Confining pressure and temperature coupled Hopkinson bar impact experiment device and method

Abstract

The invention discloses a confining pressure and temperature coupled Hopkinson bar impact test device and method, and belongs to the field of rock mechanics test devices, and the confining pressure and temperature coupled Hopkinson bar impact test device comprises a Hopkinson bar, a confining pressure and temperature loading device system, a steam generation device and a liquid nitrogen low-temperature device. The temperature and confining pressure combined loading device provided by the invention can realize combined loading of confining pressure and high temperature (normal temperature to 200 DEG C) and confining pressure and low temperature (normal temperature to-40 DEG C) of rocks, and meanwhile, the system can realize high-temperature and low-temperature repeated circulation effect on the rocks, namely, the rocks are heated to 200 DEG C by using a steam generation device firstly, and then are heated to 200 DEG C by using a steam generator; if natural cooling to normal temperature is actually carried out, at least four hours are needed; when the liquid nitrogen low-temperature system is used, the rock can be cooled to the normal temperature from 200 DEG C within 20 minutes, and if the liquid nitrogen low-temperature system is continuously used, the rock can be cooled to-40 DEG C. At present, no system can realize simultaneous loading of confining pressure, high temperature and low temperature, and repeated temperature rising and cooling.

Description

Technical Field

[0001] The invention relates to the technical field of rock mechanics test devices, and in particular to a Hopkinson bar impact test device and method for coupling confining pressure and temperature. Background Art

[0002] Under the background of major deep engineering construction and active mining of mineral resources, a large number of long and deep rock caverns have emerged. In the hydropower energy industry, many large hydropower projects that have been built or planned are mostly based on giant underground cavern groups as the main buildings. Many mineral resources have entered the deep mining stage. At present, the maximum mining depth of China's coal mines has reached about 1500m, and the mining is still going down at a rate of 15m per month per year; the mining depth of many metal mines has long exceeded 1500mm. In addition, the maximum mining depth of China's oil and gas has reached 9432 meters, which was created by the Luntan 1 well in the Tarim Oilfield, which was drilled to a depth of 8882 meters. With the increase in the mining depth of mineral resources, such as oil, coal and shale gas. The rock mass in underground engineering is in a complex geological environment of high ground stress, high temperature, high permeability water pressure and strong mining disturbance, namely "three highs and one disturbance". In addition, the rock materials in geotechnical engineering may also experience a temperature increase process, such as sudden high temperature disasters such as fires in deep mine tunnels. It is worth noting that with the increase in the depth of mineral resource mining, dynamic disasters such as rock bursts, coal and gas outbursts, and rock bursts are occurring more and more frequently, causing huge losses to people's lives and property.

[0003] To study the mechanism of dynamic disasters, we first analyze the environment of rocks in deep space. The deep rock mass is subjected to large vertical stresses generated by the deadweight of the overlying rock layers and tectonic stresses generated by geological structures, which ultimately lead to higher ground stresses, which are mainly static loads. Mine earthquakes and mining disturbances also have a certain impact on the construction of underground projects, which are dynamic loads. In addition, the strength of rocks will also be greatly affected by high temperature and water. The mechanical properties under the influence of high temperature, static load, and impact dynamic load coupling are crucial to the safe mining of deep resources. Among them, the split Hopkinson bar system is a very commonly used equipment for dynamic mechanical tests. However, when using the split Hopkinson bar impact, if the target rock block is loaded with confining pressure, the target rock block cannot be loaded with temperature; if the target rock block is loaded with temperature, the target rock block cannot be loaded with confining pressure. Patents CN202311252481.0, CN202210769474.7, CN202023170770.0, CN202110338949.2, and CN201220720702.3 realize the temperature loading of rocks, but cannot load the confining pressure. The main heating methods are heating by resistance wire, electric heating resistor, and electric heating furnace. These methods have slow heating speed and cannot achieve precise temperature control. Patent CN201410103245.7 realizes the combined loading of confining pressure and high temperature. However, the high temperature loading method is heating by resistance wire. This method has slow heating speed, uneven heating, and cannot achieve precise control of rock temperature. Summary of the invention

[0004] In order to solve the technical problems existing in the above-mentioned prior art that the Hopkinson bar device has slow heating speed, uneven heating, and cannot accurately control the rock temperature, the present invention provides a Hopkinson bar impact test device and method with confining pressure and temperature coupling.

