Pipeline axial stress inner detector calibration device and calibration method
By using a pipeline axial stress internal detector calibration device to perform axial stress loading and monitoring on a full-size pipe section, the problem of inaccurate detector calibration in existing technologies is solved, and efficient and accurate calibration of pipeline internal detectors is achieved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- PIPECHINA SOUTH CHINA CO
- Filing Date
- 2026-03-17
- Publication Date
- 2026-04-21
AI Technical Summary
In the existing technology, the calibration method for pipeline axial stress internal detectors lacks a physical calibration step, which leads to deviations between the test results and the actual situation, especially for full-size pipe sections where the calibration effect is poor.
A calibration device for an axial stress detector in a pipeline is adopted, which includes a reaction frame unit, a hydraulic loading unit, and a displacement and deformation monitoring unit. Axial stress is applied to the full-size pipe section through hydraulic loading, and the detector is calibrated by combining the data records of the displacement and deformation monitoring unit.
It achieves accurate stress loading on full-size pipe sections, ensuring that the detector can truly reflect the stress state of the inner wall inside the pipe, thus improving the accuracy and reliability of the test results.
Smart Images
Figure CN121898682A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of pipeline non-destructive testing technology, and in particular to a calibration device and calibration method for a pipeline axial stress internal detector. Background Technology
[0002] During long-term service, pipelines inevitably experience various complex factors, leading to axial stress. Internal pressure is a significant contributing factor; when a medium is transported within the pipeline, the internal pressure exerts a force on the inner wall, causing tensile or compressive stress changes in the axial direction. Temperature variations are equally important; differences in ambient temperature across seasons and times of day, as well as fluctuations in the temperature of the transported medium, cause thermal expansion and contraction of the pipeline material, resulting in axial stress. Furthermore, soil displacement is a crucial factor. In areas with complex geological conditions and poor soil stability, soil movement and settlement exert forces on buried pipelines, leading to axial stress. To effectively detect pipeline axial stress, internal pipeline axial stress detectors have been developed. These advanced devices are specifically designed for internal pipeline testing, allowing for measurement of axial stress on the pipeline wall without disrupting normal pipeline operation.
[0003] However, to ensure that the pipeline axial stress internal detector can provide accurate and reliable detection data, scientific and reasonable calibration is an essential step.
[0004] Currently, the main methods for calibrating stress detectors have certain limitations. The first method is theoretical calculation and simulation, which relies primarily on finite element analysis. However, this method has significant shortcomings; it lacks a physical calibration step, and the calculation results based solely on the theoretical model may deviate from actual conditions. The second method is small-scale specimen calibration, which uses small pieces of material to simulate the pipeline for calibration experiments. Because small pieces of material differ greatly from actual full-size pipe sections in structure, size, and stress state, they cannot accurately reflect the stress conditions experienced by the full-size pipe section during actual operation. Summary of the Invention
[0005] The purpose of this invention is to provide a calibration device and method for a pipeline axial stress internal detector, which can apply axial stress to full-size pipe sections so that the pipeline internal detector can work inside the pipeline and detect the stress condition of the inner wall, and calibrate the pipeline internal detector.
[0006] To achieve this objective, the present invention adopts the following technical solution: A calibration device for a pipe axial stress internal detector, comprising: The reaction frame unit includes a horizontal base, a fixed-end reaction support, a sliding-end reaction support, a hydraulic telescopic cylinder, and a pipe section. The fixed-end reaction support is fixedly mounted on the horizontal base, and the sliding-end reaction support is slidably mounted on the horizontal base along a first direction. One end of the hydraulic telescopic cylinder is connected to the fixed-end reaction support, and the other end of the hydraulic telescopic cylinder is connected to the sliding-end reaction support. One end of the pipe section can be connected to the fixed-end reaction support, and the other end of the pipe section can be connected to the sliding-end reaction support. A hydraulic loading unit is connected to the hydraulic telescopic cylinder, and the hydraulic loading unit is used to adjust the extension and retraction of the hydraulic telescopic cylinder; The displacement and deformation monitoring unit is used to detect the strain of the pipe section.
