A kind of based on distributed optical fiber sensing stiff column bonding slip monitoring device

Abstract

This utility model provides a stiffening column bonding slip monitoring device based on distributed optical fiber sensing, belonging to the field of stiffening column bonding slip monitoring technology. The device includes: a monitoring cylinder, an optical fiber sensor assembly, a support frame, a clamping device, and an adjustment assembly. The monitoring cylinder has a cylindrical structure, with an axial length 3 to 5 times its diameter. One end of the monitoring cylinder has an open end with a flange. The support frame is fixedly installed on the outer wall of the monitoring cylinder and includes an upper support ring and a lower support ring, connected by at least four vertical connecting rods. This invention solves the technical problems of existing stiffening column bonding slip monitoring devices being unable to achieve continuous monitoring in the entire circumference and having unreliable installation.

Description

Technical Field

[0001] This utility model belongs to the field of stiffened column bond slip monitoring technology, specifically, it relates to a stiffened column bond slip monitoring device based on distributed optical fiber sensing. Background Technology

[0002] Stiffened columns, as crucial load-bearing components in modern building structures, are widely used in important infrastructure projects such as high-rise buildings, bridges, and industrial plants. Stiffened columns typically consist of a steel frame and an outer concrete casing. The bond performance between the steel frame and the concrete directly affects the safety and durability of the entire structure. Under long-term loads, temperature changes, and earthquakes, bond-slip is prone to occur at the steel frame-concrete interface. This slippage leads to a decrease in structural stiffness and load-bearing capacity, and in severe cases, may cause structural safety accidents. Therefore, real-time monitoring of the bond-slip state of stiffened columns has become a critical requirement for engineering safety management. Traditional monitoring methods mainly include strain gauge monitoring, displacement sensor monitoring, and ultrasonic testing. While strain gauge monitoring offers high accuracy, it can only perform point-based monitoring and cannot obtain overall information about the bond interface. Furthermore, strain gauges are susceptible to failure due to environmental factors. Displacement sensor monitoring requires installing numerous sensors on the structural surface, which is not only complex to install but also has a limited monitoring range, making comprehensive coverage difficult. Although ultrasonic testing can detect internal defects, the equipment is complex, costly, and difficult to implement for continuous online monitoring. In recent years, distributed fiber optic sensing technology has developed with advantages such as continuous monitoring, resistance to electromagnetic interference, and corrosion resistance, showing great potential in the field of structural health monitoring. However, existing fiber optic sensing monitoring devices still have problems such as difficulty in installation and fixing and incomplete monitoring coverage in stiffened column applications, which cannot meet the actual needs of engineering. Utility Model Content

[0003] In view of this, the present invention provides a stiffening column bonding slip monitoring device based on distributed optical fiber sensing, which can solve the technical problems in the prior art where stiffening column bonding slip monitoring devices cannot achieve continuous monitoring in the full circumference and are not securely installed.

[0004] This utility model is implemented as follows:

[0005] This utility model provides a stiffened column bonding slip monitoring device based on distributed optical fiber sensing, comprising: a monitoring cylinder, an optical fiber sensor assembly, a support frame, a clamping device, and an adjustment assembly; the monitoring cylinder has a cylindrical structure, and its axial length is 3 to 5 times its diameter, with an open end at one end and a flange at the open end; the support frame is fixedly installed on the outer wall of the monitoring cylinder, and the support frame includes an upper support ring and a lower support ring, which are connected by at least 4 vertical connecting rods; the optical fiber sensor assembly includes... The system includes an optical fiber body, an optical fiber mounting base, and an optical fiber protective sleeve. The optical fiber body is spirally wound around the inner wall of the monitoring cylinder, and both ends of the optical fiber body are fixed to the upper and lower ends of the monitoring cylinder by the optical fiber mounting base, respectively. The clamping device includes a clamping body and a clamping arm. The clamping body is bolted to a flange, one end of the clamping arm is hinged to the clamping body, and the other end of the clamping arm is provided with a clamping claw. The adjusting assembly includes an adjusting screw and an adjusting nut. The adjusting screw passes through the clamping body and is threadedly connected to the adjusting nut. The front end of the adjusting screw abuts against the middle of the clamping arm.

