Compression resistance test method for foam glass for directly buried pipe

Abstract

The invention relates to the technical field of performance testing, and particularly discloses a compression resistance testing method for foam glass for a directly-buried pipe, which comprises the following steps: manufacturing a foam glass pipe shell sample with the same actual use size as the directly-buried pipe, and placing a mandrel for simulating a steel pipe in the foam glass pipe shell sample; meanwhile, the surface of the sample is evenly coated with a strain induction coating, and the compression resistance test sample for the foam glass for the direct buried pipe is obtained; by using the foam glass tube shell sample with the same actual size as the directly-buried tube and placing the simulation mandrel, the stress state during testing is consistent with the actual height of the directly-buried tube, the strain of the sample is monitored in real time in combination with the strain induction coating, the mechanical property change of the material in actual application can be accurately obtained, and a reliable basis is provided for design of the directly-buried tube; in actual engineering, whether the foam glass can meet the compression resistance requirements of different directly-buried pipes or not can be accurately evaluated according to the data, and the engineering safety is improved.

Description

Technical Field

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

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

[0003] There are many defects in the traditional foam glass compression test method. On the one hand, in the sample preparation link, small-sized standard samples were mostly used in the past, which are significantly different in size and shape from the foam glass shell actually used in the direct buried pipe. Small-sized samples cannot truly simulate the actual stress conditions of foam glass in the direct buried pipe, resulting in a large deviation between the test results and the actual application. In the actual direct buried pipe, the foam glass is subjected to the pressure from the surrounding soil, the influence of the internal medium and the deformation of the pipe itself, and these complex factors are completely ignored when testing small-sized samples; on the other hand, in terms of the test process, traditional tests are usually only carried out under a single normal temperature and pressure environment, without considering the complex environmental factors in which the direct buried pipe is actually located. In actual applications, direct buried pipes will encounter different temperature, humidity and soil pressure conditions. In cold areas, the soil temperature around the direct buried pipe is extremely low and the humidity is high, but traditional tests cannot simulate this environment, making it difficult to obtain the compressive performance data of foam glass under actual working conditions. Moreover, traditional tests rarely pay attention to the anisotropy of the sample, and often only test a single position of the sample, ignoring the performance differences of foam glass at different positions, resulting in a lack of comprehensiveness and representativeness of the test 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 test method for foam glass for direct buried pipes, in order to solve the above-mentioned technical defects.

[0005] To achieve the above purpose, the present invention is implemented by the following technical scheme: A compression test method for foam glass for direct buried pipes, comprising the following steps: Step 1: Prepare a foam glass shell sample with the same size as the actual size of the direct buried pipe, place a mandrel simulating a steel pipe inside the foam glass shell sample, and evenly apply a layer of strain sensing coating on the surface of the sample to obtain a foam glass compression test sample for the 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 the direct buried pipe into the interior of the compression test device, and adjust the environment inside the compression test device to the set initial conditions through the environment adjustment unit; Step 3: gradually increase the vertical and horizontal pressures at a rate of 0.1 MPa vertically and 0.05 MPa horizontally through the compression test unit, collect data from the pressure sensor, temperature sensor, humidity sensor and strain sensing coating in real time, and obtain a set of compression test data; Step 4: Adjust the test environment of the compression test sample of the foam glass for direct buried pipe by the environment adjustment unit, repeat the operation of the above step 3, and obtain multiple groups of compression test data of the compression test sample of the foam glass for direct buried pipe in different test environments; Step 5: Use the steering adjustment unit inside the compression test device to perform steering adjustment on the compression test sample for the foam glass for the directly buried pipe, perform compression tests again on different positions of the compression test sample for the foam glass for the directly buried pipe, and obtain multiple groups of compression test data of the compression test samples for the foam glass for the directly buried pipe at different test positions; 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.

[0006] 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, and a feeding port is also provided in the middle of the front of the pressure test box.

