A compression test method for foam glass used in direct buried pipes

Abstract

The present invention relates to the field of performance testing technology, and specifically discloses a compression test method for foam glass for direct-buried pipes, comprising preparing a foam glass shell sample with the same size as the actual use size of the direct-buried pipe, placing a core shaft simulating a steel pipe inside the foam glass shell sample, and uniformly applying a layer of strain sensing coating on the surface of the sample to obtain a compression test sample for the foam glass for direct-buried pipes; by using a foam glass shell sample with the same size as the actual use size of the direct-buried pipe and placing a simulated core shaft, the stress state during the test is made highly consistent with that of the actual direct-buried pipe, and the strain of the sample is monitored in real time in combination with the strain sensing coating, so that the mechanical property changes of the material in actual application can be accurately obtained, providing a reliable basis for the design of the direct-buried pipe. In actual engineering, these data can be used to accurately evaluate whether the foam glass can meet the compression requirements of different direct-buried pipes, thereby improving engineering safety.

Description

Technical Field

[0001] The present invention relates to the technical field of performance testing, in particular to a compression testing method for foam glass used in direct-buried pipes. Background Art

[0002] In the current field of direct buried pipe engineering, foam glass is an important thermal insulation material, and its compressive performance is directly related to the service life and safety of the direct buried pipe.

[0003] Traditional methods for compressive testing of foam glass have numerous drawbacks. First, during specimen preparation, small-sized standard specimens were often used, significantly different in size and shape from the foam glass shells used in direct-buried pipes. Small specimens cannot accurately simulate the actual stress conditions of foam glass in direct-buried pipes, resulting in significant discrepancies between test results and actual applications. In actual direct-buried pipes, foam glass is subject to pressure from the surrounding soil, the effects of the internal medium, and the pipe's own deformation. These complex factors are completely ignored when testing small specimens. Furthermore, traditional testing procedures are typically conducted under a single, ambient temperature and pressure environment, failing to consider the complex environmental factors encountered by direct-buried pipes. In real-world applications, direct-buried pipes are subject to varying temperatures, humidity, and soil pressures. In cold regions, the soil surrounding direct-buried pipes is extremely cold and humid, which traditional testing cannot simulate, making it difficult to obtain data on the compressive performance of foam glass under actual operating conditions. Furthermore, traditional testing rarely considers specimen anisotropy, often testing only a single location on the specimen, ignoring the performance variations of foam glass at different locations. This results in incomplete and unrepresentative results. Summary of the Invention

[0004] In view of the above situation, in order to overcome the defects of the prior art, the present invention provides a compression testing method for foam glass used in direct-buried pipes, in order to solve the above-mentioned technical defects.

[0005] To achieve the above objectives, the present invention is implemented through the following technical solutions: A compression test method for foam glass used in direct buried pipes, comprising the following steps:

[0006] Step 1: Prepare a foam glass shell specimen with the same size as the direct buried pipe, place a mandrel simulating a steel pipe inside the foam glass shell specimen, and evenly apply a layer of strain sensing coating on the surface of the specimen to obtain a foam glass compression test specimen for direct buried pipe;

[0007] Step 2: Use the automatic loading and unloading unit on the compression test device to deliver the compression test sample of the foam glass for direct buried pipe into the interior of the compression test device, and use the environmental adjustment unit to adjust the environment inside the compression test device to the set initial conditions;

[0008] Step 3: Using a compression test unit, gradually increase vertical and horizontal pressure at a rate of 0.1 MPa vertically and 0.05 MPa horizontally, and collect data from the pressure sensor, temperature sensor, humidity sensor, and strain sensing coating in real time to obtain a set of compression test data;

[0009] Step 4: Adjust the test environment of the foam glass for direct-buried pipe compression test specimens through the environment adjustment unit, repeat the operation of step 3 above, and obtain multiple sets of compression test data of the foam glass for direct-buried pipe compression test specimens under different test environments;

[0010] Step 5: Use the steering adjustment unit inside the compression test device to adjust the steering of the compression test sample for the directly buried pipe foam glass, and perform compression tests again on different positions of the compression test sample for the directly buried pipe foam glass, to obtain multiple groups of compression test data for the compression test samples for the directly buried pipe foam glass at different test positions;

[0011] Step six: Use the test support assembly to perform compression test support on different positions inside the compression test specimen of the foam glass for direct-buried pipe inside the compression test device, and cooperate with the compression test unit to perform compression test on the support position to obtain multiple groups of test data of the compression test specimen of the foam glass for direct-buried pipe at different actual application simulation positions.

[0012] Furthermore, the pressure test device includes a pressure test frame, which includes a pressure test box, a pressure test bottom plate and a pressure test top plate. The bottom of the pressure test box is fixedly provided with a pressure test bottom plate, and the top of the pressure test box is also fixedly provided with a pressure test top plate. A temperature control box and a humidity control box are respectively fixedly provided on both sides of the top of the pressure test top plate. A feeding port is also provided in the middle of the front of the pressure test box.

[0013] Furthermore, an automatic loading and unloading unit is provided on the front of the pressure test box, wherein the automatic loading and unloading unit includes a fixed frame and a feeding frame. A fixed frame is fixedly provided on the front of the pressure test box and directly in front of the feeding port, and a feeding frame is movably provided inside the fixed frame. Conveying gears are provided on both sides of the feeding frame, driving blocks are fixedly provided on both sides of the fixed frame, and conveying gears are provided inside the two driving blocks through the rotation of the built-in motor. The tooth surfaces of the two conveying gears are respectively engaged with one side of the two conveying gears for transmission, and a servo electric cylinder 1 is fixedly provided on both sides of the feeding frame, and a lifting block is fixedly provided at the bottom end of the driving shaft of the two servo electric cylinders 1. Two workpiece clamps are provided on the bottom of the two lifting blocks through linear slide rails, and silicone pads are provided on the opposite sides of the two workpiece clamps.

