Rock multi-field coupling fatigue performance testing machine and system thereof

Abstract

The invention relates to the technical field of rock performance testing, and provides a rock multi-field coupling fatigue performance testing machine and a system thereof.The rock multi-field coupling fatigue performance testing machine is characterized by comprising a main body, a pressure detection mechanism, a transfer mechanism and a centering mechanism, the pressure detection mechanism is installed on one side of the main body, and the transfer mechanism is installed on the other side of the main body; through the arrangement of structures such as the sliding air cylinder and the jacking air cylinder and the combined use of the sliding air cylinder, the jacking air cylinder and the servo motor, diversified pressure application to rocks is achieved, even jacking at the two ends, punctiform accurate pressure and peripheral pressure extrusion can be easily achieved, meanwhile, through the matched use of a water pump and a hard spray head, the pressure application range of the rocks is widened, and the working efficiency is improved. According to the technical scheme, a real water flow scouring environment is provided for the rock, the stress condition of the rock in practical application is further simulated, the test accuracy and practicability are improved, and the problems of single experiment effect and insufficient accuracy in the prior art are solved through the technical scheme.

Description

Technical Field

[0001] The present invention relates to the technical field of rock performance testing, and in particular to a rock multi-field coupling fatigue performance testing machine and a system thereof. Background Art

[0002] At present, the rock multi-field coupling fatigue performance testing machine is a high-precision physical performance testing instrument specially used to study the fatigue performance of rocks under complex environmental conditions.

[0003] Existing rock testing institutions have many limitations in rock performance testing, and it is difficult to meet the needs of accurate evaluation of rock multi-field coupled fatigue performance in complex geological environments. Traditional testing equipment can often only perform single-dimensional pressure tests, ignoring the multiple physical field coupling effects that rocks are subjected to in actual environments, such as stress, seepage, temperature, and chemical corrosion. This single-dimensional testing method leads to a large deviation between the test results and the actual situation, and cannot accurately reflect the long-term stability and fatigue life of rocks under complex conditions. In addition, the existing testing institutions have a low degree of automation in the process of rock positioning, transportation, and testing, and rely on manual operation, which is not only inefficient, but also easy to introduce human errors. The positioning and centering process of rocks usually requires manual adjustment, which is time-consuming and labor-intensive, and the positioning accuracy is difficult to guarantee. During the transportation process, the clamping and movement of rocks also lack precise control, which can easily cause rock damage or position displacement, affecting the accuracy of the test results. Summary of the invention

[0004] The present invention provides a rock multi-field coupling fatigue performance testing machine and a system thereof, which solve the problems of single experimental effect and insufficient accuracy in related technologies.

[0005] The technical solution of the present invention is as follows: A rock multi-field coupling fatigue performance testing machine and a system thereof, comprising a rock multi-field coupling fatigue performance testing machine, characterized in that it comprises a main body, a pressure detection mechanism, a transfer mechanism and a centering mechanism, wherein the pressure detection mechanism is installed on one side of the main body, the transfer mechanism is installed in the middle of the main body, and the centering mechanism is installed on the other side of the main body; The pressure detection mechanism includes a rotating motor and two sliding cylinders, the rotating motor is installed on the top of the main body, the output end of the rotating motor is connected to a coaxially arranged rotating screw through a coupling, the interior of the main body is fixedly connected to two symmetrically arranged limit rods, the rotating screw and the limit rods are movably sleeved with a circular frame, and a circular scanner is installed on the inner wall of the circular frame; The two sliding cylinders are respectively installed on the top and bottom of the main body, and a sliding shaft is installed at the output end of the sliding cylinder, and a top pressure frame is fixedly connected to the bottom of the sliding shaft, and a top pressure cylinder is installed inside the top pressure frame, and a top pressure shaft is installed at the output end of the top pressure cylinder, and a hard nozzle mounting plate is installed at the bottom of the top pressure shaft, and a water storage tank is installed on the top of the hard nozzle mounting plate, and two symmetrically arranged water inlet pipes are fixedly connected to the top of the water storage tank, and a water pump is installed on the water inlet pipe.