[0006] The technical advantages of the rigid column bonding slip monitoring device based on distributed optical fiber sensing provided by this utility model are as follows: By using a special structural design where the optical fiber sensor assembly is spirally wound around the inner wall of the monitoring cylinder, continuous monitoring of the bonding slip state of the rigid column is achieved throughout its entire circumference and length. The cylindrical structure of the monitoring cylinder is designed with a length-to-diameter ratio of 3 to 5 times, providing a stable installation foundation and sufficient monitoring length for the optical fiber sensor. The clamping device, through the connection between the flange and the monitoring cylinder and the cooperation between the clamping arm and the clamping claw, can be reliably fixed on the surface of the rigid column. The screw and nut structure of the adjusting component allows the device to adapt to rigid columns of different diameters. The overall structure is compact and reasonable, easy to install, and has high monitoring accuracy.

[0007] Based on the above technical solution, the stiffened column bonding slip monitoring device based on distributed optical fiber sensing of this utility model can be further improved as follows:

[0008] The support frame also includes a base plate, which is circular in shape. A through hole is provided at the geometric center of the base plate. The lower end of the monitoring cylinder passes through the through hole and is fixed by a fastening ring. The lower support ring is fixedly installed on the upper surface of the base plate. The outer diameter of the upper support ring is larger than that of the lower support ring. The lower end of the vertical connecting rod is welded to the lower support ring, and the upper end of the vertical connecting rod is welded to the upper support ring.

[0009] The beneficial effects of adopting the above-mentioned improvement scheme are as follows: The support frame adopts a frame structure in which the upper and lower support rings are connected by vertical connecting rods. Combined with the circular design of the base plate and the configuration of the central through hole, it provides stable radial and axial support for the monitoring cylinder. The trapezoidal design with the outer diameter of the upper support ring being larger than that of the lower support ring enhances the stability of the structure. The cooperation between the base plate and the fastening ring ensures the firm fixation of the monitoring cylinder. The overall support frame structure can effectively resist external vibration and impact, ensuring the accuracy of monitoring data and the long-term stable operation of the device.

[0010] Furthermore, the fiber optic mounting base includes a mounting base body and a clamping cover plate. The mounting base body has an annular structure, and an fiber optic groove is formed in the inner ring of the mounting base body. The depth of the fiber optic groove is 1.5 to 2 times the diameter of the fiber optic body. The clamping cover plate is connected to the mounting base body by at least 6 evenly distributed clamping bolts. The fiber optic body is placed in the fiber optic groove and clamped and fixed by the clamping cover plate. The fiber optic protective sleeve is fitted on the outer surface of the fiber optic body and is made of polytetrafluoroethylene material.

[0011] The beneficial effects of adopting the above-mentioned improved scheme are as follows: the fiber optic fixing base adopts a split structure design of annular fixing base body and clamping cover plate, and the fiber optic groove depth is precisely configured to be 1.5 to 2 times the fiber diameter, which ensures accurate positioning and reliable fixing of the fiber optic body. The six evenly distributed clamping bolts provide uniform clamping force, avoiding local stress concentration of the fiber optic. The fiber optic protective sleeve made of polytetrafluoroethylene material has excellent corrosion resistance and low friction coefficient, effectively protecting the fiber optic body from the influence of the external environment and extending the service life of the sensor.

[0012] Furthermore, the clamping device also includes a buffer spring and a limiting block. The buffer spring is located at the hinge position between the clamping arm and the clamping body, and the limiting block is fixed on the side wall of the clamping body. The clamping claw has an arc-shaped structure, and the inner surface of the clamping claw is provided with anti-slip texture, which is distributed in a cross-grid pattern. The adjusting screw has an M12 thread, and the adjusting nut has a hexagonal structure with a distance of 19mm between opposite sides.

[0013] The beneficial effects of adopting the above-mentioned improved scheme are as follows: the clamping device achieves precise control of clamping force and effective limitation of clamping range through the setting of buffer spring and limit block; the arc-shaped clamping claw structure design can better fit the circular cross section of the stiffener; the cross-grid anti-slip texture greatly improves the clamping force and anti-slip performance; the M12 threaded adjusting screw and the 19mm opposite side distance hexagonal adjusting nut provide operators with convenient adjustment means; the overall clamping system can adapt to stiffeners with different surface conditions, ensuring reliable fixation of the device.

[0014] Furthermore, the inner wall of the monitoring cylinder is provided with a spiral guide groove. The pitch of the spiral guide groove matches the winding pitch of the optical fiber body. The depth of the spiral guide groove is 2mm to 4mm, and the width of the spiral guide groove is 1.2 to 1.5 times the diameter of the optical fiber body.