[0014] Furthermore, the automatic loading and unloading unit works as follows:

[0015] The compression test specimen for direct-buried pipe foam glass is sent to the bottom of the fixed frame through the conveying frame. At this time, the driving ends of the two servo electric cylinders are used to control the two lifting blocks to move downward, and the linear slide rail at the bottom of the lifting block drives the two workpiece clamps to clamp and position the two sides of the compression test specimen for direct-buried pipe foam glass, and then the driving end of the servo electric cylinder is controlled to reset, and the compression test specimen for direct-buried pipe foam glass is brought into the interior of the feeding frame. At this time, the motors inside the driving blocks on both sides are used to drive the two conveying gears to rotate. As the two conveying gears and the conveying teeth on both sides of the feeding frame rotate and cooperate with each other, the feeding frame is transferred from the inside of the fixed frame to the inside of the pressure test box. Finally, the driving ends of the two servo electric cylinders are controlled to send the clamped compression test specimen for direct-buried pipe foam glass to the bottom of the inside of the pressure test box, completing the automatic feeding operation for the compression test specimen for direct-buried pipe foam glass. Conversely, the various components in the automatic loading and unloading unit are used to complete the automatic unloading operation of the compression test specimen for direct-buried pipe foam glass from the inside of the pressure test box to the external conveying frame.

[0016] Furthermore, a pressure test unit is also provided inside the pressure test box, wherein the pressure test unit includes an upper test pressure block, a workpiece placement rack and a side test pressure block, a sealing movable rack is movably provided at the bottom of the pressure test top plate, and a servo electric cylinder three is slidingly provided at the bottom of the sealing movable rack through a linear slide rail, an upper test pressure block is fixedly provided at the bottom end of the driving shaft of the servo electric cylinder three, servo electric cylinder two is fixedly provided at the four sides of the top of the pressure test top plate, and the bottom ends of the driving shafts of the four servo electric cylinders two are fixedly connected to the four sides of the top of the sealing movable rack, the four sides of the sealing movable rack are in sliding and sealing contact with the four sides of the inner wall of the pressure test box, and sealing rings are provided at the four sides of the sealing movable rack.

[0017] Furthermore, positioning blocks are movably provided on both sides of the interior of the pressure test box, and limiting sliders are fixedly provided on the front and rear sides of the two positioning blocks. Test frames are movably provided on the front and rear sides of the positioning blocks, and the opposite sides of the two test frames are slidingly connected to one side of the two limiting sliders respectively. Servo electric cylinders five are slidingly provided inside the two test frames through linear slide rails, and side test pressure blocks are fixedly provided on one end of the driving shaft of the two servo electric cylinders five.

[0018] Furthermore, a workpiece placement rack is movably arranged below the two positioning blocks, and a micro electric cylinder 1 is fixedly arranged below the two positioning blocks. Movable sliders are fixedly arranged at the bottom ends of the drive shafts of the two micro electric cylinders 1, and the bottoms of the two movable sliders are respectively slidably connected to the front and rear sides of the top of the workpiece placement rack.

[0019] Furthermore, the compression test unit works as follows:

[0020] The compression test specimen of foam glass for direct-buried pipe is sent to the top of the workpiece placement rack through the automatic loading and unloading unit, and then the driving shaft of servo electric cylinder two is used to control the sealing movable rack to move downward, and the sealing movable rack is used to seal the lower part of the pressure test box body, and the driving shaft of servo electric cylinder three is used to control the upper test block to perform compression test on the surface of the compression test specimen of foam glass for direct-buried pipe. At the same time, the driving shaft of servo electric cylinder five inside the two test racks controls the side test block to perform compression test on the front and back sides of the surface of the compression test specimen of foam glass for direct-buried pipe.

[0021] Furthermore, servo electric cylinders four are fixedly provided on both sides of the pressure test box body, and the driving ends of the two servo electric cylinders four are respectively fixedly connected to one side of the two positioning blocks, and a steering adjustment unit is provided inside the positioning block, wherein the steering adjustment unit includes a steering block and a bogie, and four positioning slides are also fixedly provided on both sides of the pressure test box body, and one end of the positioning slides on both sides is respectively fixedly connected to one side of the two positioning blocks, a servo electric cylinder six is fixedly provided inside the positioning block, and the driving end of the servo electric cylinder six is fixedly provided with a steering block, a bogie is rotatably provided on the surface of the steering block, and a steering matching groove is provided inside the bogie that matches the steering block, and a steering tooth groove is also provided inside the steering matching groove, a steering gear is provided inside the steering block through a built-in motor, and the tooth surface of the steering gear is meshed with the teeth of the steering tooth groove for transmission, and micro electric cylinders two are fixedly provided on all sides of the inside of the bogie, and the driving ends of the four micro electric cylinders two are fixedly provided with a support frame.

[0022] Furthermore, the steering adjustment unit works as follows:

[0023] The driving end of servo electric cylinder six is used to control the steering block to move toward the interior of the compression test specimen for foam glass used in direct-buried pipes, and the driving ends of four micro electric cylinders two inside the bogie are used to control the contact between the support frame and the inner wall of the compression test specimen for foam glass used in direct-buried pipes, and then the steering gear is controlled to rotate by the motor built into the steering block. The four support frames are used to drive the compression test specimen for foam glass used in direct-buried pipes to perform steering adjustment through the tooth surface of the steering gear and the tooth meshing transmission of the steering tooth groove, so that the compression test specimen for foam glass used in direct-buried pipes can cooperate with the compression test unit to perform compression tests in different directions; in addition, the driving end of micro electric cylinder two is used to control the contact between the support frame and the inner wall of the compression test specimen for foam glass used in direct-buried pipes, and the corresponding compression test is performed on the inner wall support position of the compression test specimen for direct-buried pipes in cooperation with the compression test unit.