[0007] Furthermore, an automatic loading and unloading unit is arranged on the front of the pressure resistance test box, wherein the automatic loading and unloading unit includes a fixed frame and a feeding frame, a fixed frame is fixedly arranged on the front of the pressure resistance test box and directly in front of the feeding port, and a feeding frame is movably arranged inside the fixed frame, conveying tooth grooves are arranged on both sides of the feeding frame, driving blocks are fixedly arranged on both sides of the fixed frame, and conveying gears are arranged inside the two driving blocks for rotation by built-in motors, and the tooth surfaces of the two conveying gears are respectively meshed with one side of the two conveying tooth grooves for transmission, servo electric cylinders 1 are fixedly arranged on both sides of the feeding frame, and lifting blocks are fixedly arranged at the bottom ends of the driving shafts of the two servo electric cylinders 1, two workpiece clamps are arranged on the bottoms of the two lifting blocks for sliding through linear slide rails, and silicone pads are arranged on the opposite sides of the two workpiece clamps.

[0008] Furthermore, the automatic loading and unloading unit works as follows: The compression test specimen of foam glass for direct buried pipe 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 rails at the bottom of the lifting blocks are used to drive the two workpiece clamps to clamp and position the two sides of the compression test specimen of foam glass for direct buried pipe, and then the driving end of the servo electric cylinder 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. At this time, the motors inside the driving blocks on both sides are used to drive the two conveying gears to rotate. With the rotation and transmission between the two conveying gears and the conveying tooth grooves on both sides of the feeding frame, 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 of foam glass for direct buried pipe to the bottom of the inside of the pressure test box, and the automatic feeding operation of the compression test specimen of foam glass for direct buried pipe is completed. Conversely, the various components in the automatic loading and unloading unit are used to complete the automatic unloading operation of the compression test specimen of foam glass for direct buried pipe inside the pressure test box to the external conveying frame.

[0009] Furthermore, a pressure test unit is also provided inside the pressure test box, wherein the pressure test unit includes an upper test block, a workpiece placement rack and a side test block, a sealing movable rack is movably provided at the bottom of the pressure test top plate, and a servo electric cylinder three is slidably provided at the bottom of the sealing movable rack through a linear slide rail, an upper test block is fixedly provided at the bottom end of the driving shaft of the servo electric cylinder three, servo electric cylinder two are fixedly provided around 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 top of the sealing movable rack around, the sealing movable rack is in sliding and sealing contact with the inner wall of the pressure test box around, and sealing rings are provided around the sealing movable rack.

[0010] Furthermore, positioning blocks are movably provided on both sides of the interior of the compression test box, and limit 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 respectively slidably connected to one side of the two limit sliders, and servo electric cylinders five are slidably provided inside the two test frames through linear slide rails, and side test pressure blocks are fixedly provided on one end of the driving shafts of the two servo electric cylinders five.

[0011] 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 driving 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.

[0012] Furthermore, the compression test unit works as follows: The compression test specimen of foam glass for direct buried pipe is sent to the top of the workpiece placement rack by 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 compression test box body, and the upper test block is controlled by the driving shaft of servo electric cylinder three to perform compression test on the upper 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.

[0013] Furthermore, servo electric cylinders four are fixedly arranged on both sides of the pressure test box, 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 arranged inside the positioning block, wherein the steering adjustment unit includes a steering block and a bogie, and four positioning slide bars are also fixedly arranged on both sides of the pressure test box, and one end of the positioning slide bars on both sides is respectively fixedly connected to one side of the two positioning blocks, a servo electric cylinder six is ​​fixedly arranged inside the positioning block, and a steering block is fixedly arranged on the driving end of the servo electric cylinder six, a bogie is rotatably arranged on the surface of the steering block, and a steering matching groove matching with the steering block is arranged inside the bogie, and a steering tooth groove is also arranged inside the steering matching groove, a steering gear is rotatably arranged inside the steering block by a built-in motor, and the tooth surface of the steering gear is meshed with the teeth of the steering tooth groove for transmission, micro electric cylinders two are fixedly arranged around the inside of the bogie, and the driving ends of the four micro electric cylinders two are fixedly arranged with a support frame.

