Drainage triaxial compression test device based on photoelastic instrument

Abstract

The utility model provides a drainage triaxial compression test device based on a photoelastic instrument, which comprises a light source and an imaging device, a photoelastic instrument main body is arranged between the light source and the imaging device, the photoelastic instrument main body comprises a front polarization frame and a rear polarization frame, the front polarization frame is provided with a front polarizer, and the rear polarization frame is provided with a rear polarizer. And a rear polarizer is mounted on the rear polarization frame. The confining pressure testing device has the advantages that the water inlet and the exhaust hole are opened, water is filled into the confining pressure cylinder through the water pump, when liquid overflows from the exhaust hole, the exhaust hole is closed in time, the confining pressure of the test is continuously controlled through liquid drainage of the water pump, and finally the imaging device transmits information to the computer. According to the method, the micro-mechanical characteristics of the particles are analyzed and processed to analyze changes of internal stress and contact force chains of the particles, the micro-mechanical characteristics of the particles are analyzed more visually, macro-mechanical information and micro-mechanical characteristics are combined for analysis, and property changes of the particles in the test process are better studied.

Description

Technical Field

[0001] The utility model relates to a drainage triaxial compression test device based on a photoelasticity instrument, belonging to the technical field of shear tests. Background Art

[0002] Photoelasticity is an optical stress measurement method that can measure the stress of transparent material components with relatively complex geometric shapes and loading conditions. In particular, it can measure stress concentration and internal stress problems that are difficult to solve with other methods. Therefore, it has received attention from the academic and engineering communities. Photoelasticity has become an effective tool for solving stress analysis problems in complex engineering structures.

[0003] Currently, triaxial compression testing is a traditional technique for measuring the shear strength parameters of rocks and soils. Traditional drained triaxial compression testing equipment is primarily used to study macroscopic mechanical properties such as soil shear strength. However, it is difficult to directly observe microscopic information, such as the stress field within particles and changes in contact force chains. This has become a significant constraint on further research into the microscopic properties within particles, and as a result, it is impossible to directly combine macroscopic and microscopic mechanical information for analysis. Utility Model Content

[0004] In view of the deficiencies in the prior art, the present invention aims to provide a drainage triaxial compression test device based on a photoelasticity instrument.

[0005] In order to achieve the above purpose, the present invention is implemented through the following technical solutions:

[0006] A drainage triaxial compression test device based on a photoelasticity instrument comprises a light source and an imaging device. A photoelasticity instrument body is arranged between the light source and the imaging device. The photoelasticity instrument body comprises a front polarization frame and a rear polarization frame. A front polarization filter is installed on the front polarization frame, and a rear polarization filter is installed on the rear polarization frame. A specimen loading frame is further arranged between the front polarization frame and the rear polarization frame. A specimen lower pressure plate is arranged vertically inside the specimen loading frame. A tension and pressure sensor is arranged below the specimen lower pressure plate. A spiral force-applying device acting on the lower pressure plate of the specimen is provided on the outside, a three-axis device is provided between the lower pressure plate of the specimen and the tensile and pressure sensors, the tensile and pressure sensors are connected to a digital display, the three-axis device is composed of a confining pressure device, an upper pressure plate, a lower pressure plate and a water pump, the upper pressure plate is connected to the lower pressure plate of the specimen, the confining pressure device is connected to the upper pressure plate, the lower pressure plate is connected to the confining pressure device, the water pump is connected to the confining pressure device through a water inlet and a pipeline, and an exhaust hole is provided on the upper part of the three-axis device.

[0007] Furthermore, the light source is a liquid crystal computer display, which is connected to a computer host, and the imaging device is a digital camera, which is connected to a computer processor.

[0008] Furthermore, the confining pressure device is composed of an outer pressure cylinder and an inner pressure cylinder, the outer pressure cylinder is connected to the upper pressure plate, the inner pressure cylinder and the outer pressure cylinder are sealed by a sealing ring, the inner pressure cylinder is connected to the lower pressure plate, and an annular fixed ring plate is arranged under the outer pressure cylinder, and the outer surface of the lower part of the inner pressure cylinder is fixedly sleeved with an annular outer plate, and the annular outer plate is located inside the fixed ring plate and is embedded in the inner side of the fixed ring plate.

