Device capable of realizing impact disturbance during uniaxial compression and test method

Abstract

The invention relates to the technical field of rock mechanics experiment equipment, and discloses a device capable of realizing impact disturbance in the whole process of uniaxial compression damage and a test method. The device comprises a rigid press machine, an impact cavity, a partition incident rod and an impact gasket, a rigid pressure head is controlled by a hydraulic system to apply static load, and accurate loading of dynamic impact is realized by utilizing an electromagnetic driving technology. 12 bullet tracks are arranged in the impact cavity, each track is provided with an annular inner side electromagnetic coil, an annular outer side electromagnetic coil and a magnetic fusiform bullet, and the bullet speed is controlled by adjusting the current direction and magnitude, so that the bullet hits the partition incident bar to transmit impact loads; an energy absorption structure is arranged in the partition incident bar, the tightness state of an energy absorption piece is adjusted through a knob switch, and switching between a single impact mode and an oscillation impact mode is achieved. The test method comprises the steps of pre-pressing a test piece, loading a static load, performing partition impact and applying synchronous impact disturbance. The device solves the problem of cooperative loading of dynamic and static loads, has the advantages of controllable impact force, multi-mode loading and high simulation of real working conditions, and is suitable for researching the dynamic mechanical response of fragile materials such as rocks and concrete.

Description

Technical Field

[0001] The present invention relates to the technical field of rock mechanics experimental equipment, and in particular to an experimental device capable of synchronously applying controllable impact disturbances during the entire uniaxial compression process, which is suitable for studying the mechanical response of brittle materials such as rock and concrete under dynamic loads. Background Art

[0002] Under long-term static stress, rock masses in underground spaces often suffer from damage due to impact disturbances caused by various external factors (such as earthquakes and explosions). This damage not only affects the stability of the underground space but also may cause serious safety hazards and economic losses to underground space projects (such as tunnels and mines).

[0003] In the fields of materials science and geotechnical engineering, uniaxial compression testing is an important means of evaluating the mechanical properties of materials. However, traditional uniaxial compression tests can often only provide static or quasi-static load conditions, and cannot accurately simulate the impact disturbances that materials are subjected to under actual working conditions. Although there are attempts to simulate dynamic and static loading devices in existing equipment, they are all carried out with dynamic loads as the main driving force for destructive force, such as the SHPB test (Hopkinson bar) system. Existing impact test equipment mostly adopts a separate design, and compression and impact loading are independent of each other, resulting in deviations between experimental conditions and actual working conditions. In addition, the precise control of the impact force and the lack of synchronization with the compression load limit the reliability of the experimental data. Therefore, the present invention develops a device that can apply impact disturbances during the entire static uniaxial compression process to simulate the actual loading conditions of rocks in underground space, which has urgent needs and important practical significance for in-depth research on the dynamic mechanical behavior of rock materials. Summary of the Invention

[0004] Based on the above background, this paper proposes a device and testing method for impact disturbance during uniaxial compression. This device utilizes electromagnetic drive technology to precisely control dynamic impact, combined with a hydraulic system to adjust the static compression load. This allows for flexible application of dynamic impact loads to rock or other material specimens during static compression, resolving the existing challenges of poor coordination between dynamic and static loading. The device comprises a rigid press, an impact chamber, a partitioned impact rod, and an impact gasket.

[0005] To achieve the above-mentioned purpose, the technical solution adopted by the present invention to solve the technical problem is: a device and a test method for realizing impact disturbance during uniaxial compression, comprising a rigid press (1), an impact cavity (4), a partitioned incident rod (5), an impact gasket (8) and a rock specimen (9); the rigid press comprises a top beam (2), a base (3), a rigid pressure head (7) and a special impact gasket (8); the upper part of the rigid pressure head (4) is controlled by a hydraulic system, and the outer part thereof is an annular impact cavity (4); the rigid press (1) can control the rigid pressure head (4) to apply a static load to the rock specimen (9) through an oil pressure control system (12).

