A multi-field coupled shear testing device

Abstract

This invention provides a multi-field coupled shear testing device, including a test host, a pressure chamber, a power distribution cabinet, and a water supply device. The test host is supported by a workbench. The confining pressure chamber, together with the vertical, horizontal, and longitudinal loading systems, applies a three-dimensional static load. Within the horizontal loading system, an impact transmission rod connects to a nitrogen high-pressure emission chamber to achieve impact loading. The sealed high-temperature chamber has a vacuum glass window on the outside, and the internal shear box chassis is raised and equipped with water channels. A membrane is used to wrap the specimen to prevent leakage. The vertical loading system has a built-in cooling device, and an acoustic emission probe is installed on the pressure rod to monitor damage in real time. This device achieves multi-field coupling of high temperature, high pressure, seepage, and impact through modular design, offering high loading accuracy and convenient operation. It solves the functional conflicts and monitoring lag problems of traditional equipment and is suitable for multi-field mechanical property testing of geotechnical materials.

Description

Technical Field

[0001] This utility model belongs to the technical field of materials mechanics testing equipment, specifically relating to a shear testing device that can realize the coupling effect of high temperature, high pressure, seepage and impact load, and is suitable for multi-field mechanical property analysis of geotechnical materials. Background Technology

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

[0003] In existing technologies, although high-temperature shearing apparatuses can perform shear tests at 800℃, their loading systems lack cooling modules, making the indenter prone to thermal deformation under high temperatures, leading to a decrease in stress loading accuracy (errors generally > ±3%). While seepage shearing devices achieve seepage through a porous chassis, they lack a membrane sealing structure, making them prone to liquid leakage during high-pressure seepage, and they cannot be applied synchronously with impact loads. Impact loading devices mostly use external pendulums or hydraulic impact methods, which are difficult to integrate with confined high-temperature environments, have impact energy transfer efficiency of less than 40%, and cannot achieve synchronous three-dimensional stress loading.

[0004] A more prominent problem is that existing equipment generally adopts a split design: high-temperature testing requires disassembling the seepage module, and confining pressure application must be paused during impact loading, resulting in severe temporal asynchrony and spatial fragmentation in multi-field coupled tests. 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 interface damage interference, and the obtained shear strength data deviates from the actual working conditions by as much as 25%-30%.

[0005] Furthermore, traditional monitoring methods are limited, often relying on contact strain gauges or offline microscopic observation, which cannot acquire material damage evolution information in real time under high temperature, high pressure, and sealed environments. Acoustic emission probes are mostly placed outside the equipment, and the signal is attenuated by the mechanical structure during transmission, resulting in a missed detection rate of over 60% for acoustic emission events in the microcrack initiation stage (<100μm). Utility Model Content

[0006] Purpose of the utility model: To provide a compact and functionally integrated multi-field coupling test device to address the shortcomings of existing equipment in multi-field collaborative simulation and structural compatibility.

[0007] To address the aforementioned problems, this utility model provides a multi-field coupled shear testing device, comprising a test host, a pressure chamber, a power distribution cabinet, and a water supply device; the test host includes a workbench, a confining pressure chamber, a vertical loading system, a horizontal loading system, a longitudinal loading system, a sealed high-temperature chamber, a shear box, and an acoustic emission probe;

[0008] The workbench serves as a supporting foundation, and the confining pressure chamber works in conjunction with each loading system to apply confining pressure.

[0009] The vertical loading system includes a top loading head, a water outlet channel, and a cooling device;

[0010] The lateral loading system includes left and right loading heads and a coaxially arranged impact transmission rod, which is connected to the nitrogen high-pressure launch chamber.

[0011] The sealed high-temperature chamber is equipped with a vacuum glass window on the outside and a shearing box is placed inside. The bottom of the shearing box has a raised base and a water channel. The specimen is wrapped with a membrane to prevent leakage.

[0012] The acoustic emission probe is mounted on the external pressure rod of the shear box.

[0013] Furthermore, the pressure head of the vertical, horizontal, and longitudinal loading system passes through a sealed high-temperature chamber and contacts the shear box to apply a three-dimensional static load to the sample.

[0014] Furthermore, the water supply device supplies water to the specimen through the water channel of the shear box chassis, and the vertical loading system has a water channel for draining seepage water.

