A pipeline full-size four-point bending test device and test method

Abstract

The present application relates to the technical field of submarine pipeline testing, and especially relates to a pipeline full-size four-point bending test device and a test method. The pipeline full-size four-point bending test device sends a load loading execution instruction to a load loading frame system through a control subsystem; a first data acquisition subsystem collects first data related to the load loading execution instruction, and a second data acquisition subsystem collects second data; the first data acquisition subsystem returns the collected first data to the control subsystem, and the second data acquisition subsystem returns the collected second data to the control subsystem; and the control subsystem controls the load loading frame system according to the returned data. The present application can simultaneously load axial load and radial load, has a perfect control system, high control precision, strong human-computer interaction capability, reasonable spatial layout, small possibility of component damage and strong comprehensive performance.

Description

Technical Field

[0001] This invention relates to the field of subsea pipeline testing technology, and in particular to a full-size four-point bending test device and test method for pipelines. Background Technology

[0002] my country possesses abundant offshore oil and gas reserves, most of which are distributed in deep-water areas such as the South China Sea. Offshore pipelines, as the lifeline for offshore oil and gas resource development, play a crucial role in the extraction and transportation of these resources. However, when laying offshore pipelines, pipelaying vessels need to lower or raise the pipelines in seawater. Due to factors such as the pipeline's own weight, the drag force caused by wave currents, and seabed topography, the pipelines will experience significant axial tension and radial pressure, leading to bending deformation. This necessitates bending tests before the pipeline enters the water to ensure that its strain performance, fatigue resistance, and other properties meet the requirements for operation and subsequent use.

[0003] The full-scale four-point bending test for pipelines involves applying axial loads and radial loads in both directions to a complete section of marine pipeline using a specific device. This simulates the actual stress conditions of a marine pipeline, allowing for the measurement of the pipeline's bending radius, strain, and other relevant parameters to ensure that the marine pipeline meets operational requirements. Specifically, the pipeline is placed on two support points at a certain distance, and then a radial load is applied to the pipeline at the same distance from the midpoint between the two support points, causing the pipeline to bend at four points under the action of the four contact points.

[0004] However, most current full-size four-point bending test devices for pipelines cannot simultaneously load and measure axial and radial loads, or even if they can load simultaneously, they suffer from problems such as low control accuracy, imperfect control systems, poor human-machine interaction, unreasonable spatial layout, and easy damage to components. Therefore, there is an urgent need to develop a full-size four-point bending test device and test method for pipelines with strong comprehensive performance and precise and complete control.

[0005] For example, application publication number CN117782846A discloses a four-point bending test device for marine flexible cables. The technical solution described in this invention application achieves four-point bending of the cable by moving the support structure up and down. However, the spatial layout is unreasonable, making it inconvenient for workers to operate at low positions. Moreover, it cannot apply and measure axial loads, and its single function cannot match actual working conditions.

[0006] For example, application publication number CN103983523A discloses a full-size four-point bending test device and test method for pipes. Although the technical solution described in this invention application can apply axial load to steel pipes and measure the strain force under axial load, the device has a simple structure, occupies a large space, is difficult to operate flexibly, and has low control precision.

[0007] Finally, the patent application CN202533325U discloses a composite load simulation test system for in-service pipelines. The technical solution described in this utility model patent is simplistic and crude in its data processing logic, resulting in low load control accuracy and a lack of an emergency shutdown judgment system, making the control system incomplete. Summary of the Invention

[0008] To address the shortcomings of existing technologies, this invention provides a full-size four-point bending test device and method for pipelines, which can simultaneously apply axial and radial loads, has a sophisticated control system, high control precision, strong human-machine interaction capabilities, a reasonable spatial layout, low component damage potential, and strong overall performance.

[0009] The first aspect of this invention provides a full-size four-point bending test device for pipelines, comprising a measurement and control system and a load loading frame system. The measurement and control system is connected to the load loading frame system. The measurement and control system includes a control subsystem and a data acquisition subsystem. The control subsystem sends a load loading execution command to the load loading frame system. The data acquisition subsystem includes a first data acquisition subsystem and a second data acquisition subsystem. The first data acquisition subsystem acquires first data related to the load loading execution command, and the second data acquisition subsystem acquires second data related to the pipeline load loading result. The first data acquisition subsystem transmits the first data back to the control subsystem, and the second data acquisition subsystem transmits the second data back to the control subsystem. The control subsystem controls the load loading frame system based on the first data and the second data.

[0010] Furthermore, it also includes a security protection system, which has a set data security threshold. The security protection system analyzes and compares the first data, the second data, and the data security threshold to control the load loading framework system.

[0011] Furthermore, the load loading frame system includes an axial load loading fixed support mechanism, an axial load loading movable support mechanism, and two radial load loading movable support mechanisms, all of which operate in the horizontal direction.

[0012] Furthermore, the axial load loading fixed support mechanism includes a fixedly installed first swing arm mounting seat and a first swing arm. One end of the first swing arm is pivotally connected to the first swing arm mounting seat, and the other end of the first swing arm is provided with a clamp mounting position. The clamp is rotatably installed on the clamp mounting position and clamps the beginning end of the pipe.

[0013] Furthermore, the axial load loading moving support mechanism includes a second swing arm mounting seat and a second swing arm that are movable in the axial direction. One end of the second swing arm is pivotally connected to the second swing arm mounting seat, and the other end of the second swing arm is provided with a clamp mounting position. The clamp is rotatably mounted on the clamp mounting position and clamps the tail end of the pipe.

[0014] Furthermore, the radial load loading moving support mechanism includes a third thrust rod and a third reaction frame. One end of the third thrust rod is mounted on the movable third reaction frame, and the other end of the third thrust rod is mounted on a rotatable clamp seat. The clamp seat has a clamp mounting position, and the clamp is rotatably mounted on the clamp mounting position. The clamp is used to connect the pipeline, and the third thrust rod performs a telescopic action to apply a radial load to the pipeline.

