Multi-dimensional dynamic and static combined loading mechanical experiment device for cylindrical rock sample
By using a sealed pressure chamber and an internal pressure mechanism to apply uniform static stress to the cylindrical specimen in the Hopkinson bar experimental setup, the complexity of the true triaxial Hopkinson bar experimental setup and the problem of static stress control were solved, achieving the effects of simplified operation and improved experimental accuracy.
Patent Information
- Application Number
- CN202520117047.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-18
- Publication Date
- 2025-12-19
- Estimated Expiration
- 2035-01-18
AI Technical Summary
The existing true triaxial Hopkinson bar experimental apparatus is complex in structure, cumbersome to operate, difficult to control the uniformity of static stress, and differs significantly from the actual stress conditions of rocks, resulting in inaccurate experimental results.
A sealed pressure chamber and an internal pressure mechanism are used to apply uniform static stress to the cylindrical specimen. Dynamic disturbance loading is then performed using a Hopkinson bar test device to construct a true triaxial static stress + dynamic disturbance load loading process, which can be achieved with only one Hopkinson bar test device.
It improves the accuracy and reference value of experimental results, simplifies the operation process, and provides good static stress uniformity, making it closer to the actual stress conditions of rocks.
Smart Images
Figure CN223692145U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model belongs to rock mechanics performance experiment technical field relates to a kind of cylinder rock sample multidimensional dynamic static combination loading mechanics experimental device. BACKGROUND
[0002] Hopkinson bar experiment is based on one-dimensional stress wave theory, used to study the dynamic mechanical properties of materials under high strain rate, which can effectively and accurately obtain the stress-strain curve of the material.
[0003] Hopkinson bar experimental device mainly includes three parts: bullet launcher, input rod, output rod, in the experimental process, the sample to be tested is placed between input rod and output rod, bullet launcher launches spindle-shaped punch, spindle-shaped punch impacts input rod at a certain speed, an incident wave is generated in input rod, incident wave passes through the sample to be tested and enters output rod, the sample to be tested produces high-speed deformation under the action of incident wave. When incident wave passes through the sample to be tested, reflection wave and transmission wave are generated simultaneously, wherein reflection wave enters input rod, and transmission wave enters output rod. By installing strain gauges on input rod and output rod, incident wave, reflection wave and transmission wave can be measured. By measuring the strain-time curve of incident wave, reflection wave and transmission wave, the stress-time curve and particle velocity-time curve of the end surface of the sample to be tested can be calculated, and then the stress-strain curve of the sample to be tested can be derived from these curves.
[0004] For deep rock and other materials, they are often subjected to stress in multiple directions, and the stress state is complex. Therefore, on the basis of Hopkinson bar experimental device, true triaxial Hopkinson bar experimental device is developed. The true triaxial Hopkinson bar experimental device is more advanced and is mainly used to study the dynamic mechanical behavior of materials under complex stress state. The true triaxial Hopkinson bar experimental device is composed of three Hopkinson bar experimental devices. In the true triaxial Hopkinson bar experiment, the sample to be tested is a cuboid or a cube structure, and the input rods and output rods of the three Hopkinson bar experimental devices contact different surfaces of the sample to be tested, so that the true triaxial Hopkinson bar can apply static stress in three directions. However, in actual experimental process, the three Hopkinson bar experimental devices do not impact at the same time. In one experiment, only the Hopkinson bar experimental device in one direction impacts, and the remaining Hopkinson bars apply static stress to the sample to be tested. The Hopkinson bar experimental device that impacts provides dynamic disturbance load, which is equivalent to the true triaxial Hopkinson bar experiment testing the dynamic behavior of materials under complex stress state by dynamic and static combined loading method.
[0005] Through true triaxial Hopkinson bar experiment, the stress-strain curve of the material under different strain rates can be obtained, which not only provides the possibility for understanding the failure mechanism of the material under high-speed impact, but also verifies the related strength criterion and obtains the material characteristic parameters.
