Hopkinson bar spallation experiment concrete test piece polishing device and use method

Abstract

The invention belongs to the field of Hopkinson bar spallation tests, and relates to a Hopkinson bar spallation test concrete sample polishing device and a use method. The grinding device comprises a left side end face grinding mechanism, a circumferential surface grinding mechanism and a right side end face grinding mechanism, in the circumferential surface grinding mechanism, a first connecting ring and a second connecting ring sleeve the two ends of a third transmission shaft, four transmission rods are movably arranged on the periphery of the third transmission shaft, and a transmission lantern ring is rotationally connected to the circumferential face of the left end of the second transmission shaft; the third connecting ring is hinged to the transmission rod, a first sliding groove is formed in the left end of the transmission rod, a first sliding block is arranged in the first sliding groove, an arc-shaped connecting block is arranged on the first sliding block, and a grinding piece is installed on the inner arc face of the arc-shaped connecting block. The use method of the polishing device comprises the following steps: polishing two end surfaces of a test piece by using the left and right end surface polishing mechanisms, and polishing the circumferential surface of the test piece by using the circumferential surface polishing mechanism. The all-around automatic grinding of the test piece is realized, and the uniformity of the surface of the test piece is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of Hopkinson bar spalling test, and particularly relates to a grinding device for a Hopkinson bar spalling test concrete specimen and a use method thereof. Background Art

[0002] The Hopkinson bar spalling test is an important method for studying the dynamic mechanical behavior and spalling failure mechanisms of brittle materials such as concrete at high strain rates. The test requires specimens with highly precise geometric dimensions and surface finish to ensure uniform stress wave propagation within the specimen. This avoids stress concentration or waveform distortion caused by surface defects or dimensional deviations, which could affect the accuracy of key parameters such as the spalling threshold and dynamic strength.

[0003] However, the existing grinding process for concrete specimens has significant shortcomings. Traditional methods mostly rely on manual operation, using sandpaper or hand-held grinding wheels for surface treatment. Its disadvantages include: (1) Difficulty in precision control: Manual grinding can easily lead to substandard specimen surface flatness, and local unevenness or tilt may cause abnormal stress wave reflection; (2) Low efficiency: Concrete specimens are hard and wear quickly, so manual grinding is time-consuming and difficult to ensure the consistency of batch specimens; (3) Poor adaptability: The Hopkinson bar experiment has strict requirements on parameters such as the specimen aspect ratio and end face parallelism. The existing general grinding equipment lacks special fixtures, and the adjustment process is cumbersome; (4) Environmental hazards: The dust generated by grinding is seriously polluted and threatens the health of manual grinding workers. Therefore, the development of an automated grinding device specifically for concrete specimens in the Hopkinson bar spalling experiment, which combines high precision, high efficiency and environmental protection, has become a key technical requirement for improving the reliability of experimental data and promoting dynamic mechanics research. Summary of the Invention

[0004] In order to solve the above technical problems, the present invention provides a grinding device and method for a concrete specimen used in a Hopkinson bar spalling test. The technical solutions adopted by the present invention are as follows: A Hopkinson bar spalling test concrete specimen grinding device includes a left end face grinding mechanism, a circumferential surface grinding mechanism, and a right end face grinding mechanism arranged from left to right. The circumferential surface grinding mechanism includes a third motor, a fourth motor, a third transmission shaft, a second transmission shaft, and a grinding plate. The fourth motor is connected to the second transmission shaft in a transmission manner. The third motor is connected to the third transmission shaft in a transmission manner. The first connecting ring is mounted on the outer periphery of the right end of the third transmission shaft. The second connecting ring is mounted on the outer periphery of the left end of the third transmission shaft. Four transmission rods are symmetrically and evenly distributed on the outer periphery of the third transmission shaft. The right end of the transmission rod is hingedly connected to the first connecting ring. The left end of the transmission rod is hingedly connected to the second connecting ring; a thread is provided on the circumferential surface of the left end of the second transmission shaft, and the threaded portion is screwed on the transmission collar, and a third connecting ring is provided on the outer circumference of the transmission collar, and the third connecting ring is hingedly connected to the transmission rod; a first sliding groove is provided on the left end portion of the transmission rod, and a first slider is slidably provided in the first sliding groove, and a plurality of threaded holes are provided on the first slider, and a through groove is provided on one side of the threaded holes corresponding to the first sliding groove, and an arc-shaped connecting block is fixedly provided on the adjacent end surfaces of the four first sliders, and a grinding sheet is fixedly installed on the inner arc surface of the arc-shaped connecting block, and the size of the cylinder surrounded by the grinding sheet matches the concrete specimen to be ground.

