optic grating strain sensing device for pipelines according to an embodiment of the present invention.

[0034] Figure 5 This is a three-dimensional structural diagram of the upper sliding component of an adjustable fiber optic grating strain sensing device according to an embodiment of the present invention.

[0035] Figure 6 This is a schematic diagram of the upper slide rail of an adjustable fiber optic grating strain sensing device for pipelines according to an embodiment of the present invention.

[0036] Figure 7 This is a schematic diagram of the structure of a dual slider assembly of an adjustable fiber optic grating strain sensing device for pipelines according to an embodiment of the present invention.

[0037] Figure 8 This is a partial structural schematic diagram of the circumferential strain fixing hoop of an adjustable fiber optic grating strain sensing device for pipelines according to an embodiment of the present invention.

[0038] The components represented by the various reference numerals in the diagram are:

[0039] This utility model includes: 1. an upper sliding assembly; 2. an upper slide rail; 3. a double slider assembly; and 4. a circumferential strain gauge fixing hoop.

[0040] 11. Fastening bolt A; 12. Fiber optic positioning groove A;

[0041] 21. Fiber optic positioning groove B; 22. Anti-slip texture A;

[0042] 31. Fastening bolt B; 32. Left clamping block; 33. Right clamping block;

[0043] 41. Pipe clamp; 42. Lower slide rail; 43. Anti-slip texture B. Detailed Implementation

[0044] like Figures 1 to 4 As shown, the tunable fiber optic grating strain sensor for pipelines includes a pair of upper sliding components 1, a pair of double slider components 3, a pair of upper slide rails 2, and a circumferential strain fixing clamp 4. The specific structure is as follows:

[0045] like Figure 5 As shown, the upper sliding assembly 1 includes two clamping blocks and two fastening bolts A11; the lower surface of the clamping block is provided with an optical fiber positioning groove A12 for placing one end of the fiber optic grating sensor; the two sides of the clamping block are designed with different shapes to facilitate assembly; the fiber optic grating sensor is tightly fixed to the upper slide rail 2 by the fastening bolts A11; when not tightened, the upper sliding assembly 1 can adjust its position along the length of the upper slide rail 2.

[0046] like Figure 6As shown, the upper surface of the upper slide rail 2 is provided with an optical fiber positioning groove B21, which together with the optical fiber positioning groove A12 at the bottom of the upper sliding component 1 forms an optical fiber positioning groove, used to fix the two ends of the fiber grating sensor. The optical fiber positioning groove should be interference-fitted with the two ends of the fiber grating sensor. The side surface of the upper slide rail 2 is provided with anti-slip texture 22 to increase the friction between the upper sliding component 1 and the double slider component 3, further increasing the firmness.

[0047] like Figure 7 As shown, the dual slider assembly 3 includes four fastening bolts B31 and two sets of clamping blocks; each set of clamping blocks consists of a left clamping block 32 and a right clamping block 33, which are designed with different shapes to facilitate assembly; one set of clamping blocks is tightly fixed to the upper slide rail 2 and the circumferential strain fixing hoop 4 by two fastening bolts B31. When not tightened, the dual slider assembly 3 can adjust its position along the length direction of the upper slide rail 2 or the lower slide rail 42.

[0048] like Figure 8 As shown, the circumferential strain fixing clamp 4 includes a pipe clamp 41 and two lower sliding rails 42; the pipe clamp 41 is an annular strip structure with an open notch, used to withstand the circumferential strain of the pipe and transfer the circumferential strain of the pipe to the fiber optic grating; the pipe clamp 41 is formed by two halves combined with bolts; opposite lower sliding rails 42 are respectively provided at the two ends of the notch, and anti-slip textures 43 are provided on the side surface of the lower sliding rail 42 to increase the friction between it and the double sliding block assembly 3 and increase the firmness; corresponding upper sliding rails 2 are respectively arranged parallel above the lower sliding rails 42, and the upper sliding rails 2 and lower sliding rails 42 at both ends are fixedly connected by the double sliding block assembly 3.

[0049] The installation process of this tunable fiber Bragg grating strain sensor for pipelines is as follows:

[0050] Preparation stage: Select a suitable circumferential strain gauge 4 according to the size and material of the pipe to be tested, and ensure that its material is the same as that of the pipe to be tested; at the same time, prepare the upper sliding assembly 1, upper slide rail 2, double slider assembly 3 and other components. These components are made of aluminum alloy to ensure the strength and stability of the device.

[0051] Install the circumferential strain fixing clamp: Place the pipe clamp 41 of the circumferential strain fixing clamp 4 onto the pipe to be tested, adjust its position and tighten it so that it can fit tightly against the pipe surface and withstand the circumferential strain of the pipe.

[0052] Install the upper slide rail and the double slider assembly: Connect one end of the double slider assembly 3 to the lower slide rail 42 of the circumferential strain fixing hoop 4, and the other end to the upper slide rail 2; ensure that the upper slide rail 2 is parallel to the lower slide rail 42 on the circumferential strain fixing hoop 4; without tightening the double slider assembly 3, the position of the double slider assembly 3 on the upper slide rail 2 and the lower slide rail 42 can be adjusted as needed to change the geometry of the device.

