A vacuum extreme temperature rock fracture test system and method

Abstract

The present invention discloses a vacuum extreme temperature rock fracture test system, which mainly includes a vacuum extreme temperature loading structure, an overall loading frame structure and a mobile trolley. The vacuum extreme temperature loading structure is located inside the overall loading frame structure. The vacuum extreme temperature loading structure is arranged on the mobile trolley, and the mobile trolley is slidably connected to the overall loading frame structure. The present invention also discloses a vacuum extreme temperature rock fracture test method. Compared with the prior art, the vacuum extreme temperature rock fracture test system prepared by the present invention integrates the extreme high temperature or extreme low temperature environment with the vacuum environment, and at the same time couples the extreme high temperature and extreme low temperature environments in the same module, realizing the synchronous monitoring of rock loading and acoustics under the vacuum ultra-high temperature or ultra-low temperature environment.

Description

Technical Field

[0001] The present invention relates to the technical field of indoor rock mechanics tests, and particularly to a vacuum extreme temperature rock fracture test system and method. Background Art

[0002] With the increasing depletion of earth resources and the continuous progress of deep space exploration technology, countries around the world have launched a series of deep space exploration programs for celestial bodies such as the moon, Mars, and asteroids. These programs cover multiple aspects such as extraterrestrial celestial body sampling, in-situ utilization of extraterrestrial geotechnical resources, and construction of extraterrestrial celestial body bases. The temperature change on the lunar surface is extremely large, ranging from -233°C to 123°C, while the temperature range on Mars is from -143°C to 35°C. The atmospheric pressure on the moon is extremely low, approximately 3×10 -13 kPa, and the atmospheric pressure on Mars is slightly higher, about 0.7 kPa. Under such extreme conditions, the rocks and soils on the moon and Mars exhibit physical and mechanical properties that are completely different from those of earth geotechnical materials. Deeply understanding the physical and mechanical behaviors of geotechnical materials on these extraterrestrial celestial bodies under extreme environments is crucial for ensuring the success of deep space exploration missions.

[0003] Currently, at home and abroad, for low-temperature environments, methods such as compression refrigeration and liquid nitrogen refrigeration are mostly used. Compression refrigeration is limited by power and size, not suitable for large-scale rock mechanics tests, and it is difficult to reach ultra-low temperatures below -150°C; while liquid nitrogen refrigeration often immerses the specimen in liquid nitrogen, which has a cold shock on the specimen, affecting the experimental results, and directly immersing in liquid nitrogen cannot be combined with a vacuum environment, and the immersion process is complex and has a certain degree of danger. On the other hand, many current loading devices cannot simultaneously achieve interactive tests of ultra-low temperature and high temperature. The measurement of rock deformation at high temperature is unstable, and due to the influence of interference factors such as frosting, fogging, and air flow disturbance in the low-temperature environment, the means for observing rock fracture in the ultra-low temperature state are limited.

[0004] Therefore, how to provide a vacuum extreme temperature rock fracture test system that can combine a vacuum environment with extreme high and low temperature environments and quantitatively study the fracture characteristics of rocks in a vacuum extreme temperature environment is a technical problem that needs to be urgently solved by those skilled in the art. Summary of the Invention

[0005] In view of the problems existing in the prior art, the technical problem to be solved by the present invention is to provide a vacuum extreme temperature rock fracture test system that can realize rock loading under the coupling of a vacuum environment and extreme high and low temperature environments, and can synchronously monitor the deformation evolution of rock fracture, obtain the surface deformation field and acoustic emission response characteristics.

[0006] To achieve the above object, the present invention provides a vacuum extreme temperature rock fracture test system. The vacuum extreme temperature rock fracture test system includes: a vacuum extreme temperature loading structure, which includes a vacuum transparent shield, a vacuum base, and an extreme temperature loading module. The bottom end of the vacuum transparent shield covers the vacuum base and is hermetically connected to the vacuum base to form a vacuum structure, and the extreme temperature loading module is located inside the vacuum structure; an overall loading frame structure, which includes an overall frame and a loading oil cylinder. There is a loading space in the middle of the overall frame, and the vacuum extreme temperature loading structure is located inside the loading space; a first loading perforation is opened at the center of the top end of the overall frame, and the loading oil cylinder is located above the first loading perforation, so that the loading rod of the loading oil cylinder passes through the first loading perforation to apply a loading force to the extreme temperature loading module, and one end of the loading oil cylinder is fixedly connected to the overall frame; a moving trolley, which is located in the loading space and is slidably connected to the overall frame, and the vacuum base is arranged on the moving trolley.

[0007] In the first aspect, the overall frame includes: a frame bottom column, on which there is a sliding guide rail, and the pulley of the moving trolley is adapted to the sliding guide rail, and the moving trolley is slidably connected to the frame bottom column; a frame column, which has a loading space, and the frame column is located above the frame bottom column and is fixedly connected to the frame bottom column; a frame cross beam, which is located above the frame column and is fixedly connected to the frame column; wherein, a first loading perforation is opened at the center of the frame cross beam, and the loading oil cylinder is located above the first loading perforation and is fixedly connected to the frame cross beam.

[0008] In the first aspect, the overall loading frame structure further includes: two counterweight structures; two counterweight support frames, each of which is in a right triangle structure, and the two counterweight support frames are symmetrically fixed at the other end of the loading oil cylinder with the axis of the loading oil cylinder as the symmetry axis. The hypotenuses of the two counterweight support frames are parallel to each other, and a support pulley is fixed at each end of the hypotenuse of each counterweight support frame; two counterweight ropes, one end of each counterweight rope is fixedly connected to a corresponding counterweight structure through a first counterweight hook, and the other end of each counterweight rope sequentially passes through the corresponding support pulley and is fixedly connected to the top end of the vacuum transparent shield through a second counterweight hook.

[0009] In the first aspect, the overall loading frame structure further includes a displacement sensor, which is located at the center of the other end of the loading oil cylinder.

[0010] In a first aspect, the vacuum extreme temperature loading structure further includes: a vacuum extraction pipe, one end of the vacuum extraction pipe being located inside the vacuum transparent shield; wherein, a vacuum pipe through-hole is formed in the vacuum base, and the other end of the vacuum extraction pipe passes through the vacuum pipe through-hole and is connected to a vacuum extraction pump; an observation port is formed on one side of the vacuum transparent shield, and the observation port is sealed with a transparent anti-fog material.