[0015] Furthermore, a bending die seat that moves horizontally is provided at one end of the third thrust rod connecting clamp. The bending die seat has a through channel for insertion into the middle of the pipe. The bending die seat includes an inner bending die seat and an outer bending die seat. The channel is reserved between the inner bending die seat and the outer bending die seat and connected by an adjusting screw. The inner bending die seat and the outer bending die seat also have a mold with an arc-shaped surface on the side facing the pipe.

[0016] Furthermore, the load loading frame system also includes a loading trolley that moves horizontally. The loading trolley includes a lifting platform and a concave roller disposed on the lifting platform. The rotation axis of the concave roller is perpendicular to the line connecting the axial load loading fixed support mechanism and the axial load loading movable support mechanism.

[0017] A second aspect of the present invention provides a method for a full-size four-point bending test of a pipe, employing the pipe full-size four-point bending test apparatus as described above, comprising the following steps:

[0018] Pipeline feeding;

[0019] Adjust the positions of the axial load loading moving support mechanism and the two radial load loading moving support mechanisms of the load loading frame system to clamp the pipe with clamps and prepare for subsequent load loading;

[0020] The measurement and control system sends a load loading command to the load loading framework system. The first data acquisition subsystem sends back the first data related to the pipeline load loading command to the control subsystem. The second data acquisition subsystem sends back the second data related to the pipeline load loading result to the control subsystem. The control subsystem analyzes and compares the first data and the second data to control the load loading framework system.

[0021] Reports are obtained through the measurement and control system;

[0022] The pipeline is inspected and verified after being loaded by the full-size four-point bending test device using the equipped endoscope system and three-coordinate articulated arm system.

[0023] Furthermore, it also includes the following steps:

[0024] The full protection system provides protection: The security protection system analyzes and compares the first data, the second data, and the data security threshold set by the security protection system itself to control the load loading frame system.

[0025] The technical solution described in this invention has the following beneficial effects:

[0026] (1) By analyzing and comparing the first data related to the load loading execution command and the second data related to the pipeline load loading result through the control subsystem, the purpose of using the aforementioned data to make multiple logical judgments is realized, so that the device has a more reliable and accurate load loading control capability. In the four-point bending test of this scheme, the load stability accuracy can reach ±0.5%FS and the linear loading accuracy can reach ±0.1%FS.

[0027] (2) The second data acquisition subsystem also records and outputs the second data related to the pipeline load loading results, providing conditions for data visualization interaction; the safety protection system is used to execute the emergency shutdown judgment logic. For example, when the test piece or actuator suffers structural damage, it can play a safety protection role and improve the safety factor when the device is used and the load loading is executed.

[0028] (3) The axial load loading fixed support mechanism, axial load loading moving support mechanism and radial load loading moving support mechanism in the load loading frame system all move in the horizontal direction, which makes it easy to conduct four-point bending tests in the horizontal position, reduces the overall height of the machine, makes it easier for workers to perform simple and safe operations, and makes the spatial layout more reasonable.

[0029] (4) The axial load loading fixed support mechanism pushes and pulls the first swing arm with the first thrust rod to load the axial load onto the pipeline. It can convert the force into torque at the structural level, making the load loading control more accurate. Similarly, the axial load loading moving support mechanism pushes and pulls the second swing arm with the second thrust rod to load the axial load onto the pipeline. It can also convert the force into torque at the structural level, making the load loading control more accurate. The radial load loading moving support mechanism, combined with the bending mold seat, can overcome the large off-center load that occurs when the sample is bent, and the test results are more accurate. Attached Figure Description

[0030] Figure 1 This is a schematic diagram illustrating the working principle of the four-point bending test device of this application.

[0031] Figure 2 This is the load loading frame system of this application.

[0032] Figure 3 A schematic diagram of a fixed support mechanism for axial load loading in a load-loading frame system.

[0033] Figure 4 for Figure 3 Schematic diagram of the cross-sectional structure of AA.

[0034] Figure 5 This is a schematic diagram of the axial load loading moving support mechanism in a load loading frame system.

[0035] Figure 6 for Figure 5 Schematic diagram of the cross-sectional structure of BB.

[0036] Figure 7 This is a schematic diagram of the radial load loading moving support mechanism in a load loading frame system.

[0037] Figure 8 for Figure 7 Side front view of the radial load-loaded moving support mechanism.

[0038] Figure 9 This is a schematic diagram of the bending die holder structure.

[0039] Figure 10 This is a schematic diagram of the fixture structure.

[0040] Figure 11 This is a schematic diagram of the material loading trolley.

[0041] Figure 12 This is a schematic diagram of the exploded structure of the load-loaded frame system.

[0042] Figure 13 This is a side view of the load-loading frame system.

[0043] Figure 14 This is an exploded structural diagram of another embodiment of the load-loading frame system.

[0044] Figure 15 This is a schematic diagram illustrating the working principle of the measurement and control system.

[0045] Figure 16 Example 1 of the interactive interface window for the measurement and control system.

[0046] Figure 17 Example 2 of the interactive interface window for the measurement and control system.

[0047] In the diagram, 1-Axial load loading fixed support mechanism, 11-First swing arm mounting seat, 12-First swing arm, 121-First limiting platform, 122-First clearance frame, 13-First base plate, 14-First thrust rod, 15-First reaction frame, 16-Fixed seat, 17-First slewing bearing, 2-Axial load loading moving support mechanism, 21-Second swing arm mounting seat, 22-Second swing arm, 221-Second limiting platform, 222-Second clearance frame, 23-Second base plate, 24-Second thrust rod, 25-Second reaction frame, 26-Moving seat, 27-Second slewing bearing, 3-Radial load loading Mobile support mechanism, 31-Third thrust rod, 32-Third reaction frame, 33-Mounting seat, 34-Third slewing bearing, 35-Third base plate, W-Clamping mounting position, V-Clamping fixture, V0-Clamping mold seat, V-1 Inner mold seat, V2-Outer mold seat, V00-Mold ring, V01-Inner mold ring, V02-Outer mold ring, N-Universal wheel, U-Clamping fixture seat, 5-Bending mold seat, 51-Inner bending mold seat, 52-Outer bending mold seat, L-Channel, T-Pressure plate, 6-Position adjustment mechanism, 7-Base, 70-Inner groove, S-Slide rail, S0-Limiting slide bar, 8-Loading trolley, 81-Lifting platform, 82-Concave roller. Detailed Implementation