[0005] The lifting mechanism comprises a first motor, a second motor, and a second motor, and the second motor is mounted on a link loader, wherein the first motor is mounted on a link loader, and the second motor is mounted on a link loader. The second motor is mounted on the link loader, and the second motor is mounted on the link loader.

[0006] Preferably, the right end face grinding mechanism includes a first motor and a first grinding column, the output shaft of the first motor is fixedly connected to the right end of the first transmission shaft, and the left end of the first transmission shaft is fixedly connected to the first grinding column.

[0007] Preferably, the right end of the transmission rod is hingedly connected to the first connecting ring through the first connecting rod, the left end of the transmission rod is hingedly connected to the second connecting ring through the second connecting rod, and the third connecting ring is hingedly connected to the transmission rod through the third connecting rod.

[0008] Preferably, the third transmission shaft is rotationally connected to the second transmission shaft via a third bearing, the fourth motor is transmission-connected to the second transmission shaft via a first belt transmission assembly, and the third motor is connected to the third transmission shaft via a second belt transmission assembly.

[0009] Preferably, the output shaft of the second motor is rotatably connected to the upper portion of the fourth support via a sixth bearing, and the output shaft of the second motor is fixedly connected to the center position of the back side of the chute opening of the third chute.

[0010] Preferably, the first motor is fixedly arranged on the right side of the upper end of the first pillar, and the first transmission shaft is rotatably connected to the first pillar through a first bearing.

[0011] Preferably, the left end face grinding mechanism, the circumferential surface grinding mechanism and the right end face grinding mechanism are fixedly mounted on a base of the long plate-like structure.

[0012] The method for using the aforementioned Hopkinson bar spalling test concrete specimen grinding device comprises the following steps: The action of the clamping cylinder is controlled to drive the third slider to move. The third slider is adaptively adjusted in the third slide groove along with the universal shaft. The second slider is moved to the right through the universal shaft, so that the right end face of the second grinding column is in contact with the left end face of the concrete specimen. The second motor is started, and the other motors are in a locked state. The third slide groove rotates and controls the rotation of the second grinding column through the universal shaft, and the left end face of the concrete specimen is ground by the second grinding column. The first motor is started, and the other motors are in a locked state. The first grinding column is driven to rotate through the first transmission shaft, and the right end face of the concrete specimen is ground by the first grinding column. During the end face grinding process, the clamping cylinder is controlled to continuously act to provide a clamping force. The third motor and the fourth motor are started, and the other motors are in the locked state. The third motor drives the third transmission shaft to rotate, and drives the first slider and the arc-shaped connecting block to rotate through the transmission rod, and the circumferential surface of the concrete specimen is polished by the polishing disc; during the polishing process of the circumferential surface, the clamping force is provided by the continuous operation of the fourth motor.

[0013] Preferably, before grinding, an arc-shaped connecting block and a first slider that match the size of the concrete specimen are selected, the first slider is installed in the first slide groove and slid into place, the concrete specimen is placed in the cylindrical space enclosed by the arc-shaped connecting block and the grinding plate, the fourth motor is started, and the other motors are all in a locked state. The fourth motor controls the second transmission shaft to rotate, so that the transmission collar moves to the left, so that each transmission rod drives the arc-shaped connecting block to close, and the arc-shaped connecting block and the grinding plate clamp the circumferential surface of the concrete specimen. After the concrete specimen is installed, the right end face of the concrete specimen automatically fits into the left end face of the first grinding column. After grinding is completed, the third motor and the fourth motor are controlled to stop rotating, and the pressing cylinder is controlled to move the third slider. The second slider is moved to the left through the third slider and the universal shaft. The fourth motor is started to control the transmission ring to move to the right, so that the arc-shaped connecting block is opened and the concrete specimen is taken out.