[0024] Beneficial effects of the present invention:

[0025] 1. By using foam glass shell specimens with the same actual dimensions as direct-buried pipes and placing simulated mandrels, the stress state during the test is highly consistent with that of the actual direct-buried pipes. Combined with the strain-sensing coating to monitor the specimen strain in real time, the changes in the mechanical properties of the material in actual applications can be accurately obtained, providing a reliable basis for direct-buried pipe design. In actual projects, these data can be used to accurately assess whether foam glass can meet the pressure resistance requirements of different direct-buried pipes, thereby improving project safety.

[0026] 2. By simulating a variety of actual environmental conditions, such as different temperature, humidity, and pressure environments through the environmental adjustment unit, the comprehensive influence of these factors on the compressive properties of foam glass can be studied, and the performance of the material under different working conditions can be fully understood. The steering adjustment unit is used to test different positions of the sample to avoid test errors caused by the anisotropy of the sample, making the test results more representative. The test support component is used to simulate the internal expansion pressure of the direct-buried pipe and test different positions. Starting from the actual application scenario, multiple groups of data at different simulated positions are obtained to more realistically and comprehensively evaluate the compressive properties of foam glass for direct-buried pipes under various working conditions, providing sufficient data support for material selection and optimization.

[0027] 3. Through the automatic loading and unloading unit in the compression test device, with the help of components such as the fixing frame, feeding frame, conveying gear, servo electric cylinder and workpiece clamp, the automatic feeding and unloading operations of the compression test specimens of foam glass for direct buried pipes are realized, which improves the test efficiency and reduces the errors that may be caused by manual operation. The automatic loading and unloading unit can complete the loading and unloading of multiple specimens in a short time, which is more stable and accurate than manual operation.

[0028] 4. The compression test unit can simultaneously perform vertical and horizontal pressure tests on the sample through the coordinated work of the upper test block, side test block and workpiece placement frame, simulating the actual stress conditions of the direct-buried pipe underground and obtaining more accurate compression performance data. The steering adjustment unit can accurately control the steering of the sample so that the test covers all directions of the sample, further improving the accuracy and comprehensiveness of the test. During the test, the steering adjustment unit can accurately rotate the sample to the specified angle to ensure that each position can be accurately tested. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The present invention will be further described below with reference to the accompanying drawings.

[0030] Figure 1 This is a flow chart of a method for compressive testing of foam glass for direct buried pipes according to an embodiment of the present invention;

[0031] Figure 2 A schematic diagram of the structure of a compression test device according to an embodiment of the present invention;

[0032] Figure 3This is a schematic diagram of the automatic loading and unloading unit structure according to an embodiment of the present invention;

[0033] Figure 4 Schematic diagram of the internal structure of a compression test box according to an embodiment of the present invention;

[0034] Figure 5 A schematic diagram of a compression test unit structure according to an embodiment of the present invention;

[0035] Figure 6 A schematic diagram of a workpiece placement rack and a positioning block structure according to an embodiment of the present invention;

[0036] Figure 7 Schematic diagram of the steering adjustment unit structure according to an embodiment of the present invention.

[0037] In the figure, 1. Compression test frame; 2. Compression test box; 3. Compression test bottom plate; 4. Compression test top plate; 5. Fixed frame; 6. Feeding frame; 7. Conveying tooth groove; 8. Conveying gear; 9. Driving block; 10. Servo electric cylinder one; 11. Lifting block; 12. Workpiece clamp; 13. Sealing movable frame; 14. Servo electric cylinder two; 15. Servo electric cylinder three; 16. Upper test pressure block; 17. Servo electric cylinder four; 18. Positioning block; 19. Workpiece placement frame; 20. Micro electric cylinder one; 21. Movable slider; 22. Limit slider; 23. Adjustment slide; 24. Servo electric cylinder five; 25. Side test pressure block; 26. Servo electric cylinder six; 27. Steering block; 28. Steering gear; 29. Steering matching groove; 30. Steering tooth groove; 31. Steering frame; 32. Micro electric cylinder two; 33. Support frame; 34. Positioning slide; 35. Test frame. DETAILED DESCRIPTION

[0038] Below, the exemplary embodiments according to the present invention will be described in detail with reference to the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments of the present invention, and it should be understood that the present invention is not limited to the exemplary embodiments described herein. Example 1

[0039] See also Figures 1 to 7 As shown, a compression test method for foam glass used in direct buried pipes includes the following steps:

[0040] Step 1: Prepare a foam glass shell specimen with the same size as the actual direct-buried pipe. Place a mandrel simulating a steel pipe inside the foam glass shell specimen so that its stress state during the test is consistent with that of the actual direct-buried pipe. At the same time, evenly apply a layer of strain-sensing coating on the surface of the specimen. This coating can generate electrical signal changes under the action of pressure, which is used to monitor the strain of the specimen in real time, and obtain a foam glass compression test specimen for direct-buried pipe.

[0041] It should be noted that a foam glass shell specimen with the same size as the actual direct-buried pipe is made and a simulated steel pipe core shaft is placed, so that the stress state of the foam glass in the test is consistent with the actual direct-buried pipe. This can accurately simulate the actual working conditions and avoid test errors caused by differences in specimen size and structure. It ensures that the test results can be directly applied to the direct-buried pipe project, providing more reliable data support for material selection and design. The strain sensing coating is evenly applied on the surface of the specimen. The coating generates electrical signal changes under pressure and monitors the strain of the specimen in real time. This enables the strain data of the material to be obtained in time during the test, intuitively reflecting the deformation of the material under pressure, helping to deeply analyze the mechanical properties of the material and promptly discover potential problems, such as local stress concentration, so as to more comprehensively evaluate the compressive performance of the foam glass.