[0007] As an optional solution for the calibration device of the pipeline axial stress detector, multiple hydraulic telescopic cylinders are provided, and the hydraulic loading unit can adjust multiple hydraulic telescopic cylinders to extend and retract simultaneously along the first direction.
[0008] As an optional solution for the calibration device of the pipeline axial stress detector, the fixed end reaction support is provided with a first clearance notch, one end of the pipe section is fixedly fitted with a first connecting flange, and the reaction frame unit further includes: A fixed end bracket is fixedly mounted on the horizontal base and located on the side of the fixed end reaction support away from the sliding end reaction support. The fixed end bracket is provided with a first locking hole. The outer diameter of the first connecting flange is larger than the inner diameter of the first locking hole. The pipe section is sequentially inserted into the first locking hole and the first clearance notch along the first direction. The first connecting flange abuts against the fixed end bracket.
[0009] As an optional solution for the calibration device of the pipeline axial stress internal detector, the reaction frame unit further includes: Several first connecting rods are disposed between the fixed end bracket and the fixed end reaction support.
[0010] As an optional solution for the calibration device of the pipeline axial stress internal detector, a number of first reinforcing members are circumferentially spaced at one end of the pipe section, and each of the first reinforcing members is connected to the first connecting flange.
[0011] As an optional solution for the calibration device of the pipeline axial stress detector, the sliding end reaction support is provided with a second clearance notch, and the other end of the pipe section is fixedly fitted with a second connecting flange. The reaction frame unit also includes: A sliding end bracket is slidably disposed on the horizontal base and located on the side of the sliding end reaction support away from the fixed end reaction support. The sliding end bracket is provided with a second locking hole. The outer diameter of the second connecting flange is larger than the inner diameter of the second locking hole. The other end of the pipe section is sequentially inserted into the second clearance notch and the second locking hole along the first direction. Several second connecting rods are disposed between the sliding end bracket and the sliding end reaction support, and the sliding end bracket abuts against the second connecting flange.
[0012] As an optional solution for the calibration device of the pipeline axial stress internal detector, the other end of the pipe section is provided with a number of second reinforcing members at circumferential intervals, and each of the second reinforcing members is connected to the second connecting flange.
[0013] As an optional solution for the calibration device of the pipeline axial stress internal detector, the bottom of the sliding end reaction support is provided with several first rollers, and the bottom of the sliding end clamp is provided with several second rollers.
[0014] The calibration method employs the calibration device for the pipeline axial stress internal detector as described in any of the preceding items, and includes the following steps: S1. Install the horizontal base onto the foundation and select pipe sections of the same material and specifications as the pipe being tested; S2. Hoist the pipe section onto the fixed end reaction support and the sliding end reaction support of the reaction frame unit; S3. Insert the pipe stress detector to be calibrated from one end of the pipe section to ensure that the probe of the pipe stress detector is in full contact with the pipe wall of the pipe section. S4. The hydraulic loading unit controls the hydraulic telescopic cylinder to load multiple target stresses at a set rate and maintain pressure for a set time. S5. Record the multi-level target stress and displacement output by the hydraulic loading unit and the corresponding strain values output by the deformation monitoring unit, and calibrate the pipeline stress detector.
[0015] As an alternative calibration method, the displacement and deformation monitoring unit includes a DIC camera or a strain gauge.
[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: The axial stress internal detector calibration device for pipelines provided by this invention has a fixed end reaction support fixedly installed at one end of a horizontal base, and a sliding end reaction support slidably installed at the other end of the horizontal base. Under the control of a hydraulic telescopic cylinder by a hydraulic loading unit, the sliding end reaction support can move along a first direction to adapt to pipe sections of different lengths; on the other hand, the hydraulic loading unit controls the hydraulic telescopic cylinder to apply multi-level target stress at a set rate, enabling axial stress loading to be applied to full-size pipe sections. The pipeline stress internal detector to be calibrated is placed into the pipe section from one end, ensuring that the probe of the pipeline stress internal detector is in full contact with the pipe wall of the pipe section. The pipeline stress internal detector is calibrated based on the multi-level target stress and displacement output by the hydraulic loading unit and the corresponding strain values output by the deformation monitoring unit.
