Rigidity-variable flexible energy storage loading test device

Abstract

The invention relates to the technical field of test equipment, and particularly discloses a variable stiffness flexible energy storage loading test device, which comprises a loading system, a hydraulic system and a control system, and the loading system comprises a confining pressure simulation device and a variable stiffness flexible energy storage loading device. According to the variable-rigidity flexible energy storage loading test device provided by the invention, the confining pressure simulation device and the variable-rigidity flexible energy storage loading device are arranged, and the confining pressure simulation device is used for applying acting force to the bottom surface and the side surface of the coal-rock mass test piece, so that the underground confining pressure environment where the coal-rock mass test piece is located is simulated; the variable-stiffness flexible energy storage loading device is used for applying acting force to the top surface of the coal-rock mass test piece and storing elastic potential energy, so that enough energy is released after the strength limit of the coal-rock mass test piece is reached in the test process, and the coal-rock mass test piece is instantaneously damaged; therefore, the violent damage phenomenon and related principles of the excavated coal body under the bearing condition can be vividly displayed.

Description

Technical Field

[0001] The invention relates to the technical field of test equipment, and in particular to a variable-rigidity flexible energy storage loading test device. Background Art

[0002] After the coal mining face is built, the opening eye advances forward to form a goaf interval, resulting in the roof being exposed. When the old roof or direct roof is an unbroken rock layer, the rock layer can be regarded as a continuous beam on an elastic foundation (coal seam and collapsed gangue), which is called an elastic foundation beam. During the bearing process of the underlying coal body, the roof will bend and deform. When the load reaches the strength limit of the coal body, the elastic deformation energy accumulated in the roof will be instantly released to the coal body due to the reduced deformation resistance of the coal body, causing the coal body to collapse and destroy in a very short time in a manner similar to an explosive collapse. However, the overall structural rigidity of the existing rigid loading test device is relatively large, and the loading structure of the test device cannot restore the coal body bearing environment when the roof is loaded. At the same time, after reaching the strength limit of the coal rock body during the test, the elastic deformation energy released by the test device is relatively small, and the coal rock specimen will not be instantly destroyed. It is difficult to vividly demonstrate the violent destruction phenomenon and related principles under the bearing conditions of the mining coal body. Therefore, it is urgent to provide a flexible energy storage loading test device suitable for stress transfer of the roof rock beam. Summary of the invention

[0003] The purpose of the present invention is to provide a variable stiffness flexible energy storage loading test device to solve the problems existing in the above-mentioned prior art.

[0004] To achieve the above object, the present invention provides a variable stiffness flexible energy storage loading test device, comprising:

[0005] A loading system, the loading system comprising a confining pressure simulation device and a variable stiffness flexible energy storage loading device; the confining pressure simulation device is used to apply force to the bottom and side surfaces of the coal-rock specimen to simulate the underground confining pressure environment in which the coal-rock specimen is located; the variable stiffness flexible energy storage loading device is used to apply force to the top surface of the coal-rock specimen and store elastic potential energy;

[0006] A hydraulic system, the hydraulic system is used to provide power for the operation of the loading system;

[0007] A control system is used to control the operation of the hydraulic system and collect test data of the loading system during the loading process.

[0008] Preferably, the confining pressure simulation device comprises:

[0009] A bottom support mechanism, the coal-rock specimen is placed on the top of the bottom support mechanism, and the bottom support mechanism is used to support and limit the coal-rock specimen;

[0010] A side loading mechanism, which is symmetrically arranged on both sides of the coal-rock mass specimen, and is used to support and limit the side wall of the coal-rock mass specimen, and is connected to the hydraulic system;

[0011] A support frame, wherein the bottom support mechanism and the side loading mechanism are both installed in the support frame.

[0012] Preferably, the support frame includes a base, a top seat and a plurality of connecting rods, both ends of the connecting rods respectively pass through the base and the top seat, both ends of the connecting rods are threadedly connected with locking nuts, and the base and the top seat are detachably connected to the connecting rods through the locking nuts.

