Shearing instrument suitable for multi-field coupling

Abstract

The invention discloses a shear apparatus suitable for multi-field coupling. The shear apparatus comprises a test host, an air pressure bin, a power distribution cabinet and a water supply device. The test host integrates a workbench, a confining pressure chamber, a three-dimensional loading system, a closed high-temperature box, a shear box and an acoustic emission probe, and can synchronously apply high temperature, high pressure, seepage and static / dynamic load. Wherein visualization and heat insulation of the closed high-temperature box are achieved through a vacuum glass window, a shear box chassis protrudes and is provided with a water channel matched with membrane sealing to prevent seepage leakage, an impact dowel bar in the transverse loading system is connected with a nitrogen high-pressure emission bin to apply an impact load, and an acoustic emission probe monitors a material damage signal in real time. According to the invention, four-field coupling simulation is realized for the first time, the loading error is less than + / -1%, the impact energy transfer efficiency is improved to 80%, the microcrack omission ratio is reduced to less than 15%, and a high-precision solution is provided for material mechanical property testing in a complex environment.

Description

Technical Field

[0001] The present invention relates to the field of material mechanical property testing equipment, and in particular to a shearing instrument suitable for multi-field coupling. Background Art

[0002] With the rapid development of deep-earth resource development, nuclear waste disposal, and geological disaster prevention and control, the demand for mechanical property testing of materials such as rock, soil, and geopolymers in extremely complex environments (such as high temperature and high pressure, seepage erosion, and dynamic impact coupling) is becoming increasingly urgent. Traditional shear instruments are often limited to single-field or simple dual-field coupling tests, making it difficult to truly simulate the synergistic effects of multi-field coupling in actual engineering, resulting in significant deviations in the evaluation of material mechanical behavior.

[0003] In the existing technology, although the high-temperature shear instrument can realize shear testing in an environment of 800°C, its loading system is not equipped with a cooling module. The pressure head is prone to thermal deformation in a high-temperature environment, resulting in a decrease in stress loading accuracy (the error is generally >±3%). Although the seepage shear device realizes seepage through a porous chassis, it lacks a membrane sealing structure. Liquid leakage is prone to occur during high-pressure seepage, and it cannot be applied synchronously with the impact load. Impact loading equipment mostly uses an external pendulum or hydraulic impact method, which is difficult to be compatible with a closed high-temperature environment. The impact energy transfer efficiency is less than 40%, and it is impossible to achieve three-dimensional stress synchronous loading.

[0004] A more prominent problem is that existing equipment generally adopts a split design: high-temperature testing requires the disassembly of the seepage module, and the application of confining pressure must be suspended during impact loading. This leads to severe temporal asynchrony and spatial fragmentation in multi-field coupled testing. For example, when simulating the failure process of deep oil and gas well casing under the combined effects of high temperature, seepage, and formation impact, existing technology requires transferring samples between multiple devices, causing interfacial damage and interference. The resulting shear strength data deviates by as much as 25%-30% from actual operating conditions.

[0005] In addition, traditional equipment has a single monitoring method, often relying on contact strain gauges or offline microscopic observation, which cannot obtain real-time information on material damage evolution in a high-temperature, high-pressure, and closed environment. Acoustic emission probes (8) are often placed outside the equipment, and the signal is attenuated by the mechanical structure during transmission, resulting in an acoustic emission event miss rate of over 60% in the microcrack initiation stage (<100μm). Summary of the Invention

[0006] In response to the technical problem in the prior art that it is difficult to simultaneously simulate the coupling effects of high temperature, high pressure, seepage and impact, the present invention provides a shear testing device with integrated multi-field coupling function, which can accurately apply three-dimensional stress, seepage and impact loads, and monitor the material damage process in real time.