[0048] The invention will be further described below with reference to the accompanying drawings:

[0049] See Figure 1As shown, a full-size four-point bending test device for pipelines includes a measurement and control system and a load loading frame system. The measurement and control system is connected to the load loading frame system. The measurement and control system includes a control subsystem and a data acquisition subsystem. The user sends a load loading execution command to the load loading frame system through the control subsystem. The data acquisition subsystem includes a first data acquisition subsystem and a second data acquisition subsystem. The first data acquisition subsystem includes a microcontroller chip one, and the second data acquisition subsystem includes a microcontroller chip two. The first data acquisition subsystem collects first data related to the load loading execution command, and the second data acquisition subsystem collects second data related to the pipeline load loading result. The first data acquisition subsystem transmits the first data back to the control subsystem, and the second data acquisition subsystem transmits the second data back to the control subsystem. The control subsystem analyzes and compares the first data and the second data to control the load loading frame system. The second data acquisition subsystem also records the collected second data and outputs it externally. The data acquisition subsystem generates a report based on the second data. In this application, multiple logical judgments are made with the first data and the second data to enable the device to have a more reliable and accurate load loading control capability. In the four-point bending test of this scheme, the load stability accuracy can reach ±0.5%FS and the linear loading accuracy can reach ±0.1%FS. Moreover, the second data acquisition subsystem will also record the acquired second data and output it to the outside, providing conditions for data visualization and interaction. Preferably, in this application, "and the first data" includes instruction data sent by the control subsystem to the load loading frame system and data on the execution of load loading instructions returned from various sensors on the load loading frame system, such as signal data corresponding to user-defined pressure values, displacement, vibration frequencies, etc., including signal data such as current output and pulse frequency converted from these data; or, for example, signal data of the actuator controlled by the digital I / O module through digital output signals, such as solenoid valve on / off, motor start / stop, etc., also including signal data such as current output and pulse frequency converted from these data; or, for example, various switching sensor signal data collected by the digital I / O module from the load loading frame system through optocoupler isolation devices, such as signal data output by the safety light curtain of the sensor on the load loading frame system, also including current output and pulse frequency signal data converted from these signal data. Preferably, the "second data" in this application includes pipeline-related data measured after the load is applied to the pipeline, such as the actual strain, deformation displacement, temperature, pressure and other data signals of the pipeline, such as the output signal data returned by strain gauges and other various sensors attached to the pipeline, including signal data such as current output and pulse frequency converted from these data.In this application, the first and second data are not directly compared with the user instructions. The reason is that the user instructions are actually a string of compiled I / O code. This string of code controls the circuit module to turn on and off, and further controls the actions of devices connected in series with the circuit module, such as solenoid valves and relays. Therefore, the comparison between the user instructions and the actual strain and displacement data of the pipeline cannot be directly realized. Only by converting the user instructions into instruction data that can be directly or indirectly executed by the load loading frame system can they be compared with the actual strain and displacement data of the pipeline.

[0050] See Figure 1 As shown, it also includes a safety protection system. This system has a set data safety threshold. The safety protection system analyzes and compares the data collected by the first data acquisition subsystem with the second data collected by the second data acquisition subsystem and the data safety threshold to control the load loading frame system. In this application, the safety protection system is an independently operating protection system that executes emergency shutdown judgment logic, set outside the control subsystem and data acquisition subsystem. This system can determine at the hardware level whether a warning threshold has been reached based on the set data safety threshold. It can automatically terminate the test process and initiate safety state recovery when structural damage occurs to the test piece or actuator, providing an additional layer of safety for the four-point bending load test with a high safety factor. For example, when the safety protection system detects that the internal pressure at the pipeline reaches 5000 psi, it immediately shuts down and initiates safety state recovery.

[0051] See Figures 2 to 14 As shown, the load loading frame system includes an axial load loading fixed support mechanism 1, an axial load loading movable support mechanism 2, and two radial load loading movable support mechanisms 3. All three mechanisms operate horizontally. In this application, the axial load loading fixed support mechanism, axial load loading movable support mechanism, and radial load loading movable support mechanism in the load loading frame system all operate horizontally, facilitating four-point bending tests of pipelines in a horizontal position. This reduces the overall height of the machine, making it easier and safer for workers to operate, and also results in a more rational spatial layout.

[0052] See Figures 2 to 4As shown in 12 to 14, the axial load loading fixed support mechanism 1 includes a fixedly arranged first swing arm mounting seat 11 and a first swing arm 12. One end of the first swing arm 12 is pivotally connected to the first swing arm mounting seat 11, and the other end of the first swing arm 12 is provided with a clamp mounting position W. The clamp V is rotatably mounted on the clamp mounting position W and clamps the head end of the pipeline. Preferably, one end of the first swing arm 12 is pivotally connected to the first swing arm mounting seat 11 via a pin-type force sensor, and the other end of the first swing arm 12 is also rotatably connected to the clamp V via a pin-type force sensor, so as to measure the torque between the first swing arm mounting seat and one end of the first swing arm as well as the torque between the other end of the first swing arm and the clamp. The aforementioned measured torque data is transmitted back to the control subsystem as first data for analysis and comparison. If the comparison result exceeds the threshold, corresponding adjustment is performed to control the load loading frame system more precisely.

[0053] See Figures 2 to 4 As shown in 12 to 14, the middle part of the first swing arm 12 is further provided with a first limit table 121 to limit the rotation angle of the clamp V. The longitudinal section of the first swing arm 12 is one of an "I" shape, an inverted shape, an inverted "day" shape or a "four-sided frame" shape. In this application, the first limit table is used to limit the swing angle of the clamp to prevent the axial load from failing to be normally loaded to the head end of the pipeline. The bottom end of the first swing arm 12 is further provided with a universal wheel N. Preferably, the axial load loading fixed support mechanism 1 further includes a first bottom plate 13, which is connected to the first swing arm mounting seat 11, provides a moving plate surface for the universal wheel N, and also provides better support for the first swing arm 12.