[0013] Preferably, the bottom support mechanism includes a bottom support plate, which is arranged at the top of the base, a support column is installed at the top of the bottom support plate, a bottom baffle is arranged at the top of the support column, and the coal rock specimen is placed at the top of the bottom baffle.

[0014] Preferably, the lateral loading mechanism includes a vertical support plate, which is fixedly mounted on the top of the base, and a second hydraulic cylinder is fixedly mounted on a side of the vertical support plate close to the coal rock specimen, the second hydraulic cylinder is arranged in a horizontal direction, and the second hydraulic cylinder is connected to the hydraulic system; a loading head is fixedly mounted on the end of the second hydraulic cylinder, and a side baffle is arranged on a side of the loading head away from the second hydraulic cylinder, and the loading head abuts against the side baffle; the side baffle is an L-shaped structure, the bottom baffle is slidably matched with the side baffle, the bottom baffle and the two side baffles form a placement groove, and the coal rock specimen is arranged in the placement groove.

[0015] Preferably, the variable stiffness flexible energy storage loading device comprises:

[0016] An elastic potential energy storage loading mechanism, wherein the elastic potential energy storage loading mechanism is mounted on the base, and a loading head of the elastic potential energy storage loading mechanism abuts against a top end of the coal rock mass specimen;

[0017] A vertical loading mechanism, which is fixedly mounted at the bottom end of the top seat and is located above the elastic potential energy storage loading mechanism, and applies a force to the coal rock specimen through a loading head of the elastic potential energy storage loading mechanism;

[0018] The elastic potential energy storage loading mechanism and the vertical loading mechanism are both connected to the hydraulic system.

[0019] Preferably, the elastic potential energy storage loading mechanism includes a vertical hydraulic cylinder fixedly mounted on the base, the vertical hydraulic cylinder is connected to the hydraulic system, the top of the vertical hydraulic cylinder is fixedly connected to a mounting sleeve, a variable stiffness flexible energy storage loading rod is detachably mounted in the mounting sleeve, and the loading head is fixedly connected to the bottom end of the variable stiffness flexible energy storage loading rod.

[0020] Preferably, the vertical loading mechanism includes a top support plate, which is fixedly mounted on the bottom end of the top seat, and the bottom end of the top support plate is fixedly connected to a first hydraulic cylinder, which is connected to the hydraulic system, and the bottom end of the first hydraulic cylinder is arranged corresponding to the variable stiffness flexible energy storage loading rod, and the loading head on the variable stiffness flexible energy storage loading rod is coaxially arranged with the first hydraulic cylinder.

[0021] Preferably, the variable stiffness flexible energy storage loading device further comprises:

[0022] A limit assembly is installed on the top seat, and the limit assembly is used to control the deformation of the variable stiffness flexible energy storage loading rod.

[0023] Preferably, the limit assembly includes a limit rod, which is fixedly connected to the top end of the mounting sleeve, the top end of the limit rod passes through the top seat and slides with the top seat, and a length scale is provided on the limit rod; a vertical adjustment screw is threadedly connected to the top seat, and a positioning sleeve is rotatably connected to the top end of the vertical adjustment screw, the positioning sleeve is located above the top seat, a locking screw is slidably sleeved in the positioning sleeve, and a plurality of threaded holes are opened on the limit rod in the vertical direction, and the locking screw is threadedly engaged with the threaded holes.

[0024] Compared with the prior art, the present invention has the following advantages and technical effects:

[0025] The variable stiffness flexible energy storage loading test device provided by the present invention, by setting a confining pressure simulation device and a variable stiffness flexible energy storage loading device, uses the confining pressure simulation device to apply force to the bottom and side surfaces of the coal rock specimen to simulate the underground confining pressure environment in which the coal rock specimen is located, and uses the variable stiffness flexible energy storage loading device to apply force to the top surface of the coal rock specimen, and stores elastic potential energy to ensure that when the strength limit of the coal rock specimen is reached during the test, sufficient energy is released to cause instantaneous destruction of the coal rock specimen, thereby being able to vividly demonstrate the severe destruction phenomenon under coal mining bearing conditions and related principles. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. 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 creative work.