[0007] To achieve the above-mentioned purpose, the present invention provides a shear instrument suitable for multi-field coupling, comprising a test host, a pressure chamber, a power distribution cabinet and a water supply device; the test host comprises a workbench, a confining pressure chamber, a three-dimensional loading system, a sealed high-temperature box, a shear box and an acoustic emission probe;

[0008] The workbench serves as a supporting base to ensure the stability of the test;

[0009] The confining pressure chamber cooperates with the three-dimensional loading system to apply confining pressure and three-dimensional static load to the specimen;

[0010] The sealed high-temperature box is provided with a vacuum glass window on the outside and a shear box is placed inside to simulate a high-temperature and high-pressure environment and observe the test process;

[0011] The bottom chassis of the shear box is raised and provided with a water channel, and the test piece and the raised portion are wrapped with a membrane to prevent leakage of the seepage liquid;

[0012] The three-dimensional loading system includes a vertical loading system, a transverse loading system and a longitudinal loading system, wherein an impact force transmission rod is coaxially arranged in the transverse loading system, and the impact force transmission rod is connected to the nitrogen high-pressure launch chamber for applying an impact load;

[0013] The acoustic emission probe is installed on the outer pressure rod of the shear box and is used to collect material damage signals.

[0014] Furthermore, the vertical loading system comprises a top loading pressure head, a water outlet channel (12) and a cooling device, wherein the cooling device is used to maintain the working performance of the pressure head in a high temperature environment.

[0015] Furthermore, the water supply device supplies water to the specimen through the shear box chassis water channel, and a water channel is provided inside the vertical loading system for sucking out the seepage water to achieve controllability of the seepage process.

[0016] Furthermore, the vacuum glass window is a double-layer vacuum structure, which has both heat insulation and visual observation functions, reducing heat loss in the high-temperature box.

[0017] Furthermore, the confining pressure chamber, three-dimensional loading system, high temperature box, seepage system and impact loading mechanism work together to simultaneously simulate the multi-field coupling effects of high temperature, high pressure, seepage and static / dynamic loads.

[0018] Furthermore, the working process of the impact loading mechanism is as follows: after the water seepage stops, the high-pressure launch chamber releases nitrogen, and the energy is transmitted to the lateral loading rod and the top loading head through the impact transmission rod, thereby realizing the application of impact load to the specimen.

[0019] Compared with the existing technology, this application has the following technical effects:

[0020] 1. Multi-field integration innovation: For the first time, the coupling of high temperature, high pressure, seepage, and static / dynamic loads is realized, and the simulation accuracy is improved by more than 50% compared with traditional equipment.

[0021] 2. Adaptability to high temperature environments: The cooling device works in conjunction with the vacuum glass window to ensure that the loading error of the indenter is less than ±1% at 800°C, meeting the testing requirements of extreme working conditions.

[0022] 3. Seepage-impact compatibility: The membrane sealing structure and waterway design achieve zero seepage leakage, and the impact energy transfer efficiency is increased to 80%, solving the functional conflict problem of traditional equipment.

[0023] 4. Damage monitoring upgrade: Acoustic emission probes are directly installed on the compression rods, reducing the missed detection rate of microcracks from >60% to <15%, enabling tracking of the entire damage evolution process.

[0024] 5. Operational convenience: Modular structure design (such as detachable shear box, independent water supply and air pressure system) facilitates sample installation, parameter adjustment and equipment maintenance. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a front view of the shearing instrument of the present invention;

[0026] Figure 2 It is a side view of the shearing instrument of the present invention;

[0027] Figure 3 This is a schematic cross-sectional view of the shearing instrument of the present invention;

[0028] Figure 4 This is a schematic diagram of the connection between the cooling device and the circulating pump of the present invention.

[0029] Reference numerals:

[0030] 1-loading mechanism, 2-lateral loading system, 3-lateral load-bearing pressure head, 4-vacuum glass-sealed high-temperature box, 5-shear box, 6-specimen joint specimen, 7-heating rod, 8-acoustic emission probe, 9-cooling device, 10-water inlet channel, 11-impact force transmission rod, 12-water outlet channel, 13-vertical loading system, 14-nitrogen tank, 15-air pressure chamber, 16-spindle-shaped punch, 17-launching chamber, 18-top loading pressure head, 19-bottom loading pressure head; 20-longitudinal loading system, 21-longitudinal loading pressure head, 22-circulation pump. DETAILED DESCRIPTION

[0031] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0032] See Figures 1 to 4 The present invention relates to a high temperature, high pressure, seepage, and impact multi-field coupled shearing instrument, which belongs to the field of material mechanical properties testing equipment and is used to study the shear mechanical behavior of materials under a variety of complex environmental conditions (high temperature, high pressure, seepage and impact coupling).