[0014] Furthermore, the steering adjustment unit works as follows: 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 for direct buried pipes, and the driving ends of four micro electric cylinders two inside the steering frame are used to control the contact between the support frame and the inner wall of the compression test specimen for foam glass for direct buried pipes, and then the steering gear is controlled to rotate by the built-in motor inside the steering block, and the four support frames are used to drive the compression test specimen for foam glass for 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 for 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 for direct buried pipes, and the corresponding compression test is performed on the inner wall support position of the compression test specimen for foam glass for direct buried pipes in cooperation with the compression test unit.

[0015] Beneficial effects of the present invention: 1. By using foam glass shell specimens with the same actual size as the direct buried pipe and placing a simulated mandrel, the stress state during the test is highly consistent with the actual direct buried pipe. 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 application can be accurately obtained, providing a reliable basis for the design of direct buried pipes. In actual projects, these data can be used to accurately evaluate whether foam glass can meet the pressure resistance requirements of different direct buried pipes, thereby improving project safety.

[0016] 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 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 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.

[0017] 3. Through the automatic loading and unloading unit in the compression test device, with the help of the fixed frame, feeding frame, conveying gear, servo electric cylinder and workpiece clamp and other components, 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.

[0018] 4. The compression test unit can perform vertical and horizontal pressure tests on the sample at the same time through the coordinated work of the upper test block, the side test block and the workpiece placement rack, 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

[0019] The present invention will be further described below in conjunction with the accompanying drawings.

[0020] Figure 1 This is a flow chart of a compression test method for foam glass used in a direct buried pipe according to an embodiment of the present invention; Figure 2 A schematic diagram of the structure of a compression test device according to an embodiment of the present invention; Figure 3 This is a schematic diagram of the automatic loading and unloading unit structure of an embodiment of the present invention; Figure 4Schematic diagram of the internal structure of the compression test box in the embodiment of the present invention; Figure 5 Schematic diagram of the structure of the compression test unit in the embodiment of the present invention; Figure 6 Schematic diagram of the structure of the workpiece placement rack and positioning block in the embodiment of the present invention; Figure 7 Schematic diagram of the structure of the steering adjustment unit in the embodiment of the present invention.

[0021] 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 cylinder 1; 11, lifting block; 12, workpiece clamp; 13, sealed movable frame; 14, servo cylinder 2; 15, servo cylinder 3; 16, upper test pressure block; 17, servo cylinder 4; 18, positioning block; 19, workpiece placement rack; 20, micro cylinder 1; 21, movable slider; 22, limit slider; 23, adjustment chute; 24, servo cylinder 5; 25, side test pressure block; 26, servo cylinder 6; 27, steering block; 28, steering gear; 29, steering mating groove; 30, steering tooth groove; 31, steering frame; 32, micro cylinder 2; 33, support frame; 34, positioning slide bar; 35, test frame. Detailed implementation manners

[0022] Next, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments of the present invention. It should be understood that the present invention is not limited by the exemplary embodiments described herein. Embodiment 1

[0023] Please refer to Figures 1 to 7 As shown, a compression test method for foam glass used in directly buried pipes includes the following steps: Step 1: Fabricate a foam glass pipe shell specimen with the same actual size as the directly buried pipe. Place a mandrel simulating a steel pipe inside the foam glass pipe shell specimen to make its stress state during the test consistent with that of the actual directly buried pipe. At the same time, evenly apply a layer of strain sensing coating on the surface of the specimen. This coating can generate changes in electrical signals under pressure and is used to monitor the strain of the specimen in real time, obtaining a compression test specimen for foam glass used in directly buried pipes; 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 direct-buried pipe projects, providing more reliable data support for material selection and design. The strain sensing coating is evenly applied to 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, which helps to deeply analyze the mechanical properties of the material and promptly discover potential problems, such as local stress concentration, thereby more comprehensively evaluating the compressive properties of the foam glass.