[0006] For oil and gas exploitation, tunnel excavation and other engineering, it involves the process of destroying deep rock, thus, it is usually necessary to sample the deep rock and carry out true triaxial hopkinson bar experiment to study the mechanical properties and failure mechanism of the deep rock, so as to predict the mechanical behavior of the deep rock and provide guidance for related engineering. The deep rock is under the action of the stress direction of the surrounding rock in the real environment, and the static stress of the deep rock is relatively uniform in the static state. However, the current true triaxial hopkinson bar experiment needs to use three hopkinson bar experimental devices, which is relatively complex in structure and is relatively troublesome to operate. The three hopkinson bar experimental devices are independent of each other, and it is difficult to control the uniformity of the static stress applied to the measured material, and stress inhomogeneity is prone to occur. At the same time, the static stress applied to the rock by the three hopkinson bars is only in three directions, which is quite different from the real static stress of the rock.
[0007] Therefore, it is necessary to provide a multi-dimensional dynamic and static combined loading rock mechanics experimental device using a thick-walled cylindrical sample, which simplifies the complexity of the true triaxial hopkinson bar experimental device for rock, reduces the gap between the experimental conditions and the real situation of the rock, and makes the experimental results closer to the real results, thereby improving the accuracy and reference value of the experimental results. The utility model discloses
[0008] In order to overcome the problems in the background art, the utility model discloses an inner pressurizing mechanism to uniformly apply static stress from inside to outside to the cylindrical sample, injects liquid into the sealed pressurizing bin to uniformly apply static stress from outside to inside to the cylindrical sample, and applies axial static stress to the cylindrical sample through the hopkinson bar experimental device to create true triaxial static stress conditions. Then, the cylindrical sample is impacted by the hopkinson bar experimental device to dynamically disturb the cylindrical sample under the true triaxial static stress conditions, that is, the true triaxial static stress + dynamic disturbance load loading process is completed, which is equivalent to the true triaxial hopkinson bar experiment. The utility model applies static pressure to the cylindrical sample through the liquid. After the liquid fills the sealed pressurizing bin, the cylindrical sample can be uniformly pressurized, and the pressurizing direction of the liquid to the cylindrical sample is relatively rich, which is closer to the real pressurizing condition of the surrounding rock to the rock, thereby improving the accuracy and reference value of the experimental results. At the same time, the utility model only needs to use one hopkinson bar experimental device, which is relatively simple in structure and easy to operate.
[0009] In order to achieve the above-mentioned purpose, the utility model discloses the following technical scheme:
[0010] The experimental device comprises a sealed pressurized bin 1, a Hopkinson bar experimental device 2, and an internal pressurizing mechanism 3, the sealed pressurized bin 1 is located between an input rod 201 and an output rod 202 of the Hopkinson bar experimental device 2, the surface of the sealed pressurized bin 1 in contact with the input rod 201 and the output rod 202 is composed of elastic pads 5, the remaining surface of the sealed pressurized bin 1 is composed of rigid plates, a cylindrical sample 4 is placed in the sealed pressurized bin 1, and the cylindrical sample is coaxial with the input rod 201, an exhaust port 6 is arranged at the top of the sealed pressurized bin 1, a first exhaust valve 7 is arranged on the exhaust port 6, a liquid inlet pipe 8 is arranged at the bottom of the sealed pressurized bin 1, and a first pressure relief valve 9 is arranged on the liquid inlet pipe 8, the internal pressurizing mechanism 3 is arranged in a through hole in the middle of the cylindrical sample 4, and the internal pressurizing mechanism 3 loads pressure on the cylindrical sample 4.