[0009] Furthermore, the bottom surface of the upper pressing plate is connected to the top surface of the test piece, the outer surface of the test piece is wrapped with a layer of transparent rubber film, and the bottom surface of the test piece is connected to the top surface of the lower pressing plate.

[0010] Furthermore, the front polarization frame, the rear polarization frame and the specimen loading frame are fixedly connected via a fastening bracket, and an imaging device bracket is fixedly provided at the bottom end of the imaging device.

[0011] Furthermore, the light source, the front polarization frame, the rear polarization frame, the specimen loading frame, and the imaging device bracket are all installed on a base.

[0012] Furthermore, the spiral force device includes a setting cylinder fixed to the specimen loading frame, a sliding member is slidably provided inside the setting cylinder, the bottom of the sliding member passes through the top of the specimen loading frame and is fixedly connected to the top of the specimen lower pressure plate, an operating box is fixedly provided on the top of the setting cylinder, a rotating rod is passed through the operating box, a manual turntable is provided at one end of the rotating rod, a bevel gear is fixedly provided at the other end of the rotating rod, a threaded rod is threadedly passed through the interior of the sliding member, and a sub-bevel gear meshing with the bevel gear is fixedly provided on the top of the threaded rod.

[0013] Furthermore, a connecting rod is fixedly provided at the top of the secondary bevel gear, a bearing 1 is fixedly provided at the top of the operating box, the outer surface of the top of the connecting rod is fixedly sleeved on the inner wall of the inner ring of the bearing 1, a bearing 2 is fixedly provided on the inner side wall of the operating box, the outer surface of the rotating rod is fixedly connected to the inner wall of the inner ring of the bearing 2, the bearing 2 is fixed on the inner side wall of the operating box, and a plurality of telescopic rods are fixedly provided between the inner wall of the setting cylinder and the sliding member.

[0014] Beneficial effects of the utility model:

[0015] When in use, place the three-axis device in the specimen loading frame, connect the three-axis device to the vertical specimen lower pressure plate and the tension and pressure sensor, then place the specimen wrapped with the transparent rubber film 25 in the three-axis device; turn on the light source and imaging device, and then start the photoelasticity instrument; rotate the vertical spiral force device to apply vertical pressure to the specimen through the vertical specimen lower pressure plate, and transmit the vertical pressure to the digital display through the tension and pressure sensor to facilitate adjustment of its size; then fix the outer pressure cylinder and the inner pressure cylinder by fixing the ring plate and the annular outer plate, and then use the sealing ring to fix the outer pressure cylinder. The pressure cylinder and the inner confining pressure cylinder are tightly connected together to form a closed space. At the same time, the water inlet and exhaust hole are opened, and water is pumped into the confining pressure cylinder. When liquid overflows from the exhaust hole, the exhaust hole is closed in time, and the water pump continues to drain the liquid to control the confining pressure of the test. Finally, the imaging device transmits the information to the computer and processes it to analyze the changes in its internal stress and contact force chain, and more intuitively analyze the microscopic properties of the particles. This experiment combines macroscopic mechanical information and microscopic mechanical characteristics for analysis to better study the changes in the properties of particles during the test. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0017] Figure 1 This is a front view of a drainage triaxial compression test device based on a photoelasticity instrument in the present invention;

[0018] Figure 2 This is a schematic diagram of the interior of a specimen loading frame of a drained triaxial compression test device based on a photoelasticity instrument in the present invention;

[0019] Figure 3 This is a schematic diagram of a triaxial device of a drained triaxial compression test device based on a photoelasticity instrument in the present invention;

[0020] Figure 4 This utility model is a spiral force applying device of a drainage triaxial compression test device based on a photoelasticity instrument;

[0021] Figure 5 This is a schematic diagram of the setting cylinder of a drainage triaxial compression test device based on a photoelasticity instrument in the present invention.

