Pipeline bending stiffness detection method and verification bench

Abstract

The present application belongs to pipeline bending stiffness detection technical field, and disclose pipeline bending stiffness detection method, specific steps are as follows: step one: install pipeline, after installing verification rack, install pipeline, wherein verification rack mainly includes a moving pair motor, two rotary pair motors, a torque sensor and a vision sensor, and the pipeline center line coincides with the rotary pair rotating shaft.The present application is provided with torque sensor, rotary pair motor, moving pair motor and vision sensor, when the rotary pair motor starts, the rotating shaft drives the fixed block and clamp to rotate, so that the pipeline bends, and when the moving pair motor starts, the rotating rod drives the gear to rotate, and the gear and the gear plate are connected, so the movable plate will move under the drive of the gear, so as to cooperate with the torque sensor and the vision sensor to realize the measurement of the pipeline pure bending without introducing other deformation.

Description

Technical Field

[0001] This invention belongs to the field of pipeline bending stiffness testing technology, specifically a pipeline bending stiffness testing method and verification bench. Background Technology

[0002] Different pipelines have different bending stiffness characteristics. When measuring bending stiffness by three-point bending, the three-point bending test equipment needs to be adjusted according to the pipeline characteristics and equipment conditions.

[0003] During three-point bending, both ends of the pipeline are free and not fixed. Friction exists between the pipeline ends and the testing equipment, and the pipeline is prone to slippage under bending force. The force and motion of the pipeline are complex and chaotic, making the measured relationship between bending force and displacement inaccurate. This results in the measured bending stiffness being influenced by other factors, the degree of which cannot be assessed, and their influence cannot be eliminated from the test results, easily leading to large measurement errors. This affects the degree of consistency between simulation results and actual conditions, causing a significant difference between the simulation results and reality, reducing the accuracy of the simulation. Large errors in the initial simulation results may lead to physical prototypes produced based on the simulation results not meeting design requirements during trial production and installation, requiring redesign and optimization, resulting in extended design cycles and increased experimental costs. Therefore, improvements are needed. Summary of the Invention

[0004] The purpose of this invention is to provide a method for testing the bending stiffness of pipelines and a verification bench to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a method for detecting the bending stiffness of pipelines, the specific steps of which are as follows:

[0006] Step 1: Install pipelines

[0007] After the verification bench is installed, the pipeline is installed. The verification bench mainly includes a moving auxiliary motor, two rotary auxiliary motors, a torque sensor and a vision sensor. The center line of the pipeline coincides with the rotation axis of the rotary auxiliary motors, and the pipeline is in the same plane.

[0008] Step Two: Testing

[0009] After the pipeline installation is completed, the test is started. The rotary joint begins to rotate and the sliding joint begins to move. During this process, the rotation of the rotary joint and the movement of the sliding joint will always ensure that the pipeline conforms to the relationship between d and α. In addition, the vision sensor will record the pure bending deformation of the pipeline at certain time intervals from the start to the end of the test and attach corresponding timestamps. The rotation angle of the rotary joint, the displacement of the sliding joint and the torque sensor measurement values ​​will be recorded at the same time intervals and attached with corresponding timestamps. The test will end after the rotary joint and the sliding joint reach the set position. The rotation angle and speed of the rotary joint, and the displacement and speed of the sliding joint can be freely set according to the actual situation, and the recording time interval can also be freely set according to the actual situation.

[0010] Step 3: Data Processing

[0011] Once the measurement is complete, a curve is generated based on the rotation angle of the rotary joint, the displacement of the prismatic joint, and the measurement values ​​of the torque sensor. The independent variable of this curve is the pipeline curvature, and the dependent variable is the bending stiffness value of the pipeline. Different stiffness values ​​are selected on this curve, and the pipeline under different curvatures is simulated in the Panyi Flexible Pipeline Virtual Simulation System according to the rotation angle of the rotary joint and the displacement of the prismatic joint. The simulation results are then compared with the pure bending deformation of the pipeline obtained by the vision sensor to find a suitable bending stiffness value that minimizes the error between the simulation results of the pipeline under different curvatures and the pure bending deformation of the pipeline recorded by the vision sensor.