[0015] Furthermore, the vacuum glass window is a heat-insulating and transparent structure, used to observe the test process inside the high-temperature chamber and reduce heat loss.

[0016] Furthermore, the impact transmission rod and the transverse loading rod are arranged coaxially. When the high-pressure launch chamber releases nitrogen gas, the energy is transferred to the top loading head through the impact transmission rod to apply the impact load.

[0017] Compared with the prior art, this application has the following technical effects:

[0018] 1. Multi-field integrated innovation: For the first time, it achieves coupling of four fields: high temperature, high pressure, seepage, and static / dynamic load, improving simulation accuracy by more than 50% compared with traditional equipment.

[0019] 2. High-temperature environment adaptability: The cooling device, in conjunction with the vacuum glass window, ensures that the loading error of the pressure head is less than ±1% at 800℃, meeting the requirements of extreme working condition testing.

[0020] 3. Seepage-impact compatibility: The membrane sealing structure and waterway design achieve zero seepage leakage and improve the impact energy transfer efficiency to 80%, solving the functional conflict problem of traditional equipment.

[0021] 4. Damage monitoring upgrade: The acoustic emission probe is directly installed on the pressure bar, reducing the microcrack missed rate from >60% to <15%, enabling full-process tracking of damage evolution.

[0022] 5. Ease of operation: The modular structure design (such as detachable shear box, independent water supply and air pressure system) facilitates sample installation, parameter adjustment and equipment maintenance. Attached Figure Description

[0023] Figure 1 This is a front view of the shearing device of this utility model;

[0024] Figure 2 This is a side view of the shearing device of this utility model;

[0025] Figure 3 This is a cross-sectional structural diagram of the shearing device of this utility model;

[0026] Figure 4 This is a schematic diagram showing the connection between the cooling device and the circulating pump of this utility model.

[0027] Figure label:

[0028] 1-Loading mechanism, 2-Transverse loading system, 3-Transverse bearing head, 4-Vacuum glass-sealed high-temperature chamber, 5-Shear box, 6-Specimen joint sample, 7-Heating rod, 8-Acoustic emission probe, 9-Cooling device, 10-Water inlet channel, 11-Impact transmission rod, 12-Water outlet channel, 13-Vertical loading system, 14-Nitrogen tank, 15-Pressure chamber, 16-Spindle-shaped punch, 17-Emission chamber, 18-Top loading head, 19-Bottom loading head; 20-Longitudinal loading system, 21-Longitudinal loading head, 22-Circulation pump. Detailed Implementation

[0029] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0030] See Figures 1-4 This utility model relates to a high-temperature, high-pressure, seepage, and impact multi-field coupled shear apparatus, belonging to the field of material mechanical property testing equipment, and is used to study the shear mechanical behavior of materials under various complex environmental conditions (high temperature, high pressure, seepage, and impact coupling).

[0031] The test system includes a test host, a nitrogen tank, a pressure chamber 15, an emission chamber 17, a power distribution cabinet, and a water supply device. The test host mainly consists of a workbench, a confining pressure chamber, a vertical loading system 13, a horizontal loading system 2, a longitudinal loading system 20, a shear box 5, a heating rod 7, and an acoustic emission probe 8. The workbench serves as the supporting foundation for the entire device, ensuring stable and reliable operation during the test. The confining pressure chamber works in conjunction with each loading system to apply stable confining pressure to the sample, simulating lateral pressure in actual engineering environments. The vertical loading system 13 includes a top loading head 18, a water outlet channel 12, a bottom loading head 19, and a water inlet channel 10; the longitudinal loading system 20 includes a loading head; the horizontal loading system 2 includes left and right bearing heads and left and right impact transmission rods 11; the vertical and longitudinal loading systems 20 apply static loads.

[0032] The sealed high-temperature chamber 4 is a key innovation of this invention. Its exterior is equipped with a vacuum glass window, which ensures a high-temperature, high-pressure environment inside while allowing researchers to easily observe the experimental process. The vacuum glass window also effectively insulates against heat, reducing heat loss. Inside the high-temperature chamber, a shear box 5 is placed to hold the test sample. Indenters pass through the sealed high-temperature chamber 4 and contact the shear box 5 vertically, horizontally, and longitudinally, enabling precise application of stress to the sample in three dimensions and comprehensively simulating complex actual stress conditions.