[0015] The beneficial effects of adopting the above-mentioned improved scheme are as follows: the spiral guide groove design on the inner wall of the monitoring cylinder is perfectly matched with the spiral winding of the optical fiber body. The matching of the spiral guide groove pitch with the optical fiber winding pitch ensures the accurate positioning of the optical fiber. The groove depth of 2mm to 4mm and the groove width design of 1.2 to 1.5 times the diameter of the optical fiber not only ensures the stable installation of the optical fiber but also avoids excessive constraint. The guiding effect of the spiral guide groove enables the optical fiber sensor to be evenly distributed on the inner surface of the monitoring cylinder, realizing high-precision spatial positioning monitoring of the bonding and sliding of the stiffening column.

[0016] Furthermore, the flange has a disc-shaped structure, a thickness of 10mm to 15mm, and an outer diameter that is 1.3 to 1.6 times the outer diameter of the monitoring cylinder. Eight bolt holes are evenly distributed around the perimeter of the flange, each bolt hole having a diameter of 12mm, and the center circle diameter of the bolt holes being equal to 0.85 times the outer diameter of the flange.

[0017] The disc-shaped structure and 10mm to 15mm thickness of the flange provide sufficient connection strength and rigidity. The ratio of the outer diameter to the outer diameter of the monitoring cylinder is 1.3 to 1.6 times, ensuring ample space for bolt installation. The precise configuration of eight evenly distributed 12mm diameter bolt holes and a center circle diameter equal to 0.85 times the outer diameter of the flange achieves uniform distribution of connection load. The flange structure provides a reliable mechanical connection interface between the clamping device and the monitoring cylinder, ensuring the stability and reliability of the entire monitoring device in complex engineering environments.

[0018] Furthermore, the outer wall of the monitoring cylinder is provided with multiple axial reinforcing ribs, which have a rectangular cross-section and a height of 3mm to 6mm.

[0019] The beneficial effects of adopting the above-mentioned improvement scheme are as follows: the multiple axial stiffeners on the outer wall of the monitoring cylinder adopt a rectangular cross-section design, and the stiffener height of 3mm to 6mm effectively improves the axial stiffness and bending resistance of the monitoring cylinder. The setting of axial stiffeners significantly enhances the structural stability of the monitoring cylinder when subjected to external loads, prevents deformation of the monitoring cylinder during long-term use, and ensures that the geometry of the internal fiber optic sensor remains stable, thereby ensuring the accuracy and consistency of the monitoring data.

[0020] Furthermore, the cross-section of the spiral guide groove is V-shaped, and the included angle of the V-shaped groove is 60° to 90°.

[0021] The beneficial effects of adopting the above-mentioned improved scheme are as follows: The spiral guide groove adopts a V-shaped cross-section structure design. The V-shaped groove angle of 60° to 90° provides good positioning constraints for the optical fiber body. The two inclined surfaces of the V-shaped structure can position the optical fiber from two directions. Compared with other cross-sectional shapes, it has a better self-centering effect. The pointed bottom design of the V-shaped groove reduces the contact area between the optical fiber and the bottom of the groove, reduces frictional resistance, and allows the optical fiber to adjust freely when it expands and contracts with temperature, avoiding stress concentration and sensing errors caused by temperature changes.

[0022] Furthermore, the end of the gripping claw has a sharp wedge-shaped structure with an acute angle of 30° to 45°.

[0023] The beneficial effects of adopting the above-mentioned improved scheme are as follows: the sharp wedge-shaped structure design at the end of the gripper can effectively embed into the tiny unevenness of the stiffener surface. The acute angle range of 30° to 45° ensures sufficient penetration while avoiding excessive damage to the stiffener surface. The sharp end of the wedge structure greatly enhances the mechanical engagement effect between the gripping device and the stiffener surface, improving the reliability of gripping and anti-slip capability. Especially under vibration and impact loads, the wedge-shaped gripper can maintain a stable gripping state, ensuring the fixation effect of the monitoring device.

[0024] Furthermore, the axial reinforcing ribs are distributed at equal angles on the outer wall surface of the monitoring cylinder, and the number of axial reinforcing ribs is 6 to 8.