[0024] 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 frame, and the compression test specimen of foam glass for direct buried pipe is transported into the interior of the compression test device by an automatic loading and unloading unit on the compression test device, and the environment inside the compression test device is adjusted to the set initial conditions by an 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; 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. Record the sample strain data, pressure value, and observe the changes in the sample appearance. When the sample is obviously deformed, cracked, or the pressure-strain curve is abnormal, stop loading, collect data from the pressure sensor, temperature sensor, humidity sensor, and strain sensing coating in real time, and set the collection frequency to 10-20 times per second to obtain a set of compression test data. Step 4. Adjust the test environment of the compression test specimen 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 then 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.

[0025] Step 5: Use the steering adjustment unit inside the compression test device to perform steering adjustment on the compression test sample for foam glass for direct buried pipes, and perform compression tests again on different positions of the compression test sample for foam glass for direct 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 foam glass for direct buried pipes at different test positions are obtained; 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, 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.

[0026] Specifically, it should be noted that the design scheme in the present application, in the preparation of the sample, adopts a foam glass shell sample with the same size as the actual size of the direct buried pipe and places a simulated mandrel 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 ensures 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 groups 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

[0027] like Figure 2 As shown, specifically, the pressure test device includes a pressure test frame 1, the pressure test frame 1 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; Among them, a temperature control box and a humidity control box are fixedly arranged on both sides of the top of the compression test top plate 4, and a feeding port is also arranged in the middle of the front of the compression test box 2, wherein a temperature sensor and a humidity sensor are also arranged at the bottom of the compression test box 2, and the output ends of the temperature control box and the humidity control box are extended to the interior of the compression test box 2; It should be noted that the internal environment of the compression test device can be adjusted by the temperature control box and the humidity control box. 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. This is helpful to study the influence of different temperature, humidity and pressure environments on the compressive properties of foam glass, making the test results more in line with the complex environment of direct buried pipes in actual use, and providing data basis for the application of direct buried pipes in different regions and working conditions.

[0028] like Figure 3As shown, an automatic loading and unloading unit is arranged on the front of the compression test box 2, wherein the automatic loading and unloading unit comprises a fixed frame 5 and a feeding frame 6, a fixed frame 5 is fixedly arranged on the front of the compression test box 2 and directly in front of the feeding port, and a feeding frame 6 is movably arranged inside the fixed frame 5, and a conveying tooth groove 7 is arranged on both sides of the feeding frame 6, a driving block 9 is fixedly arranged on both sides of the fixed frame 5, and a conveying gear 8 is arranged inside the two driving blocks 9 through a built-in motor to rotate, 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. The feeding frame 6 is movable, and servo electric cylinders 10 are fixedly arranged on both sides inside the feeding frame 6, and lifting blocks 11 are fixedly arranged on the bottom ends of the driving shafts of the two servo electric cylinders 10, and two workpiece clamps 12 are slidably arranged at the bottoms of the two lifting blocks 11 through linear slide rails, and silicone pads are arranged on the opposite sides of the two workpiece clamps 12; the surface of the compression test sample 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 sample of the foam glass for direct-buried pipe during the clamping and feeding process.

[0029] It should be noted that when the compression test specimen for foam glass used in direct-buried pipes is fed into the compression test box 2 by 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, and 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, and at this time, the driving blocks on both sides are used to The motor inside 9 drives the two conveying gears 8 to rotate, and 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, and 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 automatic feeding operation of the direct-buried pipe foam glass pressure test specimens is completed. Conversely, the automatic unloading operation of the direct-buried pipe foam glass pressure test specimens inside the pressure test box 2 to the external conveying rack is completed through the various components in the automatic loading and unloading unit.