[0042] Step 2: The manufactured compression test specimen of foam glass for direct buried pipe is transported to one side of the compression test device by a conveyor rack, and the compression test specimen of foam glass for direct buried pipe is transported into the interior of the compression test device by the automatic loading and unloading unit on the compression test device. The environment inside the compression test device is adjusted to the set initial conditions by the environmental adjustment unit, specifically, the temperature is 20°C, the humidity is 60%RH, the vertical pressure is 0.5MPa, and the horizontal pressure is 0.2MPa.

[0043] Step 3: Use the compression test unit to gradually increase the vertical and horizontal pressure at a rate of 0.1 MPa vertically and 0.05 MPa horizontally. Keep the pressure stable for 3-5 minutes each time the pressure value is increased. At the same time, record the sample strain data, pressure value, and observe the changes in the sample appearance. When the sample shows obvious deformation, cracking, or the pressure-strain curve is abnormal, stop loading and collect data from the pressure sensor, temperature sensor, humidity sensor, and strain sensing coating in real time. The collection frequency is set to 10-20 times per second to obtain a set of compression test data.

[0044] Step 4. Adjust the test environment of the compression test specimens of foam glass for direct-buried pipes through the environmental adjustment unit, adjust the temperature and humidity parameters of the internal environment of the compression test device according to a certain adjustment rule, and repeat the operation of the above step 3 to obtain multiple groups of compression test data of the compression test specimens of foam glass for direct-buried pipes in different test environments; specifically, increase the temperature by 5°C and the humidity by 10%RH each time.

[0045] Step 5: Use the steering adjustment unit inside the compression test device to adjust the steering of the compression test sample for the foam glass for directly buried pipes, and perform compression tests again on different positions of the compression test sample for the foam glass for directly buried pipes. At this time, the test environment inside the compression test device is controlled to be the same, and multiple groups of compression test data of the compression test samples for the foam glass for directly buried pipes at different test positions are obtained;

[0046] Step six: Use the test support assembly to support the compression test at different positions inside the compression test specimen of the foam glass for direct-buried pipe inside the compression test device, cooperate with the compression test unit to perform compression test on the support position, simulate the expansion pressure inside the direct-buried pipe through the test support assembly, and obtain multiple groups of test data of the compression test specimen of the foam glass for direct-buried pipe at different actual application simulation positions.

[0047] Specifically, it should be noted that the design scheme in this application adopts a foam glass shell sample with the same actual size as the direct-buried pipe and places a simulated core shaft in the sample preparation to ensure that the test stress state is close to the actual state, and the strain sensing coating can monitor the strain in real time. During the test, the environmental adjustment unit simulates a variety of actual environmental conditions, and the influence of different temperature, humidity and pressure environments on the compressive performance of foam glass can be comprehensively studied; the steering adjustment unit tests the sample at different positions to avoid test errors caused by the anisotropy of the sample, and ensure that the test results are more representative; the test support assembly is used to simulate the internal expansion pressure of the direct-buried pipe and test different positions. Starting from the actual application scenario, multiple sets of data at different simulated positions are obtained, which can more realistically and comprehensively evaluate the compressive performance of foam glass for direct-buried pipes under various working conditions, and provide a reliable basis for the design, material selection and engineering application of direct-buried pipes. Example 2

[0048] like Figure 2 As shown, specifically, the pressure test device includes a pressure test frame 1, which includes a pressure test box 2, a pressure test bottom plate 3 and a pressure test top plate 4. The bottom of the pressure test box 2 is fixedly provided with the pressure test bottom plate 3, and the top of the pressure test box 2 is also fixedly provided with the pressure test top plate 4;

[0049] Among them, the temperature control box and the humidity control box are fixedly installed on both sides of the top of the compression test top plate 4, and a feeding port is also provided in the middle of the front of the compression test box 2. The temperature sensor and the humidity sensor are also provided at the bottom of the interior of the compression test box 2. The output ends of the temperature control box and the humidity control box extend to the interior of the compression test box 2;

[0050] It should be noted that the internal environment of the compression test device can be adjusted through the temperature control box and the humidity control box, and the test environment can be adjusted to the set initial conditions such as temperature 20°C, humidity 60%RH, vertical pressure 0.5MPa, and horizontal pressure 0.2MPa. The temperature and humidity parameters can be adjusted according to a certain rule to simulate a variety of actual environmental conditions, which is helpful to study the influence of different temperature, humidity and pressure environments on the compressive properties of foam glass, so that the test results are more in line with the complex environment in actual use of direct buried pipes, and provide data basis for the application of direct buried pipes in different regions and working conditions.

[0051] like Figure 3As shown, the front of the compression test box 2 is provided with an automatic loading and unloading unit, wherein the automatic loading and unloading unit includes a fixed frame 5 and a feeding frame 6. The front of the compression test box 2 and directly in front of the feeding port is fixedly provided with a fixed frame 5, and the feeding frame 6 is movably provided inside the fixed frame 5. Both sides of the feeding frame 6 are provided with conveying tooth grooves 7. Both sides of the fixed frame 5 are fixedly provided with driving blocks 9, and the interiors of the two driving blocks 9 are provided with conveying gears 8 that are rotated by built-in motors. The tooth surfaces of the two conveying gears 8 are respectively engaged with one side of the two conveying tooth grooves 7 for transmission. The feeding frame 6 is movable, and servo electric cylinders 10 are fixedly provided on both sides of the interior thereof, and lifting blocks 11 are fixedly provided on the bottom ends of the driving shafts of the two servo electric cylinders 10, and two workpiece clamps 12 are provided on the bottoms thereof through linear slide rails, and silicone pads are provided on the opposite sides of the two workpiece clamps 12; the surface of the compression test specimen of the foam glass for direct-buried pipe is clamped and fed by the silicone pads on the opposite sides of the two workpiece clamps 12, and the silicone pads are used to ensure the stability of the compression test specimen of the foam glass for direct-buried pipe during the clamping and feeding process.