[0025] The beneficial effects of adopting the above-mentioned improvement scheme are as follows: the design of axial stiffeners distributed at equal angles on the outer wall of the monitoring cylinder achieves uniform transfer of structural load; the configuration of 6 to 8 stiffeners provides sufficient structural strength while avoiding excessive weight increase; the equal angle distribution ensures that the monitoring cylinder has similar stiffness characteristics in all directions, eliminating the weak direction of the structure; the symmetrical distribution of axial stiffeners also helps to uniformly release stress during the manufacturing process of the monitoring cylinder, reducing the impact of manufacturing defects on monitoring accuracy, and improving the overall structural reliability of the device.

[0026] Compared with existing technologies, the beneficial effects of this utility model's stiffener bonding slip monitoring device based on distributed optical fiber sensing are as follows: This utility model achieves continuous monitoring coverage of the stiffener's entire circumference and length through the ingenious arrangement of helical optical fiber sensors within a cylindrical monitoring cylinder, overcoming the limited monitoring range of traditional point sensors. The helical guide groove on the inner wall of the monitoring cylinder precisely matches the helical winding of the optical fiber sensor, ensuring accurate sensor positioning and stable operation. The clamping device adopts a combination design of wedge-shaped clamping claws and adjusting screws, reliably fixing stiffeners with different diameters and surface conditions, solving the problems of difficult installation and unstable fixation in traditional monitoring equipment. The trapezoidal frame structure and flange connection of the support frame provide stable support and reliable connection for the entire device, ensuring long-term monitoring stability. The design of the optical fiber protective sleeve and V-shaped guide groove effectively protects the sensor from environmental influences, improving the reliability and service life of the monitoring system. The entire device is compact, easy to install, and has high monitoring accuracy, capable of real-time sensing of minute slip changes at the stiffener bonding interface, providing a reliable technical means for engineering structure safety monitoring. Attached Figure Description

[0027] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the description of the embodiments of this utility model will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 This is a schematic diagram of a stiffened column bond slip monitoring device based on distributed optical fiber sensing.

[0029] Figure 2 A schematic diagram of the structure of the inner wall of the monitoring cylinder;

[0030] Figure 3 This is a schematic diagram of the structure of the fixed base;

[0031] The attached diagram lists the components represented by each number as follows:

[0032] 10. Monitoring cylinder; 20. Fiber optic sensor assembly; 30. Support frame; 40. Clamping device; 50. Adjustment assembly. Detailed Implementation

[0033] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings.

[0034] like Figure 1-3The image shows a first embodiment of a stiffened column bonding slip monitoring device based on distributed optical fiber sensing provided by this utility model. In this embodiment, it includes: a monitoring cylinder 10, an optical fiber sensor assembly 20, a support frame 30, a clamping device 40, and an adjusting assembly 50. The monitoring cylinder has a cylindrical structure, with an axial length 3 to 5 times its diameter. One end of the monitoring cylinder has an open end with a flange. The support frame is fixedly installed on the outer wall of the monitoring cylinder and includes an upper support ring and a lower support ring, which are connected by at least four vertical connecting rods. Connection; The fiber optic sensor assembly includes a fiber optic body, a fiber optic mounting base, and a fiber optic protective sleeve. The fiber optic body is spirally wound around the inner wall of the monitoring cylinder, and both ends of the fiber optic body are fixed to the upper and lower ends of the monitoring cylinder by the fiber optic mounting base, respectively. The clamping device includes a clamping body and a clamping arm. The clamping body is bolted to the flange, one end of the clamping arm is hinged to the clamping body, and the other end of the clamping arm is provided with a clamping claw. The adjustment assembly includes an adjusting screw and an adjusting nut. The adjusting screw passes through the clamping body and is threadedly connected to the adjusting nut. The front end of the adjusting screw abuts against the middle of the clamping arm.

[0035] In the above technical solution, the support frame also includes a base plate, which is circular in shape. A through hole is provided at the geometric center of the base plate, through which the lower end of the monitoring cylinder passes and is fixed by a fastening ring. The lower support ring is fixedly installed on the upper surface of the base plate. The outer diameter of the upper support ring is larger than that of the lower support ring. The lower end of the vertical connecting rod is welded to the lower support ring, and the upper end of the vertical connecting rod is welded to the upper support ring.