[0033] The test system includes a test host, a nitrogen tank, an air pressure chamber 15, a launch chamber 17, a power distribution cabinet and a water supply device. The test host is mainly composed of key components such as a workbench, a confining pressure chamber, a vertical loading system 13, a lateral loading system 2, a longitudinal loading system 20, a shear box 5, a heating rod 7 and an acoustic emission probe 8. Among them, the workbench serves as the supporting foundation of the entire device to ensure that the test process is stable and reliable. The confining pressure chamber works in conjunction with each loading system to apply a stable confining pressure to the specimen to simulate the lateral pressure in the actual engineering environment. The vertical loading system 13 includes a top loading pressure head 18, a water outlet channel 12 and a bottom loading pressure head 19, a water inlet channel 10; the longitudinal loading system 20 includes a loading pressure head; the lateral loading system 2 includes left and right bearing heads and left and right impact force transmission rods 11; the vertical and longitudinal loading systems 20 apply static loads.

[0034] The sealed high-temperature chamber 4 is a key innovation of this invention. Its exterior features a vacuum glass window, which ensures a high-temperature, high-pressure environment while allowing researchers to observe the test process. The vacuum glass window also effectively insulates the air, reducing heat loss. A shear box 5 is placed inside the chamber to accommodate the test specimens. Indenters penetrate the sealed high-temperature chamber 4 in the vertical, horizontal, and longitudinal directions, contacting the shear box 5. This allows for precise application of stress to the specimen in three dimensions, fully simulating the complex stress conditions encountered in practice.

[0035] To address the impact of high-temperature environments on the loading system, a high-temperature rod is installed in the shear box 5, and a cooling device 9 is installed on the vertical pressure head. During the high-temperature test, the high-temperature rod can simulate different temperatures to restore the scene as much as possible. The cooling device 9 can maintain the working performance of the pressure head and ensure the accuracy and stability of the loading. In addition, the acoustic emission probe 8 is installed on the pressure rod outside the shear box 5. By collecting the acoustic emission signals generated by the material during the shearing process, the damage initiation, expansion and failure process of the material are monitored in real time, providing key data for analyzing the mechanical properties and failure mechanism of the material.

[0036] To achieve seepage, the bottom chassis of the shear box 5 is raised and equipped with a water channel. A membrane is used to wrap around the specimen joints 6 and the raised area to prevent leakage of seepage fluid. The water supply system seeps into the specimen joints 6 through these water channels, allowing the specimen joints 6 to withstand vertical, lateral, and longitudinal stresses while simulating actual engineering seepage conditions such as groundwater seepage. A dedicated water channel is provided within the vertical loading system 13 to drain the seepage water, ensuring the stability and controllability of the seepage process.

[0037] Regarding impact application, after water seepage ceases, a coaxially arranged impact force transmission rod 11 is located within the transverse loading rod. This impact force transmission rod 11 is connected to a high-pressure launch chamber filled with nitrogen. When the high-pressure nitrogen is released, the enormous energy generated is transmitted to the transverse loading rod via the impact force transmission rod 11, ultimately applying an impact load to the top loading head, thereby impacting the joint specimen 6 of the specimen.

[0038] A high-temperature, high-pressure, seepage, and impact multi-field coupled shear instrument belongs to the field of material mechanical properties testing equipment, and is characterized in that it includes a test host, an air pressure chamber 15, a power distribution cabinet, and a water supply device; the test host is mainly composed of a workbench, a confining pressure chamber, a vertical loading system 13, a lateral loading system 2, a longitudinal loading system 20, a closed high-temperature box 4, a shear box 5, and an acoustic emission probe 8, wherein the workbench serves as a stable support base for the entire device to ensure that the test process is safe and reliable; the confining pressure chamber cooperates with each loading system to accurately apply stable confining pressure to the sample, thereby effectively simulating the lateral pressure effect in the actual engineering environment.

[0039] The vertical loading system 13 includes a top loading pressure head 18 and a water outlet channel 12, and the lateral loading system 2 includes left and right loading heads and left and right impact force transmission rods 11; and the vertical and longitudinal loading systems 20 are used to apply static loads to meet the requirements of applying static loading to the specimens in different test scenarios.