[0012] A pipeline bending stiffness testing and verification bench includes a base plate. A surrounding plate is fixedly installed on the top of the base plate. Two support legs are movably installed on the left and right sides of the center of the top of the base plate. The main body of the verification bench is fixedly installed on the top of each of the two support legs. Two movable plates are movably sleeved on the left and right sides of the outer surface of the main body of the verification bench. Torque sensors are fixedly installed on the top of each of the two movable plates. A rotary auxiliary motor is fixedly installed on the top of each torque sensor. The other end of the output shaft of the rotary auxiliary motor... A rotating shaft is fixedly fitted, and a fixed block is fixedly installed at the top of the rotating shaft. A clamp is movably fitted inside the fixed block. Movable auxiliary motors are fixedly fitted inside the bottom ends of the two movable plates, and a rotating rod is fixedly fitted at the other end of the output shaft of the movable auxiliary motor. A gear is fixedly fitted on the outer surface of the rotating rod. Toothed plates are fixedly fitted on the left and right sides of the bottom end of the verification platform, and the outer surfaces of the toothed plates and the outer surfaces of the gears mesh with each other. A cantilever is fixedly installed at the top of the inner wall of the rear side of the enclosure, and a vision sensor is fixedly installed on the front side of the bottom end of the cantilever.

[0013] As a preferred embodiment of the present invention, a power motor is fixedly installed in the middle of the right end of the enclosure, a power shaft is fixedly sleeved at the other end of the output shaft of the power motor, a push rod is fixedly sleeved on the left side of the outer surface of the power shaft, and the left end of the push rod is movably connected to the right end of the enclosure.

[0014] As a preferred embodiment of the present invention, a horizontal plate is fixedly installed on the right side of the top of the enclosure, a slider is movably sleeved inside the horizontal plate, and a heating plate is fixedly sleeved at the bottom of the slider.

[0015] As a preferred embodiment of the present invention, a fan is fixedly sleeved at the top of the slider, an air inlet pipe is fixedly installed at the top of the fan, an air outlet pipe is fixedly installed at the bottom of the fan, and a round rod is fixedly installed at the top of the right end of the slider, with the right side of the outer surface of the round rod and the inner surface of the push rod movably sleeved.

[0016] As a preferred embodiment of the present invention, an extension block is fixedly sleeved inside each of the two support legs, the bottom end of the outer surface of the extension block is movably sleeved with the inner surface of the base plate, and a vertical block is movably sleeved at the right end inside the extension block.

[0017] As a preferred embodiment of the present invention, a locking block is fixedly installed at the bottom of the right end of the vertical block, the right end of the locking block passes through the extension block and the base plate and extends into the interior of the base plate, a spring is fixedly installed in the middle of the left end of the vertical block, and the other end of the spring is fixedly connected to the left inner wall of the extension block.

[0018] As a preferred embodiment of the present invention, a long rod is fixedly installed on the top of the left end of the vertical block. The left end of the long rod passes through the extension block and the support leg and extends to the outside of the support leg, and a handle is fixedly sleeved thereon. The right end of the handle is movably connected to the left end of the support leg.

[0019] As a preferred embodiment of the present invention, the inner walls on the left and right sides of the extension block are respectively provided with limiting grooves, the top of the limiting groove is movably sleeved with a limiting block, and the outer surface of the limiting block is fixedly connected to the outer surface of the vertical block.

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

[0021] 1. This invention incorporates a torque sensor, a rotary auxiliary motor, a clamp, a movable auxiliary motor, and a vision sensor. When the rotary auxiliary motor is activated, the rotating shaft drives the fixed block and clamp to rotate, causing the pipeline to bend. When the movable auxiliary motor is activated, the rotating rod drives the gear to rotate. The gear and the toothed plate mesh and connect, so the movable plate moves under the action of the toothed plate. This, combined with the torque sensor and vision sensor, enables the measurement of pure pipeline bending without introducing other deformations, thereby reducing the influence of other factors on the pipeline bending stiffness detection and preventing them from affecting the consistency between the simulation results and the actual situation.