[0006] As a preferred solution of the present invention, a servo motor is installed inside the top pressure frame, and four circumferentially evenly distributed rotating shafts are rotatably installed inside the top pressure frame, one of the rotating shafts is connected to the output end of the servo motor through a coupling, and a meshing gear is fixedly sleeved on the outer circumferential surface of the rotating shaft, and a rotating circular frame is rotatably installed inside the main body, and an internal gear is fixedly connected to the inner wall of the rotating circular frame, and the four meshing gears are all meshed with the internal gear, and four circumferentially evenly distributed meshing limit racks are slidably assembled inside the top pressure frame, and the four meshing limit racks are respectively meshed with the four meshing gears, and one end of the meshing limit rack is fixedly connected to a pressure plate.

[0007] As a preferred solution of the present invention, the bottom of the top pressure frame is provided with a plurality of holes and grooves evenly distributed in an array, the bottom of the hard nozzle mounting plate is installed with a plurality of hard nozzles evenly distributed in an array, a plurality of the hard nozzles respectively pass through the interior of a plurality of the holes and grooves, and a plurality of auxiliary balls evenly distributed around the circumference are rotatably installed inside the rotating circular frame.

[0008] As a preferred solution of the present invention, the transfer mechanism includes a connecting frame and a rotating motor, the connecting frame is fixedly connected to the top of the main body, the rotating motor is installed on the top of the connecting frame, the output end of the rotating motor is connected to a coaxially arranged rotating shaft through a coupling, the bottom of the rotating shaft is fixedly connected to a transfer frame, a screw motor is installed on the top of the transfer frame, the output end of the screw motor is connected to a coaxially arranged rotating screw through a coupling, two symmetrically arranged limiting shafts are fixedly connected to the inside of the transfer frame, a sliding frame is jointly sleeved on the outer circumference of the rotating screw and the limiting shaft, a transmission motor is installed on one side of the sliding frame, the output end of the transmission motor is connected to a coaxially arranged double-screw shaft through a coupling, and two symmetrically arranged clamping blocks are movably sleeved on the double-screw shaft.

[0009] As a preferred solution of the present invention, the centering mechanism includes a synchronous motor and four limit sliders, the synchronous motor is installed inside the main body, the output end of the synchronous motor is connected to a coaxially arranged transmission shaft through a coupling, a circular plate is installed on the top of the transmission shaft, and four circumferentially evenly distributed hinged rods are movably hinged on the top of the circular plate, and the four limit sliders are circumferentially evenly distributed slidingly assembled inside the main body, the top of the limit slider is fixedly connected to a centering plate, and the limit slider and the hinged rod are hinged to each other.

[0010] A system of a rock multi-field coupling fatigue performance testing machine, S1: Rock positioning and centering: S11: Place the rock in the middle of the centering mechanism; S12: Start the synchronous motor to drive the circular plate to rotate through the transmission shaft, thereby driving the articulated rod and the limit slider to move, thereby realizing the center positioning of the rock; S2: Rock transfer: S21: Start the screw motor in the transfer mechanism to drive the rotating screw to rotate, so that the sliding frame descends to the middle of the rock; S22: Start the transmission motor to drive the double screw shaft to rotate, so that the two clamping blocks move toward the rock and clamp the rock; S23: Start the screw motor again to lift the rock and move it away from the centering mechanism; S24: starting the rotating motor to transfer the rock to the middle of the pressure detection mechanism; S25: start the transmission motor again to make the rock drop to the top pressure frame of the pressure detection mechanism; S26: separating the clamping block from the rock, and moving the clamping block to the top of the rock; S27: The rotating motor works to make the clamping block leave the pressure detection mechanism; S3: Pressure application and water flow flushing: S31: Start the sliding cylinder to move the top pressure frame to both ends of the rock; S32: Start the sliding cylinder, top pressure cylinder or servo motor according to the needs: S33: Sliding cylinder: applies pressure to both ends of the rock; S34: Top pressure cylinder: drives the top pressure shaft to slide, so that the hard nozzle can press the rock with point pressure; or retracts the top pressure cylinder, starts the water pump, and flushes the rock with the hard nozzle; S35: servo motor: drives the rotating shaft and the internal gear to rotate, and applies pressure to the surrounding of the rock through the meshing gear and the meshing limit rack; S4: Multi-dimensional testing: S41: During the process of applying pressure and flushing with water, the rotating motor is started to drive the rotating screw to rotate, so that the circular frame slides, and the rock is scanned in multiple dimensions through the circular scanner.