[0005] In order to realize the above technical solution, the present invention provides a Hopkinson bar impact test device coupled with confining pressure and temperature, comprising:

[0006] The confining pressure and temperature loading device system comprises a shell, a hydraulic column, a gasket and a pressure-bearing guide block. A plurality of grooves are provided on the inner wall surface of the shell. The hydraulic column is composed of a telescopic part and a fixed part. One end of the fixed part is fixed in the groove. The telescopic part is telescopically connected to one end of the fixed part. The other end of the telescopic part is connected to the gasket. The inner side of the gasket is detachably connected to the pressure-bearing guide block.

[0007] Hopkinson bar, the Hopkinson bar includes a coaxially arranged incident bar, a transmission bar, an absorption bar, a high-pressure air chamber and a damper, the high-pressure air chamber is placed at one end of the incident bar, a test piece is placed between the incident bar and the transmission bar, and the test piece is wrapped by the Hopkinson bar; the end of the transmission bar away from the test piece is connected to the absorption bar, and the other end of the absorption bar is placed with a damper;

[0008] The steam generating device and the liquid nitrogen cryogenic device are respectively connected to the liquid nitrogen inlet and the steam inlet arranged on the pressure guide block through pipelines.

[0009] Furthermore, the steam generating device includes a water tank, which is connected to the booster pump using a first connecting pipe, on which a flow meter is provided, the booster pump is connected to the steam generator through a second connecting pipe, the steam generator is connected to the steam inlet through a third connecting pipe, on which a steam flow meter is provided, and one end of the third connecting pipe is connected to the steam pipe.

[0010] Furthermore, the steam generator includes a resistor and a first pressure relief valve.

[0011] Furthermore, a second pressure relief valve, a pressure gauge and a temperature gauge are provided on the steam pipeline.

[0012] Furthermore, the liquid nitrogen cryogenic device includes a liquid nitrogen bottle, an air pressure pump, an electric control cabinet, a thermometer, a liquid nitrogen channel and a line. The air pressure pump is connected to the electric control cabinet through the line, the air pressure pump and the liquid nitrogen bottle are connected in parallel through the liquid nitrogen channel, the end of the liquid nitrogen channel is connected to the liquid nitrogen inlet arranged on the pressure guide block, and a thermometer is provided on the liquid nitrogen channel close to the pressure guide block.

[0013] Furthermore, the liquid nitrogen recovery device is connected to the pressure guide block through a liquid nitrogen channel.

[0014] Furthermore, strain gauges are arranged on the incident rod and the transmission rod, the two strain gauges are connected to the ultra-dynamic strain gauge, and the ultra-dynamic strain gauge is connected to the oscilloscope.

[0015] Furthermore, the pressure-bearing guide block is composed of a thermal insulation layer, a guide layer and a heat-transmitting layer which are arranged from the outside to the inside, respectively; the guide layer is provided with a liquid nitrogen pipeline and a steam channel, and the heat-transmitting layer is provided with holes.

[0016] Furthermore, the steam channel is replaced by a heating plate.

[0017] Furthermore, a Hopkinson bar impact test method with confining pressure and temperature coupling comprises the following steps:

[0018] S1: Determine the confining pressure P and temperature T that need to be applied to the rock, and divide the confining pressure P and temperature T into T=0 and P>0;

[0019] There are three situations: T<0, P≥0; T≥0, P≥0.

[0020] S2: According to different confining pressure P and temperature T, choose whether to start the hydraulic column (11) and steam generation

[0021] device (4) and a liquid nitrogen cryogenic device (6);

[0022] S3: Repeat the experiment n times until the experimental value approaches stability, and then terminate the experiment.

[0023] The beneficial effects of the present invention are:

[0024] The invention provides a Hopkinson bar impact test device with confining pressure and temperature coupling, which consists of a Hopkinson bar, a confining pressure and temperature loading device system, a steam generating device and a liquid nitrogen cryogenic device.