[0027] Figure 1 It is a structural schematic diagram of a variable stiffness flexible energy storage loading test device in Embodiment 1 of the present invention;

[0028] Figure 2 It is a structural schematic diagram of a variable stiffness flexible energy storage loading test device in Embodiment 2 of the present invention;

[0029] In the figure: 1. base; 2. top seat; 3. connecting rod; 4. locking nut; 5. bottom support plate; 6. support column; 7. bottom baffle; 8. vertical support plate; 9. second hydraulic cylinder; 10. loading head; 11. side baffle; 12. vertical hydraulic cylinder; 13. mounting sleeve; 14. variable stiffness flexible energy storage loading rod; 15. top support plate; 16. first hydraulic cylinder; 17. limit rod; 18. vertical adjustment screw; 19. positioning sleeve; 20. locking screw; 21. coal rock specimen. DETAILED DESCRIPTION

[0030] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other. The described embodiments are only some embodiments of the present invention, not all embodiments. All other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. The present invention will be described in detail below with reference to the drawings and in combination with the embodiments.

[0031] Embodiment 1

[0032] like Figure 1 As shown, the present invention provides a variable stiffness flexible energy storage loading test device, comprising:

[0033] The loading system includes a confining pressure simulation device and a variable stiffness flexible energy storage loading device; the confining pressure simulation device is used to apply force to the bottom and side surfaces of the coal-rock specimen 21 to simulate the underground confining pressure environment in which the coal-rock specimen 21 is located; the variable stiffness flexible energy storage loading device is used to apply force to the top surface of the coal-rock specimen 21 and store elastic potential energy;

[0034] Hydraulic system, the hydraulic system is used to provide power for the operation of the loading system;

[0035] The control system is used to control the operation of the hydraulic system and collect test data of the loading system during the loading process, wherein the test data includes pressure data applied to the coal rock specimen 21 and displacement data and image information of the coal rock specimen 21 at instantaneous destruction.

[0036] To further optimize the scheme, the confining pressure simulation device includes:

[0037] A bottom support mechanism, the coal-rock specimen 21 is placed on the top of the bottom support mechanism, and the bottom support mechanism is used to support and limit the coal-rock specimen 21;

[0038] A side loading mechanism, which is symmetrically arranged on both sides of the coal-rock specimen 21, and is used to support and limit the side walls of the coal-rock specimen 21, and is connected to a hydraulic system;

[0039] The support frame, the bottom support mechanism and the side loading mechanism are all installed in the support frame.

[0040] A further optimized solution is that the support frame includes a base 1, a top seat 2 and a plurality of connecting rods 3, both ends of the connecting rods 3 respectively pass through the base 1 and the top seat 2, both ends of the connecting rods 3 are threadedly connected with locking nuts 4, and the base 1 and the top seat 2 are detachably connected to the connecting rods 3 through the locking nuts 4.

[0041] According to a further optimization scheme, the bottom support mechanism includes a bottom support plate 5, which is arranged at the top of the base 1. A support column 6 is installed at the top of the bottom support plate 5. A bottom baffle 7 is arranged at the top of the support column 6. The coal rock specimen 21 is placed at the top of the bottom baffle 7.

[0042] A further optimized solution is provided, in which the lateral loading mechanism includes a vertical support plate 8, which is fixedly mounted on the top of the base 1; a second hydraulic cylinder 9 is fixedly mounted on the side of the vertical support plate 8 close to the coal rock specimen 21; the second hydraulic cylinder 9 is arranged in the horizontal direction, and the second hydraulic cylinder 9 is connected to the hydraulic system; a loading head 10 is fixedly mounted on the end of the second hydraulic cylinder 9; a side baffle 11 is arranged on the side of the loading head 10 away from the second hydraulic cylinder 9, and the loading head 10 abuts against the side baffle 11; the side baffle 11 is an L-shaped structure, the bottom baffle 7 is slidably matched with the side baffle 11, the bottom baffle 7 and the two side baffles 11 form a placement groove, and the coal rock specimen 21 is arranged in the placement groove.