[0006] As a further solution of the present invention, the impact chamber (4) is divided into 12 bullet tracks, and the inner wall (18) and outer wall (17) of each track impact chamber are respectively provided with an annular inner electromagnetic coil (14) and an annular outer electromagnetic coil (16); a magnetic shuttle bullet (15) and a partition incident rod (5) that can slide up and down are provided in the middle part of the annular inner electromagnetic coil (14) and the annular outer electromagnetic coil (16); by controlling the direction and magnitude of the current of the annular inner electromagnetic coil (14) and the annular outer electromagnetic coil (16), the reset and speed of the shuttle bullet (15) can be controlled, and the application of the impact load can be achieved when the shuttle bullet (15) hits the partition incident rod (5).

[0007] As a further solution of the present invention, there are 12 partition incident rods (5) arranged in the impact cavity (4), two grooves are arranged on the outside of the partition incident rod (5), a stud is arranged in the center of the groove, and a bolt clip (13) with damping is arranged on the stud. By rotating the bolt clip (13) to support the bottom of the impact cavity (4), the partition incident rod (5) can be prevented from moving upward and the partition incident rod (5) and the impact gasket (8) can be kept in close contact; an energy absorbing structure is arranged inside the partition incident rod (5), and the energy absorbing structure is an upper rectangular hollow The cylindrical space connected to the lower part is provided with a stud inside, an energy absorbing sheet (20) and a stop nut (19) are provided on the upper part of the stud, and a knob switch (21) is provided at the bottom. When the knob switch (21) is rotated, the stop nut (19) is lowered. At this time, the energy absorbing sheet (20) is in a loose state. When the partition incident rod (5) generates an impact, the energy absorbing sheets (20) collide with each other to consume energy. On the contrary, when the knob switch (21) is rotated, the stop nut (19) is raised. At this time, the energy absorbing sheets (20) are tightly fitted together and cannot achieve the energy absorption effect.

[0008] A device and test method for realizing impact disturbance during uniaxial compression, wherein the specific steps of the device and test method include:

[0009] Step 1: Turn on the impact chamber (4) switch to energize it and reset the position of the shuttle bullet (15).

[0010] Step 2: Place the rock specimen (9) and the impact gasket (8) and control the rigid pressure head to press down (4) through the oil pressure control system (12) to pre-press the rock specimen (9).

[0011] Step 3: Set the uniaxial compression parameters and load the rock specimen.

[0012] Step 4: When the static load reaches the set value, the shuttle-shaped bullet (15) in the impact chamber (4) begins to accelerate and hits the partitioned incident rod (5) to achieve dynamic load loading.

[0013] The energy absorption effect of the partitioned incident rod (5) is switched on or off by turning on or off the knob switch (21), thereby realizing two modes of single impact and oscillating impact. Compared with the prior art, the present invention has the following beneficial effects:

[0014] 1. The patented device and test method of this invention can realize impact disturbance during uniaxial compression. The static compression load is controlled by a hydraulic system, combined with dynamic impact loading driven by electromagnetics, to achieve the synchronous application of static and dynamic loads, more realistically simulate the composite stress state of materials such as rocks in actual engineering, and significantly improve the reliability of experimental data.

[0015] 2. The present invention provides a device and test method for realizing impact disturbance during uniaxial compression, wherein the impact force is precisely controllable: by adopting a design in which annular inner and outer electromagnetic coils (14, 16) are matched with a magnetic shuttle bullet (15), by adjusting the direction and magnitude of the current, the following are achieved: (1) Acceleration is precisely controlled: the acceleration a of the shuttle bullet is determined by the Ampere force formula F = n·B·I·L (where n is the number of coil turns, B is the magnetic induction intensity, I is the current, and L is the magnetic length of the bullet). By adjusting the current I, the acceleration a is linearly controlled (a is proportional to I), achieving an acceleration range of 0.5×10 4 m / s 2 ~5×10 4 m / s 2 (2) Real-time speed programming: The impact speed v is determined by the current-time integral relationship v = ∫a·dt, and the It curve is preset by the current controller to achieve stepless adjustment of the bullet speed from 5 to 50 m / s.