[0030] 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 arranged 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 meshed 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 inside and outside the test device, thereby improving the automation degree and test efficiency of the test and reducing the errors caused by manual operation; the servo electric cylinders 10 on both sides of the feeding frame 6 drive the lifting blocks 11, and the bottom of the lifting blocks 11 drives the workpiece clamps 12 to clamp the specimens through linear slide rails. This design can flexibly control the lifting and movement of the workpiece clamps 12 to realize accurate clamping and positioning of the specimens, and the silicone pads arranged on the opposite sides of the two workpiece clamps 12 can effectively protect the surface of the specimens, avoid damage to the specimens during the clamping process, ensure the integrity of the specimens during the feeding process, and thus ensure the accuracy of the test results.

[0031] like Figure 4 , Figure 5 and Figure 6 As shown, it is necessary to further explain that a pressure test unit is also arranged inside the pressure test box 2, wherein the pressure test unit includes an upper test block 16, a workpiece placement frame 19 and a side test block 25, a sealing movable frame 13 is movably arranged at the bottom of the pressure test top plate 4, and a servo electric cylinder three 15 is slidably arranged at the bottom of the sealing movable frame 13 through a linear slide rail, and the upper test block 16 is fixedly arranged at the bottom end of the driving shaft of the servo electric cylinder three 15, and servo electric cylinder two 14 is fixedly arranged around 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 the top of the sealing movable frame 13, and the sealing movable frame 13 is in sliding and sealing contact with the inner wall of the pressure test box 2 around the four sides, and the sealing movable frame 13 is arranged with sealing rings around the four sides; wherein, pressure sensors are arranged inside the upper test block 16 and the side test block 25.

[0032] 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, and test racks 35 are movably provided on the front and rear sides of the positioning blocks 18, and the opposite sides of the two test racks 35 are slidably connected to one side of the two limit sliders 22, respectively, and servo electric cylinders 5 24 are slidably provided inside the two test racks 35 through linear slide rails, and one end of the driving shaft of the two servo electric cylinders 5 24 is fixedly provided with a side test pressing block 25; Furthermore, a workpiece placement rack 19 is movably arranged below the two positioning blocks 18, and a micro electric cylinder 20 is fixedly arranged below the two positioning blocks 18. Movable sliders 21 are fixedly arranged at the bottom ends of the driving shafts 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 arranged at the top of the workpiece placement rack 19, and a silicone pad is arranged at the top of the arc groove.

[0033] It should be noted that when the compression test sample for foam glass used in direct-buried pipes is subjected to a compression test by using a compression test unit, the compression test sample for foam glass used in direct-buried pipes is delivered to the top of the workpiece placement rack 19 by an 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 compression test box 2, and the upper test block 16 is controlled by the driving shaft of the servo electric cylinder 3 15 to perform a compression test on the surface of the compression test sample for foam glass used in direct-buried pipes, and at the same time, the driving shaft of the servo electric cylinder 5 24 inside the two test racks 35 controls the side test block 25 to perform a compression test on the front and back sides of the surface of the compression test sample for foam glass used in direct-buried pipes.

[0034] 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 A compression test is performed above the surface, and the servo electric cylinder 5 24 inside the two test frames 35 drives the side test pressure block 25 to perform a compression test on the front and back sides of the sample surface. Pressure can be applied to the sample from multiple directions at the same time, simulating the multi-directional pressure that the buried pipe is subjected to underground, and more realistically testing the compression performance of the foam glass under actual working conditions, and obtaining more comprehensive compression 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 a micro electric cylinder 1 20 and a 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 shifting during the test, and ensure the reliability of the test results.

[0035] like Figure 6 and Figure 7As shown, it is necessary to further explain that servo electric cylinders 17 are fixedly arranged 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 arranged inside the positioning block 18, wherein the steering adjustment unit includes a steering block 27 and a bogie 31, and four positioning slide bars 34 are also fixedly arranged on both sides of the compression test box 2, and one end of the positioning slide bars 34 on both sides is respectively fixedly connected to one side of the two positioning blocks 18; Furthermore, a servo electric cylinder 6 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 6 26. A bogie 31 is rotatably installed on the surface of the steering block 27, and a steering mating groove 29 matching the steering block 27 is installed inside the bogie 31. A steering tooth groove 30 is also installed inside the steering mating groove 29. A steering gear 28 is rotatably installed inside the steering block 27 by 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 2 32 are fixedly installed around the inside of the bogie 31, and support frames 33 are fixedly installed on the driving ends of the four micro electric cylinders 2 32.