[0054] See Figure 2 , 3 As shown in 12 to 14, the axial load loading fixed support mechanism 1 further includes a first push rod 14. One end of the first push rod 14 is mounted on the first reaction frame 15, and the other end of the first push rod 14 is rotatably connected to the first swing arm 12. The first push rod 14 performs telescopic motion to push or stretch the pipeline along the axial direction. In this application, the axial force applied to the pipeline is converted into a torque through the first swing arm, so that the control accuracy is higher. A displacement sensor is built in the first push rod to detect the stroke of the first push rod, and the aforementioned measured stroke data is transmitted back to the control subsystem as first data for analysis and comparison. If the comparison result exceeds the threshold, corresponding adjustment is performed to control the load loading frame system more precisely. Preferably, the first push rod 14 may adopt a hydraulic cylinder. The first push rod 14 may be fixedly mounted on the first reaction frame 15, or may be rotatably mounted on the first reaction frame 15 (to adapt to angle changes), and relative rotation in the horizontal direction occurs between the first push rod 14 and the first swing arm 12.

[0055] See Figures 2 to 4As shown in Figures 12 to 14, the other end of the first thrust rod 14 is rotatably connected to the first swing arm 12 via a pin-type sensor. In this application, the torque between the first thrust rod and the first swing arm is measured by the aforementioned pin-type sensor, and the measured torque data is then fed back to the control subsystem for analysis and comparison. If the comparison result exceeds a threshold, corresponding adjustments are made to more accurately control the load loading frame system. The first swing arm 12 also includes a first clearance frame 122 protruding outward from the beginning of the pipe. The longitudinal section of the first clearance frame 122 is "[" shaped. The other end of the first thrust rod 14 is rotatably connected to the first clearance frame 122 via a pin-type sensor. The transverse section of the first swing arm 12 is generally "┐" shaped. The torque between the other end of the first thrust rod and the first clearance frame is measured by the aforementioned pin-type sensor. The measured torque data is then fed back to the control subsystem for analysis and comparison with the first data. If the comparison result exceeds the threshold, corresponding adjustments are made to more accurately control the load loading frame system.

[0056] See Figure 2 , 3 As shown in Figures 12 to 14, the axial load loading fixed support mechanism 1 also includes a fixed seat 16, and the first reaction frame 15 is mounted on the fixed seat 16 via a first slewing bearing 17. In this application, the first slewing bearing is used to achieve relative rotation between the first reaction frame and the fixed seat. Even if the first thrust rod 14 is fixedly mounted on the first reaction frame 15, it can better adapt to the angle changes between the first thrust rod 14 and the first swing arm 12, avoiding rigid damage.

[0057] See Figure 2 , 5As shown in 6, 12 to 14, the axial load loading mobile support mechanism 2 comprises a second swing arm mounting seat 21 and a second swing arm 22 arranged to move in the axial direction. One end of the second swing arm 22 is pivotally connected to the second swing arm mounting seat 21, and the other end of the second swing arm 22 is provided with a fixture mounting position W. The fixture V is rotatably mounted on the fixture mounting position W and clamps the tail end of the pipeline. Preferably, one end of the second swing arm 22 is pivotally connected to the second swing arm mounting seat 21 via a pin-type force sensor, and the other end of the second swing arm 22 is also rotatably connected to the fixture V via a pin-type force sensor, so as to measure the torque between the second swing arm mounting seat 21 and one end of the second swing arm and the torque between the other end of the second swing arm and the fixture. The measured torque data is then transmitted back to the control subsystem as first data for analysis and comparison. If the comparison result exceeds a threshold, corresponding adjustments are made to control the load loading frame system more accurately. Preferably, the second swing arm mounting seat 21 is moved in the axial direction via the position adjustment mechanism 6, and the specific structure of the position adjustment mechanism 6 will be described later. The axial movement of the axial load loading mobile support mechanism adjusts the distance between the axial load loading fixed support mechanism and the axial load loading mobile support mechanism to adapt to pipelines of different lengths, which broadens the applicable range of the four-point bending test apparatus for pipeline sizes. A second limit table 221 is further provided at the middle part of the second swing arm 22 to limit the rotation angle of the fixture V, and the longitudinal section of the second swing arm 22 is in the shape of an "I", an inverted shape, an inverted "day" shape, or a "four" shape. In the present application, the second limit table 221 is used to limit the swing angle of the fixture V, so as to prevent the axial load from failing to be normally loaded to the tail end of the pipeline.

[0058] See Figure 2 , 5As shown in Figures 6, 12 to 14, the bottom end of the second swing arm 22 is also provided with a caster wheel N. Preferably, the axial load loading moving support mechanism 2 further includes a second base plate 23, which is connected to the second swing arm mounting seat 21, providing a moving surface for the caster wheel N and also providing better support for the second swing arm 22. The load loading moving support mechanism 2 also includes a second thrust rod 24, one end of which is mounted on the second reaction frame 25, and the other end of which is rotatably connected to the second swing arm 22. The second thrust rod 24 performs a telescopic action to push or stretch the pipe in the axial direction. In this application, the axial force applied to the pipe is converted into torque by the second swing arm, resulting in higher control accuracy. The second thrust rod has a built-in displacement sensor to detect the stroke of the second thrust rod, and the aforementioned measured stroke data is then sent back to the control subsystem for analysis and comparison with the first data. If the comparison result exceeds the threshold, corresponding adjustments are made to more accurately control the load loading frame system. Preferably, the second thrust rod 24 can be a hydraulic cylinder. The second thrust rod 24 can be fixedly mounted on the second reaction frame 25, or it can be rotatably mounted on the second reaction frame 25 to adapt to changes in angle. The second thrust rod 24 and the second swing arm 22 rotate relative to each other in the horizontal direction. (See also...) Figure 2 , 5 As shown in Figures 6, 12 to 14, the other end of the second thrust rod 24 is rotatably connected to the second swing arm 22 via a pin-type sensor. In this application, the torque between the second thrust rod and the second swing arm is measured by the aforementioned pin-type sensor, and the measured torque data is then fed back to the control subsystem as the first data for analysis and comparison. If the comparison result exceeds the threshold, corresponding adjustments are made to more accurately control the load loading frame system.