[0011] As a preferred embodiment of the present invention: The detection formula is: 1. Rock compressive strength formula: Where p is the compressive strength, P is the pressure applied to the rock, A is the force-bearing area of ​​the rock, and the compressive strength is expressed in megapascals (MPa); 2. Formula for characteristic value of rock foundation bearing capacity: fa = \psiψr \times frk Among them, fa is the characteristic value of rock foundation bearing capacity, frk is the standard value of rock saturated uniaxial compressive strength, and ψr is the reduction factor, which is determined according to the integrity of the rock mass and the spacing, width, occurrence and combination factors of the structural plane; 3. Scouring force formula: F = \rhoρ\cdot A \cdot V^2 \cdot Cf Among them, F is the scouring force, ρ is the density of water, A is the contact area between water flow and rock, V is the water flow velocity, and Cf is the scouring coefficient. The magnitude of the scouring force depends on the water flow velocity, density and contact area factors.

[0012] The working principle and beneficial effects of the present invention are: 1. The present invention realizes diversified pressure application on rocks through the arrangement of structures such as sliding cylinders, top pressure cylinders, and the combined use of sliding cylinders, top pressure cylinders, and servo motors. Whether it is uniform top pressure at both ends, point-shaped precise pressure, or pressure extrusion all around, it can be easily achieved. At the same time, the coordinated use of water pumps and hard nozzles provides a real water flow flushing environment for rocks, further simulates the stress conditions of rocks in actual applications, and improves the accuracy and practicality of the test.

[0013] 2. The present invention, through the arrangement of structures such as synchronous motors and screw motors, can accurately position the rock in the center by driving the centering mechanism through the synchronous motor, thereby ensuring the accuracy of subsequent tests. The transfer mechanism is cleverly designed, and through the cooperation of the screw motor and the transmission motor, rapid clamping, lifting and transfer of the rock are achieved, greatly improving the test efficiency. At the same time, precise control during the transfer process ensures that the rock will not suffer additional damage during the transfer process, providing a stable foundation for subsequent pressure tests and scouring tests. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0015] Figure 1 It is a schematic diagram of the overall structure of the present invention; Figure 2 This is the overall structural diagram of the pressure detection mechanism of the present invention; Figure 3 It is a schematic diagram of the transmission structure of the rotary motor of the present invention; Figure 4 This is a schematic diagram of the servo motor transmission structure of the present invention; Figure 5 This is a schematic diagram of the bottom structure of the hard nozzle mounting plate of the present invention; Figure 6 It is a schematic diagram of the overall structure of the transfer mechanism of the present invention; Figure 7 It is a schematic diagram of the overall structure of the centering mechanism of the present invention.

[0016] In the figure: 1. pressure detection mechanism; 11. main body; 12. rotating motor; 121. rotating screw rod; 122. limiting rod; 123. circular frame; 124. circular scanner; 13. sliding cylinder; 131. sliding shaft; 132. top pressure frame; 14. top pressure cylinder; 141. top pressure shaft; 142. water storage tank; 143. hard nozzle mounting plate; 144. water inlet pipe; 145. water pump; 15. servo motor; 151. rotating shaft; 152. meshing gear; 153. meshing limiting rack; 154. pressure plate; 155. rotating circular frame; 155. internal gear; 156. auxiliary ball; 2. Transfer mechanism; 21. Connecting frame; 22. Rotating motor; 221. Rotating shaft; 222. Transfer frame; 23. Screw motor; 231. Rotating screw; 232. Limiting shaft; 24. Sliding frame; 241. Transmission motor; 242. Double screw shaft; 243. Clamping block; 3. Centering mechanism; 31. Synchronous motor; 311. Transmission shaft; 312. Circular plate; 32. Articulated rod; 321. Limiting slider; 322. Centering plate. DETAILED DESCRIPTION

[0017] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. 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 creative work are within the scope of protection of the present invention.