[0053] Installing the fiber Bragg grating sensor: Place both ends of the fiber Bragg grating sensor into the fiber positioning slots B21 of the two upper slide rails 2, and then install the upper sliding assembly 1 on the upper slide rails 2. Secure both ends of the fiber Bragg grating sensor to the upper slide rails 2 using the fastening bolts A11. Without tightening the upper sliding assembly 1, its position on the upper slide rails 2 can be adjusted to achieve pre-tensioning of the fiber Bragg grating sensor.

[0054] Working principle of the tunable fiber Bragg grating strain sensor for pipes:

[0055] Strain transfer: When the pipeline experiences circumferential strain, the pipeline clamp 41 transfers the strain to the lower slide rail 42, which in turn transfers the strain to the upper slide rail 2 via the double slider assembly 3. The upper slide rail 2 then transfers the strain to the fiber optic grating sensor, causing a change in the grating pitch of the fiber optic grating sensor, thereby enabling the monitoring of pipeline strain.

[0056] Sensitivity adjustment: By adjusting the positions of the upper sliding component 1, the upper slide rail 2 and the double slider component 3, the geometric configuration of the device can be changed, which can achieve the effect of increasing or decreasing sensitivity.

[0057] Pre-tensioning: After determining the geometric configuration of the device, the pre-tensioning force can be applied to the fiber Bragg grating sensor by finely adjusting the position of the upper sliding component 1 on the upper slide rail 2, thereby improving the measurement accuracy and stability of the fiber Bragg grating sensor.

[0058] Example

[0059] An adjustable fiber optic grating strain sensing device for pipelines includes: a pair of upper sliding components 1, a pair of double slider components 3, a pair of upper slide rails 2, and a circumferential strain fixing clamp 4.

[0060] One end of the dual slider assembly 3 is connected to the lower slide rail 42 of the circumferential strain fixing hoop 4, and the other end is connected to the upper slide rail 2; and the distance between the two dual slider assemblies 3 is l1; the two ends of the fiber optic grating sensor are respectively placed in the fiber optic positioning grooves 21 of the two upper slide rails 2, and are respectively fixed on the upper slide rails 2 by the two upper sliding assemblies 1; and the distance between the two upper sliding assemblies 1, i.e. the length of the fiber optic grating sensor, is l2.

[0061] The upper slide rail 2 is parallel to the lower slide rail 42 on the circumferential strain fixing hoop 4.

[0062] The upper sliding component 1, the upper sliding rail 2, and the double slider component 3 can be dragged horizontally to change the geometric configuration to achieve sensitivity enhancement or desensitization. At the same time, the combination of the upper sliding rail 2 and the upper sliding component 1 can also realize the pre-tensioning of the fiber optic grating sensor.

[0063] The upper sliding assembly 1 includes two clamping blocks and two fastening bolts A11. The lower surface of the clamping blocks is provided with fiber positioning grooves A12. The clamping blocks are designed with different shapes on both sides to facilitate assembly. The clamping blocks use the fastening bolts A11 to firmly fix the fiber optic grating sensor to the upper slide rail 2.

[0064] The upper surface of the upper slide rail 2 is provided with an optical fiber positioning groove B21, and the side surface of the upper slide rail 2 is provided with anti-slip texture 22 to increase the friction between the upper sliding component 1 and the double slider component 3, thereby further increasing the firmness.

[0065] The dual slider assembly 3 includes four fastening bolts B31 and two sets of clamping blocks. Each set of clamping blocks consists of a left clamping block 32 and a right clamping block 33. The left clamping block 32 and the right clamping block 33 are designed with different shapes to facilitate assembly. One set of clamping blocks is tightly fixed to the upper slide rail 2 and the circumferential strain fixing hoop 4 by two fastening bolts B31.

[0066] The circumferential strain fixing clamp 4 includes a pipe clamp 41 and two sliding rails 42. The pipe clamp 41 is used to withstand the circumferential strain of the pipe and transfer the circumferential strain of the pipe to the fiber optic grating. The side surface of the sliding rail 42 is provided with anti-slip texture 43 to increase the friction between it and the double slider assembly 3 and increase the firmness.

[0067] The upper sliding assembly 1, upper slide rail 2, and double slider assembly 3 are made of aluminum alloy, and the circumferential strain fixing clamp 4 is made of the same material as the pipe.

[0068] Assuming the coefficient of thermal expansion of the test object is α1 and the coefficient of thermal expansion of the sensitizer is α2, when the temperature changes, both the test object and the sensitizer undergo thermal expansion. The temperature change of the test object is ΔT1, and the temperature change of the sensitizer is ΔT2. The test object generates a strain of ε0. The expressions for the deformations Δl1 and Δl2 between the sensitizer and the fiber grating are as follows:

[0069] When l1 is greater than l2:

[0070] Δl1=l1ε0+α1ΔT1l1 (1)

[0071] Δl2=l1ε0+α1ΔT1l1-α2ΔT2(l1-l2) (2)

[0072] The corresponding dependent variables ε1 and ε2 are as follows:

[0073]

[0074] The sensitization coefficient k1 can be obtained.