[0014] Beneficial effects of the present invention: The present invention provides a grinding device for concrete specimens used in a Hopkinson bar spalling test and a method for use thereof. Through coordinated control of a clamping mechanism and a high-rigidity grinding assembly, precise adjustment of the specimen's dimensional accuracy (such as aspect ratio and end face parallelism) and surface finish is achieved, effectively eliminating interference factors in stress wave propagation and ensuring the accuracy of measurement of dynamic mechanical parameters (such as spalling threshold and dynamic strength) in the spalling test. During use, the present invention employs an arc-shaped connecting block that matches the size of the concrete specimen. The grinding disc within the arc-shaped connecting block can synchronously grind the circumferential surface of the specimen, thereby improving the uniformity of the specimen surface and avoiding cracks on the specimen surface due to uneven grinding. The use of the present invention reduces the occupational health risks of manual grinding and complies with green laboratory standards. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings: Figure 1 A schematic diagram of the three-dimensional structure of a grinding device according to an embodiment of the present invention; Figure 2 for Figure 1 A partial enlarged view of point A in the middle; Figure 3 for Figure 1 A full cross-sectional view of the central circumferential surface grinding mechanism; Figure 4 for Figure 3 A partial enlarged view of point B in the middle; Figure 5 for Figure 1 Schematic diagram of the three-dimensional structure of the mid-circumferential surface grinding mechanism; Figure 6 for Figure 5 A partial enlarged view of point C in the middle; Figure 7 for Figure 1 Schematic diagram of the structure of the middle transmission ring; Figure 8 for Figure 1 Top view of the end face grinding mechanism on the left side of the middle; Figure 9 for Figure 8 Cross-sectional view in the middle DD direction; Figure 10It is a right side view of the left end surface grinding mechanism according to an embodiment of the present invention; Figure 11 for Figure 1 A schematic diagram of the structure of the first chute; In the figure, 1 is the third slide, 2 is the guide column, 3 is the second slider, 4 is the first slider, 5 is the first slide, 6 is the third connecting rod, 7 is the second connecting rod, 8 is the transmission rod, 9 is the third transmission shaft, 10 is the second transmission shaft, 11 is the first pillar, 12 is the first motor, 13 is the second motor, 14 is the fourth pillar, 15 is the third pillar, 16 is the second grinding column, 17 is the support ring, 18 is the arc-shaped connecting block, 19 is the transmission collar, 20 is the third motor machine, 21 is the second pillar, 22 is the base, 23 is the fourth motor, 24 is the first connecting rod, 25 is the first connecting ring, 26 is the first transmission shaft, 27 is the concrete specimen, 28 is the fixing screw, 29 is the first grinding column, 30 is the third connecting ring, 31 is the second connecting ring, (32) is the supporting groove, 33 is the grinding disc, 34 is the third slider, 35 is the universal joint, 36 is the transmission column, 37 is the positioning ring, 38 is the second slide groove, and 39 is the pressing cylinder. DETAILED DESCRIPTION

[0016] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, but not all of the embodiments. Example 1

[0017] like Figure 1-11 As shown, a concrete specimen grinding device for a Hopkinson bar spalling test includes a right end face grinding mechanism, a circumferential surface grinding mechanism, and a left end face grinding mechanism fixedly mounted on a base 22. The base 22 is a long plate-like structure and can be placed on the workshop floor.

[0018] The right end surface grinding mechanism includes a first support 11 fixedly mounted on the right end of a base 22. A first motor 12 is fixedly mounted on the right upper end of the first support 11. The output shaft of the first motor 12 is fixedly connected to a first transmission shaft 26. Starting the first motor 12 can control the rotation of the first transmission shaft 26. The first transmission shaft 26 is rotatably connected to the first support 11 via a first bearing disposed on the upper portion of the first support 11. A first grinding column 29 is fixedly connected to the left end of the first transmission shaft 26.