[0011] In a first aspect, the extreme temperature loading module includes: a vacuum support frame located at the center of the vacuum base; two loading brackets, the two loading brackets having a circular structure, the central axes of the two loading brackets being the same as the central axis of the vacuum base, one of the loading brackets being located on the vacuum support frame and fixedly connected to the vacuum support frame, each of the loading brackets having two symmetric longitudinal support holes; two longitudinal deformation sensors, one end of each longitudinal deformation sensor passing through a corresponding longitudinal support hole and being fixedly connected to one of the loading brackets, the other end of each longitudinal deformation sensor passing through a corresponding longitudinal support hole and being fixedly connected to the other loading bracket; two loading pads, the two loading pads having a cylindrical structure, the central axes of the two loading pads being the same as the central axis of the vacuum base, one of the loading pads being located on one of the loading brackets and fixedly connected to one of the loading brackets, the other loading pad being located below the other loading bracket and fixedly connected to the other loading bracket; two heat insulation plates, the two heat insulation plates having a circular structure, the central axes of the two heat insulation plates being the same as the central axis of the vacuum base, one of the heat insulation plates being located on one of the loading pads and fixedly connected to one of the loading pads, the other heat insulation plate being located above the other loading bracket and fixedly connected to the other loading bracket; a loading block located at the center of the other heat insulation plate and fixedly connected to the other heat insulation plate; a pressing head having a cylindrical structure, the pressing head corresponding to the position of the loading block; wherein, a second loading through-hole is formed at the top end of the vacuum transparent shield, and one end of the pressing head passes through the second loading through-hole and is hermetically and slidably connected to the vacuum transparent shield.

[0012] In a first aspect, the extreme temperature loading module further includes: a heat conduction cavity, which has a cubic hollow structure and is located on one of the heat insulation plates; an observation channel adapted to the rock specimen is provided at the center of one side surface of the heat conduction cavity, and the position of the observation channel corresponds to that of the observation port; two liquid nitrogen circulation pipe through holes are provided at the top of the heat conduction cavity; a third loading perforation is also provided at the top of the heat conduction cavity; two specimen pads, both of the two specimen pads are located inside the heat conduction cavity, the central axes of the two specimen pads are the same as the central axis of the vacuum base, a uniaxial compression rock sample is arranged between the two specimen pads, one specimen pad is located at the bottom of the heat conduction cavity, and the other specimen pad passes through the third loading perforation and abuts against the other loading pad; two vacuum conveying liquid nitrogen circulation pipes, one end of one vacuum conveying liquid nitrogen circulation pipe is connected to the outlet of the liquid nitrogen circulation tank, and one end of the other vacuum conveying liquid nitrogen circulation pipe is connected to the inlet of the liquid nitrogen circulation tank; a liquid nitrogen refrigeration circulation pipe, one end of the liquid nitrogen refrigeration circulation pipe is connected to the other end of one vacuum conveying liquid nitrogen circulation pipe; a plurality of electromagnetic heating plates, the plurality of electromagnetic heating plates are located inside the heat conduction cavity and are arranged closely against the inner side wall of the heat conduction cavity; wherein, two vacuum conveying liquid nitrogen holes and an electromagnetic heating guide hole are further provided on the vacuum base, the other end of the liquid nitrogen refrigeration circulation pipe sequentially passes through one vacuum conveying liquid nitrogen hole and one liquid nitrogen circulation pipe through hole and enters the heat conduction cavity, is arranged at an interval from the plurality of electromagnetic heating plates closely against the inner side wall of the heat conduction cavity, and then sequentially passes through the other liquid nitrogen circulation pipe through hole and the other vacuum conveying liquid nitrogen hole and is connected to the other end of the other vacuum conveying liquid nitrogen circulation pipe; each electromagnetic heating plate is connected in series through an electromagnetic heating wire and is connected to a power supply through the electromagnetic heating guide hole.

[0013] In a first aspect, the extreme temperature loading module further includes: a lateral deformation sensor, both ends of the lateral deformation sensor abut against and are fixed to the outer side wall of the heat conduction cavity; a temperature sensor, the temperature sensor is arranged inside the heat conduction cavity; an acoustic emission sensor, the acoustic emission sensor is arranged inside the heat conduction cavity.

[0014] In a first aspect, the extreme temperature loading module further includes: a dual-channel PID controller; a liquid nitrogen temperature control loop, the liquid nitrogen temperature control loop includes a pressure sensor and an electric heater, the pressure sensor and the electric heater are evenly arranged at the inlet of the vacuum conveying liquid nitrogen circulation pipe, and the pressure sensor and the electric heater are respectively connected to the first channel of the dual-channel PID controller; wherein, each of the electromagnetic heating plates is connected in series through an electromagnetic heating wire and passes through the electromagnetic heating guide hole to be connected to the second channel of the dual-channel PID controller, and the dual-channel PID controller is connected to the power supply.

[0015] The present invention also provides a vacuum extreme temperature rock fracture test method for the use of the above-mentioned vacuum extreme temperature rock fracture test system. The vacuum extreme temperature rock fracture test method includes: making speckles for a uniaxial compression rock sample, lifting the vacuum transparent shield through a counterweight structure, installing the uniaxial compression rock sample between two specimen pads, and then filling the interior of the heat conduction cavity with a high thermal conductivity powder so that the uniaxial compression rock sample is surrounded by the high thermal conductivity powder between the liquid nitrogen refrigeration circulation pipe and the electromagnetic heating plate; installing a lateral deformation sensor, and arranging temperature sensors and acoustic emission sensors inside the heat conduction cavity; releasing the counterweight structure so that the vacuum transparent shield and the vacuum base form a vacuum structure, and moving the vacuum structure to the loading space through a moving trolley and fixing it to the loading position; applying a preload of 100 N to the uniaxial compression rock sample through an oil cylinder, pressing the indenter down until the loading force just touches the uniaxial compression rock sample, and then using a vacuum pump to evacuate the inside of the vacuum structure through a vacuum pipe until the target vacuum degree requirement is reached; according to the test plan, setting the target temperature and temperature loading rate through a dual-channel PID controller, arranging a light source, a high-speed camera and an infrared thermal imaging device outside the vacuum structure, and monitoring the evolution of the surface deformation field of the uniaxial compression rock sample in real time; performing mechanical loading on the uniaxial compression rock sample through the loading oil cylinder, synchronously performing optical observation and acoustic emission monitoring, obtaining the load, displacement and deformation results during the uniaxial compression process, supplementarily analyzing the evolution of the surface deformation field of the uniaxial compression rock sample monitored in real time through the digital image correlation method, and simultaneously analyzing the acoustic emission signal law during the fracture process of the uniaxial compression rock sample.