[0052] It should be noted that when the compression test specimen for foam glass used in direct-buried pipes is fed into the interior of the compression test box 2 by using the automatic loading and unloading unit, the compression test specimen for foam glass used in direct-buried pipes is fed to the bottom of the fixed frame 5 by the conveying frame. At this time, the driving ends of the two servo electric cylinders 10 are used to control the two lifting blocks 11 to move downward, and the linear slide rails at the bottom of the lifting blocks 11 are used to drive the two workpiece clamps 12 to clamp and position the two sides of the compression test specimen for foam glass used in direct-buried pipes, and then the driving end of the servo electric cylinder 10 is controlled to reset, and the compression test specimen for foam glass used in direct-buried pipes is brought into the interior of the feeding frame 6. At this time, the driving blocks on both sides are used to control the two lifting blocks 11 to move downward. 9 The motor inside drives the two conveying gears 8 to rotate. As the two conveying gears 8 and the conveying tooth grooves 7 on both sides of the feeding rack 6 rotate and cooperate with each other, the feeding rack 6 is transferred from the inside of the fixed frame 5 to the inside of the pressure test box 2. Finally, the driving ends of the two servo electric cylinders 10 are controlled to send the clamped direct-buried pipe foam glass pressure test specimens into the bottom of the pressure test box 2, and the direct-buried pipe foam glass pressure test specimens are automatically sent to the external conveying rack through the various components in the automatic loading and unloading unit.

[0053] In a specific embodiment, the present invention adopts the coordinated design of the fixed frame 5 and the feeding frame 6, and the conveying tooth grooves 7 are set on both sides of the feeding frame 6, and the conveying gears 8 in the driving blocks 9 on both sides of the fixed frame 5 are engaged with the conveying tooth grooves 7 for transmission. This structure realizes the stable movement of the feeding frame 6 in the fixed frame 5, ensuring that the compression test specimens of the foam glass for direct buried pipes can be accurately transferred in and out of the test device, improving the degree of automation and test efficiency of the test, and reducing the errors caused by manual operation; the servo electric cylinder 10 on both sides of the feeding frame 6 drives the lifting block 11, and the bottom of the lifting block 11 drives the workpiece clamp 12 to clamp the specimen through a linear slide rail. This design can flexibly control the lifting and movement of the workpiece clamp 12, and realize precise clamping and positioning of the specimen, and the silicone pads arranged on the opposite sides of the two workpiece clamps 12 can effectively protect the surface of the specimen, avoid damage to the specimen during the clamping process, ensure the integrity of the specimen during the feeding process, and thus ensure the accuracy of the test results.

[0054] like Figure 4 、 Figure 5 and Figure 6 As shown, it is necessary to further explain that a pressure test unit is also provided inside the pressure test box 2, wherein the pressure test unit includes an upper test pressure block 16, a workpiece placement frame 19 and a side test pressure block 25, and a sealing movable frame 13 is movably provided at the bottom of the pressure test top plate 4, and a servo electric cylinder three 15 is slidingly provided at the bottom of the sealing movable frame 13 through a linear slide rail, and the bottom end of the driving shaft of the servo electric cylinder three 15 is fixedly provided with an upper test pressure block 16, and servo electric cylinder two 14 is fixedly provided on all four sides of the top of the pressure test top plate 4, and the bottom ends of the driving shafts of the four servo electric cylinders two 14 are fixedly connected to all four sides of the top of the sealing movable frame 13, and the four sides of the sealing movable frame 13 are in sliding and sealing contact with the four sides of the inner wall of the pressure test box 2, and the four sides of the sealing movable frame 13 are provided with sealing rings; wherein, pressure sensors are provided inside the upper test pressure block 16 and the side test pressure block 25.

[0055] Positioning blocks 18 are movably provided on both sides of the interior of the compression test box 2, and limit sliders 22 are fixedly provided on the front and rear sides of the two positioning blocks 18. Test frames 35 are movably provided on the front and rear sides of the positioning blocks 18, and the opposite sides of the two test frames 35 are slidably connected to one side of the two limit sliders 22 respectively. Servo electric cylinders 5 24 are slidably provided inside the two test frames 35 through linear slide rails, and one end of the drive shaft of the two servo electric cylinders 5 24 is fixedly provided with a side test pressure block 25;

[0056] Furthermore, a workpiece placement rack 19 is movably provided below the two positioning blocks 18, and a micro electric cylinder 20 is fixedly provided below the inside of the two positioning blocks 18. A movable slider 21 is fixedly provided at the bottom end of the driving shaft of the two micro electric cylinders 20, and the bottoms of the two movable sliders 21 are respectively slidably connected to the front and rear sides of the top of the workpiece placement rack 19; wherein an arc groove is provided at the top of the workpiece placement rack 19, and a silicone pad is provided at the top of the arc groove.

[0057] It should be noted that when the pressure test unit is used to perform a pressure test on the pressure test sample of foam glass for direct-buried pipes, the pressure test sample of foam glass for direct-buried pipes is sent to the top of the workpiece placement rack 19 through the automatic loading and unloading unit, and then the driving shaft of the servo electric cylinder 2 14 is used to control the sealing movable rack 13 to move downward, and the sealing movable rack 13 is used to seal the lower part of the pressure test box 2, and the driving shaft of the servo electric cylinder 3 15 is used to control the upper test block 16 to perform a pressure test operation on the surface of the pressure test sample of foam glass for direct-buried pipes, and at the same time, the driving shaft of the servo electric cylinder 5 24 inside the two test racks 35 is cooperated to control the side test block 25 to perform a pressure test operation on the front and back sides of the surface of the pressure test sample of foam glass for direct-buried pipes.