[0017] The calibration method provided by this invention involves installing a horizontal base on a foundation and selecting a pipe section of the same material and specifications as the pipe to be tested. The pipe section is then hoisted onto the fixed-end and sliding-end reaction supports of the reaction frame unit. The internal stress detector to be calibrated is inserted from one end of the pipe section, ensuring full contact between the detector's probe and the pipe wall. A hydraulic loading unit controls a hydraulic telescopic cylinder to apply multi-level target stresses at a set rate and maintains pressure for a set time. The multi-level target stresses and displacements output by the hydraulic loading unit are recorded, along with the corresponding strain values output by the deformation monitoring unit, and the internal stress detector is calibrated. This calibration method can apply axial stress to a full-size pipe section, allowing the internal stress detector to operate within the pipe and detect the internal wall stress, thus calibrating the detector. Attached Figure Description
[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the content of the embodiments of the present invention and these drawings without creative effort.
[0019] Figure 1 This is an assembly diagram of the reaction frame unit in an embodiment of the present invention (pipe sections are not shown). Figure 2 This is a schematic diagram of the pipe section component in an embodiment of the present invention; Figure 3 This is a schematic diagram of the fixed-end reaction support in an embodiment of the present invention; Figure 4 This is a schematic diagram of the sliding end reaction support in an embodiment of the present invention; Figure 5 This is a schematic diagram of the structure of the fixed end card holder in an embodiment of the present invention; Figure 6 This is a schematic diagram of the sliding end holder in an embodiment of the present invention; Figure 7 This is a flowchart of the calibration method in an embodiment of the present invention.
[0020] Figure label: 1. Horizontal base; 2. Fixed end reaction support; 21. First clearance notch; 3. Sliding end reaction support; 31. Second clearance notch; 32. First roller; 4. Hydraulic telescopic cylinder; 5. Pipe section; 51. First connecting flange; 52. First reinforcing member; 53. Second connecting flange; 54. Second reinforcing member; 6. Fixed end retainer; 61. First retaining hole; 7. First connecting rod; 8. Sliding end retainer; 81. Second retaining hole; 82. Second roller; 9. Second connecting rod. Detailed Implementation
[0021] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, 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. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.
[0022] In the description of this invention, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection or a detachable connection; a mechanical connection or an electrical connection; a direct connection or an indirect connection through an intermediate medium; or the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.
[0023] In the description of this invention, unless otherwise expressly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature being directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.
[0024] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar components or components having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.
[0025] To enable axial stress loading on full-size pipe sections, allowing the pipe internal stress detector to operate within the pipe and detect the internal wall stress, and to calibrate the pipe internal stress detector, this embodiment provides a pipe axial stress internal stress detector calibration device and calibration method, which are described below in conjunction with... Figures 1 to 7 The specific content of this embodiment will be described in detail. It should be noted that the first direction mentioned in this embodiment is... Figure 1 The X direction in the equation.