[0011] Preferably, the internal pressurizing mechanism 3 comprises a waterproof hose 301, a conical channel 302, a second exhaust valve 303, and a second pressure relief valve 304, the waterproof hose 301 is arranged in the through hole in the middle of the cylindrical sample 4, the outer side wall of the waterproof hose 301 is in contact with the inner side wall of the cylindrical sample 4, the two ends of the waterproof hose 301 respectively pass through the elastic pads 5 and respectively pass out of the input rod 201 and the output rod 202, the conical channel 302 is arranged in the waterproof hose 301 at the elastic pads 5, the conical channel 302 is coaxial with the cylindrical sample 4 and the tip of the conical channel 302 faces the sealed pressurized bin 1, and the two ends of the waterproof hose 301 are respectively provided with the second exhaust valve 303 and the second pressure relief valve 304.
[0012] Preferably, the elastic pads 5 have a double-layer structure.
[0013] Preferably, the liquid inlet pipe 8 is connected with a first hydraulic pump 10.
[0014] Preferably, one end of the waterproof hose 301 provided with the second pressure relief valve 304 is connected with a second hydraulic pump 305.
[0015] Preferably, the rigid plates are made of transparent material.
[0016] The utility model discloses the beneficial effects of:
[0017] 1. The utility model discloses a sealed pressurized bin is filled with liquid to the cylindrical sample loading static pressure, and the pressure uniformity is better, and the situation is closer to the actual surrounding rock to the rock and is exerted static pressure, is favorable to improve the experimental result accuracy, makes the experimental result more has the reference value.
[0018] 2. The utility model discloses a liquid is injected to waterproof hose, with the increase of liquid injection amount, can be from the inside to the outside to the cylinder sample and exert static stress, provide support for the construction true triaxial static stress initial condition, and this mode exerted static stress also has good uniformity, and static stress direction is also more rich, further improve the experimental result accuracy.
[0019] 3. The utility model discloses only need to use a hopkinson bar experimental device to realize true triaxial static stress + dynamic disturbance load loading process, simple structure, easy operation. BRIEF DESCRIPTION OF DRAWINGS
[0020] Figure 1 It is the sealed compression chamber structure schematic diagram of the utility model;
[0021] Figure 2 It is the whole structure schematic diagram of the utility model;
[0022] Figure 3 It is the cylinder sample stress stereogram in the experimental process of the utility model;
[0023] Figure 4 It is the cylinder sample stress front view in the experimental process of the utility model;
[0024] Figure 5 It is the cylinder sample stress side view in the experimental process of the utility model.
[0025] In the drawing, 1-sealed compression chamber, 2-hopkinson experimental device, 201-input rod, 202-output rod, 203-bullet launching device, 204-velocity measuring device, 205-strain gauge, 206-video camera, 207-absorption rod, 208-damper, 3-inner pressurizing mechanism, 301-waterproof hose, 302-conical passage, 303-second exhaust valve, 304-second pressure relief valve, 305-second hydraulic pump, 4-cylinder sample, 5-elastic pad, 6-exhaust port, 7-first exhaust valve, 8-liquid inlet pipe, 9-first pressure relief valve, 10-first hydraulic pump. DETAILED DESCRIPTION
[0026] The utility model will be described in further detail below in conjunction with the drawings, but the protection scope of the present application is not limited to the content described.
[0027] As Figures 1-2As shown, the experimental device includes a sealed pressurized bin 1, a Hopkinson bar experimental device 2, an internal pressurizing mechanism 3, the sealed pressurized bin 1 is located between an input rod 201 and an output rod 202 of the Hopkinson bar experimental device 2, the surface of the sealed pressurized bin 1 in contact with the input rod 201 and the output rod 202 is composed of elastic pads 5, the remaining surface of the sealed pressurized bin 1 is composed of rigid plates, the cylindrical sample 4 is placed in the sealed pressurized bin 1, and the cylindrical sample is coaxial with the input rod 201, an exhaust port 6 is arranged at the top of the sealed pressurized bin 1, a first exhaust valve 7 is installed on the exhaust port 6, a liquid inlet pipe 8 is arranged at the bottom of the sealed pressurized bin 1, a first pressure relief valve 9 is installed on the liquid inlet pipe 8, the internal pressurizing mechanism 3 is arranged in a through hole in the middle of the cylindrical sample 4, and the internal pressurizing mechanism 3 loads pressure on the cylindrical sample 4.