[0036] Furthermore, in the above technical solution, the optical fiber mounting base includes a mounting base body and a clamping cover plate. The mounting base body has a ring structure, and an optical fiber groove is formed in the inner ring of the mounting base body. The depth of the optical fiber groove is 1.5 to 2 times the diameter of the optical fiber body. The clamping cover plate is connected to the mounting base body by at least 6 evenly distributed clamping bolts. The optical fiber body is placed in the optical fiber groove and is clamped and fixed by the clamping cover plate. The optical fiber protective sleeve is fitted on the outer surface of the optical fiber body and is made of polytetrafluoroethylene material.

[0037] Furthermore, in the above technical solution, the clamping device also includes a buffer spring and a limiting block. The buffer spring is set at the hinge position between the clamping arm and the clamping body, and the limiting block is fixed on the side wall of the clamping body. The clamping claw has an arc-shaped structure, and the inner surface of the clamping claw is provided with anti-slip texture, which is distributed in a cross-grid pattern. The thread specification of the adjusting screw is M12 thread, and the adjusting nut adopts a hexagonal structure with a distance of 19mm between opposite sides.

[0038] Furthermore, in the above technical solution, the inner wall surface of the monitoring cylinder is provided with a spiral guide groove. The pitch of the spiral guide groove matches the winding pitch of the optical fiber body. The depth of the spiral guide groove is 2mm to 4mm, and the width of the spiral guide groove is 1.2 to 1.5 times the diameter of the optical fiber body.

[0039] Furthermore, in the above technical solution, the flange has a disc-shaped structure, the thickness of the flange is 10mm to 15mm, and the outer diameter of the flange is 1.3 to 1.6 times the outer diameter of the monitoring cylinder; eight bolt holes are evenly opened around the perimeter of the flange, the diameter of the bolt holes is 12mm, and the central circle diameter of the bolt holes is equal to 0.85 times the outer diameter of the flange.

[0040] Furthermore, in the above technical solution, the outer wall surface of the monitoring cylinder is provided with multiple axial reinforcing ribs, the axial reinforcing ribs are rectangular in cross-section, and the height of the axial reinforcing ribs is 3mm to 6mm.

[0041] Furthermore, in the above technical solution, the cross-section of the spiral guide groove is V-shaped, and the included angle of the V-shaped groove is 60° to 90°.

[0042] Furthermore, in the above technical solution, the end of the gripper is a sharp wedge-shaped structure, and the acute angle of the wedge is 30° to 45°.

[0043] Furthermore, in the above technical solution, the axial reinforcing ribs are distributed at equal angles on the outer wall surface of the monitoring cylinder, and the number of axial reinforcing ribs is 6 to 8.

[0044] The monitoring device in this embodiment is mainly used for monitoring the bond slip of stiffened columns in a high-rise building. The monitoring cylinder is made of high-quality Q235 carbon steel, with an outer diameter of 200mm, an inner diameter of 180mm, an axial length of 800mm, and a wall thickness of 10mm. The inner wall of the monitoring cylinder is machined with spiral guide grooves. The spiral guide grooves have a pitch of 50mm, a depth of 3mm, and a width of 4mm. The spiral guide grooves have a V-shaped cross-section with an included angle of 75 degrees. The fiber optic sensor assembly uses single-mode optical fiber with a diameter of 250 micrometers, encased in a 0.5mm thick polytetrafluoroethylene (PTFE) protective sleeve. The optical fiber is spirally wound in the spiral guide grooves on the inner wall of the monitoring cylinder at a pitch of 50mm, with a total length of approximately 26 meters, covering the entire inner surface of the monitoring cylinder. The fiber optic mounting base is made of stainless steel, with an outer diameter of 180mm, an inner diameter of 150mm, a fiber groove width of 0.4mm, and a depth of 0.4mm. The clamping cover is connected to the fixed base body by eight M6 clamping bolts, with a clamping torque of 5 Nm. The support frame is made of welded angle steel, with an outer diameter of 250 mm for the upper support ring and 220 mm for the lower support ring. The vertical connecting rods are made of six 20 mm × 20 mm angle steels distributed at equal angles. The base plate is made of 15 mm thick steel plate with a diameter of 300 mm and a central through hole diameter of 190 mm. The clamping body of the clamping device is made of cast steel, the clamping arms are made of spring steel, and the clamping claws are machined into a wedge shape with an acute angle of 35 degrees. The adjusting screw uses M12 × 1.75 fine thread, is made of No. 45 steel and has undergone heat treatment, and the adjusting nut has a hexagonal structure with a distance between opposite sides of 19 mm. The outer wall of the monitoring cylinder is machined with eight axial reinforcing ribs, each 5 mm high and 8 mm wide, distributed at equal angles. The entire device weighs approximately 35 kg and is capable of monitoring stiffened columns with diameters ranging from 400 mm to 600 mm. In practical applications, the device was successfully installed on stiffened columns in the basement of a building, with the monitoring area located at the critical junction between the steel frame and concrete. The installation process took approximately 30 minutes. The clamping device was securely fixed to the surface of the stiffened column, and the fiber optic sensor operated stably, enabling real-time monitoring of strain changes in the stiffened column. Through three months of continuous monitoring and verification, the device demonstrated stable operation, accurate and reliable monitoring data, and effectively identified changes in the bond state of the stiffened column under temperature variations and loads, providing crucial data support for engineering safety assessments. The monitoring accuracy reaches the micro-strain level, capable of capturing extremely minute bond slip phenomena, meeting the stringent requirements of engineering monitoring. The entire device has a reasonable structural design and mature manufacturing process, possessing good practicality and potential for widespread application.