[0016] Beneficial effects:

[0017] A vacuum extreme temperature rock fracture test system of the present invention mainly includes three parts. The first part is a vacuum extreme temperature loading structure, which mainly provides a vacuum environment for the specimen and simulates extreme high temperature or extreme low temperature environment. The second part is an overall loading frame structure, which mainly provides a loading force for the specimen to simulate the crushing force on the rock when crushing the rock. The third part is a moving trolley, which is mainly used to move the vacuum extreme temperature loading structure to a specified position in the loading space of the overall frame. In the vacuum extreme temperature loading structure, there are a vacuum transparent shield and a vacuum base. The vacuum structure is formed by the vacuum transparent shield and the vacuum base to provide a vacuum environment for the specimen. The vacuum extreme temperature loading structure also includes an extreme temperature loading module, which mainly provides extreme high temperature or extreme low temperature environment for the specimen. The heat conduction of the vacuum environment is very weak, which can reduce the damage to other structures in the vacuum extreme temperature rock fracture test system caused by the diffusion of extreme high temperature or extreme low temperature environment to the entire vacuum structure. At the same time, the extreme temperature loading module is also used to monitor the deformation and fracture sound of the specimen when it is under the loading force in the extreme high temperature or extreme low temperature environment. In the overall loading frame structure, there are an overall frame and a loading oil cylinder. There is a loading space in the middle of the overall frame, which is mainly used to place the vacuum extreme temperature loading structure. At the same time, a loading force is applied to the specimen in the vacuum extreme temperature loading structure through the loading oil cylinder. The moving trolley is located in the loading space and can slide inside and outside the loading space. The vacuum extreme temperature loading structure is placed on the moving trolley so that the vacuum extreme temperature loading structure can be placed at a specified position in the loading space through the sliding of the moving trolley, which is convenient for the loading oil cylinder to apply the loading force. In summary, the vacuum extreme temperature rock fracture test system of the present invention integrates extreme high temperature or extreme low temperature environment with vacuum environment, and couples extreme high temperature and extreme low temperature environment in the same module, realizing synchronous monitoring of rock loading and acoustics under vacuum ultra-high temperature or ultra-low temperature environment. Description of the Drawings

[0018] In order to more clearly illustrate the technical solutions in the embodiments of this specification or the prior art, the following will briefly introduce the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0019] Figure 1 It is a schematic structural diagram of a vacuum extreme temperature rock fracture test system of the present invention;

[0020] Figure 2 It is a three-dimensional schematic diagram of the vacuum extreme temperature loading structure of the present invention;

[0021] Figure 3It is a schematic cross-sectional view of the vacuum extreme temperature loading structure of the present invention;

[0022] Figure 4 It is a schematic structural view of the liquid nitrogen refrigeration circulation pipe inside the heat conduction cavity of the present invention;

[0023] Figure 5 It is a schematic structural view of the Brazilian splitting fixture;

[0024] Figure 6 It is a schematic structural view of the variable-angle wedge shear fixture.

[0025] Reference numerals:

[0026] 1. Vacuum extreme temperature loading structure; 11. Vacuum transparent shield; 12. Vacuum base; 13. Extreme temperature loading module; 1301. Vacuum support frame; 1302. Loading bracket; 1303. Longitudinal deformation sensor; 1304. Loading cushion block; 1305. Heat insulation board; 1306. Loading block; 1307. Indenter; 1308. Heat conduction cavity; 1309. Specimen cushion block; 1310. Uniaxial compression rock sample; 1311. Vacuum transfer liquid nitrogen circulation pipe; 1312. Liquid nitrogen refrigeration circulation pipe; 1313. Electromagnetic heating plate; 1314. Transverse deformation sensor; 14. Vacuum exhaust pipe; 15. Observation port;

[0027] 2. Integral loading frame structure; 21. Integral frame; 211. Frame bottom column; 212. Frame column; 213. Frame cross beam; 22. Loading oil cylinder; 23. Counterweight structure; 24. Counterweight support frame; 25. Counterweight rope; 26. Displacement sensor;

[0028] 3. Mobile trolley;

[0029] 4. Brazilian splitting fixture; 41. Liquid nitrogen circulation channel; 42. Brazilian splitting rock sample; 43. First temperature conduction back plate; 44. Brazilian splitting high-permeability material;

[0030] 5. Variable-angle wedge shear fixture; 51. Wedge shear rock sample; 52. Second temperature conduction back plate; 53. Wedge shear high-permeability material. Detailed implementation manners

[0031] Next, the technical solutions in the embodiments of this specification will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of this specification. Obviously, the described embodiments are only a part of the embodiments of this specification, rather than all the embodiments. Based on the embodiments in this specification, all other embodiments obtained by those of ordinary skill in the art belong to the scope protected by the present invention.

[0032] Embodiment 1

[0033] AsFigures 1 to 6 As shown in the figure, Embodiment 1 of the present invention provides a vacuum extreme temperature rock fracture test system. The vacuum extreme temperature rock fracture test system includes: a vacuum extreme temperature loading structure 1, which includes a vacuum transparent shield 11, a vacuum base 12, and an extreme temperature loading module 13. The bottom end of the vacuum transparent shield 11 covers the vacuum base 12 and is hermetically connected to the vacuum base 12 to form a vacuum structure, and the extreme temperature loading module 13 is located inside the vacuum structure; an overall loading frame structure 2, which includes an overall frame 21 and a loading oil cylinder 22. There is a loading space in the middle of the overall frame 21, and the vacuum extreme temperature loading structure 1 is located inside the loading space; a first loading perforation is opened at the center of the top end of the overall frame 21, and the loading oil cylinder 22 is located above the first loading perforation, so that the loading rod of the loading oil cylinder 22 passes through the first loading perforation to apply a loading force to the extreme temperature loading module 13, and one end of the loading oil cylinder 22 is fixedly connected to the overall frame 21; a moving trolley 3, which is located in the loading space and is slidably connected to the overall frame 21, and the vacuum base 12 is arranged on the moving trolley 3.