[0036] Specifically, when the steering adjustment unit is used to perform steering adjustment on the compression test sample for foam glass for 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 for 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 for direct-buried pipes, and then the steering gear 28 is controlled to rotate by the motor built into the steering block 27, and the four support frames 33 are used to drive the compression test sample for foam glass for 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 for 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 for direct-buried pipes, and the compression test unit cooperates to perform corresponding compression tests on the inner wall support position of the compression test sample for foam glass for direct-buried pipes.

[0037] 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 the subsequent docking with the sample, and prepare for the sample steering adjustment and inner wall compression test; the steering gear 28 inside the steering block 27 is meshed with the steering tooth groove 30 in the steering frame 31 for transmission, 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 compression tests can be performed on different positions of the sample, avoiding test errors caused by the anisotropy of the sample, and ensuring that the test results are more representative; at the same time, the compression test unit can be cooperated to perform compression tests on the support position of the inner wall of the sample, and the compression performance of the foam glass can be evaluated from multiple angles.

[0038] 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 pipe. Starting from the actual application scenario, 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.

[0039] In addition, those skilled in the art will appreciate 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 all 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.

[0040] 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 the 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 extremely formal sense, unless explicitly defined as such herein.

[0041] The above is an explanation of the present invention and should not be considered as a limitation thereof. Although several exemplary embodiments of the present invention have been described, it will be readily appreciated 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 in the claims. It should be understood that the above is an explanation 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 sample with the same size as the actual size of the direct buried pipe, place a mandrel simulating a steel pipe inside the foam glass shell sample, and evenly apply a layer of strain sensing coating on the surface of the sample to obtain a foam glass compression test sample for the 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 the direct buried pipe into the interior of the compression test device, and adjust the environment inside the compression test device to the set initial conditions through the environment adjustment unit; Step 3: gradually increase the vertical and horizontal pressures at a rate of 0.1 MPa vertically and 0.05 MPa horizontally through the compression test unit, collect data from the pressure sensor, temperature sensor, humidity sensor and strain sensing coating in real time, and obtain a set of compression test data; Step 4: Adjust the test environment of the compression test sample of the foam glass for direct buried pipe by the environment adjustment unit, repeat the operation of the above step 3, and obtain multiple groups of compression test data of the compression test sample of the foam glass for direct buried pipe in different test environments; Step 5: Use the steering adjustment unit inside the compression test device to perform steering adjustment on the compression test sample for the foam glass for the directly buried pipe, perform compression tests again on different positions of the compression test sample for the foam glass for the directly buried pipe, and obtain multiple groups of compression test data of the compression test samples for the foam glass for the directly buried pipe at different test positions; 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.

2. A compression test method for foam glass for direct buried pipe according to claim 1, characterized in that: The pressure test device comprises a pressure test frame (1), the pressure test frame (1) comprising 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) being fixedly provided with the pressure test bottom plate (3), and the top of the pressure test box (2) being fixedly provided with the pressure test top plate (4), the two sides of the top of the pressure test top plate (4) being fixedly provided with a temperature control box and a humidity control box, respectively, and a feeding port being further provided in the middle of the front of the pressure test box (2).

3. A compression test method for foam glass for direct buried pipe according to claim 2, characterized in that: An automatic loading and unloading unit is arranged on the front of the compression test box (2), wherein the automatic loading and unloading unit comprises a fixed frame (5) and a feeding frame (6); a fixed frame (5) is fixedly arranged on the front of the compression test box (2) and directly in front of the feeding port, and a feeding frame (6) is movably arranged inside the fixed frame (5), and conveying tooth grooves (7) are arranged on both sides of the feeding frame (6); driving blocks (9) are fixedly arranged on both sides of the fixed frame (5), and the interiors of the two driving blocks (9) are connected by internal A conveying gear (8) is arranged to rotate with 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 arranged on both sides of the inside of the feeding rack (6), and a lifting block (11) is fixedly arranged at the bottom end of the driving shaft of the two servo electric cylinders (10). Two workpiece clamps (12) are slidably arranged at the bottom of the two lifting blocks (11) through linear slide rails, and silicone pads are arranged on the opposite sides of the two workpiece clamps (12).