[0058] In a specific embodiment, the pressure test box 2, the pressure test bottom plate 3 and the pressure test top plate 4 constitute a stable test space, which provides a reliable physical basis for the entire pressure test, ensures the stability of the device during the test, and avoids external factors interfering with the test results; the sealing movable frame 13 is in sliding sealing contact with the inner wall of the pressure test box 2 and is surrounded by sealing rings, and its lifting is controlled by the servo electric cylinder 2 14. During the test, the lower part of the pressure test box 2 can be sealed, which ensures the stability of the internal pressure environment on the one hand, and avoids the influence of external environmental factors on the test on the other hand, ensuring the accuracy of the test data; the servo electric cylinder 3 15 drives the upper test block 16 to press the sample The pressure test operation is performed above the surface, and the servo electric cylinder five 24 inside the two test frames 35 drives the side test pressure block 25 to perform the pressure test operation on the front and back sides of the sample surface. It can apply pressure to the sample from multiple directions at the same time, simulating the multi-directional pressure of the buried pipe in the ground, and more realistically testing the compressive performance of the foam glass under actual working conditions, and obtaining more comprehensive pressure data; an arc groove and a silicone pad are set on the top of the workpiece placement frame 19, and the height adjustment is achieved by cooperating with the micro electric cylinder 1 20 and the movable slider 21. The arc groove and the silicone pad design can better adapt to the shape of the sample, increase the stability of the sample placement, prevent the sample from displacement during the test, and ensure the reliability of the test results.

[0059] like Figure 6 and Figure 7As shown, it is necessary to further explain that a servo electric cylinder 17 is fixedly provided on both sides of the compression test box 2, and the driving ends of the two servo electric cylinders 17 are respectively fixedly connected to one side of the two positioning blocks 18, and a steering adjustment unit is provided inside the positioning block 18, wherein the steering adjustment unit includes a steering block 27 and a steering rack 31, and four positioning slide rods 34 are also fixedly provided on both sides of the compression test box 2, and one end of the positioning slide rods 34 on both sides is respectively fixedly connected to one side of the two positioning blocks 18;

[0060] Furthermore, a servo electric cylinder six 26 is fixedly installed inside the positioning block 18, and a steering block 27 is fixedly installed on the driving end of the servo electric cylinder six 26. A bogie 31 is rotatably installed on the surface of the steering block 27, and a steering matching groove 29 is provided inside the bogie 31 to match the steering block 27. A steering tooth groove 30 is also provided inside the steering matching groove 29. A steering gear 28 is provided inside the steering block 27 to rotate through a built-in motor, and the tooth surface of the steering gear 28 is meshed with the teeth of the steering tooth groove 30 for transmission. Micro electric cylinders two 32 are fixedly installed around the inside of the bogie 31, and the driving ends of the four micro electric cylinders two 32 are fixedly provided with support frames 33.

[0061] Specifically, when the steering adjustment unit is used to perform steering adjustment on the compression test sample for foam glass used in direct-buried pipes, the driving end of the servo electric cylinder six 26 is used to control the steering block 27 to move toward the interior of the compression test sample for foam glass used in direct-buried pipes, and the driving ends of the four micro electric cylinders two 32 inside the steering frame 31 are used to control the support frame 33 to contact the inner wall of the compression test sample for foam glass used in direct-buried pipes, and then the steering gear 28 is controlled to rotate by the motor built into the steering block 27. The four support frames 33 are used to drive the compression test sample for foam glass used in direct-buried pipes to perform steering adjustment through the tooth surface of the steering gear 28 and the tooth meshing transmission of the steering tooth groove 30, so that the compression test sample for foam glass used in direct-buried pipes can cooperate with the compression test unit to perform compression tests in different directions; in addition, the driving end of the micro electric cylinder two 32 is used to control the support frame 33 to contact the inner wall of the compression test sample for foam glass used in direct-buried pipes, and the corresponding compression test is performed on the inner wall support position of the compression test sample for foam glass used in direct-buried pipes in cooperation with the compression test unit.

[0062] In a specific embodiment, in the present invention, the movement of the positioning block 18 is controlled by the servo electric cylinder 4 17, and the servo electric cylinder 6 26 inside the positioning block 18 drives the steering block 27 to move toward the inside of the sample. The position of the steering block 27 can be flexibly adjusted to facilitate subsequent docking with the sample, preparing for the sample steering adjustment and inner wall pressure test; the steering gear 28 inside the steering block 27 is engaged and transmitted with the steering tooth groove 30 in the steering frame 31, and cooperates with the micro electric cylinder 2 32 to control the support frame 33 to contact the inner wall of the sample. In this way, the sample can be driven to perform steering adjustment, and pressure tests at different positions of the sample can be achieved, avoiding test errors caused by the anisotropy of the sample, and ensuring that the test results are more representative; at the same time, it can also cooperate with the pressure test unit to perform pressure tests on the support position of the inner wall of the sample, and evaluate the compressive performance of the foam glass from multiple angles.

[0063] In addition, the support frame 33 is driven by the micro electric cylinder 2 32 to contact the inner wall of the compression test sample of the foam glass for direct-buried pipes, and the compression test unit is cooperated to perform a compression test on the support position to simulate the expansion pressure inside the direct-buried pipes. Starting from the actual application scenarios, the test data of different actual application simulation positions are obtained, and the compression performance of the foam glass for direct-buried pipes under various working conditions is evaluated more realistically and comprehensively, providing a more practical basis for the design and engineering application of direct-buried pipes.