[0034] A vacuum extreme temperature rock fracture test system of the present invention mainly includes three parts. The first part is a vacuum extreme temperature loading structure, which mainly provides a vacuum environment for the specimen and simulates an extreme high temperature or extreme low temperature environment. The second part is an overall loading frame structure, which mainly provides a loading force for the specimen to simulate the crushing force on the rock when crushing the rock. The third part is a moving trolley, which is mainly used to move the vacuum extreme temperature loading structure to a specified position in the loading space of the overall frame. In the vacuum extreme temperature loading structure, there are a vacuum transparent shield and a vacuum base, and a vacuum structure is formed by the vacuum transparent shield and the vacuum base to provide a vacuum environment for the specimen. The vacuum extreme temperature loading structure also includes an extreme temperature loading module, which mainly provides an extreme high temperature or extreme low temperature environment for the specimen. The heat conduction of the vacuum environment is very weak, which can reduce the damage to other structures in the vacuum extreme temperature rock fracture test system caused by the diffusion of the extreme high temperature or extreme low temperature environment to the entire vacuum structure. At the same time, the extreme temperature loading module is also used to monitor the deformation and fracture sound conditions of the specimen when subjected to a loading force in the extreme high temperature or extreme low temperature environment. In the overall loading frame structure, there are an overall frame and a loading oil cylinder. There is a loading space in the middle of the overall frame, which is mainly used to place the vacuum extreme temperature loading structure. At the same time, a loading force is applied to the specimen in the vacuum extreme temperature loading structure through the loading oil cylinder. The moving trolley is located in the loading space and can slide inside and outside the loading space. The vacuum extreme temperature loading structure is placed on the moving trolley, so that the vacuum extreme temperature loading structure can be placed at a specified position in the loading space through the sliding of the moving trolley, which is convenient for the loading oil cylinder to apply a loading force. In summary, a vacuum extreme temperature rock fracture test system of the present invention integrates the extreme high temperature or extreme low temperature environment with the vacuum environment, and at the same time couples the extreme high temperature and extreme low temperature environments in the same module, realizing the synchronous monitoring of rock loading and acoustics in the vacuum ultra-high temperature or ultra-low temperature environment.

[0035] In some possible implementation manners, the overall frame 21 includes: a frame bottom column 211, on which there is a sliding guide rail, and the pulley of the moving trolley 3 is adapted to the sliding guide rail, and the moving trolley 3 is slidably connected to the frame bottom column 211; a frame vertical column 212, which has a loading space, and the frame vertical column 212 is located above the frame bottom column 211 and fixedly connected to the frame bottom column 211; a frame cross beam 213, which is located above the frame vertical column 212 and fixedly connected to the frame vertical column 213. Among them, a first loading perforation is opened at the center of the frame cross beam 213, and the loading oil cylinder 22 is located above the first loading perforation and fixedly connected to the frame cross beam 213.

[0036] Specifically, the bottom of the loading space is a frame bottom column. The loading space is used to place the vacuum extreme temperature loading structure. The bottom of the loading space is a frame bottom column. A sliding guide rail is provided on the frame bottom column, and pulleys are provided on the moving trolley, so that the moving trolley moves on the sliding guide rail adapted to it through the pulleys.

[0037] In some possible implementation manners, the overall loading frame structure 2 further includes: two counterweight structures 23; two counterweight support frames 24. Each of the counterweight support frames 24 is in a right triangle structure. The two counterweight support frames 24 are symmetrically fixed to the other end of the loading oil cylinder 22 with the axis of the loading oil cylinder 22 as the symmetry axis. The hypotenuses of the two counterweight support frames 24 are parallel to each other. A support pulley is fixed at each end of the hypotenuse of each counterweight support frame 24; two counterweight ropes 25. One end of each counterweight rope 25 is fixedly connected to a corresponding one of the counterweight structures 23 through a first counterweight hook. The other end of each counterweight rope 25 sequentially passes through the corresponding support pulley and is fixedly connected to the top end of the vacuum transparent cover 11 through a second counterweight hook.

[0038] Specifically, the weights of the two counterweight structures are greater than the weight of the vacuum transparent cover. The two ends of the counterweight rope are respectively connected to the counterweight structure and the vacuum transparent cover. Then, through the sliding of the counterweight rope on the support pulley of the counterweight support frame, the vacuum transparent cover is lifted by the action of gravity. When it is necessary to cover the vacuum transparent cover, only need to reduce the weights of the two counterweight structures, or remove the two counterweight structures, so that the vacuum transparent cover descends under the action of gravity and covers the vacuum base. After loading the specimen, the vacuum transparent cover covers the vacuum base and is moved to the loading space through the moving trolley. A positioning pin is provided on the loading rod of the loading oil cylinder above the loading space, so that the loading rod is aligned with the indenter.

[0039] In some possible implementation manners, the overall loading frame structure 2 further includes a displacement sensor 26, and the displacement sensor 26 is located at the center of the other end of the loading oil cylinder 22.

[0040] Specifically, the displacement sensor is arranged at the center above the loading oil cylinder and can monitor the situation of the loading force applied by the loading oil cylinder.

[0041] In some possible implementation manners, the vacuum extreme temperature loading structure 1 further includes: a vacuum extraction pipe 14. One end of the vacuum extraction pipe 14 is located inside the vacuum transparent cover 11; wherein, a vacuum pipe through hole is opened on the vacuum base 12, and the other end of the vacuum extraction pipe 14 passes through the vacuum pipe through hole and is connected to a vacuum pump; an observation port 15 is opened on one side of the vacuum transparent cover 11, and the observation port 15 is sealed with a transparent anti-fog material.

[0042] Specifically, the vacuum structure composed of the vacuum transparent shield and the vacuum base is a closed environment. The vacuum structure is evacuated by using a vacuum pump through the through-hole of the vacuum tube, so that the vacuum structure is in a vacuum environment. A part of the vacuum extraction tube is embedded in the vacuum base to achieve the evacuation of the vacuum structure, and the vacuum degree in the vacuum structure can reach 10 Pa. Since extreme high temperature or extreme low temperature environment simulation will be carried out in the vacuum structure, during this process, due to the temperature difference between the inside and the outside, fog may appear on the wall of the vacuum transparent shield, which will obscure the observation line of sight. Therefore, an observation port is opened and sealed with a transparent anti-fog material to avoid the problem of blurred line of sight caused by the temperature difference between the inside and the outside. In addition, the inside of the vacuum transparent shield can be dried, and an anti-fog spray can be sprayed on the outer surface of the vacuum transparent shield to prevent frosting on the outer surface due to the temperature difference. In addition, a vacuum pressure valve is reserved above the vacuum transparent shield, which can display the vacuum degree in the vacuum structure.