[0025] The proposed combined loading device for temperature and confining pressure can realize the combined loading of confining pressure and high temperature (normal temperature to 200℃) and confining pressure and low temperature (normal temperature to -40℃) on rocks. At the same time, the system can realize repeated high and low temperature cycles on rocks, that is, first use the steam generator to heat the rock to 200℃. If it is cooled to normal temperature naturally, it will take at least 4 hours; use the liquid nitrogen cryogenic system to cool the rock from 200℃ to normal temperature within 20 minutes. If the liquid nitrogen cryogenic system is continued to be used, the rock can be cooled to -40℃. At present, there is no system that can realize the simultaneous loading of confining pressure and high and low temperatures, as well as repeated heating and cooling. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0027] Figure 1 It is a schematic diagram of the overall structure of a Hopkinson bar impact test device coupled with confining pressure and temperature;

[0028] Figure 2 It is the overall structural diagram of the Hopkinson bar;

[0029] Figure 3 It is the front view of the Hopkinson bar;

[0030] Figure 4 is a cross-sectional view of the Hopkinson bar;

[0031] Figure 5 is an overall schematic diagram of a steam generating device;

[0032] Figure 6 It is the overall schematic diagram of the liquid nitrogen cryogenic device;

[0033] Figure 7 This is the internal structure diagram of the pressure guide block;

[0034] Figure 8 A schematic diagram of a second embodiment of a Hopkinson bar impact test device coupled with confining pressure and temperature;

[0035] Fig. 9 The figure is a flow chart of a Hopkinson bar impact test method with coupling of confining pressure and temperature.

[0036] The above drawings include the following reference numerals:

[0037] 1. Hopkinson bar; 11. Hydraulic column; 111. Fixed part; 112. Telescopic part; 12. Hydraulic oil; 13. Gasket; 14. Pressure guide block; 141. Liquid nitrogen inlet; 142. Steam inlet; 1421. Steam pipeline; 143. Insulation layer; 144. Guide layer; 1441. Liquid nitrogen pipeline; 1442. Steam channel; 145. Heat-transmitting layer; 1451. Hole; 15. Shell; 16. Intelligent digital pressure gauge; 2. Test piece; 3. Confining pressure and temperature loading device system; 31. High-pressure gas chamber; 311. Punch; 32. Incident rod; 33. Strain gauge; 34. Transmission rod; 35. Absorption rod; 36. Damper; 4. Steam generating device; 41. Water tank; 42. First connecting pipe; 421. Flow meter; 43. Pressure pump; 44. Second connecting pipe; 45. Steam generator; 451. First pressure relief valve; 452. Resistor; 46. Third connecting pipe; 461. Steam flow meter; 47. Second pressure relief valve; 48. Pressure gauge; 49. Thermometer; 5. Steam recovery device; 6. Liquid nitrogen cryogenic device; 61. Liquid nitrogen bottle; 62. Air pressure pump; 63. Electric control cabinet; 64. Thermometer; 65. Liquid nitrogen channel; 66. Line; 7. Liquid nitrogen recovery device; 8. Heating plate. DETAILED DESCRIPTION

[0038] 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 present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0039] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0040] Unless otherwise specifically stated, the relative arrangement of the parts and steps described in these embodiments, numerical expressions and numerical values ​​do not limit the scope of the present invention. At the same time, it should be understood that, for ease of description, the sizes of the various parts shown in the accompanying drawings are not drawn according to the actual proportional relationship. The technology, methods and equipment known to ordinary technicians in the relevant field may not be discussed in detail, but in appropriate cases, the technology, methods and equipment should be regarded as a part of the authorization specification. In all examples shown and discussed here, any specific value should be interpreted as being merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters represent similar items in the following drawings, so once a certain item is defined in an accompanying drawing, it does not need to be further discussed in subsequent drawings.

[0041] See also Figures 1 to 7 As shown, the present invention provides a Hopkinson bar impact test device coupled with confining pressure and temperature, comprising:

[0042] The Hopkinson rod 1 comprises a shell 15, a hydraulic column 11, a gasket 13 and a pressure guide block 14. A plurality of grooves are provided on the inner wall surface of the shell 15. The hydraulic column 11 is composed of a telescopic part 112 and a fixed part 111. One end of the fixed part 111 is fixed in the groove. The telescopic part 112 is telescopically connected to one end of the fixed part 111. The other end of the telescopic part 112 is connected to the gasket 13. The inner side of the gasket 13 is detachably connected to the pressure guide block 14.