[0028] Figure 2 Among them, the input rod 201, the output rod 202, the bullet launching device 203, the speed measuring device 204, the strain gauge 205, the camera 206, the absorbing rod 207, and the damper 208 all belong to the components of the conventional Hopkinson bar experimental device.
[0029] Before the formal start of the experiment, first place the sealed pressurized bin 1 in which the cylindrical sample 4 has been placed between the input rod 201 and the output rod 202 of the Hopkinson bar experimental device 2, then adjust the input rod 201 and the output rod 202 so that the input rod 201 and the output rod 202 clamp the sealed pressurized bin 1, and confirm that the cylindrical sample 4 is coaxial with the input rod 201, since the surface of the sealed pressurized bin 1 in contact with the input rod 201 and the output rod 202 is composed of elastic pads 5, the input rod 201 and the output rod 202 clamp the sealed pressurized bin 1 at the same time, and also clamp the cylindrical sample 4, and the input rod 201 and the output rod 202 exert a static stress (such as Figure 3 、 4 Among them P 3) Adjust to meet the experimental requirements, then open the first pressure relief valve 9 and the first exhaust valve 7, inject liquid into the sealed pressurized bin 1 through the liquid inlet pipe 8, usually water can be used, as the liquid enters the sealed pressurized bin 1, the gas in the sealed pressurized bin 1 is exhausted from the exhaust port 6, when the sealed pressurized bin 1 is filled with liquid, the gas is completely exhausted, the first exhaust valve 7 is closed, and the injection of liquid into the sealed pressurized bin 1 is continued until the static stress exerted by the liquid on the cylindrical sample 4 meets the experimental requirements, the first pressure relief valve 9 is closed, and the sealed pressurized bin 1 is in a sealed state, the liquid exerts a constant static stress on the cylindrical sample 4 from the outside to the inside (such as Figure 3 、 4 Among them P 2, the static stress is uniform and the direction is rich), operate the internal pressurizing mechanism 3, so that the internal pressurizing mechanism 3 exerts a constant static stress on the cylindrical sample 4 from the inside to the outside (such as Figure 3 、 4 Among them P1), until the inner pressurizing mechanism 3 applies a static stress to the cylindrical sample 4 to meet the experimental requirements, at which time the cylindrical sample 4 is in the initial condition of three-dimensional static stress (as shown in Figure 3 、 4 , 5), and then the Hopkinson bar experimental device 2 is started, and the subsequent experiment is performed according to the Hopkinson bar experimental process, the bullet launching device 203 launches the spindle-shaped punch to impact the input rod 201, and provides a dynamic disturbance load for the cylindrical sample 4 (as shown in Figure 3 、 4 , P 4).
[0030] The inner pressurizing mechanism 3 includes a waterproof hose 301, a conical passage 302, a second exhaust valve 303, and a second pressure relief valve 304. The waterproof hose 301 is arranged in the middle through hole of the cylindrical sample 4, and the outer wall of the waterproof hose 301 is in contact with the inner wall of the cylindrical sample 4. Both ends of the waterproof hose 301 pass through the elastic pad 5 and are respectively drawn out from the input rod 201 and the output rod 202. The conical passage 302 is arranged in the waterproof hose 301 at the elastic pad 5. The conical passage 302 is coaxial with the cylindrical sample 4, and the tip of the conical passage 302 faces the sealed loading bin 1. The second exhaust valve 303 and the second pressure relief valve 304 are arranged at both ends of the waterproof hose 301.