[0043] In some possible implementation manners, the extreme temperature loading module includes: a vacuum support frame 1301, which is located at the center of the vacuum base 12; two loading brackets 1302, the two loading brackets 1302 are of a circular structure, the central axes of the two loading brackets 1302 are the same as the central axis of the vacuum base 12, one of the loading brackets 1302 is located on the vacuum support frame 1301 and fixedly connected to the vacuum support frame 1301, and each of the loading brackets 1302 has two symmetric longitudinal support holes; two longitudinal deformation sensors 1303, one end of each of the longitudinal deformation sensors 1303 passes through a corresponding longitudinal support hole and is fixedly connected to one of the loading brackets 1302, and the other end of each of the longitudinal deformation sensors 1303 passes through a corresponding longitudinal support hole and is fixedly connected to the other loading bracket 1302; two loading pads 1304, the two loading pads 1304 are of a cylindrical structure, the central axes of the two loading pads 1304 are the same as the central axis of the vacuum base 12, one of the loading pads 1304 is located on one of the loading brackets 1302 and fixedly connected to one of the loading brackets 1302, and the other loading pad 1304 is located below the other loading bracket 1302 and fixedly connected to the other loading bracket 1302; two heat insulation plates 1305, the two heat insulation plates 1305 are of a circular structure, the central axes of the two heat insulation plates 1305 are the same as the central axis of the vacuum base 12, one of the heat insulation plates 1305 is located on one of the loading pads 1304 and fixedly connected to one of the loading pads 1304, and the other heat insulation plate 1305 is located above the other loading bracket 1302 and fixedly connected to the other loading bracket 1302; a loading block 1306, which is located at the center of the other heat insulation plate 1305 and fixedly connected to the other heat insulation plate 1305; a pressure head 1307, the pressure head 1307 is of a cylindrical structure, and the pressure head 1307 corresponds to the position of the loading block 1306; wherein, a second loading perforation is formed at the top of the vacuum transparent shield 11, and one end of the pressure head 1307 passes through the second loading perforation and is hermetically and slidably connected to the vacuum transparent shield 11.

[0044] Specifically, the vacuum support frame is used to support the loading brackets. The two loading brackets are the main supports of the extreme temperature loading module. The two longitudinal deformation sensors are connected between the two loading brackets. While the two longitudinal deformation sensors support the two loading brackets, they are also used to test the deformation of the specimen in the longitudinal direction during the loading process. Since the two longitudinal deformation sensors are fixed in the external bracket and do not come into direct contact with the high-temperature and low-temperature regions, and the heat conduction efficiency in the vacuum environment is relatively low, the two longitudinal deformation sensors are less affected by temperature, so the measurement results are more accurate. The functions of the two loading pads are, first, to support the heat conduction cavity, and second, to shorten the downward pressing distance of the indenter under the condition of loading force. The functions of the two heat insulation plates are to isolate the temperature transmitted from the heat conduction cavity and prevent it from affecting other structures such as the loading cylinder. The main function of the loading block is to shorten the downward pressing distance of the indenter under the condition of loading force. The indenter mainly moves downward by applying a loading force through the loading cylinder. The two longitudinal deformation sensors can be wirelessly connected to an external monitoring and display system. At the same time, through holes for the longitudinal deformation sensors can also be opened on the vacuum base, and the two longitudinal deformation sensors are connected to the external monitoring and display system through sensor cables.

[0045] In some possible implementation manners, the extreme temperature loading module 13 further includes: a heat conduction cavity 1308, the heat conduction cavity 1308 has a cubic hollow structure, and the heat conduction cavity 1308 is located on one of the heat insulation plates 1305; an observation channel adapted to the rock specimen is provided at the center of one side surface of the heat conduction cavity 1308, and the position of the observation channel corresponds to the position of the observation port 15; two liquid nitrogen circulation pipe through holes are provided at the top of the heat conduction cavity 1308; a third loading through hole is further provided at the top of the heat conduction cavity 1308; two specimen pads 1309, both of the two specimen pads 1309 are located inside the heat conduction cavity 1308, the central axes of the two specimen pads 1309 are the same as the central axis of the vacuum base 12, a uniaxial compression rock sample 1310 is arranged between the two specimen pads 1309, one specimen pad 1309 is located at the bottom of the heat conduction cavity 1308, and the other specimen pad 1309 passes through the third loading through hole and abuts against the other loading pad 1304; two vacuum conveying liquid nitrogen circulation pipes 1311, one end of one vacuum conveying liquid nitrogen circulation pipe 1311 is connected to the outlet of the liquid nitrogen circulation tank, and one end of the other vacuum conveying liquid nitrogen circulation pipe 1311 is connected to the inlet of the liquid nitrogen circulation tank; a liquid nitrogen refrigeration circulation pipe 1312, one end of the liquid nitrogen refrigeration circulation pipe 1312 is connected to the other end of one vacuum conveying liquid nitrogen circulation pipe 1311; a plurality of electromagnetic heating plates 1313, the plurality of electromagnetic heating plates 1313 are located inside the heat conduction cavity 1308, and the plurality of electromagnetic heating plates 1313 are arranged close to the inner side wall of the heat conduction cavity 1308; wherein, two vacuum conveying liquid nitrogen holes and an electromagnetic heating guide hole are further provided on the vacuum base 12, the other end of the liquid nitrogen refrigeration circulation pipe 1312 sequentially passes through one vacuum conveying liquid nitrogen hole and one liquid nitrogen circulation pipe through hole and enters the heat conduction cavity 1308, is arranged at an interval from the plurality of electromagnetic heating plates 1313 close to the inner side wall of the heat conduction cavity 1308, and then sequentially passes through the other liquid nitrogen circulation pipe through hole and the other vacuum conveying liquid nitrogen hole and is connected to the other end of the other vacuum conveying liquid nitrogen circulation pipe 1311; each of the electromagnetic heating plates 1313 is connected in series through an electromagnetic heating wire and is connected to a power supply through the electromagnetic heating guide hole.

[0046] Specifically, the heat conduction cavity is mainly used to place the specimen and provide extreme high temperature or extreme low temperature. An observation channel through which the whole specimen can be seen is provided on one side of the heat conduction cavity. The observation channel corresponds to the observation port, and the situation of the specimen during the test can be observed through the observation port and the observation channel; two specimen pads are located inside the heat conduction cavity, and the specimen is located between the two specimen pads. The heat conduction cavity has a third loading perforation, and the specimen pad located above the specimen passes through the third loading perforation and contacts the loading pad during the pressing process of the indenter; two vacuum delivery liquid nitrogen circulation pipes are used to deliver liquid nitrogen to the liquid nitrogen refrigeration circulation pipe and output the liquid nitrogen in the liquid nitrogen refrigeration circulation pipe; the liquid nitrogen refrigeration circulation pipe is arranged closely around the inner side wall of the heat conduction cavity to provide an extreme low temperature environment, and a plurality of electromagnetic heating plates are arranged closely and spaced from the liquid nitrogen refrigeration circulation pipe along the inner side wall of the heat conduction cavity to provide an extreme high temperature environment. The low temperature environment and the high temperature environment are coupled together inside the heat conduction cavity, saving the equipment space; after the specimen is installed in the heat conduction cavity, it is necessary to fill the heat conduction cavity with a high thermal conductivity powder material so that the space between the specimen and the liquid nitrogen refrigeration circulation pipe and the electromagnetic heating plates is filled with the high conductivity powder material to improve the heat conduction efficiency. The high conductivity powder material can be graphene powder; the liquid nitrogen circulation tank is used to output and receive liquid nitrogen.