[0022] 2. This invention incorporates a power motor, a push rod slider, a heating plate, and a fan. When the power motor starts, the power shaft drives the push rod to rotate. Since the push rod and the round rod are movably connected, the round rod, under the action of the push rod, will move the slider and the fan along the inner surface of the horizontal plate, thereby accelerating the air circulation inside the enclosure and reducing the impact of high temperature on the pipeline. The presence of the heating plate ensures that the pipeline will not be affected by the low ambient temperature during testing, thus improving the applicability of the verification bench.

[0023] 3. This invention, by setting up an extension block, a vertical block, a locking block, a spring, and a long rod, allows the long rod to move the vertical block along the inner surface of the extension block and compress the spring when the handle is pulled. At the same time, the locking block, which is fixedly connected to the vertical block, will also move along with it, thereby separating the locking block from the base plate and locking the position of the extension block. Then, pulling the main body of the verification platform will separate the main body of the verification platform from the base plate. The cooperation of each mechanism enables the rapid disassembly and assembly of the main body of the verification platform, thus eliminating the need for bolt fixing. Attached Figure Description

[0024] Figure 1 This is a flowchart of the data processing of the present invention;

[0025] Figure 2 This is a schematic diagram of the structure of the present invention;

[0026] Figure 3 This is a cross-sectional view of the rear side of the present invention;

[0027] Figure 4 This is a cross-sectional view of the front of the present invention;

[0028] Figure 5 This is a schematic cross-sectional view of the side of the present invention;

[0029] Figure 6 This is a cross-sectional view of the support leg of the present invention;

[0030] Figure 7This is a cross-sectional view of the extension block of the present invention;

[0031] Figure 8 for Figure 6 A magnified schematic diagram of the local structure at point A;

[0032] Figure 9 for Figure 7 A magnified schematic diagram of the structure at point B in the middle.

[0033] In the diagram: 1. Base plate; 2. Enclosure plate; 3. Horizontal plate; 4. Support leg; 5. Main body of the verification platform; 6. Movable plate; 7. Torque sensor; 8. Rotary auxiliary motor; 9. Rotating shaft; 10. Fixed block; 11. Clamp; 12. Moving auxiliary motor; 13. Rotating rod; 14. Gear; 15. Toothed plate; 16. Cantilever; 17. Vision sensor; 18. Power motor; 19. Power shaft; 20. Push rod; 21. Slider; 22. Heating plate; 23. Fan; 24. Air inlet pipe; 25. Air outlet pipe; 26. Round rod; 27. Extension block; 28. Vertical block; 29. ​​Locking block; 30. Spring; 31. Long rod; 32. Handle; 33. Limiting groove; 34. Limiting block. Detailed Implementation

[0034] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0035] like Figures 1 to 9 As shown in the figure, this embodiment of the invention provides a method for detecting the bending stiffness of pipelines, and the specific steps are as follows:

[0036] Step 1: Install pipelines

[0037] After the verification bench is installed, the pipeline is installed. The verification bench mainly includes a moving auxiliary motor, two rotary auxiliary motors, a torque sensor and a vision sensor. The center line of the pipeline coincides with the rotation axis of the rotary auxiliary motors, and the pipeline is in the same plane.

[0038] Step Two: Testing

[0039] After the pipeline installation is completed, the test is started. The rotary joint begins to rotate and the sliding joint begins to move. During this process, the rotation of the rotary joint and the movement of the sliding joint will always ensure that the pipeline conforms to the relationship between d and α. In addition, the vision sensor will record the pure bending deformation of the pipeline at certain time intervals from the start to the end of the test and attach corresponding timestamps. The rotation angle of the rotary joint, the displacement of the sliding joint and the torque sensor measurement values ​​will be recorded at the same time intervals and attached with corresponding timestamps. The test will end after the rotary joint and the sliding joint reach the set position. The rotation angle and speed of the rotary joint, and the displacement and speed of the sliding joint can be freely set according to the actual situation, and the recording time interval can also be freely set according to the actual situation.