[0018] Example 1 like Figure 1 to Figure 7As shown, a rock multi-field coupling fatigue performance testing machine includes a main body 11, a pressure detection mechanism 1, a transfer mechanism 2 and a centering mechanism 3, wherein the pressure detection mechanism 1 is installed on one side of the main body 11, the transfer mechanism 2 is installed in the middle of the main body 11, and the centering mechanism 3 is installed on the other side of the main body 11; The pressure detection mechanism 1 includes a rotating motor 12 and two sliding cylinders 13. The rotating motor 12 is installed on the top of the main body 11. The output end of the rotating motor 12 is connected to a coaxially arranged rotating screw 121 through a coupling. Two symmetrically arranged limiting rods 122 are fixedly connected inside the main body 11. A circular frame 123 is movably sleeved on the rotating screw 121 and the limiting rod 122. A circular scanner 124 is installed on the inner wall of the circular frame 123. The two sliding cylinders 13 are respectively installed on the top and bottom of the main body 11, and a sliding shaft 131 is installed at the output end of the sliding cylinder 13, and a top pressure frame 132 is fixedly connected to the bottom of the sliding shaft 131. A top pressure cylinder 14 is installed inside the top pressure frame 132, and a top pressure shaft 141 is installed at the output end of the top pressure cylinder 14, and a hard nozzle mounting plate 143 is installed at the bottom of the top pressure shaft 141. A water storage tank 142 is installed on the top of the hard nozzle mounting plate 143, and two symmetrically arranged water inlet pipes 144 are fixedly connected to the top of the water storage tank 142, and a water pump 145 is installed on the water inlet pipe 144.

[0019] like Figure 1~Figure 5 As shown, a servo motor 15 is installed inside the top pressure frame 132, and four rotating shafts 151 with uniform circumference are rotatably installed inside the top pressure frame 132, one of the rotating shafts 151 is connected to the output end of the servo motor 15 through a coupling, and a meshing gear 152 is fixedly sleeved on the outer circumferential surface of the rotating shaft 151, and a rotating circular frame 155 is rotatably installed inside the main body 11, and an internal gear 155 is fixedly connected to the inner wall of the rotating circular frame 155, and the four meshing gears 152 are all meshed with the internal gear 155, and the internal sliding assembly of four meshing limit racks 153 with uniform circumference is provided inside the top pressure frame 132, and the four meshing limit racks 153 are respectively meshed with the four meshing gears 152, and one end of the meshing limit rack 153 is fixedly connected to a pressure plate 154.

[0020] like Figure 1~Figure 5 As shown, the bottom of the top pressure frame 132 is provided with a plurality of holes and grooves distributed in an array at equal intervals, the bottom of the hard nozzle mounting plate 143 is installed with a plurality of hard nozzles distributed in an array at equal intervals, the plurality of hard nozzles pass through the interior of the plurality of holes and grooves respectively, and the interior of the rotating circular frame 155 is rotatably installed with a plurality of auxiliary balls 156 evenly distributed around the circumference.