[0064] In addition, it will be understood by those skilled in the art that various aspects of the present invention may be illustrated and described by a number of patentable categories or situations, including any new and useful process, machine, product or combination of substances, or any new and useful improvements thereto. Accordingly, various aspects of the present invention may be performed entirely by hardware, entirely by software (including firmware, resident software, microcode, etc.), or by a combination of hardware and software. The above hardware or software may be referred to as "data blocks", "modules", "engines", "units", "components" or "systems". In addition, various aspects of the present invention may be represented as a computer product located in one or more computer-readable media, which includes computer-readable program code.

[0065] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It should also be understood that terms such as those defined in common dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology and should not be interpreted in an idealized or highly formal sense, unless expressly defined as such herein.

[0066] The above is an illustration of the present invention and should not be considered as limiting thereof. Although several exemplary embodiments of the present invention have been described, it will be readily understood by those skilled in the art that many modifications may be made to the exemplary embodiments without departing from the novel teachings and advantages of the present invention. Therefore, all such modifications are intended to be included within the scope of the present invention as defined by the claims. It should be understood that the above is an illustration of the present invention and should not be considered as being limited to the specific embodiments disclosed, and modifications to the disclosed embodiments and other embodiments are intended to be included within the scope of the appended claims. The present invention is defined by the claims and their equivalents.

Claims

1. A compression test method for foam glass used in direct buried pipes, characterized in that: The steps include: Step 1: Prepare a foam glass shell specimen with the same size as the direct buried pipe, place a mandrel simulating a steel pipe inside the foam glass shell specimen, and evenly apply a layer of strain sensing coating on the surface of the specimen to obtain a foam glass compression test specimen for direct buried pipe; Step 2: Use the automatic loading and unloading unit on the compression test device to deliver the compression test sample of the foam glass for direct buried pipe into the interior of the compression test device, and use the environmental adjustment unit to adjust the environment inside the compression test device to the set initial conditions; Step 3: Using a compression test unit, gradually increase vertical and horizontal pressure at a rate of 0.1 MPa vertically and 0.05 MPa horizontally, and collect data from the pressure sensor, temperature sensor, humidity sensor, and strain sensing coating in real time to obtain a set of compression test data; Step 4: Adjust the test environment of the foam glass for direct-buried pipe compression test specimens through the environment adjustment unit, repeat the operation of step 3 above, and obtain multiple sets of compression test data of the foam glass for direct-buried pipe compression test specimens under different test environments; Step 5: Use the steering adjustment unit inside the compression test device to adjust the steering of the compression test sample for the directly buried pipe foam glass, and perform compression tests again on different positions of the compression test sample for the directly buried pipe foam glass, to obtain multiple groups of compression test data for the compression test samples for the directly buried pipe foam glass at different test positions; Step 6: Use the test support assembly to perform compression testing on different positions inside the compression test specimen for the directly buried pipe foam glass inside the compression test device, and cooperate with the compression test unit to perform compression testing on the support position to obtain multiple sets of test data for the compression test specimen for the directly buried pipe foam glass at different actual application simulation positions; The pressure test device comprises a pressure test frame (1), the pressure test frame (1) comprises a pressure test box (2), a pressure test bottom plate (3) and a pressure test top plate (4), the bottom of the pressure test box (2) is fixedly provided with the pressure test bottom plate (3), and the top of the pressure test box (2) is also fixedly provided with the pressure test top plate (4), the two sides of the top of the pressure test top plate (4) are respectively fixedly provided with a temperature control box and a humidity control box, and the middle of the front of the pressure test box (2) is also provided with a feeding port; the pressure test box (2) is fixedly provided with a pressure test bottom plate (3) and a pressure test top plate (4). Positioning blocks (18) are movably provided on both sides of the interior of the box (2), and limiting sliders (22) are fixedly provided on the front and rear sides of the two positioning blocks (18), and test frames (35) are movably provided on the front and rear sides of the positioning blocks (18), and the opposite sides of the two test frames (35) are slidably connected to one side of the two limiting sliders (22), and the interiors of the two test frames (35) are slidably provided with servo electric cylinders (24) through linear slide rails, and one end of the driving shaft of the two servo electric cylinders (24) is fixedly provided with a side test pressing block (25); Servo electric cylinders (17) are fixedly provided on both sides of the pressure test box (2), and the driving ends of the two servo electric cylinders (17) are fixedly connected to one side of the two positioning blocks (18), and a steering adjustment unit is provided inside the positioning block (18), wherein the steering adjustment unit includes a steering block (27) and a steering rack (31). Four positioning slide bars (34) are also fixedly provided on both sides of the pressure test box (2), and one end of the positioning slide bars (34) on both sides is fixedly connected to one side of the two positioning blocks (18), and a servo electric cylinder (26) is fixedly provided inside the positioning block (18), and the driving end of the servo electric cylinder (26) is fixedly provided. A steering block (27) is provided, a steering rack (31) is rotatably provided on the surface of the steering block (27), and a steering matching groove (29) matching with the steering block (27) is provided inside the steering rack (31), and a steering tooth groove (30) is further provided inside the steering matching groove (29), a steering gear (28) is provided inside the steering block (27) through a built-in motor, and the tooth surface of the steering gear (28) is meshed with the teeth of the steering tooth groove (30) for transmission, micro electric cylinders (32) are fixedly provided around the inside of the steering rack (31), and the driving ends of the four micro electric cylinders (32) are fixedly provided with support frames (33).