[0040] Step 3: Data Processing

[0041] Once the measurement is complete, a curve is generated based on the rotation angle of the rotary joint, the displacement of the prismatic joint, and the measurement values ​​of the torque sensor. The independent variable of this curve is the pipeline curvature, and the dependent variable is the bending stiffness value of the pipeline. Different stiffness values ​​are selected on this curve, and the pipeline under different curvatures is simulated in the Panyi Flexible Pipeline Virtual Simulation System according to the rotation angle of the rotary joint and the displacement of the prismatic joint. The simulation results are then compared with the pure bending deformation of the pipeline obtained by the vision sensor to find a suitable bending stiffness value that minimizes the error between the simulation results of the pipeline under different curvatures and the pure bending deformation of the pipeline recorded by the vision sensor.

[0042] When testing the bending stiffness of pipelines, the following geometric conditions must be met: the influence of gravity must be ignored; the pipeline undergoes pure bending deformation in a horizontal plane; the curvature at any point on the pipeline is the same during pure bending deformation, and its curvature changes accordingly as the pure bending deformation progresses; the pipeline remains a circular arc throughout the pure bending deformation process. The bending stiffness calculation formula is: M = EI * K, where: EI is the bending stiffness of the pipeline; M is the torque at the pipeline end; K is the curvature of the arc formed by the pipeline during pure bending deformation; and d and α must always satisfy the following relationship: When α = 0, it is a semicircle, where: L is the pipeline length; d is the chord length corresponding to the arc formed by the pipeline; α is the angle between the chord length corresponding to the arc formed by the pipeline and the line connecting any endpoint of the pipeline and the center of the arc formed by the pipeline.

[0043] The pipeline bending stiffness testing and verification bench includes a base plate 1. A surrounding plate 2 is fixedly installed on the top of the base plate 1. Support legs 4 are movably installed on the left and right sides of the middle of the top of the base plate 1, and there are two support legs 4. The main body of the verification bench 5 is fixedly installed on the top of each of the two support legs 4. Movable plates 6 are movably sleeved on the left and right sides of the outer surface of the main body of the verification bench 5, and there are two movable plates 6. Torque sensors 7 are fixedly installed on the top of each of the two movable plates 6. A rotary auxiliary motor 8 is fixedly installed on the top of the torque sensor 7. A rotating shaft 9 is fixedly sleeved on the other end of the output shaft of the rotary auxiliary motor 8. A fixing block 10 is fixedly installed at the top of the rotating shaft 9. A clamp 11 is movably sleeved inside the fixing block 10. A moving auxiliary motor 12 is fixedly sleeved inside the bottom of the two moving plates 6 respectively. A rotating rod 13 is fixedly sleeved at the other end of the output shaft of the moving auxiliary motor 12. A gear 14 is fixedly sleeved on the outer surface of the rotating rod 13. Toothed plates 15 are fixedly sleeved on the left and right sides of the bottom of the verification platform body 5 respectively. The outer surface of the toothed plate 15 and the outer surface of the gear 14 are meshed and connected. A cantilever 16 is fixedly installed at the top of the rear inner wall of the enclosure 2. A vision sensor 17 is fixedly installed on the front side of the bottom end of the cantilever 16.

[0044] When the auxiliary moving motor 12 is started, the rotating rod 13 will drive the gear 14 to rotate. The gear 14 and the toothed plate 15 are meshed together, so the gear 14 will cause the movable plate 6 to move. When the auxiliary rotating motor 8 is started, the rotating shaft 9 will drive the fixed block 10 and the clamp 11 to rotate. The fixed block 10 and the clamp 11 are fixed together by bolts, which makes it easy to replace the clamp 11. By changing the clamp 11, the measurable diameter range of the pipeline harness can be increased. The cooperation of the various mechanisms can reduce the influence of other factors on the pipeline bending stiffness detection, thereby reducing the measurement error and preventing it from affecting the degree of consistency between the simulation results and the actual situation.

[0045] Among them, a power motor 18 is fixedly installed in the middle of the right end of the enclosure 2, and a power shaft 19 is fixedly sleeved on the other end of the output shaft of the power motor 18. A push rod 20 is fixedly sleeved on the left side of the outer surface of the power shaft 19, and the left end of the push rod 20 is movably connected to the right end of the enclosure 2.

[0046] When the power motor 18 starts, it will cause the power shaft 19 to drive the push rod 20 to rotate.