[0026] The pipeline axial stress internal detector calibration device provided in this embodiment includes a reaction frame unit, a hydraulic loading unit, and a displacement and deformation monitoring unit. The reaction frame unit, as the basic support structure of the entire calibration device, includes a horizontal base 1, a fixed-end reaction support 2, a sliding-end reaction support 3, a hydraulic telescopic cylinder 4, and a pipe section component 5. The fixed-end reaction support 2 is fixedly mounted on the horizontal base 1, providing a stable support point for the entire device and ensuring that there is no shaking or displacement during subsequent loading and testing, thus guaranteeing the accuracy of the calibration results. The sliding-end reaction support 3 is slidably mounted on the horizontal base 1 along a first direction. The hydraulic telescopic cylinder 4, as a key component connecting the fixed-end reaction support 2 and the sliding-end reaction support 3, has one end connected to the fixed-end reaction support 2 and the other end connected to the sliding-end reaction support 3, providing strong power support for the movement of the sliding-end reaction support 3 and the axial stress loading of the pipe section component 5. One end of the pipe segment 5 can be connected to the fixed-end reaction support 2, and the other end can be connected to the sliding-end reaction support 3, forming a complete force system and providing an ideal experimental object for subsequent stress loading and testing. The hydraulic loading unit is connected to the hydraulic telescopic cylinder 4, which has the ability to precisely adjust the extension and retraction of the hydraulic telescopic cylinder 4. It can accurately control the movement of the hydraulic telescopic cylinder 4 according to preset parameters and experimental requirements. Under the control of the hydraulic loading unit, the hydraulic telescopic cylinder 4 can generate forces of different magnitudes and rates (i.e., the axial stress on the pipe segment 5). On the one hand, it can drive the sliding-end reaction support 3 to move smoothly in the first direction. The flexibility and precision of this movement make the calibration device easily adaptable to pipe segments 5 of different lengths, greatly improving the versatility and applicability of the device. Whether the pipe segment 5 is short or long, accurate and effective calibration experiments can be performed on this calibration device. On the other hand, the hydraulic loading unit can control the hydraulic telescopic cylinder 4 to load multiple levels of target stress at a set rate. This multi-stage stress loading method can simulate various complex stress conditions experienced by pipelines during actual operation, gradually loading from low to high stress, thus more realistically reflecting the stress state of the pipeline. By applying axial stress to the full-size pipe section 5, an accurate and reliable stress source is provided for the subsequent calibration of the pipeline stress detector, ensuring that the calibration results can truly reflect the stress conditions of the pipeline under actual working conditions. The displacement and deformation monitoring unit can detect the strain of the pipe section 5 in real time and accurately during the axial stress loading process.
[0027] In the actual calibration process, the pipeline stress detector to be calibrated is first carefully inserted into the pipe segment 5 from one end, ensuring that the probe of the pipeline stress detector is in full contact with the pipe wall of the pipe segment 5. This ensures that the detector can accurately sense the stress changes of the pipe segment 5. Then, the hydraulic loading unit is activated. Under the precise control of the hydraulic loading unit, the hydraulic telescopic cylinder 4 starts to work, driving the sliding end reaction support 3 to move, so that the pipe segment 5 is in a suitable stress state, and is loaded to the multi-level target stress at a set rate. At the same time, the displacement and deformation monitoring unit monitors the strain of the pipe segment 5 in real time and accurately records the monitored strain values. Based on the multi-level target stress output by the hydraulic loading unit and the corresponding strain values output by the displacement and deformation monitoring unit, the pipeline stress detector is comprehensively and accurately calibrated.
[0028] Furthermore, multiple hydraulic telescopic cylinders 4 are provided, and the hydraulic loading unit can adjust multiple hydraulic telescopic cylinders 4 to extend and retract simultaneously along the first direction. By increasing the number of hydraulic telescopic cylinders 4, multiple hydraulic telescopic cylinders 4 working together can generate a greater resultant force. When axial stress is applied to the pipe section 5, each hydraulic telescopic cylinder 4 exerts force together, superimposing their respective forces. This superposition effect allows the entire device to output a force far exceeding that of a single hydraulic telescopic cylinder 4. In practical applications, this increased force has significant advantages. On the one hand, it can quickly reach the target stress. In the process of axial stress calibration of pipelines, it is often necessary to quickly load the pipe section 5 to a specific stress level to simulate the rapid stress changes of the pipeline in actual operation. The combined action of multiple hydraulic telescopic cylinders 4 can greatly shorten the loading time and improve calibration efficiency. On the other hand, the increased force facilitates the miniaturization design of the hydraulic telescopic cylinders 4. Since multiple small hydraulic telescopic cylinders 4 working together can achieve the same force effect as a single large hydraulic telescopic cylinder 4, smaller and lighter hydraulic telescopic cylinders 4 can be selected in the design. This helps to reduce the overall weight and volume of the device and reduce space occupation. The simultaneous operation of multiple hydraulic telescopic cylinders 4 can also make the pipe section 5 bear relatively uniform force, avoiding stress concentration when under force, which would lead to excessive local stress and less stress in other parts.