[0045] Specifically, the principle of this invention is as follows: Based on the working principle of distributed optical fiber sensing technology, this invention utilizes the strain-sensitive characteristics of optical fiber sensors to monitor the bond slip state of the stiffening column. When relative slippage occurs between the internal steel skeleton and the concrete of the stiffening column, minute strain changes occur on the surface of the stiffening column. These strain changes are transmitted to the helically wound optical fiber sensors through the wall of the monitoring cylinder. The optical fiber sensors convert the strain information into changes in optical signals. By analyzing the spectral characteristics of the optical signals, the strain distribution information can be accurately obtained, thereby calculating the location and degree of bond slip. The cylindrical structure of the monitoring cylinder can uniformly surround a section of the stiffening column. The helical guide groove guides the optical fiber sensors to be distributed in a helical pattern, achieving full circumferential coverage of the monitoring area. Compared with a straight-line arrangement, the helical winding method can obtain more spatial information. When bond slip occurs, the helical optical fiber can sense strain changes from multiple angles, improving the accuracy and reliability of monitoring. The clamping device forms a mechanical engagement with the surface of the stiffening column through wedge-shaped clamping claws, ensuring the strain transmission efficiency between the monitoring cylinder and the stiffening column and avoiding monitoring distortion caused by loose connections. The threaded adjustment mechanism of the adjustment component allows the device to adapt to stiffeners of different diameters, and optimal strain transmission is ensured by adjusting the clamping force. The frame structure of the support bracket provides stable support for the monitoring cylinder, avoiding the impact of external vibrations on monitoring accuracy. The entire device achieves signal acquisition and transmission mechanically, eliminating the need for complex electronic equipment and featuring simple structure and high reliability.

[0046] In use, first adjust the opening size of the clamping device according to the diameter of the stiffening column to be monitored. Rotate the adjusting nut to push the clamping arm open to the appropriate position using the adjusting screw. Fit the entire monitoring device onto the stiffening column, ensuring the monitoring cylinder surrounds the target monitoring section. Adjust the axial position of the device to ensure the monitoring area covers the critical bonding interface. Gradually tighten the adjusting nut, allowing the clamping claws to gradually press against the surface of the stiffening column. Stop adjusting when you feel significant resistance, ensuring the clamping force is appropriate. Check the tightness of all connections, especially the bolt connections between the flange and the clamping body, and the compression of the fiber optic mounting base. Connect the signal end of the fiber optic sensor to the corresponding fiber optic demodulation equipment for system debugging and calibration. During normal monitoring, periodically check the device's fixation, especially increasing the frequency under harsh environmental conditions. When the monitoring position needs adjustment, loosen the clamping device for repositioning. After monitoring, disassemble the device in reverse order of installation, taking care to protect the fiber optic sensor from damage. The entire operation is simple and convenient, requiring no specialized technicians, significantly reducing monitoring costs and technical barriers.