[0047] Among them, a horizontal plate 3 is fixedly installed on the right side of the top of the enclosure 2, and a slider 21 is movably sleeved inside the horizontal plate 3. A heating plate 22 is fixedly sleeved at the bottom inside the slider 21.

[0048] The presence of the horizontal plate 3 and the slider 21 will serve to provide support and fixation.

[0049] The top of the slider 21 is fixedly fitted with a fan 23, the top of the fan 23 is fixedly fitted with an air inlet pipe 24, the bottom of the fan 23 is fixedly fitted with an air outlet pipe 25, the top of the right end of the slider 21 is fixedly fitted with a round rod 26, and the right side of the outer surface of the round rod 26 is movably fitted with the inner surface of the push rod 20.

[0050] When push rod 20 rotates, it will generate a thrust on round rod 26, causing round rod 26 to move along with slider 21 and fan 23.

[0051] Among them, the two support legs 4 are respectively fixedly sleeved with extension blocks 27, the bottom end of the outer surface of the extension block 27 is movably sleeved with the inner surface of the base plate 1, and the right end of the extension block 27 is movably sleeved with a vertical block 28.

[0052] The inner surface of the extension block 27 and the outer surface of the vertical block 28 are both smooth, ensuring that the vertical block 28 will not get stuck when it moves along the inside of the extension block 27.

[0053] Among them, a locking block 29 is fixedly installed at the bottom right end of the vertical block 28. The right end of the locking block 29 passes through the extension block 27 and the base plate 1 and extends into the interior of the base plate 1. A spring 30 is fixedly installed in the middle of the left end of the vertical block 28. The other end of the spring 30 is fixedly connected to the left inner wall of the extension block 27.

[0054] Due to the restoring effect of spring 30, the vertical block 28 will move and then return to its original position.

[0055] Among them, a long rod 31 is fixedly installed on the top of the left end of the vertical block 28. The left end of the long rod 31 passes through the extension block 27 and the support leg 4 and extends to the outside of the support leg 4 and is fixedly sleeved with a handle 32. The right end of the handle 32 is movably connected to the left end of the support leg 4.

[0056] When the handle 32 is pulled, the long rod 31 will cause the vertical block 28 to move.

[0057] Among them, the inner walls on the left and right sides of the extension block 27 are respectively provided with limiting grooves 33, the top of the limiting groove 33 is movably sleeved with a limiting block 34, and the outer surface of the limiting block 34 is fixedly connected to the outer surface of the vertical block 28.

[0058] The cooperation between the limiting groove 33 and the limiting block 34 will restrict the movement of the vertical block 28, thereby preventing the vertical block 28 from detaching from the interior of the extension block 27.

[0059] Working principle and usage process:

[0060] First, the operator starts the rotary auxiliary motor 8, causing the rotating shaft 9 to drive the fixed block 10 and the clamp 11 to rotate, thus bending the pipeline. Simultaneously, the operator starts the movable auxiliary motor 12, causing the rotating rod 13 to drive the gear 14 to rotate. Since the gear 14 and the toothed plate 15 are meshed, the gear 14 will cause the two movable plates 6 to move the two ends of the pipeline respectively. During this process, the rotation of the clamp 11 and the movement of the movable plates 6 will always ensure that the pipeline conforms to the specified direction. The relationship is as follows: Simultaneously, the vision sensor 17 records the pure bending deformation of the pipeline at regular time intervals from the start to the end of the test, adding corresponding timestamps. The rotation angle of the fixture 11, the displacement of the movable plate 6, and the measurement values ​​of the torque sensor 7 are recorded at the same time intervals, also adding corresponding timestamps. The test ends after the fixture 11 and the movable plate 6 reach the set position. During the pure bending deformation process, the pipeline is always an arc segment on a circle. The straight-line distance between the two ends of the pipeline, i.e., the chord length d corresponding to this arc segment, has an angle α with the line connecting any endpoint of the pipeline and the center of the arc formed by the pipeline. By measuring the end face torque and applying the stiffness calculation formula M=EI*K, the bending stiffness can be calculated. Changing the chord length d and the angle α can make the pipeline be in different bending deformation states. The bending stiffness can be calculated by measuring the torque under different pure bending deformation states. The pipeline bending stiffness value generates a curve showing how the pipeline bending stiffness changes with different pure bending deformation states. The independent variable of this curve is the pipeline curvature, and the dependent variable is the pipeline bending stiffness value. Different stiffness values ​​are selected on this curve, and the pipeline under different curvatures is simulated in the Panyi Flexible Pipeline Virtual Simulation System according to the rotation angle of the fixture 11 and the displacement of the movable plate 6. The simulation results are then compared with the pure bending deformation of the pipeline obtained by the vision sensor 17 to find a suitable bending stiffness value that minimizes the sum of the errors between the simulation results of the pipeline under different curvatures and the pure bending deformation of the pipeline recorded by the vision sensor 17. This reduces the influence of other factors on the test results, reduces measurement errors, and prevents them from affecting the degree of consistency between the simulation results and the actual situation, thus preventing the simulation results from deviating significantly from the actual situation and reducing the accuracy of the simulation.