2. A compression test method for foam glass for direct buried pipes according to claim 1, characterized in that: The front of the pressure test box (2) is provided with an automatic loading and unloading unit, wherein the automatic loading and unloading unit comprises a fixed frame (5) and a feeding frame (6), the front of the pressure test box (2) and located in front of the feeding port is fixedly provided with a fixed frame (5), and the inside of the fixed frame (5) is movably provided with a feeding frame (6), both sides of the feeding frame (6) are provided with conveying tooth grooves (7), both sides of the fixed frame (5) are fixedly provided with driving blocks (9), and the insides of the two driving blocks (9) are provided with internal A conveying gear (8) is provided for rotation by a motor, and the tooth surfaces of the two conveying gears (8) are respectively meshed with one side of the two conveying tooth grooves (7) for transmission. A servo electric cylinder (10) is fixedly provided on both sides of the interior of the feeding rack (6), and a lifting block (11) is fixedly provided at the bottom end of the driving shaft of the two servo electric cylinders (10). The bottom of the two lifting blocks (11) is provided with two workpiece clamps (12) slidingly provided through linear slide rails, and a silicone pad is provided on the opposite side of the two workpiece clamps (12).

3. The compression test method for foam glass for direct buried pipe according to claim 2, characterized in that: The working mode of the automatic loading and unloading unit is as follows: The compression test specimen of foam glass for direct buried pipe is sent to the bottom of the fixed frame (5) by the conveying frame. At this time, the driving ends of the two servo electric cylinders (10) are used to control the two lifting blocks (11) to move downward, and the linear slide rails at the bottom of the lifting blocks (11) drive the two workpiece clamps (12) to clamp and position the two sides of the compression test specimen of foam glass for direct buried pipe. Then, the driving end of the servo electric cylinder (10) is controlled to reset, and the compression test specimen of foam glass for direct buried pipe is brought into the interior of the feeding frame (6). At this time, the motors inside the driving blocks (9) on both sides are used to drive the two conveying gears (8) to rotate. As the two The conveying gear (8) and the conveying tooth grooves (7) on both sides of the feeding rack (6) rotate and cooperate with each other to transfer the feeding rack (6) from the inside of the fixed rack (5) to the inside of the pressure test box (2). Finally, the driving ends of the two servo electric cylinders (10) are controlled to send the clamped direct buried pipe foam glass pressure test specimens to the bottom of the pressure test box (2), completing the automatic feeding operation for the direct buried pipe foam glass pressure test specimens. Conversely, the automatic unloading operation is completed for the direct buried pipe foam glass pressure test specimens inside the pressure test box (2) to the external conveying rack through the various components in the automatic loading and unloading unit.

4. The compression test method for foam glass for direct buried pipe according to claim 1, characterized in that: The pressure test box (2) is also provided with a pressure test unit, wherein the pressure test unit includes an upper test pressure block (16), a workpiece placement frame (19) and a side test pressure block (25). The bottom of the pressure test top plate (4) is movably provided with a sealing movable frame (13), and the bottom of the sealing movable frame (13) is slidably provided with a servo electric cylinder three (15) through a linear slide rail. The bottom end of the driving shaft of the servo electric cylinder three (15) is fixedly provided with an upper test pressure block (16). The top of the pressure test top plate (4) is fixedly provided with servo electric cylinder two (14) on all four sides, and the bottom ends of the driving shafts of the four servo electric cylinders two (14) are fixedly connected to the top of the sealing movable frame (13) on all four sides. The sealing movable frame (13) is in sliding and sealing contact with the inner wall of the pressure test box (2) on all four sides, and a sealing ring is provided on all four sides of the sealing movable frame (13).

5. The compression test method for foam glass for direct buried pipe according to claim 1, characterized in that: A workpiece placement rack (19) is movably provided below the two positioning blocks (18), and a micro-electric cylinder (20) is fixedly provided below the interior of the two positioning blocks (18). A movable slider (21) is fixedly provided at the bottom end of the driving shaft of each of the two micro-electric cylinders (20), and the bottoms of the two movable sliders (21) are respectively slidably connected to the front and rear sides of the top of the workpiece placement rack (19).

6. A compression test method for foam glass for direct buried pipes according to claim 5, characterized in that: The compression test unit works as follows: The compression test specimen for the foam glass used for direct buried pipes is fed to the top of the workpiece placement rack (19) by the automatic loading and unloading unit, and then the driving shaft of the servo electric cylinder 2 (14) is used to control the sealing movable rack (13) to move downward, and the sealing movable rack (13) is used to seal the lower part of the interior of the compression test box (2). The driving shaft of the servo electric cylinder 3 (15) is used to control the upper test block (16) to perform a compression test operation on the upper surface of the compression test specimen for the foam glass used for direct buried pipes, and at the same time, the driving shafts of the servo electric cylinder 5 (24) inside the two test racks (35) are used to control the side test block (25) to perform a compression test operation on the front and back sides of the surface of the compression test specimen for the foam glass used for direct buried pipes.

7. The compression test method for foam glass for direct buried pipe according to claim 1, characterized in that: The steering adjustment unit works as follows: The steering block (27) is controlled by the driving end of the servo electric cylinder six (26) to move toward the interior of the compression test specimen for foam glass used in direct-buried pipes, and the driving ends of the four micro electric cylinders two (32) inside the steering frame (31) are used to control the support frame (33) to contact the inner wall of the compression test specimen for foam glass used in direct-buried pipes, and then the steering gear (28) is controlled by the motor built into the steering block (27) to rotate, and the four support frames (33) are used to drive the compression test specimen for foam glass used in direct-buried pipes to perform steering adjustment through the tooth surface of the steering gear (28) and the tooth meshing transmission of the steering tooth groove (30), so that the compression test specimen for foam glass used in direct-buried pipes can cooperate with the compression test unit to perform compression tests in different directions; in addition, the support frame (33) is controlled by the driving end of the micro electric cylinder two (32) to contact the inner wall of the compression test specimen for direct-buried pipes, and the corresponding compression test is performed on the inner wall support position of the compression test specimen for direct-buried pipes in cooperation with the compression test unit.

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