[0059] See Figure 2 , 5 As shown in Figures 12 to 14, the second swing arm 22 is also provided with a second clearance frame 222 protruding outward along the tail end of the pipe. The longitudinal section of the second clearance frame 222 is shaped like a "]". The other end of the second thrust rod 24 is rotatably connected to the second clearance frame 222 through a pin-type sensor. The transverse section of the second swing arm 22 is generally shaped like a "┌". The torque between the other end of the second thrust rod and the second clearance frame is measured by the aforementioned pin-type sensor. The measured torque data is then fed back to the control subsystem for analysis and comparison with the first data. If the comparison result exceeds the threshold, corresponding adjustments are made to more accurately control the load loading frame system.

[0060] See Figure 2 , 5As shown in Figures 12 to 14, the axial load loading moving support mechanism 2 also includes a movable seat 26, and the second reaction frame 25 is mounted on the movable seat 26 via a second slewing bearing 27. In this application, the second slewing bearing 27 is used to achieve relative rotation between the second reaction frame 25 and the movable seat 26. Even if the second thrust rod 24 is fixedly mounted on the second reaction frame 25, it can better adapt to the angle changes between the second thrust rod 24 and the second swing arm 22, avoiding rigid damage. Preferably, the movable seat 26 moves in the axial direction. The movable seat 26 can move together with the second swing arm mounting seat 21, or it can move independently with the second thrust rod 24 and the second swing arm mounting seat 21 to use pipes of different lengths. The position of the movable seat 26 can be adjusted by moving it in the axial direction using the position adjustment mechanism 6.

[0061] See Figure 2 , 7 As shown in Figures 8, 12 to 14, the radial load loading moving support mechanism 3 includes a third thrust rod 31 and a third reaction frame 32. One end of the third thrust rod 31 is mounted on the movable third reaction frame 32, and the other end of the third thrust rod 31 is mounted on a rotatable clamp seat. The clamp seat U has a clamp mounting position W, and the clamp V is rotatably mounted on the clamp mounting position W. The clamp V is used to connect the pipe. The third thrust rod 31 performs a telescopic movement to apply a radial load to the pipe. In this application, the third thrust rod has a built-in displacement sensor to detect the stroke of the third thrust rod. The aforementioned measured stroke data is then sent back to the control subsystem for analysis and comparison with the first data. If the comparison result exceeds a threshold, corresponding adjustments are made to more accurately control the load loading frame system. Preferably, the third thrust rod 31 can be a hydraulic cylinder. The third thrust rod 31 can be fixedly mounted on the third reaction frame 32, or it can be rotatably mounted on the third reaction frame 32 to adapt to angle changes.

[0062] See Figure 2 , 7 As shown in Figures 8, 12 to 14, the longitudinal section of the clamp seat U is C-shaped, and the clamp V is rotatably mounted on the clamp mounting position W via a pin-type sensor. In this application, the clamp V is rotatably mounted on the clamp mounting position W via a pin-type sensor, thereby measuring the torque between the clamp V and the clamp seat U. The measured torque is then used as the first data and transmitted back to the control subsystem for analysis and comparison, which can subsequently serve as a reference for the pipe bending deformation.

[0063] See Figure 2 , 7As shown in Figures 8, 12 to 14, the other end of the third thrust rod 31 is connected to the clamp seat U via a ball joint. In this application, the other end of the third thrust rod is connected to the clamp seat via a ball joint, which facilitates flexible movement, prevents rigid damage to components, and extends service life. The radial load loading moving support mechanism 3 may also include a mounting seat 33 that is movable in the axial direction, and the third reaction frame 32 is mounted on the mounting seat 33 via a third slewing bearing 34. In this application, the third slewing bearing 34 is used to achieve relative rotation between the third reaction frame 32 and the mounting seat 33. Even if the third thrust rod 31 is fixed on the third reaction frame 32, the angle of the third thrust rod 31 can change with the bending deformation of the pipe, avoiding rigid damage. The mounting seat 33 can be moved in the axial direction via the position adjustment mechanism 6. This structural design is beneficial for adjusting the position of the clamped pipe middle section to accommodate pipes of different lengths. Preferably, the mounting bases of the two radial load-loading moving support mechanisms 3 can move simultaneously, which can better ensure that the center position of the specimen remains basically unchanged when the axial load is applied, and overcome the large deviation that occurs when the specimen is bent and deformed. Alternatively, they can move separately.

[0064] See Figure 2 , 7 As shown in Figures 8, 12 to 14, a caster wheel N is mounted on the bottom end of the clamp seat U. Preferably, the radial load loading moving support mechanism 3 further includes a third base plate 35, which is fixed on the mounting base 33, thereby providing a moving surface for the caster wheel and providing better support.

[0065] See Figure 2 , 9 As shown in Figures 12 and 13, the device also includes a bending die holder 5 that moves horizontally. The bending die holder 5 is located between two clamp seats U connected to the other end of the third thrust rod 31. The bending die holder 5 has a through channel L for insertion into the middle of the pipe. Preferably, the bending die holder 5 slides on a sliding rail laid in the radial direction to follow the bending in the middle of the pipe in the radial direction. More preferably, the sliding rail used by the bending die holder has an "I" shaped cross-section, and a sliding clip is provided at the bottom of the bending die holder. The sliding clip is engaged with the "I" shaped sliding rail for sliding.