[0033] To address the impact of high-temperature environments on the loading system, a high-temperature rod is installed inside the shear box 5, and a cooling device 9 is provided for the vertical indenter. During high-temperature testing, the high-temperature rod can simulate different temperatures to replicate the actual conditions as closely as possible, while the cooling device 9 maintains the working performance of the indenter, ensuring the accuracy and stability of the loading process. Furthermore, an acoustic emission probe 8 is mounted on the pressure bar outside the shear box 5. By collecting acoustic emission signals generated within the material during shearing, it monitors the initiation, propagation, and failure processes of damage in real time, providing crucial data for analyzing the material's mechanical properties and failure mechanisms.

[0034] Regarding the seepage function, the bottom of the shear box 5 has a raised base with water channels. A membrane is used to wrap the jointed specimen 6 and the raised portion to prevent seepage leakage. The water supply device seeps into the jointed specimen 6 through the water channels, allowing the jointed specimen 6 to withstand vertical, horizontal, and longitudinal stresses while simulating seepage conditions in actual engineering projects, such as groundwater seepage. The vertical loading system 13 has a dedicated water channel for extracting seepage water, ensuring the stability and controllability of the seepage process.

[0035] Regarding the impact application, after the seepage stops, the transverse loading rod has a coaxially arranged impact transmission rod 11 inside, which is connected to a high-pressure launch chamber filled with nitrogen. When the high-pressure nitrogen is released, the huge energy generated is transmitted to the transverse loading rod through the impact transmission rod 11, and finally applies an impact load to the top loading head, realizing the impact effect on the jointed specimen 6.

[0036] A high-temperature, high-pressure, seepage, and impact multi-field coupled shear tester, belonging to the field of material mechanical property testing equipment, is characterized by comprising a test host, a pressure chamber 15, a power distribution cabinet, and a water supply device. The test host mainly consists of a workbench, a confining pressure chamber, a vertical loading system 13, a horizontal loading system 2, a longitudinal loading system 20, a sealed high-temperature chamber 4, a shear box 5, and an acoustic emission probe 8. The workbench serves as a stable support foundation for the entire device, ensuring the safety and reliability of the test process. The confining pressure chamber cooperates with each loading system to accurately apply stable confining pressure to the sample, thereby effectively simulating the lateral pressure action in actual engineering environments.

[0037] The vertical loading system 13 includes a top loading head 18 and a water outlet channel 12, and the horizontal loading system 2 includes left and right loading heads and left and right impact transmission rods 11; and the vertical and longitudinal loading systems 20 are used to apply static loads to meet the needs of applying static loads to the specimens under different test scenarios.

[0038] The sealed high-temperature chamber 4 is an important innovation of this utility model. It is equipped with a vacuum glass window on the outside. While ensuring that the internal high temperature and high pressure environment can be maintained, the vacuum glass window allows the experimental personnel to clearly and intuitively observe the experimental process. In addition, its good heat insulation performance can effectively reduce heat loss.

[0039] The high-temperature chamber is equipped with a shear box 5 for placing the test sample; and pressure heads are provided vertically, horizontally and longitudinally. These pressure heads pass through the sealed high-temperature chamber 4 and contact the shear box 5, thereby realizing the precise application of stress to the sample in three-dimensional space, and comprehensively and realistically simulating the actual complex stress state.

[0040] The high-temperature, high-pressure, seepage, and impact multi-field coupled shear apparatus is characterized in that, in order to cope with the adverse effects of the high-temperature environment on the loading system, a cooling device 9 is provided vertically; 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.

[0041] The acoustic emission probe 8 is mounted on the pressure bar outside the shear box 5. By collecting the acoustic emission signals generated inside the material during the shearing process, it can monitor the entire process of damage initiation, propagation and failure of the material in real time, providing key data support for analyzing the mechanical properties and failure mechanisms of the material.

[0042] The bottom of the shear box 5 is designed with a raised structure and is equipped with water channels. While placing the jointed specimen 6, the bottom of the chassis is wrapped with a membrane to prevent fluid leakage during seepage, thus ensuring the accuracy and reliability of the test.

[0043] The water supply device supplies water to the jointed specimen 6 through a water channel set at the bottom of the shear box 5, so that the jointed specimen 6 can withstand vertical, horizontal and lateral pressures while simulating seepage conditions in actual engineering environments such as groundwater seepage.