[0029] Furthermore, the fixed-end reaction support 2 is provided with a first clearance notch 21, and one end of the pipe segment 5 is fixedly fitted with a first connecting flange portion 51. The reaction frame unit also includes a fixed-end retainer 6, which is fixedly mounted on the horizontal base 1 and located on the side of the fixed-end reaction support 2 away from the sliding-end reaction support 3. The fixed-end retainer 6 is provided with a first retaining hole 61, and the outer diameter of the first connecting flange portion 51 is larger than the inner diameter of the first retaining hole 61. The pipe segment 5 passes through the first retaining hole 61 and the first clearance notch 21 in sequence along the first direction. When the pipe segment 5 passes through the first retaining hole 61, since the outer diameter of the first connecting flange portion 51 is larger than the inner diameter of the first retaining hole 61, the first connecting flange portion 51 cannot continue to pass through the first retaining hole 61, thus naturally forming an abutment state with the fixed-end retainer 6. When the pipe segment 5 is subjected to axial stress loading, the fixed-end retainer 6 can play a role in restricting the position of the pipe segment 5 through the first connecting flange portion 51. When the hydraulic loading unit applies axial stress to the pipe section 5, the pipe section 5 will exhibit a tendency to stretch along the axial direction. Without effective restraint, the pipe section 5 may move under the action of axial force, leading to inaccurate stress loading and affecting the reliability of calibration results. The abutment structure between the fixed end holder 6 and the first connecting flange 51 forms a robust "constraint mechanism" that can effectively resist the movement of the pipe section 5 under axial stress. The fixed end holder 6 can firmly hold the pipe section 5 through the first connecting flange 51, ensuring that the pipe section 5 maintains a relatively fixed position in the axial direction. This restraint effect allows the stress to be accurately applied to the pipe section 5, ensuring the accuracy and stability of stress loading, thereby providing reliable experimental conditions for the calibration of the pipeline axial stress detector.
[0030] Furthermore, the reaction frame unit also includes several first connecting rods 7, all of which are disposed between the fixed end bracket 6 and the fixed end reaction support 2. During the axial stress loading process of the pipe segment 5, the fixed end bracket 6 and the fixed end reaction support 2 will bear enormous forces. The fixed end bracket 6 needs to stably fix the pipe segment 5 and resist its tendency to move under axial stress; while the fixed end reaction support 2 must withstand the reaction force from the hydraulic telescopic cylinder 4. Relying solely on the structural strength of the fixed end bracket 6 and the fixed end reaction support 2, structural deformation or even damage may occur under complex stress environments and long-term loading. The placement of the first connecting rods 7 effectively changes the mechanical transmission path at the fixed end. When the pipe segment 5 is subjected to axial stress loading, the force is transmitted to the fixed end bracket 6 through the first connecting flange 51, and then part of the force is transmitted to the fixed end reaction support 2 along the first connecting rods 7. This method of force distribution ensures that the stress borne by the fixed-end bracket 6 and the fixed-end reaction support 2 is evenly distributed, avoiding localized stress concentration. Simultaneously, the first connecting rod 7 itself possesses certain tensile, compressive, and bending resistance capabilities, enabling it to work in conjunction with the fixed-end bracket 6 and the fixed-end reaction support 2 to jointly withstand external forces, thereby significantly improving the overall structural strength of the fixed end. In practical applications, this enhanced structural strength ensures that the reaction frame unit remains stable during long-term calibration work, preventing deformation or damage due to stress.