[0019] The circumferential surface grinding mechanism includes a second transmission shaft 10 and a grinding disc 33. The second transmission shaft 10 is mounted on the periphery of the first transmission shaft 26 and is rotatably connected to the first transmission shaft 26 via a second bearing. A fourth motor 23 is fixedly mounted below the first motor 12 and is in transmission connection with the second transmission shaft 10 via a first belt drive assembly. Activating the fourth motor 23 controls the rotation of the second transmission shaft 10 via the first belt drive assembly. A third transmission shaft 9 is mounted on the periphery of the second transmission shaft 10 and is rotatably connected to the second transmission shaft 10 via a third bearing. A second support 21 is mounted on the right end of the third transmission shaft 9 and is rotatably connected to the right end of the third transmission shaft 9 via a fourth bearing. The second support 21 supports the third transmission shaft 9. A third motor 20 is mounted below the second support 21 and is connected to the third transmission shaft 9 via a second belt drive assembly. Activating the third motor 20 controls the rotation of the third transmission shaft 9 via the second belt drive assembly. A first connecting ring 25 is provided on the left side of the upper end of the second pillar 21. The first connecting ring 25 is fixedly connected to the right end of the third transmission shaft 9 and can rotate with the third transmission shaft 9. A second connecting ring 31 is provided on the left side of the first connecting ring 25. The second connecting ring 31 is fixedly connected to the left end of the third transmission shaft 9 and can rotate with the third transmission shaft 9. Four transmission rods 8 are symmetrically and evenly distributed on the outer periphery of the third transmission shaft 9. The right end of each transmission rod 8 is hingedly connected to the first connecting ring 25 through the first connecting rod 24, and the left end of the transmission rod 8 is hingedly connected to the second connecting ring 31 through the second connecting rod (7). A thread is provided on the circumferential surface of the left end of the second transmission shaft 10, and a transmission collar 19 threadedly connected to the second transmission shaft 10 is screwed on the threaded portion. A third connecting ring 30 is connected to the outer periphery of the transmission collar 19, and the third connecting ring 30 is hingedly connected to each transmission rod 8 through the third connecting rod 6. During use, the fourth motor 23 controls the rotation of the second transmission shaft 10, thereby enabling the transmission collar 19 to move left and right along the second transmission shaft 10, thereby controlling the opening and closing of each transmission rod 8. A first chute 5 is fixedly mounted on the left end of each transmission rod 8, and the first chute 5 can move with each transmission rod 8. A first slider 4 is slidably arranged in the first chute 5, and each first slider 4 is provided with a plurality of threaded holes. The first chute 5 has through slots at positions corresponding to the threaded holes. The fixing screw 28 passes through the through slot on the first chute 5 and is screwed into the threaded hole on the first slider 4. After the first slider 4 is in place in the first chute 5, it is squeezed and fixed by tightening the fixing screw 28, thereby improving the stability of the first slider 4. An arc-shaped connecting block 18 is fixedly provided on the adjacent end surface of each first slider 4. The four arc-shaped connecting blocks 18 form a cylindrical shape for accommodating the concrete specimen 27. A grinding disc 33 is fixedly installed on the inner arc surface of the arc-shaped connecting block 18. The grinding disc 33 is used to grind the circumferential surface of the concrete specimen 27. The size of the cylinder formed by the four grinding discs 33 matches the concrete specimen 27 to be ground.

[0020] The left end face grinding mechanism includes a second motor 13, a fourth support 14, a third support 15, and a second grinding support 16. The fourth support 14 and the third support 15 are fixedly mounted on the left end of the base 22. The third support 15 includes two oppositely arranged F-shaped vertical plates. The adjacent sides of the two F-shaped vertical plates are provided with second slide grooves 38. The second slider 3 is slidably connected in the second slide groove 38. The upper horizontal plate of the F-shaped vertical plate is provided with a guide column slide groove. The guide column 2 is movably mounted in the guide column slide groove. The lower end of the guide column 2 is fixedly connected to the upper surface of the second slider 3. When the second slider 3 moves horizontally in the second slide groove 38, it is guided and limited by the guide column 2. The center position of the second slider 3 is rotatably connected to a horizontal transmission column 36. The outer periphery of the transmission column 36 is rotatably connected to a positioning ring 37 through a fifth bearing. The second slider 3 is clamped and fixed on the positioning ring 37, so that the positioning ring 37 and the transmission column 36 can move left and right with the second slider 3. The right end of the transmission column 36 is fixedly connected to the second grinding column 16, and the second grinding column 16 can rotate along with the transmission column 36. A support ring 17 is fixedly installed on the outer periphery of the right end of the second grinding column 16, and a support groove (32) that matches the support ring 17 is opened at the left end of each arc-shaped connecting block 18. A universal shaft 35 is provided at the left end of the transmission column 36. The left end of the transmission column 36 is movably connected to the right end of the universal shaft 35 through a hinged structure. A third slide 1 is provided on the left side of the universal shaft 35. The left end of the universal shaft 35 is movably connected to the third slider 34 in the third slide 1. A clamping cylinder 39 is fixedly installed at one end of the third slide 1. The piston rod of the clamping cylinder 39 is fixedly connected to the third slider 34. The action of the clamping cylinder 39 enables the third slider 34 to slide in the third slide 1, thereby achieving horizontal movement of the second grinding column 16. A second motor 13 installed on the fourth pillar 14 is provided on the left side of the third slide 1. The output shaft of the second motor 13 is rotatably connected to the upper part of the fourth pillar 14 through the sixth bearing. The fourth pillar 14 is fixedly installed at the leftmost end of the base 22. The output shaft of the second motor 13 is fixedly connected to the center position of the back side of the slide opening of the third slide 1. The second motor 13 can control the rotation of the third slide 1. During the rotation of the third slide 1, it can drive the transmission column 36 and the second grinding column 16 to rotate. Example 2