[0021] In this embodiment, after the rock moves to between the two top pressure frames 132, the two sliding cylinders 13 are started synchronously, and the start of the sliding cylinder 13 causes the sliding shaft 131 to move, and the movement of the sliding shaft 131 causes the top pressure frame 132 to move to the two ends of the rock. Subsequently, the sliding cylinder 13, the top pressure cylinder 14 or the servo motor 15 are started according to demand, and the start of the sliding cylinder 13 causes the top pressure frames 132 on both sides to move, and the pressure is applied to the two ends of the rock. The start of the top pressure cylinder 14 causes the top pressure frame 132 to move to the two ends of the rock. The shaft 141 slides, and the sliding of the top pressure shaft 141 makes the hard nozzles distributed in an array at equal intervals press against the rock in a point-like pressure. The top pressure cylinder 14 can also be retracted, and the water pump 145 is turned on after retraction. The water pump 145 sends water to the water storage tank 142 through the water inlet pipe 144 and the external water tank. The water storage tank 142 sends water to the hard nozzles, and then the water is sent out from the hard nozzles to flush the rocks. The servo motor 15 is turned on, so that one of the rotating shafts 151 rotates. This rotating shaft The rotation of 151 causes one of the meshing gears 152 to rotate, and the rotation of this meshing gear 152 drives the internal gear 155 to rotate. The rotation of the internal gear 155 causes the other three meshing gears 152 to rotate synchronously. When the internal gear 155 rotates, the auxiliary ball 156 on the rotating circular frame 155 is used for auxiliary rotation. When the four meshing gears 152 rotate synchronously, the four meshing limiting racks 153 are driven to move synchronously toward the four sides of the rock, and pressure is applied to the surrounding areas of the rock. During the process of applying various pressures to the rock and flushing it with water flow, the rotating motor 12 is turned on, and the rotation of the rotating motor 12 causes the rotating screw rod 121 to rotate. The rotation of the rotating screw rod 121 causes the circular frame 123 to slide, and the sliding limiting rod 122 of the circular frame 123 limits it. During the sliding process of the circular frame 123, the circular scanner 124 on the circular frame 123 scans the rock during the extrusion and water pressure flushing process, thereby realizing multi-dimensional testing of the rock.

[0022] Example 2 like Figure 6As shown, the transfer mechanism 2 includes a connecting frame 21 and a rotating motor 22, the connecting frame 21 is fixedly connected to the top of the main body 11, the rotating motor 22 is installed on the top of the connecting frame 21, the output end of the rotating motor 22 is connected to a coaxially arranged rotating shaft 221 through a coupling, the bottom of the rotating shaft 221 is fixedly connected to a transfer frame 222, a screw motor 23 is installed on the top of the transfer frame 222, the output end of the screw motor 23 is connected to a coaxially arranged rotating screw 231 through a coupling, two symmetrically arranged limiting shafts 232 are fixedly connected inside the transfer frame 222, and a sliding frame 24 is jointly sleeved on the outer circumferential surfaces of the rotating screw 231 and the limiting shaft 232, a transmission motor 241 is installed on one side of the sliding frame 24, and the output end of the transmission motor 241 is connected to a coaxially arranged double-screw shaft 242 through a coupling, and two symmetrically arranged clamping blocks 243 are movably sleeved on the double-screw shaft 242.

[0023] like Figure 7 As shown, the centering mechanism 3 includes a synchronous motor 31 and four limit sliders 321. The synchronous motor 31 is installed inside the main body 11. The output end of the synchronous motor 31 is connected to a coaxially arranged transmission shaft 311 through a coupling. A circular plate 312 is installed on the top of the transmission shaft 311. Four circumferentially evenly distributed articulated rods 32 are movably hinged on the top of the circular plate 312. The four limit sliders 321 are circumferentially evenly distributed slidingly assembled inside the main body 11. The top of the limit slider 321 is fixedly connected to a centering plate 322, and the limit slider 321 and the articulated rod 32 are hinged to each other.

[0024] In this embodiment, before rock detection, the rock to be detected is first placed in the middle of the centering mechanism 3. After the placement is completed, the synchronous motor 31 is turned on. The start of the synchronous motor 31 causes the transmission shaft 311 to rotate. The rotation of the transmission shaft 311 causes the circular plate 312 to rotate. The rotation of the circular plate 312 causes the four hinged rods 32 to slide at an angle. When the hinged rods 32 slide at an angle, they drive the limit slider 321 to slide toward the center position of the circular plate 312. During the sliding process of the limit slider 321, because the limit slider The limit of block 321 slides the sliding position of the limit slider 321, so that the centering plate 322 moves to the center position of the centering mechanism 3, so as to center the position of the rock. After the center positioning is completed, the transfer mechanism 2 is turned on, and the screw motor 23 in the transfer mechanism 2 is started first. The rotation of the screw motor 23 causes the rotating screw 231 to rotate, and the rotation of the rotating screw 231 causes the sliding frame 24 to descend. The sliding frame 24 descends to the middle position of the rock. At this time, the transmission motor 241 is turned on, and the transmission motor 241 is turned on. The start of the machine 241 causes the double screw shaft 242 to rotate. The double screw shaft 242 has two screw shafts with opposite screw directions. When the double screw shaft 242 rotates, the two clamping blocks 243 move toward the rock position to clamp the rock. After the clamping is completed, the screw motor 23 is turned on to rotate, so that the rock leaves the centering mechanism 3. After the rock leaves the centering mechanism 3, the rotating motor 22 is turned on. The start of the rotating motor 22 causes the rotating shaft 221 to drive the transfer frame 222 to rotate, and the transfer frame 22 2 rotates so that the rock moves to the middle of the pressure detection mechanism 1. At this time, the transmission motor 241 is turned on again to make the rock descend and place the rock on the top pressure frame 132 of the lower half of the pressure detection mechanism 1. Then the transmission motor 241 is turned on to separate the clamping block 243 from the rock. Then the screw motor 23 is turned on to move the clamping block 243 to the top of the rock. At this time, the rotating motor 22 is turned on to rotate the clamping block 243 away from the pressure detection mechanism 1, so that the position of the rock is placed more accurately.