[0031] Furthermore, a plurality of first reinforcing members 52 are circumferentially spaced at one end of the pipe section 5, each of which is connected to the first connecting flange portion 51. During the actual operation of the pipe section 5, the first connecting flange portion 51, as the key part for the contact and connection between the pipe section 5 and the fixed end bracket 6, bears enormous axial force. Especially under axial stress loading, the first connecting flange portion 51 needs to accurately transfer the stress on the pipe section 5 to the fixed end bracket 6, while also resisting the reaction force from the fixed end bracket 6. If the structural strength of the first connecting flange portion 51 is insufficient, problems such as deformation, cracks, or even breakage can easily occur, thereby affecting the fixing effect of the pipe section 5 and the accuracy of stress transfer, leading to deviations in calibration results. With the addition of multiple first reinforcing members 52, the first reinforcing members 52 are evenly distributed circumferentially at one end of the pipe section 5, forming an organic whole with the first connecting flange portion 51. When the first connecting flange 51 is subjected to external force, the first reinforcing member 52 can share part of the stress, dispersing the stress over a larger area of the pipe section 5. This stress dispersion mechanism effectively reduces the local stress borne by the first connecting flange 51, improving its fatigue resistance and damage resistance. At the same time, the first reinforcing member 52 can also enhance the connection stiffness between the pipe section 5 and the first connecting flange 51, reducing the relative displacement and deformation between them, and ensuring that stress can be transmitted stably and accurately.
[0032] Furthermore, a second clearance notch 31 is provided on the sliding end reaction support 3, and a second connecting flange portion 53 is fixedly fitted on the other end of the pipe segment 5. The reaction frame unit also includes a sliding end retainer 8 and several second connecting rods 9. The sliding end retainer 8 is slidably mounted on the horizontal base 1 and is located on the side of the sliding end reaction support 3 away from the fixed end reaction support 2. This sliding arrangement gives the sliding end retainer 8 a certain degree of freedom, thereby better adapting to different stress loading conditions. A second retaining hole 81 is provided on the sliding end retainer 8, and the outer diameter of the second connecting flange portion 53 is larger than the inner diameter of the second retaining hole 81. The other end of the pipe segment 5 passes through the second clearance notch 31 and the second retaining hole 81 in sequence along the first direction. When the pipe segment 5 is in place, the second connecting flange portion 53 cannot continue to pass through the second retaining hole 81 due to its larger outer diameter, thus naturally forming a tight abutment with the sliding end retainer 8. This abutment relationship not only achieves the initial positioning of the pipe segment 5 at the sliding end, but also provides a stable connection basis for subsequent stress transmission. Several second connecting rods 9 are disposed between the sliding end retainer 8 and the sliding end reaction support 3, with the sliding end retainer 8 abutting against the second connecting flange 53. During the axial stress loading process of the pipe section 5, the sliding end retainer 8 needs to withstand the reaction force from the pipe section 5 and transfer these forces to the sliding end reaction support 3. The placement of the second connecting rods 9 effectively changes the force transmission path, allowing the stress to be evenly distributed between the sliding end retainer 8 and the sliding end reaction support 3, avoiding the occurrence of local stress concentration. At the same time, the second connecting rods 9 themselves have certain tensile, compressive, and bending resistance capabilities, and they can work together with the sliding end retainer 8 and the sliding end reaction support 3 to jointly withstand external forces, thereby significantly improving the overall structural strength of the sliding end.
[0033] Furthermore, several second reinforcing members 54 are circumferentially spaced at the other end of the pipe segment 5, each of which is connected to the second connecting flange portion 53. By adding multiple second reinforcing members 54, they are evenly distributed circumferentially at the other end of the pipe segment 5, forming an organic whole with the second connecting flange portion 53. When the second connecting flange portion 53 is subjected to external force, the second reinforcing members 54 can share some of the stress, dispersing it over a larger area of the pipe segment 5. This stress dispersion mechanism effectively reduces the local stress borne by the second connecting flange portion 53, improving its fatigue resistance and damage resistance. Simultaneously, the second reinforcing members 54 also enhance the connection stiffness between the pipe segment 5 and the second connecting flange portion 53, reducing relative displacement and deformation between them, ensuring stable and accurate stress transmission.