[0031] Before the formal experiment starts, the inner pressurizing mechanism 3 needs to apply a constant static stress from the inside to the outside of the cylindrical sample 4. First, open the second exhaust valve 303 and the second pressure relief valve 304, inject liquid into the waterproof hose 301 from the pipe opening at one end of the waterproof hose 301 where the second pressure relief valve 304 is arranged, usually use water, and the liquid flows along the waterproof hose 301 to expel the gas in the waterproof hose 301 from the end of the waterproof hose 301 where the second exhaust valve 303 is arranged. When the gas in the waterproof hose 301 is expelled, close the second exhaust valve 303, as shown in Figure 1 After the second exhaust valve 303 is closed, liquid is injected into the waterproof hose 301, and the liquid reaches the right conical passage 302 from the right waterproof hose 301 in Figure 1 , then the liquid enters the conical passage 302 through the larger radius end of the conical passage 302, flows out of the conical passage 302 through the smaller radius end of the conical passage 302, and flows into the waterproof hose 301 in the middle through hole of the cylindrical sample 4, and continues to be injected into Figure 1The liquid flows through the waterproof hose 301 on the left. After reaching the tapered channel 302 on the left, the liquid flows into the tapered channel 302 through the smaller radius end and out through the larger radius end. Since the second exhaust valve 303 is closed, the liquid entering the waterproof hose 301 will expand the radius of the waterproof hose 301. Because the flow velocity of the liquid decreases significantly when it flows into the tapered channel 302 from the smaller radius end, the liquid in the waterproof hose 301 located in the through hole in the middle of the cylindrical sample 4 stays in this section of the waterproof hose 301 for a longer period, expanding the radius of this section of the waterproof hose 301. This, in turn, applies static stress from the inside out to the cylindrical sample 4 (such as...). Figure 3 , 4 5 P 1. The static stress is uniform and has multiple directions. During the experiment, the experimenter can monitor the static stress from the inside to the outside of the cylindrical sample 4 in real time, and adjust the flow rate of the liquid injected into the waterproof hose 301 according to the monitoring results, so that the static stress from the inside to the outside of the cylindrical sample 4 is kept in a relatively constant state. Figure 1 Only one embodiment is shown, in which the second pressure relief valve 304 is installed... Figure 1 The second vent valve 303 is installed at the left end of the waterproof hose 301. Figure 1 The right end of the 301 waterproof hose, from Figure 1 Liquid is injected into the left end of the waterproof hose 301, with the liquid flowing in the opposite direction to the above-mentioned direction, to achieve the same effect.
[0032] The elastic pad 5 has a double-layer structure.
[0033] The inlet pipe 8 is connected to a first hydraulic pump 10. The first hydraulic pump 10 pumps the liquid into the sealed pressurized chamber 1.
[0034] One end of the waterproof hose 301, equipped with a second pressure relief valve 304, is connected to a second hydraulic pump 305. The second hydraulic pump 305 pumps liquid into the waterproof hose 301.
[0035] The rigid plate is made of a transparent material, allowing for easy observation of the interior of the sealed pressurized chamber 1.
[0036] The utility model discloses a working process: before formally starting experiment, first, the cylindrical sample is put into the sealed pressurizing bin (the sealed pressurizing bin 1 rigid board portion is provided with the passageway that can add or take out the cylindrical sample and the bin door that can seal passageway, and the passageway and bin door belong to conventional technology, not shown in the drawing), and the sealed pressurizing bin is arranged between the input rod and the output rod of the hopkinson bar experimental device, and the input rod and the output rod are adjusted, so that the input rod and the output rod clamp the sealed pressurizing bin and the cylindrical sample, and the static stress that the input rod and the output rod exert on the cylindrical sample is adjusted to meet the experimental requirement, then the first exhaust valve and the first pressure relief valve are opened, the first liquid pump is started, and the liquid is pumped into the sealed hydraulic bin through the liquid inlet pipe, when the sealed hydraulic bin is filled with liquid, the first exhaust valve is closed, and the liquid is continuously pumped into the sealed pressurizing bin until the static stress that the liquid exerts on the cylindrical sample meets the experimental requirement, the first pressure relief valve is closed, then the second exhaust valve and the second pressure relief valve are opened, the second hydraulic pump is started, and the liquid is pumped into the waterproof hose, when the liquid enters the waterproof hose and expels the gas, the second exhaust valve is closed, and the liquid is continuously pumped into the waterproof hose until the static stress that the liquid exerts on the cylindrical sample meets the experimental requirement, then the hopkinson bar experimental device is started to carry out experiment, and the subsequent experimental operation is carried out according to the conventional hopkinson bar experimental operation, during the experiment, the staff can adjust the liquid flow that is pumped into the waterproof hose to keep the static stress that the liquid in the waterproof hose exerts on the cylindrical sample in a relatively constant state.