[0025] A system of a rock multi-field coupling fatigue performance testing machine, characterized in that: S1: Rock positioning and centering: S11: placing the rock in the middle of the centering mechanism 3; S12: Start the synchronous motor 31 to drive the circular plate 312 to rotate through the transmission shaft 311, thereby driving the hinge rod 32 and the limit slider 321 to move, thereby achieving the center positioning of the rock; S2: Rock transfer: S21: Start the screw motor 23 in the transfer mechanism 2 to drive the rotating screw 231 to rotate, so that the sliding frame 24 descends to the middle of the rock; S22: Start the transmission motor 241 to drive the double screw shaft 242 to rotate, so that the two clamping blocks 243 move toward the rock and clamp the rock; S23: Start the screw motor 23 again to lift the rock and move it away from the centering mechanism 3; S24: starting the rotary motor 22 to transport the rock to the middle of the pressure detection mechanism 1; S25: Start the transmission motor 241 again to make the rock drop onto the top pressure frame 132 of the pressure detection mechanism 1; S26: Separate the clamping block 243 from the rock, and move the clamping block 243 to the top of the rock; S27: The rotating motor 22 works to make the clamping block 243 leave the pressure detection mechanism 1; S3: Pressure application and water flow flushing: S31: Start the sliding cylinder 13 to move the top pressure frame 132 to both ends of the rock; S32: Start the sliding cylinder 13, the pressing cylinder 14 or the servo motor 15 according to the requirements: S33: Sliding cylinder 13: Apply pressure to both ends of the rock; S34: the top pressure cylinder 14 drives the top pressure shaft 141 to slide, so that the hard nozzle performs point-like pressure on the rock; or the top pressure cylinder 14 is retracted, and the water pump 145 is started to flush the rock through the hard nozzle; S35: the servo motor 15 drives the rotating shaft 151 and the inner gear 155 to rotate, and applies pressure to the surrounding of the rock through the meshing gear 152 and the meshing limit rack 153; S4: Multi-dimensional testing: S41: During the process of applying pressure and flushing with water, the rotating motor 12 is started to drive the rotating screw 121 to rotate, so that the circular frame 123 slides, and the circular scanner 124 performs a multi-dimensional scan on the rock.

[0026] Specifically, a system of a rock multi-field coupling fatigue performance testing machine is characterized in that: The detection formula is: 1. Rock compressive strength formula: Where p is the compressive strength, P is the pressure applied to the rock, A is the force-bearing area of ​​the rock, and the compressive strength is expressed in megapascals (MPa); 2. Formula for characteristic value of rock foundation bearing capacity: fa = \psiψr \times frk Among them, fa is the characteristic value of rock foundation bearing capacity, frk is the standard value of rock saturated uniaxial compressive strength, and ψr is the reduction factor, which is determined according to the integrity of the rock mass and the spacing, width, occurrence and combination factors of the structural plane; 3. Scouring force formula: F = \rhoρ\cdot A \cdot V^2 \cdot Cf Among them, F is the scouring force, ρ is the density of water, A is the contact area between water flow and rock, V is the water flow velocity, and Cf is the scouring coefficient. The magnitude of the scouring force depends on the water flow velocity, density and contact area factors.