[0047] In some possible implementation manners, the extreme temperature loading module 13 further includes: a lateral deformation sensor 1314, with both ends of the lateral deformation sensor 1314 abutted against and fixed to the outer side wall of the heat conduction cavity 1308; a temperature sensor disposed inside the heat conduction cavity 1308; and an acoustic emission sensor disposed inside the heat conduction cavity 1308.

[0048] Specifically, the lateral deformation sensor is used to test the deformation of the specimen when subjected to a loading force. Since the lateral deformation sensor is fixed to the outer side of the heat conduction cavity and does not directly contact the high temperature and low temperature regions, and the heat conduction efficiency in the vacuum environment is relatively low, the lateral deformation sensor is less affected by temperature, so the measurement result is more accurate; the temperature sensor is used to monitor the temperature of the environment where the specimen is located; the acoustic emission sensor is used to monitor the sound when the specimen breaks; the lateral deformation sensor, the temperature sensor and the acoustic emission sensor can be wirelessly connected to an external monitoring and display system. At the same time, through holes for the lateral deformation sensor, the temperature sensor and the acoustic emission sensor can also be opened on the vacuum base, and the lateral deformation sensor, the temperature sensor and the acoustic emission sensor are respectively connected to the external monitoring and display system through sensor cables.

[0049] In some possible implementation manners, the extreme temperature loading module 13 further includes: a dual-channel PID controller; a liquid nitrogen temperature control loop, the liquid nitrogen temperature control loop includes a pressure sensor and an electric heater, the pressure sensor and the electric heater are evenly arranged at the inlet of the vacuum conveying liquid nitrogen circulation pipe, and the pressure sensor and the electric heater are respectively connected to the first channel of the dual-channel PID controller; wherein, each of the electromagnetic heating plates 1313 is connected in series through an electromagnetic heating wire and passes through the electromagnetic heating guide hole to be connected to the second channel of the dual-channel PID controller, and the dual-channel PID controller is connected to the power supply.

[0050] Specifically, the dual-channel PID controller has two control channels, which control extreme high temperature and extreme low temperature simultaneously; a certain pressure is required for the liquid nitrogen to be transported to the liquid nitrogen refrigeration circulation pipe, the transport rate of the liquid nitrogen is related to the pressure value, the input temperature of the liquid nitrogen is controlled by the electric heater, and different set temperatures are controlled by adjusting the power of the electric heater under the condition of constant refrigeration capacity; the input speed and input temperature of the liquid nitrogen are controlled through the first channel of the dual-channel PID controller, and the heating temperature of the electromagnetic heating plate is controlled through the second channel of the dual-channel PID controller, so as to realize independent control of low temperature and high temperature, and the low temperature environment and the high temperature environment can be used alternately.

[0051] Embodiment 2

[0052] Such as Figures 1 to 6As shown in the figure, Embodiment 2 of the present invention provides a vacuum extreme temperature rock fracture test method for use in the vacuum extreme temperature rock fracture test system described in Embodiment 1. The vacuum extreme temperature rock fracture test method includes: making speckles for the uniaxial compression rock sample, lifting the vacuum transparent shield through the counterweight structure, installing the uniaxial compression rock sample between two specimen pads, and then filling the high thermal conductivity powder inside the heat conduction cavity so that the uniaxial compression rock sample is surrounded by the high thermal conductivity powder between the liquid nitrogen refrigeration circulation pipe or the electromagnetic heating plate; installing a lateral deformation sensor, and arranging temperature sensors and acoustic emission sensors inside the heat conduction cavity; releasing the counterweight structure so that the vacuum transparent shield and the vacuum base form a vacuum structure, and moving the vacuum structure to the loading space through a moving trolley and fixing it to the loading position; applying a pre-load of 100 N to the uniaxial compression rock sample through an oil cylinder, pressing the indenter down until the loading force just touches the uniaxial compression rock sample, and then using a vacuum pump to evacuate the inside of the vacuum structure through a vacuum pipe until the target vacuum degree requirement is reached; according to the test plan, setting the target temperature and temperature loading rate through a dual-channel PID controller, arranging a light source, a high-speed camera and an infrared thermal imaging device outside the vacuum structure, and monitoring the evolution of the surface deformation field of the uniaxial compression rock sample in real time; performing mechanical loading on the uniaxial compression rock sample through the loading oil cylinder, synchronously performing optical observation and acoustic emission monitoring, obtaining the load, displacement and deformation results during the uniaxial compression process, supplementarily analyzing the evolution of the surface deformation field of the uniaxial compression rock sample monitored in real time through the digital image correlation method, and simultaneously analyzing the acoustic emission signal law during the fracture process of the uniaxial compression rock sample.