[0043] The confining pressure and temperature loading device system 3 includes a coaxially arranged incident rod 32, a transmission rod 34, an absorption rod 35, a high-pressure gas chamber 31 and a damper 36. The high-pressure gas chamber 31 is placed at one end of the incident rod 32, and a specimen 2 is placed between the incident rod 32 and the transmission rod 34. The specimen 2 is wrapped with a Hopkinson rod 1; the end of the transmission rod 34 away from the specimen 2 is connected to the absorption rod 35, and the other end of the absorption rod 35 is placed with a damper 36. The steam generating device 4 and the liquid nitrogen cryogenic device 6 are respectively connected to the liquid nitrogen inlet 141 and the steam inlet 142 arranged on the pressure guide block 14 through pipelines.

[0044] That is to say, when the Hopkinson bar impact test device coupled with confining pressure and temperature provided by the present invention is actually used, after the test piece 2 is placed at the corresponding position, the telescopic part 112 of the hydraulic column 11 is controlled to perform telescopic movement to clamp the test piece 2. Then, according to the test requirements, a temperature change environment is applied to the test piece 2 through the steam generating device 4 and / or the liquid nitrogen cryogenic device 6. Finally, the high-pressure gas chamber 31 is controlled to launch the punch 311 toward the test piece 2 to complete the test.

[0045] The ejected punch 311 finally passes through the transmission rod 34 and hits the damper 36 to prevent the punch from rushing out of the test facility, thereby causing unknown risks.

[0046] During this process, if it is necessary to apply confining pressure to the specimen 2, the telescopic portion of the hydraulic column 11 is controlled to continue to extend toward the position of the specimen 2, so as to achieve the effect of increasing the surrounding rock for the specimen.

[0047] The specific operation details are as follows:

[0048] The gasket 13 and the pressure guide block 14 are made of a material with high compressive strength and capable of withstanding high temperature (200 degrees Celsius) and low temperature (-30 degrees Celsius), such as austenitic heat-resistant steel. The hydraulic column 11 makes the rock confining pressure loading more accurate and can greatly increase the upper limit of the confining pressure. The pressure guide block 14 and the gasket 13 are detachable devices, which are connected and disassembled through grooves and guide rails. Figures 1 to 4 It is a Hopkinson bar 1 confining pressure and temperature loading device system 3. When the rock needs to be loaded with high temperature and confining pressure, the steam generating device 4 is used, the temperature is set to the target temperature, and the steam flows out of the steam generating device 4, passes through the steam pipe 1421, and then flows into the recovery unit. Since the liquid nitrogen pipe 1441 is a device that can bear pressure and conduct temperature, the continuous inflow of steam will cause the liquid nitrogen pipe 1441 to heat up, thereby causing the rock to reach a predetermined temperature. The hydraulic system is used to load the confining pressure of the rock to the target confining pressure, so that the loading of high temperature and confining pressure can be achieved. If only high temperature needs to be loaded, it is only necessary to start the steam generation. If only confining pressure needs to be loaded, it is only necessary to start the confining pressure loading device.