[0027] The above are only preferred embodiments of the present invention and are 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 protection scope of the present invention.

Claims

1. A rock multi-field coupling fatigue performance testing machine, characterized in that: It comprises a main body (11), a pressure detection mechanism (1), a transfer mechanism (2) and a centering mechanism (3), wherein the pressure detection mechanism (1) is installed on one side of the main body (11), the transfer mechanism (2) is installed in the middle of the main body (11), and the centering mechanism (3) is installed on the other side of the main body (11); The pressure detection mechanism (1) comprises a rotating motor (12) and two sliding cylinders (13); the rotating motor (12) is mounted on the top of the main body (11); the output end of the rotating motor (12) is connected to a coaxially arranged rotating screw (121) via a coupling; two symmetrically arranged limiting rods (122) are fixedly connected to the inside of the main body (11); a circular frame (123) is movably sleeved on the rotating screw (121) and the limiting rods (122); a circular scanner (124) is mounted on the inner wall of the circular frame (123); The two sliding cylinders (13) are respectively mounted on the top and bottom of the main body (11); a sliding shaft (131) is mounted on the output end of the sliding cylinder (13); a top-pressing frame (132) is fixedly connected to the bottom of the sliding shaft (131); a top-pressing cylinder (14) is mounted inside the top-pressing frame (132); a top-pressing shaft (141) is mounted on the output end of the top-pressing cylinder (14); a hard nozzle mounting plate (143) is mounted on the bottom of the top-pressing shaft (141); a water storage tank (142) is mounted on the top of the hard nozzle mounting plate (143); two symmetrically arranged water inlet pipes (144) are fixedly connected to the top of the water storage tank (142); a water pump (145) is mounted on the water inlet pipe (144).

2. A rock multi-field coupling fatigue performance testing machine according to claim 1, characterized in that: A servo motor (15) is installed inside the pressing frame (132). Four rotating shafts (151) evenly distributed around the circumference are rotatably installed inside the pressing frame (132). One of the rotating shafts (151) is connected to the output end of the servo motor (15) via a coupling. A meshing gear (152) is fixedly sleeved on the outer circumference of the rotating shaft (151). A rotating circular frame (155) is rotatably installed inside the main body (11). An internal gear (155) is fixedly connected to the inner wall of the rotating circular frame (155). The four meshing gears (152) are all meshed with the internal gear (155). Four meshing limiting racks (153) evenly distributed around the circumference are slidably mounted inside the pressing frame (132). The four meshing limiting racks (153) are respectively meshed with the four meshing gears (152). One end of the meshing limiting rack (153) is fixedly connected to a pressure plate (154).

3. A rock multi-field coupling fatigue performance testing machine according to claim 2, characterized in that: The bottom of the top pressure frame (132) is provided with a plurality of holes and slots distributed in an array at equal intervals, the bottom of the hard nozzle mounting plate (143) is installed with a plurality of hard nozzles distributed in an array at equal intervals, the plurality of hard nozzles respectively pass through the interior of the plurality of holes and slots, and the interior of the rotating circular frame (155) is rotatably installed with a plurality of auxiliary balls (156) evenly distributed around the circumference.

4. A rock multi-field coupling fatigue performance testing machine according to claim 3, characterized in that: The transfer mechanism (2) comprises a connection frame (21) and a rotating motor (22); the connection frame (21) is fixedly connected to the top of the main body (11); the rotating motor (22) is mounted on the top of the connection frame (21); the output end of the rotating motor (22) is connected to a coaxially arranged rotating shaft (221) via a coupling; the bottom of the rotating shaft (221) is fixedly connected to the transfer frame (222); a lead screw motor (23) is mounted on the top of the transfer frame (222); the output end of the lead screw motor (23) is connected to the coaxially arranged rotating shaft (221) via a coupling A coaxially arranged rotating screw (231) is connected, and two symmetrically arranged limiting shafts (232) are fixedly connected inside the transfer frame (222). A sliding frame (24) is sleeved on the outer circumference of the rotating screw (231) and the limiting shaft (232). A transmission motor (241) is installed on one side of the sliding frame (24). The output end of the transmission motor (241) is connected to a coaxially arranged double screw shaft (242) through a coupling, and two symmetrically arranged clamping blocks (243) are movably sleeved on the double screw shaft (242).