[0044] The vertical loading system 13 is equipped with a dedicated water channel to extract seepage water during the test, thereby ensuring that the seepage process can be carried out stably and controllably, thus meeting the test's precise requirements for seepage conditions.

[0045] The high-temperature, high-pressure, seepage, and impact multi-field coupled shearing device is characterized in that, after the seepage operation is stopped, an impact force transmission rod 11 is arranged coaxially inside the transverse loading rod. The impact force transmission rod 11 is connected to a high-pressure launch chamber filled with nitrogen gas to form a preparation structure for impact loading.

[0046] The high-temperature, high-pressure, seepage, and impact multi-field coupled shear apparatus is characterized in that, when an impact load needs to be applied, the enormous energy generated by the nitrogen gas released from the high-pressure launch chamber can be effectively transmitted to the transverse loading rod through the impact force transmission rod 11, and finally act on the top loading head, thereby achieving the impact effect on the specimen and meeting the testing requirements for the impact performance of the specimen under specific test scenarios.

[0047] The high-temperature, high-pressure, seepage, and impact multi-field coupled shear apparatus is characterized in that the confining pressure chamber, vertical loading system 13, transverse loading system 2, and longitudinal loading system 20 work together to apply precise stress to the sample in three dimensions, comprehensively simulating the actual complex stress state; at the same time, the air pressure chamber 15 and the power distribution cabinet are connected to the test host to provide the necessary air pressure support and power supply for the test, ensuring the normal operation of the entire test system.

[0048] Achieving the seepage function:

[0049] The bottom of the shear box 5 is designed with a raised structure and includes water channels. A membrane is used to wrap the jointed specimen 6 and the raised portion, effectively preventing seepage leakage and ensuring the accuracy and reliability of the test. The water supply device supplies seepage water to the jointed specimen 6 through the water channels at the bottom of the shear box 5, simulating seepage conditions in actual engineering projects, such as groundwater seepage, while the specimen 6 is subjected to vertical, lateral, and longitudinal stresses. Furthermore, the vertical loading system 13 has a dedicated water channel inside to extract seepage water during the test, ensuring that the seepage process is stable and controllable, meeting the precise requirements of the test for seepage conditions.

[0050] Design for impact application:

[0051] After the seepage operation is stopped, a coaxially arranged impact transmission rod 11 is installed inside the transverse loading rod. This impact transmission rod 11 is connected to a high-pressure launch chamber filled with nitrogen gas, forming a preparation structure for impact loading. When an impact load needs to be applied, the enormous energy generated by the nitrogen gas released from the high-pressure launch chamber can be effectively transferred to the transverse loading rod through the impact transmission rod 11, and finally act on the top loading head, thereby realizing the impact effect on the joint specimen 6 and meeting the testing requirements for the impact performance of the joint specimen 6 under specific test scenarios.

[0052] System collaboration:

[0053] The confining pressure chamber, vertical loading system 13, lateral loading system 2, and longitudinal loading system 20 work together to apply precise stress to the specimen in three dimensions, comprehensively simulating complex actual stress states. Meanwhile, the pressure chamber 15 and the power distribution cabinet are connected to the main testing unit, providing necessary air pressure support and power supply to ensure the normal operation of the entire testing system.

[0054] Example 1: Overall Assembly and Connection of the Device

[0055] 1.1 Assembly of the components of the test host

[0056] 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 supporting foundation for the entire device.

[0057] 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. All connections within the confining pressure chamber are sealed with high-strength sealing material to ensure stable confining pressure is applied during the test.

[0058] Loading system installation: Install the vertical loading system 13, the horizontal 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 that they do not affect the sealing of the confining pressure chamber. The left and right loading heads and the left and right impact transmission rods 11 of the horizontal loading system 2 should be accurately installed to ensure that the left and right loading heads can flexibly load during the test, and the installation of the impact transmission rods 11 must ensure their stability and accuracy in transmitting impact force.

[0059] 1.2 Installation of the sealed high-temperature chamber 4 and the shear box 5

[0060] Installation of the sealed high-temperature chamber 4: Install the sealed high-temperature chamber 4 in a suitable position inside the pressure chamber, ensuring a tight connection between it and the pressure chamber to prevent heat loss. The vacuum glass window is installed on the outside of the sealed high-temperature chamber 4; during installation, ensure the glass window has good sealing and thermal insulation performance.