[0040] The sealed high-temperature box 4 is an important innovation of the present invention. It is provided with a vacuum glass window on the outside. While ensuring that the high-temperature and high-pressure environment can be maintained inside, the vacuum glass window facilitates the experimenters to observe the test process clearly and intuitively, and its good thermal insulation performance can effectively reduce heat loss.

[0041] A shear box 5 is provided inside the high-temperature box for placing the sample to be tested; and pressure heads are provided vertically, horizontally and longitudinally. These pressure heads pass through the sealed high-temperature box 4 and contact the shear box 5, thereby realizing the precise application of stress to the sample in the three-dimensional spatial direction, and comprehensively and realistically simulating the actual complex stress state.

[0042] The high-temperature, high-pressure, seepage, and impact multi-field coupled shear instrument is characterized in that, in order to cope with the adverse effects that a high-temperature environment may have on the loading system, a cooling device 9 is vertically arranged; during the high-temperature test, the cooling device 9 can effectively maintain the working performance of the pressure head and ensure the accuracy and stability of the loading process.

[0043] The acoustic emission probe 8 is installed on the pressure rod outside the shear box 5. By collecting the acoustic emission signals generated inside the material during the shearing process, the entire process of damage initiation, expansion and destruction of the material is monitored in real time, providing key data support for analyzing the mechanical properties and failure mechanism of the material.

[0044] The chassis at the bottom of the shear box 5 is designed as a raised structure and is provided with a water channel. While being used to place the specimen joint sample 6, the chassis adopts a membrane to wrap the specimen joint sample 6 and the raised part to prevent fluid leakage during the seepage process, thereby ensuring the accuracy and reliability of the test.

[0045] The water supply device supplies seepage water to the specimen joint sample 6 through the chassis water channel set at the bottom of the shear box 5, so that the specimen joint sample 6 can simulate the seepage conditions in actual engineering environments such as groundwater seepage while bearing vertical, horizontal and transverse pressures.

[0046] The vertical loading system 13 is internally provided with a special water channel for sucking out the seepage water during the test, thereby ensuring that the seepage process can proceed stably and controllably, thereby meeting the precise requirements of the test for seepage conditions.

[0047] The high-temperature, high-pressure, seepage, and impact multi-field coupled shear instrument is characterized in that after the water seepage operation is stopped, a coaxially arranged impact force transmission rod 11 is provided inside the transverse loading rod, and the impact force transmission rod 11 is connected to a high-pressure launch chamber filled with nitrogen to form a preparation structure for impact loading.

[0048] The high-temperature, high-pressure, seepage, and impact multi-field coupled shear instrument is characterized in that when an impact load needs to be applied, the huge energy generated by the nitrogen released from the high-pressure launch chamber can be effectively transmitted to the lateral loading rod through the impact transmission rod 11, and finally act on the top loading head, thereby realizing the impact effect on the specimen and meeting the test requirements for the impact performance of the specimen in specific test scenarios.

[0049] The high-temperature, high-pressure, seepage, and impact multi-field coupled shear instrument is characterized in that the confining pressure chamber, vertical loading system 13, lateral loading system 2, and longitudinal loading system 20 work together to accurately apply stress to the specimen in three dimensions and fully simulate the actual complex stress state; at the same time, the air pressure chamber 15 and the power distribution cabinet are respectively connected to the test host to provide the necessary air pressure support and power supply for the test, thereby ensuring the normal operation of the entire test system.

[0050] Implementation of seepage function:

[0051] The chassis at the bottom of the shear box 5 is designed as a raised structure and is equipped with a water channel. The test specimen joint sample 6 and the raised part are wrapped with a membrane to effectively prevent leakage of seepage fluid and ensure the accuracy and reliability of the test. The water supply device supplies seepage water to the test specimen joint sample 6 through the water channel at the bottom chassis of the shear box 5, so that the test specimen joint sample 6 simulates the seepage conditions in actual engineering such as groundwater seepage while bearing vertical, lateral and longitudinal stresses. In addition, a special water channel is provided inside the vertical loading system 13 to suck out the seepage water during the test, thereby ensuring that the seepage process can be carried out stably and controllably, meeting the precise requirements of the test for seepage conditions.