[0075]

[0076] Similarly, when l1 is less than l2:

[0077] The sensitization coefficient k2 can be obtained.

[0078]

[0079] Since the material properties and thermal expansion coefficients of the clamping support and the object under test are inherent material characteristics and cannot be substantially adjusted, the geometric configuration can be changed by adjusting the upper sliding component 1, the upper slide rail 2 and the double slider component 3 to achieve increased or decreased sensitivity in order to meet the needs of increased sensitivity.

[0080] According to formulas (5) and (6), when the thermal expansion coefficient of the sensitizing device is greater than the thermal expansion coefficient of the analyte, adjusting the slider to make l1 less than l2 can achieve sensitization; adjusting the slider to make l1 greater than l2 can achieve desensitization, and as the difference between l1 and l2 increases, the sensitization / desensitization coefficient increases accordingly.

[0081] According to formulas (5) and (6), when the thermal expansion coefficient of the sensitizing device is less than the thermal expansion coefficient of the test object, adjusting the slider to make l1 greater than l2 can achieve sensitization; adjusting the slider to make l1 less than l2 can achieve desensitization, and as the difference between l1 and l2 increases, the sensitization / desensitization coefficient increases accordingly.

[0082] This adjustable fiber Bragg grating strain sensor for pipelines has advantages such as simple installation process, small size, and resistance to electromagnetic interference. By freely changing the sensitivity coefficient of the monitoring device, it can adapt to different engineering requirements. At the same time, the combination of the upper slide rail 2 and the upper sliding component 1 realizes the pre-tensioning of the fiber Bragg grating sensor, further improving the accuracy and reliability of monitoring.

Claims

1. A tunable fiber optic grating strain sensing device for pipelines, characterized in that, The device includes an upper sliding assembly (1), an upper slide rail (2), a double slider assembly (3), and a circumferential strain fixing clamp (4). The circumferential strain fixing clamp (4) includes a pipe clamp (41) and a lower slide rail (42). The pipe clamp (41) is an annular strip structure with an open notch. At the two ends of the notch, there are corresponding lower slide rails (42). Above the lower slide rails (42), there are corresponding upper slide rails (2) arranged in parallel. The upper slide rails (2) and lower slide rails (42) at both ends are fixedly connected by the double slider assembly (3). When the double slider assembly (3) is not tightened, it can be adjusted along the length direction of the upper slide rail (2) or the lower slide rail (42). The upper sliding assembly (1) is fixedly installed on the top of the upper slide rail (2). When the upper sliding assembly (1) is not tightened, it can be adjusted along the length direction of the upper slide rail (2). The two ends of the fiber optic grating sensor are fixedly set between the upper sliding assembly (1) and the upper slide rail (2) at both ends.

2. The adjustable fiber optic grating strain sensing device for pipelines according to claim 1, characterized in that, An optical fiber positioning groove is provided between the bottom of the upper sliding assembly (1) and the top of the upper slide rail (2), and the two ends of the fiber optic grating sensor are set in the optical fiber positioning groove.

3. The adjustable fiber optic grating strain sensing device for pipelines according to claim 2, characterized in that, The fiber positioning slot is composed of fiber positioning slot A (12) located at the bottom of the upper sliding assembly (1) and fiber positioning slot B (21) located at the top of the upper slide rail (2).

4. The adjustable fiber optic grating strain sensing device for pipelines according to claim 1, characterized in that, The dual slider assembly (3) consists of a left clamping block (32) and a right clamping block (33) that are fixedly connected. Slide grooves that cooperate with the upper slide rail (2) and the lower slide rail (42) are respectively provided on the upper and lower positions of the inner sides of the left clamping block (32) and the right clamping block (33).

5. The adjustable fiber optic grating strain sensing device for pipelines according to claim 4, characterized in that, The left clamping block (32) and the right clamping block (33) are fixedly connected by fastening bolts B (31) and matching nuts.

6. The adjustable fiber optic grating strain sensing device for pipelines according to claim 1, characterized in that, The upper sliding assembly (1) is fastened to the upper slide rail (2) by fastening bolt A (11).

7. The adjustable fiber optic grating strain sensing device for pipelines according to claim 1, characterized in that, The upper slide rail (2) is provided with anti-slip texture A (22) on the side that cooperates with the upper sliding component (1) or the double slider component (3).

8. The adjustable fiber optic grating strain sensing device for pipelines according to claim 1, characterized in that, The side of the lower slide rail (42) that cooperates with the double slider assembly (3) is provided with anti-slip texture B (43).

9. The adjustable fiber optic grating strain sensing device for pipelines according to claim 1, characterized in that, The material of the circumferential strain fixing hoop (4) is the same as that of the pipe to be tested.

10. The adjustable fiber optic grating strain sensing device for pipelines according to claim 1, characterized in that, The upper sliding assembly (1), upper slide rail (2) and double slider assembly (3) are made of aluminum alloy.

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