[0022] Figure: 1. Light source; 2. Imaging device; 3. Photoelasticity instrument body; 4. Front polarizer; 5. Rear polarizer; 6. Front polarizer frame; 7. Rear polarizer frame; 8. Specimen loading frame; 9. Specimen lower pressure plate; 10. Tension and pressure sensor; 11. Screw force device; 12. Three-axis device; 13. Confining pressure device; 14. Upper pressure plate; 15. Lower pressure plate; 16. Water pump; 17. Water inlet; 18. Exhaust hole; 19. External pressure cylinder; 20. Internal pressure cylinder ; 21. Sealing ring; 22. Fixed collar plate; 23. Annular outer plate; 24. Test piece; 25. Transparent rubber membrane; 26. Digital display; 27. Fastening bracket; 28. Base; 29. Imaging device bracket; 30. Setting cylinder; 31. Sliding part; 32. Operating box; 33. Turning rod; 34. Manual turntable; 35. Bevel gear; 36. Threaded rod; 37. Auxiliary bevel gear; 38. Bearing 1; 39. Bearing 2; 40. Telescopic rod. DETAILED DESCRIPTION

[0023] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0024] See also Figure 1-3 The utility model provides a technical solution: a drainage triaxial compression test device based on a photoelasticity instrument, comprising a light source 1 and an imaging device 2, a photoelasticity instrument body 3 is arranged between the light source 1 and the imaging device 2, the photoelasticity instrument body 3 comprises a front polarization frame 6 and a rear polarization frame 7, a front polarization filter 4 is mounted on the front polarization frame 6, a rear polarization filter 5 is mounted on the rear polarization frame 7, a specimen loading frame 8 is further arranged between the front polarization frame 6 and the rear polarization frame 7, a specimen lower pressing plate 9 is arranged vertically inside the specimen loading frame 8, a tensile pressure sensor 10 is arranged below the specimen lower pressing plate 9, and a specimen loading frame 8 is arranged on the outside. A spiral force-applying device 11 is provided for acting on the lower pressure plate 9 of the specimen, a three-axis device 12 is provided between the lower pressure plate 9 of the specimen and the tensile and pressure sensor 10, the tensile and pressure sensor 10 is connected to the digital display 26, the three-axis device 12 is composed of a confining pressure device 13, an upper pressure plate 14, a lower pressure plate 15 and a water pump 16, the upper pressure plate 14 is connected to the lower pressure plate 9 of the specimen, the confining pressure device 13 is connected to the upper pressure plate 14, the lower pressure plate 15 is connected to the confining pressure device 13, the water pump 16 is connected to the confining pressure device 13 through a water inlet 17 and a pipeline, and an exhaust hole 18 is provided on the upper part of the three-axis device 12.

[0025] See Figure 1-3, the light source 1 is a liquid crystal computer display, which is connected to a computer host, the imaging device 2 is a digital camera, which is connected to a computer processor, the confining pressure device 13 is composed of an outer pressure cylinder 19 and an inner pressure cylinder 20, the outer pressure cylinder 19 is connected to the upper pressure plate 14, the inner pressure cylinder 20 and the outer pressure cylinder 19 are sealed by a sealing ring 21, and the inner pressure cylinder 20 is connected to the lower pressure plate 15 together, and an annular fixed ring plate 22 is provided below the outer pressure cylinder 19, and the outer surface of the lower part of the inner pressure cylinder 20 is fixedly sleeved with an annular outer plate 23, the annular outer plate 23 is located inside the fixed ring plate 22 and is embedded in the inner side of the fixed ring plate 22, the bottom surface of the upper pressure plate 14 is connected to the top surface of the specimen 24, and the outer surface of the specimen 24 is wrapped with a layer of transparent rubber film 25, and the bottom surface of the specimen 24 is connected to the top surface of the lower pressure plate 15, The front polarization frame 6, the rear polarization frame 7 and the specimen loading frame 8 are fixedly connected by a fastening bracket 27. An imaging device bracket 29 is fixedly provided at the bottom end of the imaging device 2. The light source 1, the front polarization frame 6, the rear polarization frame 7, the specimen loading frame 8 and the imaging device bracket 29 are all installed on the base 28. The light source 1 constituted by the LCD computer display and the imaging device constituted by the digital camera are provided with a photoelasticity instrument body 3. The LCD computer display is connected to the computer host so that the screen can provide light sources of various colors. The output end of the digital camera is connected to the computer processor, which processes the output information and displays the information on another display of the computer processor. The window of the imaging device 2 is aligned with the polarizer. Water is injected into the three-axis device 12 through the water pump 16 to control the confining pressure of the test. The inner confining pressure cylinder 20 and the outer pressure cylinder 19 are sealed together by the sealing ring 21 to form a sealed space.