[0021] The method for using the Hopkinson bar spalling test concrete specimen grinding device described in Example 1 includes the following steps: 1. Fixing concrete specimens27.

[0022] Select an arcuate connecting block 18 and first slider 4 that match the dimensions of concrete specimen 27, install first slider 4 into first chute 5, and place concrete specimen 27 in the cylindrical space enclosed by arcuate connecting block 18. Start fourth motor 23, while all other motors are locked. Fourth motor 23 controls the rotation of second drive shaft 10, causing drive collar 19 to move leftward, causing each drive rod 8 to close arcuate connecting block 18. Arcuate connecting block 18 and the grinding disc 33 on its inner surface securely grip the circumferential surface of concrete specimen 27. After concrete specimen 27 is installed, its right end automatically aligns with the left end of first grinding column 29.

[0023] 2. Grind the left and right end faces of the concrete specimen 27.

[0024] The action of the control pressing cylinder 39 drives the third slider 34 to move. During the movement, the third slider 34 is adaptively adjusted in the third chute 1 along with the universal shaft 35, and the second slider 3 is moved to the right through the universal shaft 35. During the movement of the second slider 3, the support ring 17 is inserted into the support groove (32). Before insertion, lubricant can be applied to the inner surface of the support ring 17 to reduce the friction between the support ring 17 and the support groove (32). With the continuous action of the pressing cylinder 39, the right end face of the second grinding column 16 is finally made to fit the left end face of the concrete specimen 27. The guide column 2 plays a guiding role during the movement of the second slider 3. The second motor 13 is started, and the other motors are in a locked state. The third chute 1 rotates and the second grinding column 16 is controlled to rotate through the universal shaft 35. The left end face of the concrete specimen 27 is ground by the second grinding column 16.

[0025] The first motor 12 is started, and the other motors are locked. The first grinding column 29 is driven to rotate through the first transmission shaft 26 , and the right end surface of the concrete specimen 27 is ground by the first grinding column 29 .

[0026] During the end surface grinding process, the pressing cylinder 39 is controlled to continuously operate to provide a certain pressing force to the second grinding column 16 to ensure the grinding effect of the left and right end surfaces of the concrete specimen 27.

[0027] 3. Grind the circumferential surface of the concrete specimen 27.

[0028] The third motor 20 and the fourth motor 23 are started, and the speed of the fourth motor 23 is fine-tuned. The other motors are locked. The third motor 20 drives the third transmission shaft 9 to rotate, which in turn drives the first slider 4 and the arc-shaped connecting block 18 via the transmission rod 8. The grinding disc 33 grinds the circumferential surface of the concrete specimen 27. During the grinding process, the continuous operation of the fourth motor 23 provides a certain clamping force to the grinding disc 33 to ensure a good grinding effect on the circumferential surface of the concrete specimen 27.

[0029] 4. Remove the polished concrete specimen 27.

[0030] After grinding is completed, the third motor 20 and the fourth motor 23 are controlled to stop rotating, and the pressing cylinder 39 is controlled to move the third slider 34. The second slider 3 is moved to the left through the third slider 34 and the universal joint 35. The fourth motor 23 is started to control the transmission collar 19 to move to the right, so that the arc-shaped connecting block 18 is opened and the concrete specimen 27 is taken out.

[0031] Through the above four steps, the synchronous grinding of the entire circumference of the concrete specimen 27 is completed.