[0066] The bending die holder 5 includes an inner bending die holder 51 and an outer bending die holder 52. A channel L is reserved between the inner bending die holder 51 and the outer bending die holder 52, and they are connected by an adjusting screw. The inner bending die holder 51 and the outer bending die holder 52 are also provided with a mold with an arc-shaped surface on the side facing the pipe. In this application, the bending die holder can limit the bending deformation of the middle part of the pipe in the mold with an arc-shaped surface. The bending deformation of the middle part of the pipe fits the mold better, thereby ensuring uniform deformation of the sample. In actual operation, molds of different specifications can be replaced and the width of the channel can be adjusted by adjusting the screw.

[0067] See Figure 14As shown, it also includes a bending die holder 5 that moves horizontally. The bending die holder 5 has a through channel L for insertion into the middle of the pipe. The radial load loading moving support mechanism 3 includes a third thrust rod 31. One end of the third thrust rod 31 is mounted on a movable third reaction frame 32. The bending die holder 5 is movably mounted on the other end of the two third thrust rods 31. The bending die holder 5 includes an inner bending die holder 51 and an outer bending die holder 52. A channel L is reserved between the inner bending die holder 51 and the outer bending die holder 52 and they are connected by an adjusting screw. The inner bending die holder 51 and the outer bending die holder 52 are also provided with a mold with an arc-shaped surface on the side facing the pipe. In another embodiment of this application, the bending die holder that moves horizontally can undergo axial displacement or radial displacement, so that after the radial load moving support mechanism adjusts its position in the axial direction, it will follow the radial direction when bending deformation occurs in the middle of the pipe.

[0068] See Figures 2 to 14 As shown, clamp V is mounted on clamp mounting position W via a pin-type sensor. Clamp V is generally "giant" in shape and includes a clamping mold base V0, which includes an inner mold base V1 and an outer mold base V2. The inner mold base V1 and the outer mold base V2 are detachably connected by fasteners. Preferably, the fasteners are mating bolts and nuts. In this application, finite element analysis software was also used to perform mechanical analysis and optimization design of the clamp shape during the clamping process, thereby minimizing stress concentration at the clamped part of the pipe.

[0069] See Figure 10 As shown, the clamp V also includes a mold ring V00 sleeved on the outer wall of the pipe. The mold ring V00 includes an inner mold ring V01 and an outer mold ring V02, which are detachably mounted on the inner mold base V1 and the outer mold base V2 respectively via pressure plates T. In this application, mounting the mold ring on the mold base allows for better fit with the pipe and further prevents stress concentration at the clamping point. The inner mold ring V01 and the outer mold ring V02 each include multiple mold ring blocks, which are detachably mounted on the inner mold base V1 and the outer mold base V2 respectively via multiple pressure plates T. In this application, the inner and outer mold rings are assembled in a modular manner, which facilitates the replacement of mold ring blocks according to different pipe specifications without completely disassembling the mold ring blocks, making it convenient and quick.

[0070] See Figure 2 , 12As shown in Figure 14, the position adjustment mechanism 6 includes a worm screw jack, which is driven by a geared motor; or, the position adjustment mechanism 6 includes a hydraulic cylinder, which is driven by a compressor; or, the position adjustment mechanism 6 includes a meshing chain and gears, with the gears driven by a motor. Further, the position adjustment mechanism 6 also includes an absolute encoder, which transmits first data back to the control subsystem via a first data acquisition subsystem. In this application, the absolute encoder's main working principle is to read the encoded information on the code disk using a photoelectric detection device and convert it into an electrical signal. Therefore, when the position adjustment mechanism pulls the corresponding component for position adjustment, it can bring back a precise position feedback signal of the corresponding component, which is then transmitted back to the control subsystem as signal data for the load loading frame system's action execution mechanism.

[0071] See Figure 2 , 12 As shown in Figure 14, the system also includes a base 7, which has an inner groove 70. The position adjustment mechanism 6 is placed in the inner groove 70, and a slide rail S is formed on the edge of the groove wall of the inner groove 70. The slide rail S also includes a limiting slide bar S0 that is arranged opposite to each other. The cross-section of the limiting slide bar S0 is "┌┐".

[0072] See Figure 2 , 11 As shown in Figures 12 to 14, the load loading frame system also includes a loading trolley 8 that moves horizontally. The loading trolley 8 includes a concave roller 82 mounted on a lifting platform 81. The rotation axis of the concave roller 82 is perpendicular to the line connecting the axial load loading fixed support mechanism 1 and the axial load loading movable support mechanism 2. The loading trolley 8 is also equipped with a photoelectric proximity switch. Preferably, the loading trolley 8 slides along a sliding rail under the traction of the position adjustment mechanism 6. The sliding rail is configured to intersect the line connecting the axial load loading fixed support mechanism 1 and the axial load loading movable support mechanism 2. Preferably, the concave roller 82 is driven by a geared motor. In this application, the loading trolley uses a photoelectric proximity switch to detect whether the light beam is blocked or reflected, for example, by a clamp, thereby determining whether the pipeline has reached the four-point bending test device. After unloading, the loading trolley resets.

[0073] This application also relates to a method for a full-size four-point bending test of a pipe, using the aforementioned full-size four-point bending test apparatus, including the following steps:

[0074] S1: Pipeline loading:

[0075] The loading trolley uses a photoelectric proximity switch to detect and align the first and last ends of the pipe loaded on the loading trolley with the clamps on the axial load fixed support mechanism and the axial load moving support mechanism in a full-size four-point bending test device for pipes, respectively. The loading trolley is reset after unloading the pipe.

[0076] In this application, resetting the loading trolley means moving the loading trolley away from a full-size four-point bending test device for pipes and lowering its height to no higher than the height of the radial load loading moving support mechanism, so as to avoid hindering the normal operation of the radial load loading moving support mechanism.