[0034] Furthermore, the bottom of the sliding end reaction support 3 is provided with several first rollers 32, and the bottom of the sliding end retainer 8 is provided with several second rollers 82. The first rollers 32 and the second rollers 82 are located on the horizontal base 1. The arrangement of the first rollers 32 and the second rollers 82 greatly improves the movement flexibility of the sliding end reaction support 3 and the sliding end retainer 8 on the horizontal base 1. When the pipe segment 5 is subjected to axial stress loading, the pipe segment 5 will undergo axial expansion and contraction deformation. The sliding end reaction support 3 and the sliding end retainer 8 need to move accordingly with the deformation of the pipe segment 5 to maintain stable support and stress transmission for the pipe segment 5. Without the rollers, the sliding end reaction support 3 and the sliding end retainer 8 have sliding friction with the horizontal base 1, which has a large friction force. This not only requires more energy to overcome the friction force to move them, but may also lead to uneven movement and jamming, affecting the accuracy and stability of axial stress loading. The first rollers 32 and the second rollers 82 transform sliding friction into rolling friction, greatly reducing the friction force. According to the principles of tribology, rolling friction is much smaller than sliding friction. This allows the sliding end reaction support 3 and the sliding end clamp 8 to move easily on the horizontal base 1 under a small external force. They can quickly and accurately adjust their positions to follow the axial deformation of the pipe section 5, thereby ensuring the continuity and stability of the axial stress loading process and improving the efficiency and accuracy of the calibration experiment.
[0035] like Figure 7As shown, this embodiment also provides a calibration method. This calibration method uses the aforementioned pipeline axial stress internal detector calibration device to calibrate the pipeline axial stress internal detector, including the following steps: S1, install the horizontal base 1 on the foundation, and select a pipe section 5 of the same material and specification as the pipeline to be tested; S2, hoist the pipe section 5 onto the fixed end reaction support 2 and the sliding end reaction support 3 of the reaction frame unit; S3, place the pipeline stress internal detector to be calibrated into the pipe section 5 from one end, ensuring that the probe of the pipeline stress internal detector is in full contact with the pipe wall of the pipe section 5; S4, the hydraulic loading unit controls the hydraulic telescopic cylinder 4 to load at a set rate (e.g., 10KN / S) to multiple target stresses (e.g., 20%, 40%, 60% yield strength), and hold the pressure for a set time under each target stress; S5, record the corresponding strain values output by the hydraulic loading unit and the deformation monitoring unit, and calibrate the pipeline stress internal detector. The set pressure holding time at each target stress is to allow the pipeline to reach a stable deformation state under that stress level, enabling the detector to fully sense and accurately measure the stress value at that time. Simultaneously, the pressure holding process also verifies the detector's performance stability under prolonged continuous stress, such as whether there is drift or increased error. Through in-depth analysis and processing of the recorded multi-level target stresses and corresponding strain values, an accurate correspondence between target stress and strain values is established. Then, based on this correspondence, the pipeline stress detector is calibrated, and its parameters and algorithms are adjusted to ensure that the measured stress values closely match the actual stress values, thereby improving the detector's measurement accuracy and reliability and ensuring that it can provide accurate data support for the safe operation of pipelines in actual pipeline inspections.
[0036] Furthermore, the displacement and deformation monitoring unit includes a DIC camera or a strain gauge. The DIC camera, based on digital image correlation technology, can non-contactly measure the displacement and strain field on the surface of the pipe segment 5, offering advantages such as full-field measurement, high precision, and high resolution. It can visually acquire the deformation of the pipe segment 5 under different stress levels. The strain gauge, on the other hand, is attached to the surface of the pipe segment 5 to directly measure the strain value at that point, featuring accurate measurement and fast response.
[0037] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.
Claims
1. A calibration device for a pipe axial stress internal detector, characterized in that, include: The reaction frame unit includes a horizontal base (1), a fixed end reaction support (2), a sliding end reaction support (3), a hydraulic telescopic cylinder (4), and a pipe section (5). The fixed end reaction support (2) is fixedly installed on the horizontal base (1), and the sliding end reaction support (3) is slidably installed on the horizontal base (1) along a first direction. One end of the hydraulic telescopic cylinder (4) is connected to the fixed end reaction support (2), and the other end of the hydraulic telescopic cylinder (4) is connected to the sliding end reaction support (3). One end of the pipe section (5) can be connected to the fixed end reaction support (2), and the other end of the pipe section (5) can be connected to the sliding end reaction support (3). A hydraulic loading unit is connected to the hydraulic telescopic cylinder (4), and the hydraulic loading unit is used to adjust the extension and retraction of the hydraulic telescopic cylinder (4); The displacement and deformation monitoring unit is used to detect the strain of the pipe section (5).