[0049] When the rock needs to be loaded with low temperature and confining pressure, a liquid nitrogen cryogenic device 6 is used, and the temperature is set to the target temperature. The liquid nitrogen flows out of the liquid nitrogen cryogenic device 6, passes through the liquid nitrogen pipeline 1441, and then flows into the recovery unit. Since the liquid nitrogen pipeline 1441 is a device that can bear pressure and conduct temperature, the liquid nitrogen that continuously flows in will cause the liquid nitrogen pipeline 1441 to cool down, thereby causing the rock to reach a predetermined temperature. At the same time, the hydraulic system is used to load the confining pressure of the rock to the target confining pressure, so that the loading of low temperature and confining pressure can be achieved. If only low temperature needs to be loaded, it is only necessary to start the liquid nitrogen cryogenic device 6. When it is necessary to apply high temperature first and then low temperature, first start the steam generating device 4 to heat the rock to a predetermined high temperature T1, such as 200°C, and then continue to keep warm for a period of time t1. When cooling is required, first turn off the steam generator 4, then turn on the liquid nitrogen cryogenic device 6, first use a small flow of liquid nitrogen to slowly cool the liquid nitrogen pipeline 1441, when the liquid nitrogen pipeline 1441 is reduced to 80-100°C, increase the liquid nitrogen flow to continue to quickly cool the liquid nitrogen pipeline 1441 to a predetermined temperature T2, such as -30°C, and then keep the liquid nitrogen pipeline 1441 warm for t2. If heating is still required, then it is necessary to stop and turn off the liquid nitrogen cryogenic device 6, then use the steam generator 4, first slowly heat the liquid nitrogen pipeline 1441 to 25°C with a small flow of steam, and then use a large flow of steam to quickly heat the rock inside the liquid nitrogen pipeline 1441 to a predetermined temperature. If the hydraulic column 11 is not used to apply stress to the specimen 2, then the device can be used to study the impact load under high temperature on the mechanical properties and energy attenuation of the rock, and can also be used to study the impact load under low temperature on the mechanical properties and energy attenuation of the rock, as well as the impact of high and low temperature cycles on the mechanical properties and energy attenuation of the rock. If the liquid nitrogen cryogenic device 6 and the steam generating device 4 are not started, only the hydraulic column 11 can be used to study the impact load on the mechanical properties and energy attenuation of the rock under the action of confining pressure. If the hydraulic column 11, the steam generating device 4, and the liquid nitrogen cryogenic device 6 are started at the same time, the impact load on the mechanical properties and energy attenuation of the rock under the coupling of high temperature, low temperature, and confining pressure can be studied.

[0050] As a preferred embodiment, the steam generating device 4 includes a water tank 41, the water tank 41 is connected to the pressure pump 43 using a first connecting pipe 42, the first connecting pipe 42 is provided with a flow meter 421, the pressure pump 43 is connected to the steam generator 45 through a second connecting pipe 44, the steam generator 45 is connected to the steam inlet 142 through a third connecting pipe 46, the third connecting pipe 46 is provided with a steam flow meter 461, and one end of the third connecting pipe 46 is connected to the steam pipe 1421.

[0051] The steam generator 45 includes a resistor 452 and a first pressure relief valve 451 .

[0052] The steam pipe 1421 is provided with a second pressure relief valve 47 , a pressure gauge 48 and a temperature gauge 49 .

[0053] Figure 5 It is an electromagnetic steam generator 45. The specific operation process is as follows: first, the water in the water tank 41 controls the flow rate through the flow meter 421, and a certain flow rate of water is applied to a certain pressure through the pressure pump 43, and then transported to the steam generator 4, wherein the steam generator 4 heats the internal resistor 452 through the electric control cabinet 63, and when the high-temperature resistor 452 contacts the water, steam will be generated, wherein the temperature of the resistor 452 can be controlled by controlling the voltage connected to the resistor 452 (Ohm's law) inside the steam generator 4, thereby controlling the steam generation rate. The flow rate of water vapor is measured by the steam flow meter 461, and then fed back to the electric control cabinet 63 of the steam generator 4, and adjusted in real time through a pre-set program. Among them, after a certain flow of water vapor enters the sub-cylinder, the steam temperature can be known through the temperature meter 48, and the pressure gauge 48 can know the internal pressure of the sub-cylinder. The temperature data, pressure data, and steam flow data will be fed back to the electric control cabinet 63 connected to the steam generator 4 in real time, thereby adjusting the flow rate and temperature of steam generation in real time. The steam reaching the predetermined temperature is discharged through the steam output steam pipe 1421. The steam output steam pipe 1421 is connected to the steam inlet 142, and then the steam enters Figure 5 The steam is discharged through the steam channel 1442, and then discharged through the steam outlet. Since the steam temperature is too high, the discharged steam will go into the recovery device. Since water vapor continuously flows in and out of the pressure guide block 14, the pressure guide block 14 is heated by the temperature of the steam. When the high-temperature pressure guide block 14 contacts the rock, the rock will be heated. When heating the rock, the hydraulic column 11 can be used to apply confining pressure to the rock.

[0054] As a preferred embodiment, the liquid nitrogen cryogenic device 6 includes a liquid nitrogen bottle 61, an air pressure pump 62, an electric control cabinet 63, a thermometer 64, a liquid nitrogen channel 65 and a line 66. The air pressure pump 62 is connected to the electric control cabinet 63 through the line 66, and the air pressure pump 62 and the liquid nitrogen bottle 61 are connected in parallel through the liquid nitrogen channel 65. The end of the liquid nitrogen channel 65 is connected to the liquid nitrogen inlet 141 provided on the pressure guide block 14, and a thermometer 64 is provided on the liquid nitrogen channel 65 close to the pressure guide block 14.