[0052] Design for impact application:

[0053] After the water seepage operation ceases, a coaxially arranged impact force transmission rod 11 is installed inside the transverse loading rod. This impact force transmission rod 11 is connected to a high-pressure launch chamber filled with nitrogen, forming a preparatory structure for impact loading. When an impact load is required, the enormous energy generated by the nitrogen released from the high-pressure launch chamber is effectively transmitted to the transverse loading rod via the impact force transmission rod 11, and ultimately acts on the top loading head, thereby achieving an impact effect on the specimen joint specimen 6, meeting the impact performance testing requirements of the specimen joint specimen 6 in specific test scenarios.

[0054] Systems work together:

[0055] The confining pressure chamber, vertical loading system 13, transverse loading system 2, and longitudinal loading system 20 work together to precisely apply stress to the specimen in three dimensions, fully simulating the complex stress conditions encountered in real life. Simultaneously, the air pressure chamber 15 and power distribution cabinet, each connected to the main test unit, provide the necessary air pressure and power supply, ensuring the proper functioning of the entire test system.

[0056] Example 1: Overall assembly and connection of the device

[0057] 1.1 Assembly of test host components

[0058] Workbench installation: First, fix the workbench on the base of the test host according to the design requirements, ensuring its levelness and stability as the support foundation of the entire device.

[0059] Confining pressure chamber setup: Install the confining pressure chamber on the workbench, ensuring a good seal between the chamber and the workbench to prevent leakage. Use high-strength sealing materials to seal all joints of the confining pressure chamber to ensure stable confining pressure during the test.

[0060] Loading System Installation: Install the vertical loading system 13, the lateral loading system 2, and the longitudinal loading system 20 in sequence. The top loading head 18 and the water outlet channel 12 of the vertical loading system 13 must be securely installed, and the connection points of the water outlet channel 12 must ensure they do not affect the sealing of the confining pressure chamber. The left and right loading heads and the left and right impact force transmission rods 11 of the lateral loading system 2 must be accurately installed and in place to ensure that the left and right loading heads can flexibly load during the test. The impact force transmission rod 11 must be installed to ensure stability and accuracy when transmitting impact force.

[0061] 1.2 Installation of sealed high temperature box 4 and shear box 5

[0062] Installation of the sealed high-temperature box 4: Install the sealed high-temperature box 4 in a suitable position inside the confined pressure chamber, ensuring a tight connection between it and the confined pressure chamber to prevent heat loss. The vacuum glass window is installed outside the sealed high-temperature box 4. During installation, ensure that the glass window has good sealing and thermal insulation properties.

[0063] Shear box 5 installation: Place the shear box 5 in the designated position inside the sealed high-temperature chamber 4, ensuring that the vertical and horizontal indenters can accurately pass through the sealed high-temperature chamber 4 and contact the specimen inside the shear box 5. The installation position of the shear box 5 must be precisely calibrated to ensure that the actual complex stress state can be fully simulated when stress is applied to the specimen.

[0064] 1.3 Connection of acoustic emission probe 8, air pressure chamber 15, power distribution cabinet and water supply device

[0065] Installation of acoustic emission probe 8: The acoustic emission probe 8 is installed on the pressure rod outside the shear box 5 and connected to the data acquisition system through a signal transmission line to ensure that the acoustic emission signal generated inside the material during the shearing process can be accurately collected.

[0066] Connection of air pressure chamber 15: The air pressure chamber 15 is connected to the test host through an air pipe to provide necessary air pressure support for the test. The connection parts must be well sealed to prevent gas leakage.

[0067] Power distribution cabinet connection: The power distribution cabinet is connected to the test host through cables to ensure a stable power supply for the test. At the same time, the power supply lines are reasonably wired to avoid line crossing and confusion.

[0068] Water supply device connection: The water supply device is connected to the water channel at the bottom chassis of the shear box 5 and the water channel inside the vertical loading system 13 through a water pipe. The connection parts must ensure watertightness, and valves must be installed at appropriate positions on the water pipes to control the on-off and flow of the water.

[0069] Example 2: Specific operating steps of the test process

[0070] 2.1 Sample preparation and placement

[0071] Select a sample that meets the test requirements, place the sample on the bottom plate in the shear box 5, and then carefully wrap the joint sample 6 and the raised part of the sample with a film to ensure that the wrapping is tight to prevent fluid leakage during the seepage process.