[0077] S2: Adjust the position of the axial load loading moving support mechanism and the two radial load loading moving support mechanisms to clamp the pipe with clamps and prepare for subsequent load loading;

[0078] In this application, the first and last ends of the pipe are clamped by clamps mounted on the axial load loading fixed support mechanism and the axial load loading movable support mechanism, respectively. In this application, the position adjustment mechanism is controlled by the control subsystem to adjust the axial load loading movable support mechanism and the two radial load loading movable support mechanisms along the axial direction, thereby adapting to pipes of different lengths. The displacement of the two radial load loading movable support mechanisms can be controlled to achieve equal displacement, ensuring that the center position of the pipe sample remains essentially unchanged, thus overcoming the large eccentric load that occurs when the pipe bends. When the pipe bends, the clamp seats also move accordingly with the bending deformation.

[0079] S3: The user sends a load loading command to the load loading frame system through the measurement and control system:

[0080] The user sends a load loading command to the load loading framework system through the control subsystem. The first data acquisition subsystem sends back the first data related to the pipeline load loading command to the control subsystem, and the second data acquisition subsystem sends back the second data related to the pipeline load loading result to the control subsystem. The control subsystem analyzes and compares the first and second data to control the load loading framework system. The second data acquisition subsystem records the acquired second data and outputs it externally. In this application, data acquisition backup is implemented, resulting in a higher security level.

[0081] In this application, the working mechanism of the measurement and control system includes, but is not limited to, the following:

[0082] (1) Analysis and comparison of the first data related to the pipeline load loading command in the control subsystem:

[0083] The "first data related to the load loading execution command" includes command data sent by the control subsystem to the load loading frame system and data on the execution of the load loading command returned from various sensors on the load loading frame system. For example, signal data corresponding to user-defined pressure values, displacement, vibration frequencies, etc., including signal data such as current output and pulse frequency converted from these data; or, for example, signal data of the actuator controlled by the digital I / O module through digital output signals, such as solenoid valve on / off, motor start / stop, etc., also including signal data such as current output and pulse frequency converted from these data; furthermore, various switching sensor signal data collected by the digital I / O module from the load loading frame system through optocoupler isolation devices, such as signal data output by the safety light curtain of the sensor on the load loading frame system, also including current output and pulse frequency signal data converted from these signal data.

[0084] Therefore, the control subsystem analyzes and compares the first data related to the pipeline load loading command. This can be achieved by analyzing and comparing the executed load loading command data returned by the load loading frame system with the command data sent by the user to the load loading frame system. Further control of the load loading frame system can then be achieved, for example, by analyzing and comparing the load magnitude command data sent by the user to the load loading frame system with the executed load loading command data returned by the load loading frame system's sensors. To facilitate human-machine interaction, the command data sent to the load loading frame system and the executed load loading command data returned by the load loading frame system are processed by the industrial control computer and displayed on a monitor, for example, through window 1 of specific software, such as the user-defined drive frequency data.

[0085] (2) The control subsystem analyzes and compares the first data related to the pipeline load loading command and the second data related to the pipeline load loading result:

[0086] The "second data related to the pipeline load loading result" includes pipeline-related data measured after the load is applied to the pipeline, such as the actual strain, deformation displacement, temperature, pressure and other data signals of the pipeline, such as the output signal data returned by strain gauges and other various sensors attached to the pipeline, including signal data such as current output and pulse frequency converted from these data.

[0087] Therefore, the control subsystem analyzes and compares the first data related to the pipeline load loading command and the second data related to the pipeline load loading result. This can be achieved by analyzing and comparing the data of the executed load loading command returned by the load loading framework system with the data collected from the pipeline, such as the actual strain, deformation displacement, temperature, and pressure at the pipeline location, to determine whether the pipeline has been tested on the device. For example, this can be used to determine whether the device is under load or unloaded. After processing by the industrial control computer, the data is displayed on the monitor, for example, through window 1 of specific software. (See [link to relevant documentation]). Figure 16 , 17 As shown.

[0088] (3) The second data acquisition subsystem records and outputs second data related to the pipeline load loading results:

[0089] The second data acquisition subsystem records and outputs second data related to the pipeline load loading result. For example, after being analyzed by the industrial control computer of the data processing subsystem, the data is output and displayed on the monitor, such as through window 2 of a specific software.

[0090] S4: Users receive reports through the measurement and control system.

[0091] In this application, see Figure 15 As shown, the illustrated measurement and control system includes a display (or interactive interface) connected to an industrial control computer. The first measurement subsystem includes a microcontroller chip (N1-9149) and acquisition boards (N1-9208, N1-9266, N1-9403), and the second measurement subsystem includes a microcontroller chip (N1-9188) and acquisition boards (N1-9212, N1-9235, N1-9208). Preferably, the second data acquisition subsystem records and outputs second data related to the pipeline load loading results, which is then analyzed and processed by the industrial control computer. The results are presented in a visual report, for example, through window 2 of the display. The industrial control computer has corresponding application calculation programs, such as calculating the displacement of each hydraulic cylinder based on the known pipeline deformation, and can further generate complete load vs. time, strain vs. time, stress vs. time, and temperature vs. time curves, etc. The test data is very comprehensive. After the test is completed, the user decides whether to generate an overall test report. In this application, the interactive interface is user-friendly and aesthetically pleasing, and the operation is simple and reliable. Users can edit, configure, and flexibly select different control steps and test parameters in the composite loading interface, and freely adjust the execution order of each control step. They can also control a parameter individually in the independent interface of each parameter. The operation is convenient and flexible. The measurement and control system can also play back and scientifically analyze the test data, providing important basis for product improvement and new product development.

[0092] Furthermore, considering issues such as system compatibility, data security, and ease of operation, the measurement and control system adopts a "distributed architecture." Both the control subsystem and the data acquisition subsystem have a main control unit, such as an industrial computer, and measurement and control functional units, such as microcontroller chips. The main control unit is deployed in the central control room as the control hub of the measurement and control section, used to complete tasks such as human-machine interaction, sending control commands, and parsing test data. The measurement and control functional units are deployed nearby at the test site. This design can achieve a certain degree of separation between acquisition and control, and is more adaptable to actual use scenarios.