[0016] 3. The present invention provides a device and test method for realizing impact disturbance during uniaxial compression, simulating multi-mode impact loading during stress wave propagation: (1) Multi-track synchronous / asynchronous impact: Synchronous impact: 12 independent tracks are simultaneously fed with the same current, so that the bullets synchronously hit the partitioned incident rod (5), and the total impact force is superimposed; Asynchronous impact: Each track is triggered one by one according to a preset time delay (0-100ms); (2) Single impact / oscillation impact: The tightness of the energy absorption structure is adjusted by a knob switch, and the single impact mode (energy absorption closed) and the oscillation impact mode (energy absorption opened) can be switched to meet the requirements of different experimental scenarios for impact waveform and energy transfer. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 Schematic diagram of the overall structure of the device of this patent

[0018] Figure 2 This is a schematic diagram of the working structure of the patent of this invention

[0019] Figure 3 This is the static and dynamic loading part of the patent of this invention

[0020] Figure 4 Schematic diagram of the impact chamber structure of the patent of this invention

[0021] Figure 5 Schematic diagram of the internal structure of the impact chamber of the patent of this invention

[0022] Figure 6 This is the cross-sectional structure diagram of the impact cavity of the patent of this invention

[0023] Figure 7 Schematic diagram of the partitioned incident rod and internal structure of the patented invention

[0024] Figure 8 Schematic diagram of the switch status of the partitioned incident rod energy absorption device of the present invention

[0025] In the figure: 1. Rigid press, 2. Top beam, 3. Base, 4. Impact chamber, 5. Partitioned incident rod, 6. Compression gasket, 7. Rigid pressure head, 8. Impact gasket, 9. Rock specimen, 10. Transmission rod / rigid gasket, 11. Pressure platform, 12. Oil pressure control system, 13. Bolt clip, 14. Annular inner electromagnetic coil, 15. Shuttle bullet, 16. Annular outer electromagnetic coil, 17. Outer wall of impact chamber, 18. Inner wall of impact chamber, 19. Stop nut, 20. Energy absorbing sheet, 21. Knob switch. DETAILED DESCRIPTION

[0026] The present invention will be described in further detail below with reference to the accompanying drawings.

[0027] The method of realizing impact disturbance during uniaxial compression is as follows: Figure 1-8As shown, the power of the equipment is turned on, a rock specimen (9) and an impact gasket (8) are placed, and the rigid pressure head is controlled to press down (4) through the oil pressure control system (12) to pre-press the rock specimen (9).

[0028] After the pre-compression is completed, the bolt buckle (13) is tightened, and the partition incident rod (5) is tightly pressed against the compression gasket (6); at this time, the magnetic field formed by the power supply of the annular inner electromagnetic coil (14) and the annular outer electromagnetic coil (16) causes the shuttle bullet (15) to reset and be located above the impact cavity (4).

[0029] The computer sets the loading parameters of the static load and the dynamic load and starts loading. When the loading reaches the set static load, the electric signal is released, and the annular inner electromagnetic coil (14) and the annular outer electromagnetic coil (16) start to accelerate the shuttle bullet (15) to hit the partition incident rod (5), and then transfer the impact load to the compression gasket (6) to finally complete the impact loading of the rock specimen (9).

[0030] In summary, the present invention utilizes a hydraulic system to control a rigid ram to apply static loads, while utilizing electromagnetic drive technology to achieve precise dynamic impact loading. The mechanical structure and electrical control system of the impact rod and grouting sleeve enable precise control and operation of rock impact. This system is highly efficient, stable, and safe, and can be widely applied in various engineering applications requiring precise control and operation.

Claims

1. A device and test method for realizing impact disturbance during uniaxial compression, characterized by: The invention comprises a rigid press (1), an impact cavity (4), a partitioned incident rod (5), an impact gasket (8) and a rock specimen (9); the rigid press comprises a top beam (2), a base (3), a rigid pressing head (7) and a specially made impact gasket (8); the upper part of the rigid pressing head (4) is controlled by a hydraulic system, and the outer part thereof is an annular impact cavity (4); the rigid press (1) can control the rigid pressing head (4) to apply a static load to the rock specimen (9) through an oil pressure control system (12).