[0072] 2.2 Seepage test

[0073] Seepage water supply: Start the water supply device and supply seepage water to the test specimen joint sample 6 through the water channel installed in the bottom chassis of the shear box 5, simulating the seepage conditions in actual engineering such as groundwater seepage. During the water supply process, the water supply flow rate is adjusted according to the test requirements to achieve the preset value.

[0074] Static Loading: The vertical loading system 13, the lateral loading system 2, and the longitudinal loading system 20 are simultaneously activated to apply vertical, lateral, and longitudinal static loads to the specimen, simulating the complex stress conditions found in actual engineering environments. During the loading process, the control system precisely controls the magnitude and rate of the loading force, ensuring stability and accuracy.

[0075] Stabilizing seepage: While applying static loads, specialized channels within the vertical loading system 13 draw out seepage water, ensuring a stable and controllable seepage process, meeting the precise seepage conditions required for the test. By observing flow changes in the water supply and drainage system, the loading force and water flow rate are adjusted to gradually stabilize the seepage process.

[0076] 2.3 Impact test

[0077] Stop the water seepage operation: when it is necessary to apply an impact load, stop the water seepage operation, turn off the water supply device, and stop the seepage of the specimen joint sample 6.

[0078] Impact loading: The high-pressure launch chamber is activated to release nitrogen. The enormous energy generated by the nitrogen is transmitted to the lateral loading rod via the impact force transmission rod 11 coaxially arranged inside the lateral loading rod, and ultimately acts on the top loading head, achieving an impact on the specimen joint specimen 6. During the impact loading process, the control system precisely controls the release amount and release time of nitrogen to achieve the desired impact load magnitude and impact frequency.

[0079] Data Acquisition: During the impact test, the acoustic emission probe 8 collects the acoustic emission signals generated by the material during shear and impact in real time and transmits the signals to the data acquisition system. Simultaneously, other related sensors (such as strain sensors and force sensors) also collect corresponding data, jointly recording the various mechanical responses of the specimen joints during the test.

[0080] Example 3: Action mechanism of cooling device 9

[0081] During high temperature testing, the vertical and longitudinal pressure heads will experience thermal expansion issues due to the high temperature environment, which will affect the performance of the loading system and the accuracy of the test results. To address this issue, the present invention provides a cooling device 9 on the vertical pressure head.

[0082] Selection of cooling medium: The cooling device 9 uses high-efficiency coolant as the cooling medium. The coolant has the characteristics of good thermal conductivity, high boiling point, and stable chemical properties, and can maintain good cooling performance in high temperature environments.

[0083] Cooling cycle: The coolant circulates within the cooling device 9, removing heat through heat exchange between the coolant and the pressure head, thereby maintaining the pressure head's operating performance. Specifically, the coolant enters from one end of the cooling device 9, absorbs heat transferred from the pressure head, and flows to the other end of the cooling device 9. The coolant is then returned to the cooling device 9 by the circulating pump 22 for cooling, and this cycle repeats.

[0084] Temperature monitoring and control: A temperature sensor is installed in the cooling device 9 to monitor the temperature of the coolant in real time. When the coolant temperature rises to a certain value, the control system automatically adjusts the coolant flow rate and the operating power of the cooling device 9 to ensure that the cooling effect always meets the test requirements.

[0085] Example 4: Advantages of vacuum glass windows

[0086] The provision of a vacuum glass window outside the sealed high-temperature box 4 is an important innovation of the present invention, which has many advantages:

[0087] Convenient observation: The vacuum glass window is made of high-transparency and high-refractive-index materials. Experimenters can clearly and intuitively observe various phenomena during the test, such as sample deformation and flow of seepage liquid, through the vacuum glass window without opening the high-temperature chamber, making it convenient to monitor and record the test process in real time.

[0088] Significant thermal insulation effect: Since the interior of the vacuum glass window is a vacuum layer, heat transfer is mainly through radiation, and the coefficient of radiation heat transfer in a vacuum environment is extremely low. Therefore, the vacuum glass window can effectively reduce heat loss, maintain the temperature inside the sealed high-temperature box 4 stable, and ensure the uniformity and accuracy of the test environment.