[0026] See Figure 1 、 Figure 4 and Figure 5The screw force applying device 11 includes a setting cylinder 30 fixed to the specimen loading frame 8, and a sliding member 31 is slidably provided inside the setting cylinder 30. The bottom of the sliding member 31 passes through the top of the specimen loading frame 8 and is fixedly connected to the top of the specimen lower pressing plate 9. An operating box 32 is fixed on the top of the setting cylinder 30, and a rotating rod 33 is passed through the inside of the operating box 32. A manual turntable 34 is provided at one end of the rotating rod 33, and a bevel gear 35 is fixed on the other end of the rotating rod 33. A threaded rod 36 is threadedly passed through the interior of the sliding member 31, and a sub-bevel gear 37 meshing with the bevel gear 35 is fixed on the top of the sub-bevel gear 37. A connecting rod is fixed on the top of the sub-bevel gear 37. A bearing 38 is fixed on the top of the operating box 32. The outer surface of the top of the connecting rod is fixedly sleeved on the inner wall of the inner ring of the bearing 38. The inner side wall of the operating box 32 is fixedly provided with a The second bearing 39 is provided, and the outer surface of the rotating rod 33 is fixedly connected to the inner wall of the inner ring of the second bearing 39. The second bearing 39 is fixed to the inner wall of the operating box 32. A plurality of telescopic rods 40 are fixed between the inner wall of the setting cylinder 30 and the sliding member 31. The manual turntable 34 is rotated to drive the rotation of the rotating rod 33, and the bevel gear 35 on the rotating rod 33 is rotated, thereby driving the meshing sub-bevel gear 37 to rotate. The rotation of the sub-bevel gear 37 drives the rotation of the threaded rod 36. The threaded rod 36 rotates in place, and finally drives the sliding member 31 to move up and down on the threaded rod 36. The telescopic rod 40 plays a role in pulling the sliding member 31 up and down vertically, so as to drive the connected specimen lower pressure plate 9 to apply vertical pressure to the specimen. The design of the bearing and the sub-bearing ensures the rotation stability of the corresponding components. The internal thread of the sliding member 31 is penetrated by the threaded rod 36, that is, the interior of the sliding member 31 has a thread groove matching the threaded rod 36. Figure 4 It can be seen directly from the figure that the length of the thread groove is greater than the length of the telescopic rod itself.

[0027] During the specific operation, the three-axis device 12 is placed in the specimen loading frame 8, and the three-axis device 12 is connected to the vertical specimen lower pressure plate 9 and the tension and pressure sensor 10. Then, the specimen 24 wrapped with a transparent rubber film 25 is placed in the three-axis device 12, the light source and the imaging device are turned on, and then the photoelasticity instrument is started. The vertical spiral force device 11 is rotated to apply vertical pressure to the specimen through the vertical specimen lower pressure plate 9. The vertical pressure is transmitted to the digital display 26 through the tension and pressure sensor 10 to facilitate its adjustment. Then, the outer pressure cylinder 19 and the inner pressure cylinder 20 are fixed by fixing the collar plate 22 and the annular outer plate 23. Then use the sealing ring 21 to tightly connect the outer pressure cylinder 19 and the inner pressure cylinder 20 to form a closed space. At the same time, open the water inlet 17 and the exhaust hole 18, and fill the pressure cylinder with water through the water pump 16. When liquid overflows from the exhaust hole 18, close the exhaust hole in time and continue to drain the liquid through the water pump 16 to control the confining pressure of the test. Finally, the imaging device transmits the information to the computer and processes it to analyze the changes in its internal stress and contact force chain, so as to more intuitively analyze the microscopic properties of the particles. This experiment combines macroscopic mechanical information and microscopic mechanical characteristics for analysis to better study the changes in the properties of the particles during the test.

[0028] Although this specification is described according to implementation methods, not every implementation method contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