[0061] Shear box 5 installation: Place 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 sample inside shear box 5. The installation position of shear box 5 must be precisely calibrated to ensure that it can fully simulate the actual complex stress state when stress is applied to the sample.

[0062] 1.3 Connection of acoustic emission probe 8, pressure chamber 15, power distribution cabinet and water supply device

[0063] Installation of acoustic emission probe 8: Install acoustic emission probe 8 on the pressure bar outside shear box 5, and connect it to the data acquisition system through signal transmission line to ensure accurate acquisition of acoustic emission signals generated inside the material during shearing.

[0064] Connection of pressure chamber 15: The pressure chamber 15 is connected to the test host through an air pipe to provide the necessary air pressure support for the test. The connection should be well sealed to prevent gas leakage.

[0065] Power distribution cabinet connection: The power distribution cabinet is connected to the test host via a cable to ensure a stable power supply for the test. At the same time, the power supply lines are laid out in a reasonable manner to avoid line crossing and confusion.

[0066] Water supply device connection: The water supply device is connected to the water channel at the bottom of the shear box 5 and the water channel inside the vertical loading system 13 through water pipes. The connection points must be leak-proof, and valves should be installed at appropriate locations on the water pipes to control the flow and flow rate of the water.

[0067] Example 2: Specific operating steps of the experiment

[0068] 2.1 Sample preparation and placement

[0069] Select a specimen that meets the test requirements, place the specimen on the base plate inside the shear box 5, and then carefully wrap the jointed specimen 6 and the protruding parts with a membrane to ensure that the wrapping is tight and to prevent fluid leakage during the seepage process.

[0070] 2.2 Seepage Test

[0071] Seepage Water Supply: The water supply device is activated, and water is supplied to the jointed specimen 6 through the water channel located at the bottom of the shear box 5 to simulate seepage conditions in actual engineering projects, such as groundwater seepage. During the water supply process, the water flow rate is adjusted according to the test requirements to reach the preset value.

[0072] Static loading: The vertical loading system 13, the transverse loading system 2, and the longitudinal loading system 20 are activated simultaneously to apply vertical, transverse, and longitudinal static loads to the specimen to simulate the complex stress state in a real engineering environment. During the loading process, the magnitude and rate of the loading force are precisely controlled by the control system to ensure the stability and accuracy of the loading process.

[0073] Stabilized seepage: While applying static load, a dedicated water channel within the vertical loading system 13 draws out seepage water to ensure the stability and controllability of the seepage process, meeting the precise requirements of the test for seepage conditions. By observing the flow rate changes of the water supply and drainage systems, the loading force and water supply flow rate are adjusted to gradually stabilize the seepage process.

[0074] 2.3 Impact Test

[0075] Stop the seepage operation: When it is necessary to apply an impact load, stop the seepage operation, turn off the water supply device, and stop the seepage of the jointed specimen 6.

[0076] Impact loading: The high-pressure launch chamber is activated, releasing nitrogen gas. The enormous energy generated by the nitrogen gas is transmitted to the transverse loading rod through the impact force transmission rod 11, which is coaxially arranged inside the transverse loading rod, and finally acts on the top loading head to achieve the impact on the jointed specimen 6. During the impact loading process, the release amount and release time of nitrogen gas are precisely controlled by the control system to obtain the required impact load and impact frequency.

[0077] Data Acquisition: During the impact test, the acoustic emission probe 8 collects the acoustic emission signals generated inside the material during shearing and impact in real time and transmits the signals to the data acquisition system. At the same time, other related sensors (such as strain sensors, force sensors, etc.) also collect corresponding data, jointly recording the various mechanical responses of the jointed specimen during the test.

[0078] Example 3: The working mechanism of cooling device 9

[0079] During high-temperature testing, the vertical and longitudinal indenters experience thermal expansion due to the high-temperature environment, which affects the performance of the loading system and the accuracy of the test results. To address this issue, this invention incorporates a cooling device 9 in the vertical indenter.

[0080] Selection of cooling medium: 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 environment.

[0081] Cooling cycle process: The coolant circulates within the cooling device 9, carrying away heat through heat exchange between the coolant and the pressure head, thereby maintaining the working performance of the pressure head. Specifically, the coolant enters from one end of the cooling device 9, absorbs the heat transferred from the pressure head, flows to the other end of the cooling device 9, and is then returned to the cooling device 9 by the circulating pump 22 for cooling, thus repeating the cycle.