[0089] Example 5: Verification of multi-field coupling effect

[0090] After completing the test, the collected data was analyzed and processed in detail. By comparing the test results under different test conditions, the effectiveness and accuracy of the high-temperature, high-pressure, seepage, and impact multi-field coupled shear instrument of the present invention under simulated multi-field coupling were verified.

[0091] Data analysis method: Professional data processing software is used to conduct in-depth analysis of the collected acoustic emission signals, strain data, force data, etc., and to extract the mechanical performance parameters of the material under multi-field coupling, such as damage factor, energy absorption rate, etc.

[0092] Comparison of experimental results: Compare with the test results under other single environmental conditions, and verify with theoretical calculation results and observation data in actual engineering, analyze the influence of multi-field coupling on the mechanical properties of materials, and verify the accuracy and reliability of the present invention in simulating the shear mechanical behavior of materials under complex environmental conditions.

[0093] The above shows and describes the basic principles, main features and advantages of the present invention. It is obvious to those skilled in the art that the present invention is not limited to the details of the above exemplary embodiments, and that the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the present invention. Therefore, from all points of view, the embodiments should be regarded as illustrative and non-restrictive. The scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes that come within the meaning and range of equivalents of the claims be included in the present invention. Any reference signs in the claims should not be construed as limiting the claim to which they relate.

[0094] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A shear instrument suitable for multi-field coupling, characterized in that: The test machine comprises a test host, an air pressure chamber (15), a power distribution cabinet and a water supply device; the test host comprises a workbench, a confining pressure chamber, a three-dimensional loading system, a sealed high-temperature box (4), a shear box (5), a heating rod (7) and an acoustic emission probe (8); The workbench serves as a supporting base to ensure the stability of the test; The confining pressure chamber cooperates with the three-dimensional loading system to apply confining pressure and three-dimensional static load to the specimen; The sealed high-temperature box (4) is provided with a vacuum glass window on the outside and a shear box (5) is placed inside to simulate a high-temperature and high-pressure environment and observe the test process; The bottom chassis of the shear box (5) is raised and provided with a water channel, and a membrane is used to wrap the test piece joint specimen (6) and the raised portion to prevent leakage of seepage fluid; The three-dimensional loading system comprises a vertical loading system (13), a transverse loading system (2) and a longitudinal loading system (20), wherein an impact force transmission rod (11) is coaxially arranged in the transverse loading system (2), and the impact force transmission rod (11) is connected to a nitrogen high-pressure launch chamber for applying an impact load; The impact system comprises a nitrogen tank (14) that provides high-pressure driving gas, which is stored in a connected air pressure chamber. The spindle-shaped punch (16) strikes the impact rod at high speed, thereby generating a one-dimensional stress wave in the specimen. The firing chamber (17) generally includes a gas storage chamber, a firing cavity, and other structures for storing high-pressure gas (such as nitrogen). During the experiment, the high-pressure gas is rapidly released by controlling the opening of a valve to control the impact rate of the punch. The heating rod (7) is installed inside the high-temperature box and can be set to different heating paths. The acoustic emission probe (8) is installed on the outer pressure rod of the shear box (5) and is used to collect material damage signals.

2. The shearing instrument according to claim 1, wherein The vertical loading system (13) comprises a top loading pressure head (18), a water outlet channel (12) and a cooling device (9), wherein the cooling device (9) is used to maintain the working performance of the pressure head in a high temperature environment.

3. The shearing instrument according to claim 1, wherein The water supply device supplies water to the test piece through the water channel of the shear box (5) chassis, and a water channel is provided inside the vertical loading system (13) for sucking out seepage water, so as to achieve controllability of the seepage process.

4. The shearing instrument according to claim 1, wherein The vacuum glass window is a double-layer vacuum structure, which has both heat insulation and visual observation functions, reducing heat loss in the high-temperature box.

5. The shearing instrument according to claim 1, wherein The confining pressure chamber, three-dimensional loading system, high temperature box, seepage system and impact loading mechanism work together to simultaneously simulate the multi-field coupling effects of high temperature, high pressure, seepage and static / dynamic loads.

6. The shearing instrument according to claim 1, wherein The working process of the impact loading mechanism is as follows: after the water seepage stops, the high-pressure launch chamber releases nitrogen, and the energy is transmitted to the transverse loading rod and the top loading head through the impact force transmission rod (11), thereby realizing the application of the impact load to the specimen.

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