[0093] This also includes the following steps:

[0094] S5: Test Result Detection and Verification:

[0095] The system utilizes an endoscope and a three-coordinate articulated arm to inspect and verify pipelines after load loading using a full-size four-point bending test device.

[0096] This also includes the following steps:

[0097] The system provides full protection:

[0098] The safety protection system analyzes and compares the first data related to the load loading execution command collected by the first data acquisition subsystem and the second data related to the pipeline load loading result collected by the second data acquisition subsystem with the data safety threshold set by the safety protection system itself in order to control the load loading framework system.

[0099] In this application, an independently operating safety protection system is set up in addition to the data acquisition subsystem and the control subsystem. This system determines the alarm threshold at the hardware level, can automatically terminate the test process, and initiate a safe state recovery, providing an additional layer of safety for the composite loading test system. The safety protection system is equipped with an automatic protection function, which refers to the protection function in the event of structural damage to the specimen or actuator during the loading process. The safety protection system can achieve dual safety protection to avoid danger or damage to personnel, equipment, and specimens in emergency situations.

[0100] Although specific embodiments of the present invention have been described above, those skilled in the art can make modifications to them without departing from the spirit and principles of the present invention. The scope of protection of the present invention is defined by its claims and their equivalents.

Claims

1. A four-point bending test device for a full-size pipe, characterized in that: It includes a measurement and control system and a load loading frame system, wherein the measurement and control system is connected to the load loading frame system, and the measurement and control system includes a control subsystem and a data acquisition subsystem; The control subsystem sends a load loading execution command to the load loading framework system. The data acquisition subsystem includes a first data acquisition subsystem and a second data acquisition subsystem. The first data acquisition subsystem acquires first data related to the load loading execution command, and the second data acquisition subsystem acquires second data related to the pipeline load loading result. The first data acquisition subsystem transmits the first data back to the control subsystem, the second data acquisition subsystem transmits the second data back to the control subsystem, and the control subsystem controls the load loading frame system based on the first data and the second data.

2. The pipe full-size four-point bending test device according to claim 1, characterized in that: It also includes a security protection system, which has a set data security threshold. The security protection system analyzes and compares the first data, the second data and the data security threshold to control the load loading framework system.

3. A pipe full-size four-point bending test device according to claim 1 or 2, characterized in that: The load loading frame system includes an axial load loading fixed support mechanism (1), an axial load loading movable support mechanism (2), and two radial load loading movable support mechanisms (3). The axial load loading fixed support mechanism (1), the axial load loading movable support mechanism (2), and the radial load loading movable support mechanism (3) all operate in the horizontal direction.

4. The pipe full-size four-point bending test device according to claim 3, characterized in that: The axial load loading fixed support mechanism (1) includes a first swing arm mounting seat (11) and a first swing arm (12) fixedly installed. One end of the first swing arm (12) is pivotally connected to the first swing arm mounting seat (11), and the other end of the first swing arm (12) is provided with a clamp mounting position. The clamp is rotatably installed on the clamp mounting position and clamps the beginning end of the pipe.

5. The pipe full-size four-point bending test device according to claim 3, characterized in that: The axial load loading moving support mechanism (2) includes a second swing arm mounting seat (21) and a second swing arm (22) that are movable in the axial direction. One end of the second swing arm (22) is pivotally connected to the second swing arm mounting seat (21), and the other end of the second swing arm (22) is provided with a clamp mounting position. The clamp is rotatably mounted on the clamp mounting position and clamps the tail end of the pipe.

6. The pipe full-size four-point bending test device according to claim 3, characterized in that: The radial load loading moving support mechanism (3) includes a third thrust rod (31) and a third reaction frame (32). One end of the third thrust rod (31) is mounted on the movable third reaction frame (32), and the other end of the third thrust rod (31) is mounted on a rotatable clamp seat. The clamp seat has a clamp mounting position, and the clamp is rotatably mounted on the clamp mounting position. The clamp is used to connect the pipe, and the third thrust rod (31) performs a telescopic action to apply a radial load to the pipe.

7. The pipe full-size four-point bending test device according to claim 6, characterized in that: Located at one end of the connecting clamp of the third thrust rod (31), a bending die seat (5) that moves in the horizontal direction is also provided. The bending die seat (5) forms a through channel to be inserted into the middle of the pipe. The bending die seat (5) includes an inner bending die seat (51) and an outer bending die seat (52). The channel is reserved between the inner bending die seat (51) and the outer bending die seat (52) and they are connected by an adjusting screw. The inner bending die seat (51) and the outer bending die seat (52) are also provided with a mold with an arc surface on the side facing the pipe.

8. The pipe full-size four-point bending test device according to claim 3, characterized in that: The load loading frame system also includes a loading trolley (8) that moves in the horizontal direction. The loading trolley (8) includes a lifting platform (81) and a concave roller (82) disposed on the lifting platform (81). The rotation axis of the concave roller (82) is perpendicular to the line connecting the axial load loading fixed support mechanism (1) and the axial load loading moving support mechanism (2).

9. A method for a full-size four-point bending test of a pipe, using the full-size four-point bending test apparatus according to any one of claims 1 to 8, characterized in that, Includes the following steps: Pipeline feeding; Adjust the positions of the axial load loading moving support mechanism (2) and the two radial load loading moving support mechanisms (3) of the load loading frame system to clamp the pipe with clamps and prepare for subsequent load loading; The measurement and control system sends load loading commands to the load loading framework system. The first data acquisition subsystem sends the first data related to the pipeline load loading command back to the control subsystem. The second data acquisition subsystem sends the second data related to the pipeline load loading result back to the control subsystem. The control subsystem analyzes and compares the first and second data to control the load loading framework system. Reports are obtained through the measurement and control system; The pipeline is inspected and verified after being loaded by the full-size four-point bending test device using the equipped endoscope system and three-coordinate articulated arm system.

10. A method for a full-size four-point bending test of a pipe according to claim 9, characterized in that, It also includes the following steps: The full protection system provides protection: The security protection system analyzes and compares the first data, the second data, and the data security threshold set by the security protection system itself to control the load loading frame system.

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