[0037] Finally, it is pointed out that the above preferred embodiments are only used for describing the technical scheme of the utility model and not for limiting, although the utility model has been described in detail through the above preferred embodiments, but those skilled in the art should understand that various changes can be made to it in form and in detail without departing from the range defined by the utility model claims.
Claims
1. A multidimensional dynamic and static combined loading mechanical experimental device for cylindrical rock specimens, characterized in that: The experimental device comprises a sealed pressurized bin (1), a Hopkinson bar experimental device (2), and an internal pressurizing mechanism (3). The sealed pressurized bin (1) is located between an input rod (201) and an output rod (202) of the Hopkinson bar experimental device (2). The surface of the sealed pressurized bin (1) in contact with the input rod (201) and the output rod (202) is composed of elastic pads (5), and the remaining surface of the sealed pressurized bin (1) is composed of rigid plates. A cylindrical sample (4) is placed in the sealed pressurized bin (1), and the cylindrical sample (4) is coaxial with the input rod (201). An exhaust port (6) is arranged at the top of the sealed pressurized bin (1), and a first exhaust valve (7) is installed on the exhaust port (6). A liquid inlet pipe (8) is arranged at the bottom of the sealed pressurized bin (1), and a first pressure relief valve (9) is installed on the liquid inlet pipe (8). The internal pressurizing mechanism (3) is arranged in a through hole in the middle of the cylindrical sample (4), and the internal pressurizing mechanism (3) loads pressure on the cylindrical sample (4).
2. The multi-dimensional dynamic and static combined loading mechanical experiment device for a cylindrical rock sample according to claim 1, characterized in that: The internal pressurizing mechanism (3) comprises a waterproof hose (301), a conical channel (302), a second exhaust valve (303), and a second pressure relief valve (304). The waterproof hose (301) is arranged in the through hole in the middle of the cylindrical sample (4), and the outer side wall of the waterproof hose (301) is in contact with the inner side wall of the cylindrical sample (4). The two ends of the waterproof hose (301) respectively pass through the elastic pads (5) and are respectively drawn out from the input rod (201) and the output rod (202). A conical channel (302) is arranged in the waterproof hose (301) at the elastic pads (5). The conical channel (302) is coaxial with the cylindrical sample (4), and the tip of the conical channel (302) faces the inside of the sealed pressurized bin (1). The two ends of the waterproof hose (301) are respectively provided with a second exhaust valve (303) and a second pressure relief valve (304).
3. The multi-dimensional dynamic and static combined loading mechanical experiment device for cylindrical rock samples according to claim 1, characterized in that: The elastic pads (5) have a double-layer structure.
4. The multi-dimensional dynamic and static combined loading mechanical experiment device for a cylindrical rock sample according to any one of claims 1-3, characterized in that: A first hydraulic pump (10) is connected to the liquid inlet pipe (8).
5. The multi-dimensional dynamic and static combined loading mechanical experiment device for cylindrical rock samples according to claim 2, characterized in that: One end of the waterproof hose (301) provided with the second pressure relief valve (304) is connected to a second hydraulic pump (305).
6. The multi-dimensional dynamic and static combined loading mechanical experiment device for cylindrical rock samples according to claim 1, characterized in that: The rigid plates are made of transparent material.