[0053] Specifically, by placing a uniaxially compressed rock sample in a vacuum extreme temperature rock fracture test system and filling a heat conduction cavity with heat conduction rate powder, the heat conduction rate powder can be graphene powder; after loading the sample, temperature sensors and acoustic emission sensors are arranged inside the heat conduction cavity, and the temperature of the specimen and the sound condition during specimen fracture are monitored through the temperature sensors and acoustic emission sensors. Then, a vacuum transparent shield is covered on the vacuum base to form a vacuum structure, and then it is moved to the designated loading position in the loading space by a moving trolley. A preloading force is applied to make the indenter contact the loading block and the loading pad contact the specimen pad. Then, the inside of the vacuum structure is evacuated to make it in a vacuum environment, and the vacuum degree inside the vacuum structure can reach 10 Pa. Then, the target temperature and the temperature loading rate are set through a dual-channel PID controller. If it is an extreme low temperature environment, the temperature of the liquid nitrogen input and the rate of liquid nitrogen input are controlled through the first channel of the dual-channel PID controller, and the lowest temperature can reach -180 °C. If it is an extreme high temperature environment, the temperature of the electromagnetic heating plate is controlled through the second channel of the dual-channel PID controller, and the highest temperature can reach 400 °C. Then, a light source, a high-speed camera, and an infrared thermal imaging device are arranged outside the vacuum structure. When the specimen is in the designed vacuum temperature environment, loading is carried out through a loading oil cylinder, and pressure is applied to the specimen during the downward pressing of the indenter. The deformation of the specimen is monitored through longitudinal deformation sensors and transverse deformation sensors, and the evolution of the surface deformation field of the uniaxially compressed rock sample is monitored in real time through the high-speed camera and the infrared thermal imaging device. Then, combined with the sound condition during specimen fracture monitored by the acoustic emission sensors, rock fracture analysis under vacuum extreme temperature conditions is carried out. Further, the test of a vacuum extreme temperature rock fracture test system of a vacuum extreme temperature rock fracture test method in the second embodiment can be carried out by replacing the uniaxial compression fixture of the uniaxially compressed rock sample with a Brazilian splitting fixture and a variable angle wedge shear fixture to achieve different rock mechanics test measurements; when carrying out the Brazilian splitting test, a liquid nitrogen circulation channel 41 for passing through the liquid nitrogen refrigeration circulation pipe is reserved in the Brazilian splitting fixture, and a first temperature conduction back plate 43 is added behind the Brazilian split rock sample 42 in the Brazilian splitting fixture to achieve temperature conduction to the Brazilian split rock sample 42 from different directions and improve the temperature conduction efficiency. A Brazilian splitting high-transparency material 44 is arranged in front of the Brazilian split rock sample 42 to increase the contact between the Brazilian split rock sample 42 and the first temperature conduction back plate 43 without blocking the observation of the fracture of the Brazilian split rock sample 42.When conducting the variable-angle wedge shear test, a second temperature conduction backplate 52 is added behind the wedge shear rock sample 51 of the variable-angle wedge shear fixture to achieve temperature conduction to the wedge shear rock sample 51 from different directions, improving the temperature conduction efficiency. A wedge shear high-transparency material 53 is arranged in front of the wedge shear rock sample 51 to increase the contact between the wedge shear rock sample 51 and the second temperature conduction backplate 52 without blocking the observation of the fracture of the wedge shear rock sample 51.;

[0054] It should be noted that the method for testing rock fracture at vacuum extreme temperature in the second embodiment is used for the operation of the system for testing rock fracture at vacuum extreme temperature described in the first embodiment. Therefore, the performance principle of the system for testing rock fracture at vacuum extreme temperature will not be elaborated here, and for the unelaborated parts, reference can be made to the first embodiment.

[0055] The preferred specific embodiments of the present invention have been described in detail above. It should be understood that those of ordinary skill in the art can make many modifications and variations based on the concept of the present invention without creative work. Therefore, all technical solutions that can be obtained by those skilled in the art in the technical field of the present invention through logical analysis, reasoning, or limited experiments based on the concept of the present invention on the basis of the existing technology should be within the protection scope determined by the claims.

Claims

1. A vacuum extreme temperature rock fracture test system, characterized in that: The vacuum extreme temperature rock fracture test system includes: A vacuum extreme temperature loading structure, comprising a vacuum transparent shield, a vacuum base and an extreme temperature loading module, wherein the bottom end of the vacuum transparent shield is arranged on the vacuum base and is sealed and connected to the vacuum base to form a vacuum structure, and the extreme temperature loading module is located inside the vacuum structure; An integral loading frame structure, the integral loading frame structure comprises an integral frame and a loading cylinder, the integral frame has a loading space in the middle, the vacuum extreme temperature loading structure is located inside the loading space; a first loading through-hole is provided at the center of the top of the integral frame, the loading cylinder is located above the first loading through-hole, so that the loading rod of the loading cylinder passes through the first loading through-hole to apply a loading force to the extreme temperature loading module, one end of the loading cylinder is fixedly connected to the integral frame; the loading force is applied to the uniaxially compressed rock sample in the vacuum extreme temperature loading structure through the loading cylinder; A moving trolley, the moving trolley is located in the loading space and is slidably connected to the overall frame, and the vacuum base is arranged on the moving trolley; The extreme temperature loading module comprises: The heat conduction cavity is a cubic hollow structure; two liquid nitrogen circulation pipe through holes are provided on the top of the heat conduction cavity; Two vacuum liquid nitrogen circulation pipes, one end of one of the vacuum liquid nitrogen circulation pipes is connected to the outlet of the liquid nitrogen circulation tank, and the other end of the vacuum liquid nitrogen circulation pipe is connected to the inlet of the liquid nitrogen circulation tank; A liquid nitrogen refrigeration circulation pipe, one end of which is connected to the other end of one of the vacuum conveying liquid nitrogen circulation pipes; A plurality of electromagnetic heating plates, wherein the plurality of electromagnetic heating plates are located in the heat conduction cavity, and the plurality of electromagnetic heating plates are arranged close to the inner wall of the heat conduction cavity; A lateral deformation sensor, two ends of which are abutted against and fixed to the outer side wall of the heat conduction cavity; An acoustic emission sensor, wherein the acoustic emission sensor is arranged inside the heat conduction cavity; A temperature sensor, wherein the temperature sensor is arranged inside the heat conduction cavity; Among them, the vacuum base is also provided with two vacuum liquid nitrogen delivery holes and an electromagnetic heating guide hole, the other end of the liquid nitrogen refrigeration circulation pipe sequentially passes through one of the vacuum liquid nitrogen delivery holes and one of the liquid nitrogen circulation pipe through holes to enter the heat conduction cavity, is closely attached to the inner wall of the heat conduction cavity and is spaced apart from a plurality of the electromagnetic heating plates, and then sequentially passes through another liquid nitrogen circulation pipe through hole and another vacuum liquid nitrogen delivery hole to be connected to the other end of another vacuum liquid nitrogen circulation pipe; each of the electromagnetic heating plates is connected in series through an electromagnetic heating wire and passes through the electromagnetic heating guide hole to be connected to a power source; The integral loading frame structure further comprises a displacement sensor, and the displacement sensor is located at the center of the other end of the loading cylinder.