[0061] When the ambient temperature is too high, the operator starts the power motor 18, causing the power shaft 19 to drive the push rod 20 to rotate. This causes the inner wall of the push rod 20 to exert a thrust on the outer surface of the round rod 26, pushing the round rod 26, along with the slider 21 and the fan 23, to move along the inner surface of the horizontal plate 3. At the same time, the fan 23 is started, allowing air to enter the fan 23 from the air inlet pipe 24 and then exit from the air outlet pipe 25, thereby accelerating the air circulation inside the enclosure 2 and cooling it down. When the temperature is too low, the operator starts the heating plate 22 and then starts the power motor 18 and the fan 23 to raise the temperature. The cooperation of the various mechanisms increases the applicability of the verification platform.

[0062] After the test is completed, the operator pulls the handle 32, causing the long rod 31 to move along the inner surface of the extension block 27 with the vertical block 28 and compress the spring 30. This causes the vertical block 28 to separate from the inside of the base plate 1 with the locking block 29, thereby releasing the locking block 29 from the position of the extension block 27. Then, the operator can push the verification platform upward to separate it from the base plate 1, which facilitates its inspection and maintenance, thus improving its convenience.

[0063] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0064] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for detecting the bending stiffness of pipelines, characterized in that, The specific steps are as follows: Step 1: Install pipelines After the verification bench is installed, the pipeline is installed. The verification bench mainly includes a moving auxiliary motor, two rotary auxiliary motors, a torque sensor and a vision sensor. The center line of the pipeline coincides with the rotation axis of the rotary auxiliary motors, and the pipeline is in the same plane. Step Two: Testing After the pipeline installation is completed, the test is started. The rotary joint begins to rotate and the sliding joint begins to move. During this process, the rotation of the rotary joint and the movement of the sliding joint will always ensure that the pipeline conforms to the relationship between d and α. In addition, the vision sensor will record the pure bending deformation of the pipeline at certain time intervals from the start to the end of the test and attach corresponding timestamps. The rotation angle of the rotary joint, the displacement of the sliding joint and the torque sensor measurement values ​​will be recorded at the same time intervals and attached with corresponding timestamps. The test will end after the rotary joint and the sliding joint reach the set position. The rotation angle and speed of the rotary joint, and the displacement and speed of the sliding joint can be freely set according to the actual situation, and the recording time interval can also be freely set according to the actual situation. Step 3: Data Processing Once the measurement is complete, a curve is generated based on the rotation angle of the rotary joint, the displacement of the prismatic joint, and the measured values ​​of the torque sensor. The independent variable of this curve is the pipeline curvature, and the dependent variable is the bending stiffness value of the pipeline. Different stiffness values ​​are selected on this curve, and the pipeline under different curvatures is simulated in the Panyi Flexible Pipeline Virtual Simulation System according to the rotation angle of the rotary joint and the displacement of the prismatic joint. The simulation results are then compared with the pure bending deformation of the pipeline obtained by the vision sensor to find a suitable bending stiffness value that minimizes the error between the simulation results of the pipeline under different curvatures and the pure bending deformation of the pipeline recorded by the vision sensor.