[0043] Further optimizing the scheme, the variable stiffness flexible energy storage loading device includes:

[0044] An elastic potential energy storage loading mechanism, the elastic potential energy storage loading mechanism is installed on the base 1, and the loading head 10 of the elastic potential energy storage loading mechanism abuts against the top of the coal rock specimen 21;

[0045] A vertical loading mechanism, which is fixedly mounted at the bottom end of the top seat 2 and is located above the elastic potential energy storage loading mechanism. The vertical loading mechanism applies a force to the coal rock specimen 21 through the loading head 10 of the elastic potential energy storage loading mechanism;

[0046] The elastic potential energy storage loading mechanism and the vertical loading mechanism are both connected with the hydraulic system.

[0047] A further optimized solution is that the elastic potential energy storage loading mechanism includes a vertical hydraulic cylinder 12 fixedly mounted on a base 1, the vertical hydraulic cylinder 12 is connected to a hydraulic system, a mounting sleeve 13 is fixedly connected to the top of the vertical hydraulic cylinder 12, a variable stiffness flexible energy storage loading rod 14 is detachably mounted in the mounting sleeve 13, and a loading head 10 is fixedly connected to the bottom of the end of the variable stiffness flexible energy storage loading rod 14.

[0048] A further optimized solution is that the vertical loading mechanism includes a top support plate 15, which is fixedly mounted on the bottom end of the top seat 2. The bottom end of the top support plate 15 is fixedly connected to a first hydraulic cylinder 16, which is connected to the hydraulic system. The bottom end of the first hydraulic cylinder 16 is arranged corresponding to the variable stiffness flexible energy storage loading rod 14, and the loading head 10 on the variable stiffness flexible energy storage loading rod 14 is coaxially arranged with the first hydraulic cylinder 16.

[0049] The variable stiffness flexible energy storage loading test device provided by the present invention has a working principle as follows: when in use, firstly, a coal rock specimen 21 is placed on the bottom baffle 7, and then two L-shaped side baffles 11 are arranged around the coal rock specimen 21, and a force is applied to the side baffles 11 by the second hydraulic cylinder 9, and the side baffles 11 and the bottom baffle 7 are used to simulate the confining pressure environment of the coal rock specimen 21 in the underground; then, the vertical hydraulic cylinder 12 is controlled to shorten, and in this process, the variable stiffness flexible energy storage loading rod 14 is moved by The loading head 10 applies a vertical force to the coal rock specimen 21. At this time, the variable stiffness flexible energy storage loading rod 14 will deform. The deformation of the variable stiffness flexible energy storage loading rod 14 can store elastic potential energy. Therefore, after the coal rock specimen 21 reaches the strength limit, the elastic potential energy stored in the variable stiffness flexible energy storage loading rod 14 can be released instantly, causing the coal rock specimen 21 to show an instantaneous destruction effect, which is convenient for studying the severe destruction phenomenon and related principles under simulated coal mining bearing conditions.

[0050] In addition, when the strength of the coal rock specimen 21 is relatively high and the ultimate strength of the coal rock specimen 21 cannot be reached by using only the variable stiffness flexible energy storage loading rod 14, the first hydraulic cylinder 16 is controlled to extend, and the first hydraulic cylinder 16 is used to apply a force to the variable stiffness flexible energy storage loading rod 14, thereby increasing the force acting on the coal rock specimen 21, and when the strength limit of the coal rock specimen 21 is reached, the release of the elastic potential energy stored in the variable stiffness flexible energy storage loading rod 14 is not affected.

[0051] Embodiment 2

[0052] like Figure 2 As shown, the difference between this embodiment and the first embodiment is that, in order to facilitate the calculation of the elastic potential energy stored in the variable stiffness flexible energy storage loading rod 14 and to better verify the simulation test results, the variable stiffness flexible energy storage loading device also includes:

[0053] The limit assembly is installed on the top seat 2 and is used to control the deformation of the variable-rigidity flexible energy storage loading rod 14 .