Claims

1. A stiffened column bond slip monitoring device based on distributed optical fiber sensing, characterized in that, include: The system comprises a monitoring cylinder, a fiber optic sensor assembly, a support frame, a clamping device, and an adjusting assembly. The monitoring cylinder has a cylindrical structure, with an axial length 3 to 5 times its diameter. One end of the monitoring cylinder has an open end with a flange. The support frame is fixedly installed on the outer wall of the monitoring cylinder and includes an upper support ring and a lower support ring, connected by at least four vertical connecting rods. The fiber optic sensor assembly includes a fiber optic body, a fiber optic mounting base, and a fiber optic protective sleeve. The fiber optic body is spirally wound around the inner wall of the monitoring cylinder, with both ends fixed to the upper and lower ends of the monitoring cylinder via the fiber optic mounting base. The clamping device includes a clamping body and a clamping arm. The clamping body is bolted to the flange, and one end of the clamping arm is hinged to the clamping body, while the other end of the clamping arm has a clamping claw. The adjusting assembly includes an adjusting screw and an adjusting nut. The adjusting screw passes through the clamping body and is threadedly connected to the adjusting nut, with the front end of the adjusting screw abutting against the middle of the clamping arm.

2. The stiffened column bond slip monitoring device based on distributed optical fiber sensing according to claim 1, characterized in that, The support frame also includes a base plate, which is circular in shape. A through hole is provided at the geometric center of the base plate. The lower end of the monitoring cylinder passes through the through hole and is fixed by a fastening ring. The lower support ring is fixedly installed on the upper surface of the base plate. The outer diameter of the upper support ring is larger than that of the lower support ring. The lower end of the vertical connecting rod is welded to the lower support ring, and the upper end of the vertical connecting rod is welded to the upper support ring.

3. The stiffened column bond slip monitoring device based on distributed optical fiber sensing according to claim 2, characterized in that, The fiber optic mounting base includes a mounting base body and a clamping cover plate. The mounting base body has a ring structure, and an optical fiber groove is formed in the inner ring of the mounting base body. The depth of the optical fiber groove is 1.5 to 2 times the diameter of the optical fiber body. The clamping cover plate is connected to the mounting base body by at least 6 evenly distributed clamping bolts. The optical fiber body is placed in the optical fiber groove and is clamped and fixed by the clamping cover plate. The optical fiber protective sleeve is fitted on the outer surface of the optical fiber body and is made of polytetrafluoroethylene material.

4. The stiffened column bond slip monitoring device based on distributed optical fiber sensing according to claim 3, characterized in that, The clamping device also includes a buffer spring and a limiting block. The buffer spring is located at the hinge position between the clamping arm and the clamping body, and the limiting block is fixed on the side wall of the clamping body. The clamping claw has an arc-shaped structure, and the inner surface of the clamping claw is provided with anti-slip texture, which is distributed in a cross-grid pattern. The adjusting screw has an M12 thread, and the adjusting nut has a hexagonal structure with a distance of 19mm between opposite sides.

5. The stiffened column bond slip monitoring device based on distributed optical fiber sensing according to claim 4, characterized in that, The inner wall of the monitoring cylinder is provided with a spiral guide groove. The pitch of the spiral guide groove matches the winding pitch of the optical fiber body. The depth of the spiral guide groove is 2mm to 4mm, and the width of the spiral guide groove is 1.2 to 1.5 times the diameter of the optical fiber body.

6. The stiffened column bond slip monitoring device based on distributed optical fiber sensing according to claim 5, characterized in that, The flange has a disc-shaped structure, a thickness of 10mm to 15mm, and an outer diameter that is 1.3 to 1.6 times the outer diameter of the monitoring cylinder. Eight bolt holes are evenly distributed around the perimeter of the flange, each bolt hole having a diameter of 12mm, and the center circle diameter of the bolt holes being 0.85 times the outer diameter of the flange.

7. The stiffened column bond slip monitoring device based on distributed optical fiber sensing according to claim 6, characterized in that, The outer wall of the monitoring cylinder is provided with multiple axial reinforcing ribs, which have a rectangular cross-section and a height of 3mm to 6mm.

8. The stiffened column bond slip monitoring device based on distributed optical fiber sensing according to claim 7, characterized in that, The cross-section of the spiral guide groove is V-shaped, and the included angle of the V-shaped groove is 60° to 90°.

9. A stiffened column bond slip monitoring device based on distributed optical fiber sensing according to claim 8, characterized in that, The end of the gripper is a sharp wedge-shaped structure with an acute angle of 30° to 45°.

10. A stiffened column bond slip monitoring device based on distributed optical fiber sensing according to claim 9, characterized in that, The axial reinforcing ribs are distributed at equal angles on the outer wall surface of the monitoring cylinder, and the number of axial reinforcing ribs is 6 to 8.

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