[0055] As a preferred embodiment, the liquid nitrogen recovery device 7 is connected to the pressure guide block 14 through a liquid nitrogen channel 65 .

[0056] Figure 6It is a liquid nitrogen cryogenic system. The preloaded temperature of the rock is input into the electric control system. The electric control system controls the air pressure pump 62 through a pre-set program. Then the liquid nitrogen in the liquid nitrogen bottle 61 is passed through the liquid nitrogen pipeline 1441. The temperature is measured and the flow is controlled first. Then the liquid nitrogen is input into the liquid nitrogen inlet 141 and flows out from the liquid nitrogen outlet. The temperature of the liquid nitrogen flowing out is measured by the thermometer 64 and fed back to the electric control cabinet 63 in real time. The liquid nitrogen flowing out enters the liquid nitrogen recovery unit again. The liquid nitrogen will pressurize and cool the rock in the process of flowing in and out of the pressure guide block. The pressure and temperature of the rock are measured by the temperature measurement inside the hydraulic liquid nitrogen channel 65 and the multi-purpose pressure gauge 48. Once the temperature reaches the preset temperature, the cooling will stop.

[0057] As a preferred embodiment, in order to test the strain generated by the test piece 2 during the test, strain gauges 33 are provided on the incident rod 32 and the transmission rod 34, and the two strain gauges 33 are connected to the ultra-dynamic strain gauge, and the ultra-dynamic strain gauge is connected to the oscilloscope.

[0058] As a preferred embodiment, Figure 7 As shown, the pressure-bearing guide block 14 is composed of a heat-insulating layer 143, a guide layer 144 and a heat-transmitting layer 145, which are arranged from the outside to the inside, respectively. The guide layer 144 is provided with a liquid nitrogen pipeline 1441 and a steam channel 1442, and the heat-transmitting layer 145 is provided with a hole 1451. That is, when liquid nitrogen or water vapor passes through the liquid nitrogen pipeline 1441 and / or the steam channel 1442, the heat-insulating layer 143 can prevent the temperature from being lost to the external environment; the guide layer 144 can prevent the pressure-bearing guide block 14 from being deformed due to high or low temperature; and the hole 1451 provided in the heat-transmitting layer 145 can quickly transfer the temperature to the test piece 2.

[0059] As a preferred embodiment, Figure 8 As shown, it is found through experiments that replacing the steam channel 1442 with the heating plate 8 can also achieve the effect of alternately heating the test piece 2 in the above test process.

[0060] like Fig. 9 As shown, a Hopkinson bar impact test method with confining pressure and temperature coupling includes the following steps:

[0061] S1: Determine the confining pressure P and temperature T that need to be applied to the rock, and divide the confining pressure P and temperature T into T=0 and P>0;

[0062] There are three situations: T<0, P≥0; T≥0, P≥0.

[0063] S2: According to different confining pressure P and temperature T, choose whether to start the hydraulic column (11) and steam generation

[0064] device (4) and a liquid nitrogen cryogenic device (6);

[0065] S3: Repeat the experiment n times until the experimental value approaches stability, and then terminate the experiment.

[0066] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used here to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0067] In addition, it should be noted that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. If not otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of the present invention.

[0068] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A Hopkinson bar impact test device with confining pressure and temperature coupling, characterized in that: include: A Hopkinson rod (1), the Hopkinson rod (1) comprising an outer shell (15), a hydraulic column (11), a gasket (13) and a pressure-bearing guide block (14); a plurality of grooves are provided on the inner wall surface of the outer shell (15); the hydraulic column (11) is composed of a telescopic portion (112) and a fixed portion (111); one end of the fixed portion (111) is fixed in the groove; the telescopic portion (112) is telescopically connected to one end of the fixed portion (111); the other end of the telescopic portion (112) is connected to the gasket (13); the inner side of the gasket (13) is detachably connected to the pressure-bearing guide block (14); A confining pressure and temperature loading device system (3), the confining pressure and temperature loading device system (3) comprising a coaxially arranged incident rod (32), a transmission rod (34), an absorption rod (35), a high-pressure air chamber (31) and a damper (36), wherein the high-pressure air chamber (31) is disposed at one end of the incident rod (32), a test piece (2) is placed between the incident rod (32) and the transmission rod (34), and the test piece (2) is wrapped with the Hopkinson rod (1); the absorption rod (35) is connected to one end of the transmission rod (34) away from the test piece (2), and the damper (36) is placed at the other end of the absorption rod (35); A steam generating device (4) and a liquid nitrogen cryogenic device (6), wherein the steam generating device (4) and the liquid nitrogen cryogenic device (6) are respectively connected to a liquid nitrogen inlet (141) and a steam inlet (142) provided on the pressure guide block (14) through pipelines.