[0054] A further optimized solution is that the limit assembly includes a limit rod 17, which is fixedly connected to the top end of the mounting sleeve 13, the top end of the limit rod 17 passes through the top seat 2 and slides with the top seat 2, and a length scale is provided on the limit rod 17; a vertical adjustment screw 18 is threadedly connected to the top seat 2, and a positioning sleeve 19 is rotatably connected to the top end of the vertical adjustment screw 18, the positioning sleeve 19 is located above the top seat 2, and a locking screw 20 is slidably sleeved in the positioning sleeve 19, and a plurality of threaded holes are opened in the vertical direction on the limit rod 17, and the locking screw 20 is threadedly engaged with the threaded holes.

[0055] When in use, the shortening distance of the vertical hydraulic cylinder 12 is controlled by the limit rod 17. At this time, the deformation of the variable stiffness flexible energy storage loading rod 14 is fixed, and the coal rock specimen 21 has not reached the strength limit. The limit rod 17 is fixed by the locking screw 20 in the positioning sleeve 19 to keep the position of the limit rod 17 and the variable stiffness flexible energy storage loading rod 14 unchanged. When the locking screw 20 is not aligned with the threaded hole on the limit rod 17, the locking screw 20 can be aligned with the threaded hole on the limit rod 17 by adjusting the height of the vertical adjustment screw 18, and the limit rod 17 is fixed by the locking screw 20. Then the first hydraulic cylinder 16 is controlled to extend, and the first hydraulic cylinder 16 is used to apply a force to the variable stiffness flexible energy storage loading rod 14, thereby increasing the force acting on the coal rock specimen 21 until the strength limit of the coal rock specimen 21 is reached.

[0056] The above are only preferred specific implementations of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by any technician familiar with the technical field within the technical scope disclosed in the present application should be covered within the protection scope of the present application.

Claims

1. A variable stiffness flexible energy storage loading test device, characterized in that: include: A loading system, the loading system comprising a confining pressure simulation device and a variable stiffness flexible energy storage loading device; The confining pressure simulation device is used to apply force to the bottom and side surfaces of the coal-rock mass specimen (21) to simulate the underground confining pressure environment in which the coal-rock mass specimen (21) is located; the variable stiffness flexible energy storage loading device is used to apply force to the top surface of the coal-rock mass specimen (21) and store elastic potential energy; A hydraulic system, the hydraulic system is used to provide power for the operation of the loading system; A control system is used to control the operation of the hydraulic system and collect test data of the loading system during the loading process.

2. The variable stiffness flexible energy storage loading test device according to claim 1 is characterized in that: The confining pressure simulation device comprises: A bottom support mechanism, the coal-rock mass specimen (21) is placed on the top of the bottom support mechanism, and the bottom support mechanism is used to support and limit the position of the coal-rock mass specimen (21); A side loading mechanism, the side loading mechanism being symmetrically arranged on both sides of the coal-rock mass specimen (21), the side loading mechanism being used to support and limit the side wall of the coal-rock mass specimen (21), and the side loading mechanism being connected to the hydraulic system; A support frame, wherein the bottom support mechanism and the side loading mechanism are both installed in the support frame.

3. The variable stiffness flexible energy storage loading test device according to claim 2 is characterized in that: The support frame comprises a base (1), a top seat (2) and a plurality of connecting rods (3); the two ends of the connecting rods (3) respectively penetrate the base (1) and the top seat (2); the two ends of the connecting rods (3) are threadedly connected with locking nuts (4); the base (1) and the top seat (2) are detachably connected to the connecting rods (3) via the locking nuts (4).

4. The variable stiffness flexible energy storage loading test device according to claim 3 is characterized in that: The bottom support mechanism comprises a bottom support plate (5), the bottom support plate (5) is arranged at the top of the base (1), a support column (6) is installed at the top of the bottom support plate (5), a bottom baffle (7) is arranged at the top of the support column (6), and the coal rock specimen (21) is placed at the top of the bottom baffle (7).