5. A rock multi-field coupling fatigue performance testing machine according to claim 4, characterized in that: The centering mechanism (3) comprises a synchronous motor (31) and four limit sliders (321); the synchronous motor (31) is mounted inside the main body (11); the output end of the synchronous motor (31) is connected to a coaxially arranged transmission shaft (311) via a coupling; a circular plate (312) is mounted on the top of the transmission shaft (311); four circumferentially evenly distributed hinged rods (32) are movably hinged on the top of the circular plate (312); the four limit sliders (321) are circumferentially evenly distributed and slidably assembled inside the main body (11); the top of the limit slider (321) is fixedly connected to a centering plate (322); and the limit slider (321) and the hinged rod (32) are hinged to each other.

6. The system of a rock multi-field coupling fatigue performance testing machine according to claim 5 is characterized in that: S1: Rock positioning and centering: S11: placing the rock in the middle of the centering mechanism (3); S12: starting the synchronous motor (31) to drive the circular plate (312) to rotate via the transmission shaft (311), thereby driving the hinged rod (32) and the limit slider (321) to move, thereby achieving center positioning of the rock; S2: Rock transfer: S21: starting the screw motor (23) in the transfer mechanism (2) to drive the rotating screw (231) to rotate, so that the sliding frame (24) descends to the middle of the rock; S22: starting the transmission motor (241) to drive the double screw shaft (242) to rotate, so that the two clamping blocks (243) move toward the rock and clamp the rock; S23: start the screw motor (23) again to lift the rock and move it away from the centering mechanism (3); S24: starting the rotating motor (22) to transfer the rock to the middle of the pressure detection mechanism (1); S25: starting the transmission motor (241) again to allow the rock to descend onto the top pressure frame (132) of the pressure detection mechanism (1); S26: Separating the clamping block (243) from the rock, and moving the clamping block (243) to the top of the rock; S27: the rotating motor (22) operates to make the clamping block (243) leave the pressure detection mechanism (1); S3: Pressure application and water flow flushing: S31: starting the sliding cylinder (13) to move the top pressure frame (132) to both ends of the rock; S32: Start the sliding cylinder (13), the pressing cylinder (14) or the servo motor (15) as required: S33: Sliding cylinder (13): applies pressure to both ends of the rock; S34: the top pressure cylinder (14): drives the top pressure shaft (141) to slide, so that the hard nozzle applies point pressure to the rock; or retracts the top pressure cylinder (14), starts the water pump (145), and flushes the rock through the hard nozzle; S35: servo motor (15): drives the rotating shaft (151) and the internal gear (155) to rotate, and applies pressure to the surrounding of the rock through the meshing gear (152) and the meshing limit rack (153); S4: Multi-dimensional testing: S41: During the process of applying pressure and flushing with water, the rotating motor (12) is started to drive the rotating screw (121) to rotate, so that the circular frame (123) slides, and the rock is scanned in multiple dimensions by the circular scanner (124).

7. The system of a rock multi-field coupling fatigue performance testing machine according to claim 6 is characterized in that: The detection formula is:

1. Rock compressive strength formula: Where p is the compressive strength, P is the pressure applied to the rock, A is the force-bearing area of ​​the rock, and the compressive strength is expressed in megapascals (MPa); 2. Formula for characteristic value of rock foundation bearing capacity: fa = \psiψr \times frk Among them, fa is the characteristic value of rock foundation bearing capacity, frk is the standard value of rock saturated uniaxial compressive strength, and ψr is the reduction factor, which is determined according to the integrity of the rock mass and the spacing, width, occurrence and combination factors of the structural plane; 3. Scouring force formula: F = \rhoρ\cdot A \cdot V^2 \cdot Cf Among them, F is the scouring force, ρ is the density of water, A is the contact area between water flow and rock, V is the water flow velocity, and Cf is the scouring coefficient. The magnitude of the scouring force depends on the water flow velocity, density and contact area factors.

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