2. The Hopkinson bar impact test device with confining pressure and temperature coupling according to claim 1, characterized in that: The steam generating device (4) comprises a water tank (41), the water tank (41) is connected to a pressure pump (43) by a first connecting pipe (42), a flow meter (421) is provided on the first connecting pipe (42), the pressure pump (43) is connected to a steam generator (45) by a second connecting pipe (44), the steam generator (45) is connected to the steam inlet (142) by a third connecting pipe (46), a steam flow meter (461) is provided on the third connecting pipe (46), and one end of the third connecting pipe (46) is connected to a steam pipeline (1421).

3. The Hopkinson bar impact test device coupled with confining pressure and temperature according to claim 2, characterized in that: The steam generator (45) comprises a resistor (452) and a first pressure relief valve (451).

4. The Hopkinson bar (1) impact test device with confining pressure and temperature coupling according to claim 2 is characterized in that: The steam pipeline (1421) is provided with a second pressure relief valve (47), a pressure gauge (48) and a temperature gauge (49).

5. The Hopkinson bar (1) impact test device with confining pressure and temperature coupling according to claim 1 is characterized in that: The liquid nitrogen cryogenic device (6) comprises a liquid nitrogen bottle (61), a gas pressure pump (62), an electric control cabinet (63), a thermometer (64), a liquid nitrogen channel (65) and a line (66); the gas pressure pump (62) is connected to the electric control cabinet (63) via the line (66); the gas pressure pump (62) and the liquid nitrogen bottle (61) are connected in parallel via the liquid nitrogen channel (65); the end of the liquid nitrogen channel (65) is connected to a liquid nitrogen inlet (141) provided on the pressure-bearing guide block (14); and a thermometer (64) is provided on the liquid nitrogen channel (65) close to the pressure-bearing guide block (14).

6. The Hopkinson bar impact test device coupled with confining pressure and temperature according to claim 5, characterized in that: The liquid nitrogen recovery device (7) is connected to the pressure-bearing guide block (14) via the liquid nitrogen channel (65).

7. The Hopkinson bar impact test device coupled with confining pressure and temperature according to claim 1, characterized in that: The incident rod (32) and the transmission rod (34) are provided with strain gauges (33), the two strain gauges (33) are connected to an ultra-dynamic strain gauge, and the ultra-dynamic strain gauge is connected to an oscilloscope.

8. The Hopkinson bar impact test device with confining pressure and temperature coupling according to any one of claims 1 to 7, characterized in that: The pressure-bearing guide block (14) is composed of a heat-insulating layer (143), a guide layer (144), and a heat-transmitting layer (145) which are arranged respectively from the outside to the inside; a liquid nitrogen pipeline (1441) and a steam channel (1442) are arranged on the guide layer (144); and a hole (1451) is arranged on the heat-transmitting layer (145).

9. The Hopkinson bar impact test device with confining pressure and temperature coupling according to claim 8, characterized in that: The steam channel (1442) is replaced by a heating plate (8).

10. A Hopkinson bar impact test method with confining pressure and temperature coupling, characterized in that: Includes steps: S1: Determine the confining pressure P and temperature T that need to be applied to the rock, and divide the confining pressure P and temperature T into T=0 and P>0; T<0,P≥0; T≥0, P≥0; S2: according to different conditions of the confining pressure P and the temperature T, selecting whether to start the hydraulic column (11), the steam generating device (4) and the liquid nitrogen cryogenic device (6); S3: Repeat the experiment n times until the experimental value approaches stability, and then terminate the experiment.

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