[0032] In the embodiments of the present invention, technical features not described in detail are all existing technologies or conventional technical means and will not be described in detail here.

[0033] Finally, it should be noted that the above embodiments are only specific implementation methods of the present invention, which are used to illustrate the technical solutions of the present invention, rather than to limit them, and the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any person skilled in the art can modify or easily think of changes to the technical solutions described in the above embodiments within the technical scope disclosed by the present invention, or make equivalent replacements for some of the technical features therein; and these modifications, changes or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be included in the protection scope of the present invention.

Claims

1. A grinding device for a concrete specimen in a Hopkinson bar spalling test, comprising a left end face grinding mechanism, a circumferential surface grinding mechanism, and a right end face grinding mechanism arranged from left to right, characterized in that: The circumferential surface grinding mechanism comprises a third motor (20), a fourth motor (23), a third transmission shaft (9), a second transmission shaft (10) and a grinding sheet (33), wherein the fourth motor (23) is connected to the second transmission shaft (10) in a transmission manner, and the third motor (20) is connected to the third transmission shaft (9) in a transmission manner, a first connecting ring (25) is sleeved on the outer periphery of the right end of the third transmission shaft (9), and a second connecting ring (31) is sleeved on the outer periphery of the left end of the third transmission shaft (9), and four transmission rods (8) are symmetrically and evenly arranged on the outer periphery of the third transmission shaft (9), wherein the right end of the transmission rod (8) is hingedly connected to the first connecting ring (25), and the left end of the transmission rod (8) is hingedly connected to the second connecting ring (31); the second transmission shaft (10) A thread is provided on the circumferential surface of the left end, and the threaded portion is screwed to the transmission collar (19). A third connecting ring (30) is provided on the outer periphery of the transmission collar (19), and the third connecting ring (30) is hingedly connected to the transmission rod (8); a first chute (5) is provided on the left end portion of the transmission rod (8), and a first slider (4) is slidably provided in the first chute (5). The first slider (4) is provided with a plurality of threaded holes, and a through groove is provided at a position on one side of the first chute (5) corresponding to the threaded holes. An arc-shaped connecting block (18) is fixedly provided on the adjacent end surfaces of the four first sliders (4), and a grinding sheet (33) is fixedly installed on the inner arc surface of the arc-shaped connecting block (18). The size of the cylindrical shape surrounded by the grinding sheet (33) matches the concrete specimen (27) to be ground.

2. A Hopkinson bar spalling test concrete specimen grinding device according to claim 1, characterized in that: The left end face grinding mechanism includes a second motor (13), a third pillar (15) and a second grinding pillar (16), the third pillar (15) includes two oppositely arranged F-shaped vertical plates, the adjacent sides of the two F-shaped vertical plates are provided with a second slide groove (38), the second slide groove (38) is slidably connected to the second slider (3), the upper horizontal plate of the F-shaped vertical plate is provided with a guide column slide groove, the guide column (2) is movably installed in the guide column slide groove, the lower end of the guide column (2) is fixedly connected to the upper surface of the second slider (3), the second slider (3) is internally rotatably connected to the horizontal transmission column (36), and the outer periphery of the transmission column (36) is rotatably connected to the positioning ring ( 37), the second slider (3) is clamped on the positioning ring (37), the right end of the transmission column (36) is fixedly connected to the second grinding column (16), the outer periphery of the right end of the second grinding column (16) is fixedly installed with a support ring (17), the left end of the arc-shaped connecting block (18) is provided with a support groove (32) that matches the support ring (17), the left end of the transmission column (36) and the right end of the universal shaft (35) are movably connected through a hinged structure, the left end of the universal shaft (35) and the third slider (34) in the third slide groove (1) are hinged and movably connected, one end of the third slide groove (1) is fixedly installed with a clamping cylinder (39), and the piston rod of the clamping cylinder (39) is fixedly connected to the third slider (34).

3. A Hopkinson bar spalling test concrete specimen grinding device according to claim 2, characterized in that: The right end surface grinding mechanism comprises a first motor (12) and a first grinding column (29), wherein the output shaft of the first motor (12) is fixedly connected to the right end of the first transmission shaft (26), and the left end of the first transmission shaft (26) is fixedly connected to the first grinding column (29).