4. A compression test method for foam glass for direct buried pipe according to claim 3, 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) are used to 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 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. The conveying gear (8) and the conveying tooth grooves (7) on both sides of the feeding rack (6) are rotated and matched 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 into the lower part of the pressure test box (2), and the direct buried pipe foam glass pressure test specimens are automatically sent. Conversely, the direct buried pipe foam glass pressure test specimens in the pressure test box (2) are automatically unloaded to the external conveying rack through the various components in the automatic loading and unloading unit.

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

6. A compression test method for foam glass for direct buried pipes according to claim 5, characterized in that: 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), 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 limit sliders (22), and servo electric cylinders (24) are slidably provided inside the two test frames (35) via linear slide rails, and side test pressure blocks (25) are fixedly provided on one end of the drive shafts of the two servo electric cylinders (24).

7. A compression test method for foam glass for direct buried pipe according to claim 6, characterized in that: A workpiece placement rack (19) is movably arranged below the two positioning blocks (18), and a micro-electric cylinder (20) is fixedly arranged below the two positioning blocks (18). A movable slide block (21) is fixedly arranged at the bottom end of the driving shaft of the two micro-electric cylinders (20), and the bottoms of the two movable slide blocks (21) are respectively slidably connected to the front and rear sides of the top of the workpiece placement rack (19).

8. A compression test method for foam glass for direct buried pipes according to claim 7, characterized in that: The compression test unit works as follows: The compression test specimen for the foam glass used in the direct buried pipe 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 upper test block (16) is controlled by the driving shaft of the servo electric cylinder 3 (15) to perform a compression test on the upper surface of the compression test specimen for the foam glass used in the direct buried pipe, and at the same time, the driving shafts of the servo electric cylinder 5 (24) in the two test racks (35) are used to control the side test block (25) to perform a compression test on the front and rear sides of the surface of the compression test specimen for the foam glass used in the direct buried pipe.

9. A compression test method for foam glass for direct buried pipe according to claim 6, characterized in that: Servo electric cylinders (17) are fixedly arranged 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 two positioning blocks (18), and a steering adjustment unit is arranged inside the positioning block (18), wherein the steering adjustment unit comprises a steering block (27) and a steering rack (31), and four positioning slide bars (34) are also fixedly arranged on both sides of the compression test box (2), and one end of the positioning slide bars (34) on both sides is respectively fixedly connected to one side of the two positioning blocks (18), and a servo electric cylinder (26) is fixedly arranged inside the positioning block (18), and the driving end of the servo electric cylinder (26) is fixedly arranged. A steering block (27) is provided, a steering rack (31) is rotatably provided on the surface of the steering block (27), a steering matching groove (29) matching with the steering block (27) is provided inside the steering matching groove (29), a steering tooth groove (30) is also provided inside the steering matching groove (29), a steering gear (28) is rotatably provided inside the steering block (27) through a built-in motor, and the tooth surface of the steering gear (28) meshes 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 support frames (33) are fixedly provided at the driving ends of the four micro electric cylinders (32).

10. A compression test method for foam glass for direct buried pipes according to claim 9, characterized in that: The steering adjustment unit works as follows: The driving end of the servo electric cylinder six (26) controls the steering block (27) 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) 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 motor built into the steering block (27) controls the steering gear (28) to rotate, and the four support frames (33) 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 driving end of the micro electric cylinder two (32) controls the support frame (33) to contact the inner wall of the compression test specimen for foam glass used in direct buried pipes, and cooperates with the compression test unit to perform corresponding compression tests on the inner wall support position of the compression test specimen for foam glass used in direct buried pipes.

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