[0082] 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 will automatically adjust the coolant flow rate and the operating power of the cooling device 9 to ensure that the cooling effect always meets the test requirements.

[0083] Example 4: Advantages of Vacuum Glass Windows

[0084] The installation of a vacuum glass window on the outside of the sealed high-temperature chamber 4 is a key innovation of this invention, offering several advantages:

[0085] Convenient observation: The vacuum glass window is made of a material with high transparency and high refractive index. Experimenters can clearly and intuitively observe various phenomena during the test process, such as sample deformation and flow of seepage liquid, without opening the high-temperature chamber. This facilitates real-time monitoring and recording of the test process.

[0086] Significant heat insulation effect: Since the inside of the vacuum glass window is a vacuum layer, heat transfer is mainly through radiation. Moreover, the coefficient of radiation heat transfer is extremely low in a vacuum environment. Therefore, the vacuum glass window can effectively reduce heat loss, maintain the temperature stability inside the sealed high-temperature chamber 4, and ensure the uniformity and accuracy of the test environment.

[0087] Example 5: Verification of Multi-Field Coupling Effect

[0088] After the experiment was completed, the collected data were analyzed and processed in detail. By comparing the test results under different test conditions, the effectiveness and accuracy of the high temperature and high pressure, seepage and impact multi-field coupled shearing instrument of this invention in simulating multi-field coupling action were verified.

[0089] 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 and energy absorption rate.

[0090] Experimental results comparison: The results were compared with those under other single environmental conditions, and were also corroborated with theoretical calculations and observation data from actual engineering projects. The influence of multi-field coupling on the mechanical properties of materials was analyzed, and the accuracy and reliability of this invention in simulating the shear mechanical behavior of materials under complex environmental conditions were verified.

[0091] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. It will be apparent to those skilled in the art that this utility model is not limited to the details of the exemplary embodiments described above, and that it can be implemented in other specific forms without departing from the spirit or basic characteristics of this utility model. Therefore, the embodiments should be considered exemplary and non-limiting in all respects. The scope of this utility model is defined by the appended claims rather than the foregoing description, and thus all variations falling within the meaning and scope of equivalents of the claims are intended to be included within this utility model. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0092] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A multi-field coupled shear testing device, characterized in that, It includes a test host, a pressure chamber, a power distribution cabinet and a water supply device; the test host includes a workbench, a confining pressure chamber, a vertical loading system (13), a horizontal loading system (2), a longitudinal loading system (20), a sealed high-temperature chamber (4), a shear box (5) and an acoustic emission probe (8); The workbench serves as a supporting foundation, and the confining pressure chamber works in conjunction with each loading system to apply confining pressure. The vertical loading system (13) includes a top loading head (18), a water outlet channel (12), and a cooling device (9); The lateral loading system (2) includes left and right loading heads and an impact transmission rod (11) arranged coaxially, and the impact transmission rod (11) is connected to the nitrogen high-pressure launch chamber; The sealed high-temperature chamber is equipped with a vacuum glass window on the outside and a shear box (5) is placed inside. The bottom of the shear box (5) has a raised base and a water channel. The joint sample (6) is wrapped with a membrane to prevent leakage. The acoustic emission probe (8) is mounted on the external pressure rod of the shear box (5).

2. The testing apparatus according to claim 1, characterized in that, The pressure head of the vertical, horizontal and longitudinal loading system passes through the sealed high temperature chamber (4) and contacts the shear box (5) to apply a three-dimensional static load to the sample.

3. The testing apparatus according to claim 1, characterized in that, The water supply device supplies water to the jointed specimen (6) through the water channel of the shear box (5) chassis, and the vertical loading system (13) has a water channel for draining seepage water.

4. The testing apparatus according to claim 1, characterized in that, The vacuum glass window is a heat-insulating and transparent structure, used to observe the test process inside the high-temperature chamber and reduce heat loss.

5. The testing apparatus according to claim 1, characterized in that, The impact transmission rod and the transverse loading rod are arranged coaxially. When the high-pressure launch chamber releases nitrogen, the energy is transmitted to the top loading head (18) through the impact transmission rod (11) to apply the impact load.

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