2. A pipeline bending stiffness testing and verification bench, including a base plate (1), characterized in that: A surrounding plate (2) is fixedly installed on the top of the base plate (1). Support legs (4) are movably installed on the left and right sides of the middle of the top of the base plate (1). There are two support legs (4). A verification platform body (5) is fixedly installed on the top of each of the two support legs (4). Movable plates (6) are movably sleeved on the left and right sides of the outer surface of the verification platform body (5). There are two movable plates (6). A torque sensor (7) is fixedly installed on the top of each of the two movable plates (6). A rotary auxiliary motor (8) is fixedly installed on the top of each torque sensor (7). A rotating shaft (9) is fixedly sleeved on the other end of the output shaft of the rotary auxiliary motor (8). The top of the rotating shaft (9) is fixedly... A fixed block (10) is fixedly installed, and a clamp (11) is movably sleeved inside the fixed block (10). A movable auxiliary motor (12) is fixedly sleeved inside the bottom end of the two movable plates (6). A rotating rod (13) is fixedly sleeved at the other end of the output shaft of the movable auxiliary motor (12). A gear (14) is fixedly sleeved on the outer surface of the rotating rod (13). Toothed plates (15) are fixedly sleeved on the left and right sides of the bottom end of the verification platform body (5). The outer surface of the toothed plate (15) and the outer surface of the gear (14) are meshed and connected. A cantilever (16) is fixedly installed at the top of the rear inner wall of the enclosure (2). A vision sensor (17) is fixedly installed on the front side of the bottom end of the cantilever (16).

3. The pipeline bending stiffness testing and verification bench according to claim 2, characterized in that: A power motor (18) is fixedly installed in the middle of the right end of the enclosure (2). A power shaft (19) is fixedly sleeved on the other end of the output shaft of the power motor (18). A push rod (20) is fixedly sleeved on the left side of the outer surface of the power shaft (19). The left end of the push rod (20) is movably connected to the right end of the enclosure (2).

4. The pipeline bending stiffness testing and verification bench according to claim 2, characterized in that: A horizontal plate (3) is fixedly installed on the right side of the top of the enclosure (2). A slider (21) is movably sleeved inside the horizontal plate (3). A heating plate (22) is fixedly sleeved at the bottom inside the slider (21).

5. The pipeline bending stiffness testing and verification bench according to claim 4, characterized in that: A fan (23) is fixedly sleeved at the top of the slider (21). An air inlet pipe (24) is fixedly installed at the top of the fan (23). An air outlet pipe (25) is fixedly installed at the bottom of the fan (23). A round rod (26) is fixedly installed at the top of the right end of the slider (21). The right side of the outer surface of the round rod (26) is movably sleeved with the inner surface of the push rod (20).

6. The pipeline bending stiffness testing and verification bench according to claim 2, characterized in that: An extension block (27) is fixedly sleeved inside each of the two support legs (4). The bottom end of the outer surface of the extension block (27) is movably sleeved with the inner surface of the base plate (1). A vertical block (28) is movably sleeved inside the right end of the extension block (27).

7. The pipeline bending stiffness testing and verification bench according to claim 6, characterized in that: A locking block (29) is fixedly installed at the bottom right end of the vertical block (28). The right end of the locking block (29) passes through the extension block (27) and the base plate (1) and extends into the interior of the base plate (1). A spring (30) is fixedly installed in the middle of the left end of the vertical block (28). The other end of the spring (30) is fixedly connected to the left inner wall of the extension block (27).

8. The pipeline bending stiffness testing and verification bench according to claim 6, characterized in that: A long rod (31) is fixedly installed on the top of the left end of the vertical block (28). The left end of the long rod (31) passes through the extension block (27) and the support leg (4) and extends to the outside of the support leg (4) and is fixedly sleeved with a handle (32). The right end of the handle (32) is movably connected to the left end of the support leg (4).

9. The pipeline bending stiffness testing and verification bench according to claim 6, characterized in that: Limiting grooves (33) are respectively opened on the inner walls of the left and right sides of the extension block (27). The top of the limiting groove (33) is movably sleeved with a limiting block (34). The outer surface of the limiting block (34) is fixedly connected to the outer surface of the vertical block (28).

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