2. The calibration device for the pipeline axial stress internal detector according to claim 1, characterized in that, Multiple hydraulic telescopic cylinders (4) are provided, and the hydraulic loading unit can adjust multiple hydraulic telescopic cylinders (4) to extend and retract simultaneously along the first direction.
3. The calibration device for the pipeline axial stress internal detector according to claim 1, characterized in that, The fixed-end reaction support (2) is provided with a first clearance notch (21), and one end of the pipe section (5) is fixedly fitted with a first connecting flange (51). The reaction frame unit also includes: A fixed end bracket (6) is fixedly mounted on the horizontal base (1) and located on the side of the fixed end reaction support (2) away from the sliding end reaction support (3). The fixed end bracket (6) is provided with a first locking hole (61). The outer diameter of the first connecting flange (51) is larger than the inner diameter of the first locking hole (61). The pipe section (5) is sequentially inserted into the first locking hole (61) and the first clearance notch (21) along the first direction. The first connecting flange (51) abuts against the fixed end bracket (6).
4. The calibration device for the pipeline axial stress internal detector according to claim 3, characterized in that, The reaction frame unit also includes: Several first connecting rods (7) are disposed between the fixed end bracket (6) and the fixed end reaction support (2).
5. The calibration device for the pipeline axial stress internal detector according to claim 3, characterized in that, One end of the pipe section (5) is provided with a plurality of first reinforcing members (52) spaced apart circumferentially, and each of the first reinforcing members (52) is connected to the first connecting flange (51).
6. The calibration device for the pipeline axial stress internal detector according to claim 1, characterized in that, The sliding end reaction support (3) is provided with a second clearance notch (31), and the other end of the pipe section (5) is fixedly fitted with a second connecting flange (53). The reaction frame unit also includes: The sliding end bracket (8) is slidably disposed on the horizontal base (1) and located on the side of the sliding end reaction support (3) away from the fixed end reaction support (2). The sliding end bracket (8) is provided with a second locking hole (81). The outer diameter of the second connecting flange (53) is larger than the inner diameter of the second locking hole (81). The other end of the pipe section (5) passes through the second clearance notch (31) and the second locking hole (81) in sequence along the first direction. Several second connecting rods (9) are disposed between the sliding end bracket (8) and the sliding end reaction support (3), and the sliding end bracket (8) abuts against the second connecting flange (53).
7. The calibration device for the pipeline axial stress internal detector according to claim 6, characterized in that, The other end of the pipe section (5) is provided with a plurality of second reinforcing members (54) spaced apart circumferentially, and each second reinforcing member (54) is connected to the second connecting flange (53).
8. The calibration device for the pipe axial stress internal detector according to claim 6, characterized in that, The bottom of the sliding end reaction support (3) is provided with a plurality of first rollers (32), and the bottom of the sliding end card holder (8) is provided with a plurality of second rollers (82).
9. A calibration method, characterized in that, The calibration of the pipeline axial stress internal detector using the calibration device as described in any one of claims 1-8 includes the following steps: S1. Install the horizontal base (1) onto the foundation and select a pipe section (5) of the same material and specification as the pipe to be tested. S2. Hoist the pipe section (5) onto the fixed end reaction support (2) and the sliding end reaction support (3) of the reaction frame unit; S3. Insert the pipeline stress detector to be calibrated from one end of the pipe section (5) to ensure that the probe of the pipeline stress detector is in full contact with the pipe wall of the pipe section (5). S4. The hydraulic loading unit controls the hydraulic telescopic cylinder (4) to load the target stress at a set rate and hold the pressure for a set time. S5. Record the multi-level target stress and displacement output by the hydraulic loading unit and the corresponding strain values output by the deformation monitoring unit, and calibrate the pipeline stress detector.
10. The calibration method according to claim 9, characterized in that, The displacement and deformation monitoring unit includes a DIC camera or a strain gauge.