Claims

1. A drained triaxial compression test device based on a photoelasticity instrument, characterized by: The invention comprises a light source (1) and an imaging device (2), wherein a photoelasticity instrument body (3) is provided between the light source (1) and the imaging device (2), wherein the photoelasticity instrument body (3) comprises a front polarization frame (6) and a rear polarization frame (7), wherein a front polarization filter (4) is installed on the front polarization frame (6), and a rear polarization filter (5) is installed on the rear polarization frame (7), and a specimen loading frame (8) is provided between the front polarization frame (6) and the rear polarization frame (7), wherein a specimen lower pressing plate (9) is provided vertically inside the specimen loading frame (8), a tension and pressure sensor (10) is provided below the specimen lower pressing plate (9), a spiral force applying device (11) for acting on the specimen lower pressing plate (9) is provided on the outside of the specimen loading frame (8), a three-axis device (12) is provided between the specimen lower pressing plate (9) and the tension and pressure sensor (10), and the tension and pressure sensor (10) is connected to a digital display (26); The three-axis device (12) is composed of a confining pressure device (13), an upper pressure plate (14), a lower pressure plate (15) and a water pump (16); the upper pressure plate (14) is connected to the lower pressure plate (9) of the specimen; the confining pressure device (13) is connected to the upper pressure plate (14); the lower pressure plate (15) is connected to the confining pressure device (13); the water pump (16) is connected to the confining pressure device (13) through a water inlet (17) and a pipeline; an exhaust hole (18) is provided on the upper part of the three-axis device (12).

2. The drained triaxial compression test device based on a photoelasticity instrument according to claim 1, characterized in that: The light source (1) is a liquid crystal computer display, which is connected to a computer host. The imaging device (2) is a digital camera, which is connected to a computer processor.

3. The drained triaxial compression test device based on a photoelasticity instrument according to claim 2, characterized in that: The confining pressure device (13) is composed of an outer pressure cylinder (19) and an inner pressure cylinder (20), the outer pressure cylinder (19) is connected to the upper pressure plate (14), the inner pressure cylinder (20) and the outer pressure cylinder (19) are sealed and connected via a sealing ring (21), the inner pressure cylinder (20) is connected to the lower pressure plate (15), an annular fixed collar plate (22) is provided below the outer pressure cylinder (19), and an outer surface fixed sleeve of the lower part of the inner pressure cylinder (20) is provided with an annular outer plate (23), the annular outer plate (23) is located inside the fixed collar plate (22) and is embedded in the inner side of the fixed collar plate (22).

4. The drained triaxial compression test device based on a photoelasticity instrument according to claim 3, characterized in that: The bottom surface of the upper pressing plate (14) is connected to the top surface of the test piece (24), the outer surface of the test piece (24) is wrapped with a layer of transparent rubber film (25), and the bottom surface of the test piece (24) is connected to the top surface of the lower pressing plate (15).

5. The drained triaxial compression test device based on photoelasticity according to claim 4, characterized in that: The front polarization frame (6), the rear polarization frame (7) and the specimen loading frame (8) are fixedly connected via a fastening bracket (27), and an imaging device bracket (29) is fixedly provided at the bottom end of the imaging device (2).

6. The drained triaxial compression test device based on a photoelasticity instrument according to claim 5, characterized in that: The light source (1), the front polarization frame (6), the rear polarization frame (7), the specimen loading frame (8), and the imaging device bracket (29) are all mounted on a base (28).

7. The drained triaxial compression test device based on photoelasticity according to claim 6, characterized in that: The spiral force applying device (11) includes a setting cylinder (30) fixed to the specimen loading frame (8), a sliding member (31) is slidably provided inside the setting cylinder (30), the bottom of the sliding member (31) passes through the top of the specimen loading frame (8) and is fixedly connected to the top of the specimen lower pressing plate (9), an operating box (32) is fixedly provided at the top of the setting cylinder (30), a rotating rod (33) is passed through the inside of the operating box (32), a manual turntable (34) is provided at one end of the rotating rod (33), a bevel gear (35) is fixedly provided at the other end of the rotating rod (33), a threaded rod (36) is threadedly passed through the inside of the sliding member (31), and a secondary bevel gear (37) meshing with the bevel gear (35) is fixedly provided at the top of the threaded rod (36).

8. The drained triaxial compression test device based on photoelasticity according to claim 7, characterized in that: A connecting rod is fixedly provided at the top of the secondary bevel gear (37), a bearing 1 (38) is fixedly provided at the top of the inner side of the operating box (32), the outer surface of the top of the connecting rod is fixedly sleeved on the inner wall of the inner ring of the bearing 1 (38), a bearing 2 (39) is fixedly provided on the inner side wall of the operating box (32), the outer surface of the rotating rod (33) is fixedly connected to the inner wall of the inner ring of the bearing 2 (39), the bearing 2 (39) is fixed to the inner side wall of the operating box (32), and a plurality of telescopic rods (40) are fixedly provided between the inner wall of the setting cylinder (30) and the sliding member (31).

Images