2. A vacuum extreme temperature rock fracture test system as claimed in claim 1, characterized in that: The overall framework includes: A frame bottom column, wherein the frame bottom column is provided with a sliding guide rail, the pulley of the moving trolley is adapted to the sliding guide rail, and the moving trolley is slidably connected to the frame bottom column; A frame column, wherein the frame column has a loading space, and the frame column is located above the frame bottom column and is fixedly connected to the frame bottom column; A frame crossbeam, the frame crossbeam is located above the frame column and is fixedly connected to the frame column; Wherein, a first loading through hole is opened at the center of the frame cross beam, and the loading cylinder is located above the first loading through hole and fixedly connected to the frame cross beam.

3. A vacuum extreme temperature rock fracture test system as claimed in claim 2, characterized in that: The overall loading frame structure also includes: Two counterweight structures; Two counterweight support frames, each of which is a right-angled triangle structure, and the two counterweight support frames are symmetrically fixed to the other end of the loading cylinder with the axis of the loading cylinder as the symmetry axis, and a supporting pulley is respectively fixed at both ends of the hypotenuse of each counterweight support frame; Two counterweight ropes, one end of each counterweight rope is fixedly connected to a corresponding counterweight structure through a first counterweight hook, and the other end of each counterweight rope passes through the corresponding support pulley in turn and is fixedly connected to the top of the vacuum transparent shield through a second counterweight hook.

4. A vacuum extreme temperature rock fracture test system as claimed in claim 3, characterized in that: The vacuum extreme temperature loading structure also includes: A vacuum exhaust pipe, one end of which is located in the vacuum transparent shield; Among them, a vacuum tube through hole is opened on the vacuum base, and the other end of the vacuum exhaust pipe passes through the vacuum tube through the vacuum tube through hole and is connected to the vacuum exhaust pump; an observation port is opened on one side of the vacuum transparent shield, and the observation port is sealed by a transparent anti-fog material.

5. A vacuum extreme temperature rock fracture test system as claimed in claim 4, characterized in that: The extreme temperature loading module comprises: A vacuum support frame, wherein the vacuum support frame is located at the center of the vacuum base; Two loading brackets, the two loading brackets are circular in structure, the central axes of the two loading brackets are the same as the central axis of the vacuum base, one loading bracket is located on the vacuum support frame and is fixedly connected to the vacuum support frame, and each loading bracket has two symmetrical longitudinal support holes; Two longitudinal deformation sensors, one end of each longitudinal deformation sensor passes through a matching longitudinal support hole and is fixedly connected to one loading bracket, and the other end of each longitudinal deformation sensor passes through a matching longitudinal support hole and is fixedly connected to another loading bracket; Two loading pads, the two loading pads are cylindrical structures, the central axes of the two loading pads are the same as the central axis of the vacuum base, one loading pad is located on one loading bracket and is fixedly connected to the one loading bracket, and the other loading pad is located below the other loading bracket and is fixedly connected to the other loading bracket; Two insulation plates, the two insulation plates are circular in structure, the central axes of the two insulation plates are the same as the central axis of the vacuum base, one insulation plate is located on one loading pad and fixedly connected to the loading pad, and the other insulation plate is located above another loading bracket and fixedly connected to the other loading bracket; A loading block, the loading block is located at the center of another of the insulation boards and is fixedly connected to the other of the insulation boards; A pressure head, the pressure head is a cylindrical structure, and the position of the pressure head corresponds to the position of the loading block; A second loading through hole is provided at the top of the vacuum transparent shield, and one end of the pressure head passes through the second loading through hole and is sealed and slidably connected to the vacuum transparent shield.

6. A vacuum extreme temperature rock fracture test system as claimed in claim 5, characterized in that: The heat conduction cavity is located on one of the insulation plates; an observation channel adapted to the rock sample is provided at the center of one side of the heat conduction cavity, and the observation channel corresponds to the position of the observation port; a third loading through hole is also provided at the top of the heat conduction cavity; The extreme temperature loading module further comprises: Two sample pads, both of which are located inside the heat conduction cavity, the central axes of the two sample pads are the same as the central axis of the vacuum base, a uniaxial compression rock sample is arranged between the two sample pads, one sample pad is located at the bottom of the heat conduction cavity, and the other sample pad passes through the third loading through hole and abuts against the other loading pad.

7. A vacuum extreme temperature rock fracture test system as claimed in claim 6, characterized in that: The extreme temperature loading module further comprises: Dual channel PID controller; A liquid nitrogen temperature control circuit, the liquid nitrogen temperature control circuit comprising a pressure sensor and an electric heater, the pressure sensor and the electric heater are both arranged at the inlet of the vacuum conveying liquid nitrogen circulation pipe, and the pressure sensor and the electric heater are respectively connected to the first channel of the dual-channel PID controller; Each of the electromagnetic heating plates is connected in series through an electromagnetic heating wire and passes through the electromagnetic heating guide hole to be connected to the second channel of the dual-channel PID controller, and the dual-channel PID controller is connected to the power supply.

8. A vacuum extreme temperature rock fracture test method, using a vacuum extreme temperature rock fracture test system as claimed in claim 7, characterized in that: The vacuum extreme temperature rock fracture test method comprises: To produce speckles for a uniaxially compressed rock sample, a vacuum transparent shield is lifted by a counterweight structure, the uniaxially compressed rock sample is installed between two sample pads, and then a high thermal conductivity powder is filled in a heat conduction cavity, so that the uniaxially compressed rock sample and a liquid nitrogen refrigeration circulation tube or an electromagnetic heating plate are surrounded by the high thermal conductivity powder; Install a lateral deformation sensor, and arrange a temperature sensor and an acoustic emission sensor inside the heat conduction cavity; The counterweight structure is released, so that the vacuum transparent shield and the vacuum base form a vacuum structure, and the vacuum structure is moved into the loading space and fixed to the loading position by a moving trolley; A preload of 100 N is applied to the uniaxially compressed rock sample through an oil cylinder, and the pressure head is pressed down until the loading force just contacts the uniaxially compressed rock sample, and then a vacuum pump is used to evacuate the vacuum structure through a vacuum exhaust pipe until the target vacuum degree requirement is reached; According to the test plan, the target temperature and the temperature loading rate are set by a dual-channel PID controller, and a light source, a high-speed camera and an infrared thermal imaging device are arranged outside the vacuum structure to monitor the evolution of the deformation field on the surface of the uniaxially compressed rock sample in real time; The uniaxially compressed rock sample is mechanically loaded by the loading cylinder, and optical observation and acoustic emission monitoring are performed simultaneously to obtain the load, displacement and deformation results during the uniaxial compression process. The evolution of the surface deformation field of the uniaxially compressed rock sample monitored in real time is supplemented by a digital image correlation method, and the acoustic emission signal law of the uniaxially compressed rock sample fracture process is analyzed at the same time.

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