5. The variable stiffness flexible energy storage loading test device according to claim 4 is characterized in that: The lateral loading mechanism comprises a vertical support plate (8), wherein the vertical support plate (8) is fixedly mounted on the top of the base (1); a second hydraulic cylinder (9) is fixedly mounted on the side of the vertical support plate (8) close to the coal rock specimen (21); the second hydraulic cylinder (9) is arranged in the horizontal direction and is connected to the hydraulic system; a loading head (10) is fixedly mounted on the end of the second hydraulic cylinder (9); a side baffle (11) is arranged on the side of the loading head (10) away from the second hydraulic cylinder (9); the loading head (10) is in contact with the side baffle (11); the side baffle (11) is an L-shaped structure; the bottom baffle (7) and the side baffle (11) are slidably matched; the bottom baffle (7) and the two side baffles (11) form a placement groove; the coal rock specimen (21) is arranged in the placement groove.

6. The variable stiffness flexible energy storage loading test device according to claim 3 is characterized in that: The variable stiffness flexible energy storage loading device comprises: An elastic potential energy storage loading mechanism, the elastic potential energy storage loading mechanism being mounted on the base (1), the loading head (10) of the elastic potential energy storage loading mechanism being in contact with the top of the coal rock mass specimen (21); A vertical loading mechanism, the vertical loading mechanism is fixedly mounted on the bottom end of the top seat (2), and the vertical loading mechanism is located above the elastic potential energy storage loading mechanism, and the vertical loading mechanism applies a force to the coal rock mass specimen (21) through a loading head (10) of the elastic potential energy storage loading mechanism; The elastic potential energy storage loading mechanism and the vertical loading mechanism are both connected to the hydraulic system.

7. The variable stiffness flexible energy storage loading test device according to claim 6, characterized in that: The elastic potential energy storage loading mechanism comprises a vertical hydraulic cylinder (12) fixedly mounted on the base (1), the vertical hydraulic cylinder (12) being connected to the hydraulic system, a mounting sleeve (13) being fixedly connected to the top end of the vertical hydraulic cylinder (12), a variable stiffness flexible energy storage loading rod (14) being detachably mounted in the mounting sleeve (13), and the loading head (10) being fixedly connected to the bottom end of the variable stiffness flexible energy storage loading rod (14).

8. The variable stiffness flexible energy storage loading test device according to claim 7, characterized in that: The vertical loading mechanism comprises a top support plate (15), wherein the top support plate (15) is fixedly mounted on the bottom end of the top seat (2), and the bottom end of the top support plate (15) is fixedly connected to a first hydraulic cylinder (16), wherein the first hydraulic cylinder (16) is connected to the hydraulic system, and the bottom end of the first hydraulic cylinder (16) is arranged corresponding to the variable stiffness flexible energy storage loading rod (14), and the loading head (10) on the variable stiffness flexible energy storage loading rod (14) is coaxially arranged with the first hydraulic cylinder (16).

9. The variable stiffness flexible energy storage loading test device according to claim 7, characterized in that: The variable stiffness flexible energy storage loading device also includes: A limit assembly is installed on the top seat (2), and is used to control the deformation of the variable-rigidity flexible energy storage loading rod (14).

10. The variable stiffness flexible energy storage loading test device according to claim 9, characterized in that: The limit assembly comprises a limit rod (17), the limit rod (17) is fixedly connected to the top end of the installation sleeve (13), the top end of the limit rod (17) passes through the top seat (2) and is slidably matched with the top seat (2), and a length scale is provided on the limit rod (17); a vertical adjustment screw (18) is threadedly connected to the top seat (2), and a positioning sleeve (19) is rotatably connected to the top end of the vertical adjustment screw (18), and the positioning sleeve (19) is located above the top seat (2), and a locking screw (20) is slidably sleeved in the positioning sleeve (19), and a plurality of threaded holes are opened on the limit rod (17) along the vertical direction, and the locking screw (20) is threadedly matched with the threaded holes.

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