2. The device and test method for realizing impact disturbance during uniaxial compression according to claim 1, characterized in that: The synchronous coupling of the static load and the dynamic load is achieved in the following manner: the oil pressure control system (12) monitors the static load pressure value in real time, and when the static load reaches a preset threshold, an electric trigger signal is sent to the electromagnetic drive system, and the annular inner electromagnetic coil (14) and the annular outer electromagnetic coil (16) respond to the signal to drive the shuttle bullet (15) to impact the partitioned incident rod (5).

3. The device and test method for realizing impact disturbance during uniaxial compression according to claim 1 or 2, characterized in that: The 12 bullet tracks in the impact chamber (4) can be independently controlled by differentially setting the current magnitude and direction of the annular inner electromagnetic coil (14) and the annular outer electromagnetic coil (16) of each track to achieve: (a) The impact velocity of each shuttle bullet (15) is independently adjusted; (b) The impact timing of each track is set independently; (c) Bullet reset direction independent operation.

4. The device and test method for realizing impact disturbance during uniaxial compression according to claim 1, characterized in that: The impact cavity (4) is provided with a bullet track. The inner wall (18) and the outer wall (17) of each impact cavity are respectively provided with an annular inner electromagnetic coil (14) and an annular outer electromagnetic coil (16). A magnetic shuttle-shaped bullet (15) and a partition incident rod (5) that can slide up and down are provided in the middle part between the annular inner electromagnetic coil (14) and the annular outer electromagnetic coil (16). The resetting and speed control of the shuttle-shaped bullet (15) can be achieved by controlling the current direction and magnitude of the annular inner electromagnetic coil (14) and the annular outer electromagnetic coil (16). When the shuttle-shaped bullet (15) hits the partition incident rod (5), the impact load can be applied.

5. The device and test method for realizing impact disturbance during uniaxial compression according to claim 1, characterized in that: The impact chamber (4) is divided into 12 bullet tracks, and the annular inner electromagnetic coil (14) and the annular outer electromagnetic coil (16) of each track can be independently controlled.

6. The device and test method for realizing impact disturbance during uniaxial compression according to claim 1, characterized in that: There are 12 partition incident rods (5) arranged in the impact cavity (4), two grooves are arranged on the outside of the partition incident rod (5), a stud is arranged in the center of the groove, and a bolt buckle (13) with damping is arranged on the stud. By rotating the bolt buckle (13) to support the bottom of the impact cavity (4), the partition incident rod (5) can be prevented from moving upward and the partition incident rod (5) and the impact gasket (8) can be kept in close contact; an energy absorbing structure is arranged inside the partition incident rod (5), and the energy absorbing structure is a rectangular space connected to the lower part. The cylindrical space has a stud arranged inside, an energy absorbing sheet (20) and a stop nut (19) are arranged on the upper part of the stud, and a knob switch (21) is arranged on the bottom. When the knob switch (21) is rotated, the stop nut (19) is lowered. At this time, the energy absorbing sheet (20) is in a loose state. When the partition incident rod (5) generates an impact, the energy absorbing sheets (20) collide with each other to consume energy. On the contrary, when the knob switch (21) is rotated, the stop nut (19) is raised. At this time, the energy absorbing sheets (20) are tightly fitted together and cannot achieve the energy absorption effect.

7. The device and test method for realizing impact disturbance during uniaxial compression according to claim 6, characterized in that: The operation steps of the energy absorbing structure include: S1. Rotate the bolt buckle (13) to tighten the bottom of the impact chamber (4) and lock the partition incident rod (5) position; S2. When the energy absorption is turned on: the knob switch (21) rotates to drive the stop nut (19) down → the energy absorption sheet (20) is turned to a loose state; S3. When the energy absorption needs to be turned off: the knob switch (21) is rotated to drive the stop nut (19) to rise → the energy absorption sheet (20) is compressed as a whole.

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