4. The grinding device for a concrete specimen of a Hopkinson bar spalling test according to claim 1, characterized in that: The right end of the transmission rod (8) is hingedly connected to the first connecting ring (25) via the first connecting rod (24), the left end of the transmission rod (8) is hingedly connected to the second connecting ring (31) via the second connecting rod (7), and the third connecting ring (30) is hingedly connected to the transmission rod (8) via the third connecting rod (6).

5. A Hopkinson bar spalling test concrete specimen grinding device according to claim 4, characterized in that: The third transmission shaft (9) is rotatably connected to the second transmission shaft (10) via a third bearing, the fourth motor (23) is transmission-connected to the second transmission shaft (10) via a first belt transmission assembly, and the third motor (20) is connected to the third transmission shaft (9) via a second belt transmission assembly.

6. A Hopkinson bar spalling test concrete specimen grinding device according to claim 2, characterized in that: The output shaft of the second motor (13) is rotatably connected to the upper portion of the fourth support (14) via a sixth bearing, and the output shaft of the second motor (13) is fixedly connected to the center position of the back side of the chute opening of the third chute (1).

7. The grinding device for a concrete specimen of a Hopkinson bar spalling test according to claim 3, characterized in that: The first motor (12) is fixedly arranged on the right side of the upper end of the first pillar (11), and the first transmission shaft (26) is rotatably connected to the first pillar (11) via a first bearing.

8. The grinding device for concrete specimens of Hopkinson bar spalling test according to claim 1, characterized in that: The left end face grinding mechanism, the circumferential surface grinding mechanism and the right end face grinding mechanism are fixedly mounted on a base (22) of a long plate-like structure.

9. The method for using the Hopkinson bar spalling test concrete specimen grinding device according to claim 3, characterized in that: The following steps are involved: The action of the control pressing cylinder (39) drives the third slider (34) to move. The third slider (34) is adaptively adjusted in the third slide groove (1) along with the universal shaft (35). The second slider (3) is moved to the right through the universal shaft (35), so that the right end face of the second grinding column (16) is in contact with the left end face of the concrete specimen (27). The second motor (13) is started, and the other motors are in a locked state. The third slide groove (1) rotates and controls the rotation of the second grinding column (16) through the universal shaft (35). The left end face of the concrete specimen (27) is ground through the second grinding column (16); the first motor (12) is started, and the other motors are in a locked state. The first grinding column (29) is driven to rotate through the first transmission shaft (26), and the right end face of the concrete specimen (27) is ground through the first grinding column (29); during the end face grinding process, the control pressing cylinder (39) is continuously moved to provide a clamping force; The third motor (20) and the fourth motor (23) are started, and the other motors are in a locked state. The third motor (20) drives the third transmission shaft (9) to rotate, and drives the first slider (4) and the arc-shaped connecting block (18) to rotate through the transmission rod (8), and the circumferential surface of the concrete specimen (27) is polished by the polishing sheet (33); during the polishing process of the circumferential surface, the clamping force is provided by the continuous operation of the fourth motor (23).

10. The method for using the Hopkinson bar spalling test concrete specimen grinding device according to claim 9, characterized in that: Before grinding, select an arc-shaped connecting block (18) and a first slider (4) that match the size of the concrete specimen (27), install the first slider (4) into the first slide groove (5) and slide the first slider (4) into place, place the concrete specimen (27) into the cylindrical space enclosed by the arc-shaped connecting block (18) and the grinding plate (33), start the fourth motor (23), and the other motors are in a locked state. The fourth motor (23) controls the second transmission shaft (10) to rotate, so that the transmission ring (19) moves to the left, so that each transmission rod (8) drives the arc-shaped connecting block (18) to close, and the arc-shaped connecting block (18) and the grinding plate (33) clamp the circumferential surface of the concrete specimen (27). After the concrete specimen (27) is installed, the right end face of the concrete specimen (27) automatically fits with the left end face of the first grinding column (29); After the grinding is completed, the third motor (20) and the fourth motor (23) are controlled to stop rotating, and the pressing cylinder (39) is controlled to move the third slider (34), so that the second slider (3) moves to the left through the third slider (34) and the universal shaft (35). The fourth motor (23) is started to control the transmission ring (19) to move to the right, so that the arc-shaped connecting block (18) is opened and the concrete specimen (27) is taken out.

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