An apparatus and method for testing the deformation of extrusion structures in a long-arm centrifuge.

Abstract

This invention discloses a device and method for testing the extrusion deformation of a centrifuge. A barrier is installed on a base plate, a curved platform is located between two barriers, and a pusher plate is movably installed on the barriers, with a sealed contact between the lower surface of the pusher plate and the curved platform. The curved platform, pusher plate, barriers, and barriers form an extrusion chamber for placing the extrusion model. A power component is fixedly connected to the pusher plate, pushing the pusher plate to extrude the model. The method includes uniformly laying the extrusion model in the extrusion chamber; hoisting the entire device into the centrifuge to conduct a centrifugal extrusion simulation test under hypergravity; and observing the extrusion model to obtain its deformation characteristics. This invention employs a servo motor, reducer, and ball screw transmission method, enabling large-stroke, low-speed, and stable drive of the drive components under hypergravity conditions. It allows real-time observation of the extrusion deformation process of the model and can simulate large-scale spatiotemporal geological extrusion deformation phenomena.

Description

Technical Field

[0001] This invention belongs to the field of structural physics simulation technology, specifically relating to a test device and method for extrusion structural deformation of a long-arm centrifuge. Background Technology

[0002] Structural physics simulation is an effective means of studying the characteristics, genesis, and dynamic processes of tectonic deformation on large spatiotemporal scales. Compressional tectonic deformation is one of the important manifestations of crustal movement, typically occurring during plate collisions, the formation of folded mountains, and other processes. Studying compressional tectonic deformation plays a crucial role in understanding and responding to geological phenomena caused by crustal stress, designing safe engineering structures, and predicting geological hazards.

[0003] When conducting compressional tectonic deformation simulation experiments under normal gravity, low-strength materials are typically used to meet similarity criteria. However, these materials are significantly affected by factors such as the experimental environment and operating methods, leading to substantial random errors in the results. Using a hypergravity centrifuge to create a hypergravity environment for geological structural physics simulation experiments can realize tectonic movements over hundreds of kilometers and millions of years, reproducing the formation and evolution of large-scale compressional fractures in the Earth's spheres and their development mechanisms. This lays a solid foundation for analyzing tectonic deformation and topographic features under the simulated regional tectonic environment and historical tectonic movement periods. However, the hypergravity environment (up to 300g) significantly affects the shape and performance of the components of the tectonic deformation device. The material strength of conventional compressional tectonic deformation devices often fails to meet requirements, and existing drive equipment cannot achieve stable long-stroke, low-speed drive under hypergravity. Furthermore, there is a lack of hypergravity experimental methods related to large-scale spatiotemporal compressional tectonic deformation. Therefore, it is urgent to design a hypergravity model experimental device and method for compressional tectonic deformation to study the characteristics, formation mechanisms, and dynamic processes of large-scale spatiotemporal compressional tectonic deformation.

[0004] Existing three-dimensional extrusion and stretching devices typically have low driving accuracy and poor dynamic stability; tectonic geomorphological physical simulation experimental devices also have low experimental accuracy and poor stability, resulting in unreliable experimental results; large centrifuge-based geological structural physical simulation experimental devices under hypergravity fields can only simulate at low centrifugal accelerations, limiting the time and spatial range they can simulate. Therefore, existing technologies lack a suitable extrusion structural deformation device for hypergravity conditions. Summary of the Invention

[0005] In order to solve the problems existing in the background art, the purpose of this invention is to provide a test device and method for extrusion structure deformation suitable for long-arm centrifuges, so as to achieve high-precision quantitative simulation of extrusion structure deformation in large space-time.

[0006] The technical solution adopted in this invention is as follows:

[0007] I. A test device for extrusion deformation of a long-arm centrifuge, characterized in that:

[0008] It includes a push plate, a power assembly, a base plate, a baffle, a curved platform, and enclosures. Two enclosures are fixedly installed on both sides of the base plate. The curved platform is located in the middle of the two enclosures and is installed on the base plate. The two ends of the push plate are movably installed on the two enclosures. The baffle is fixedly installed on the curved platform. The lower surface of the push plate is in contact with the curved platform. The curved platform, push plate, baffle, and two enclosures form an extrusion chamber for placing the extrusion mold. Two power assemblies are fixedly connected to both ends of the push plate. The power assemblies are used to push the push plate to move back and forth to extrude the extrusion mold.

[0009] The power assembly includes a nut pusher block, a lead screw, a planetary reducer, and a servo motor. The output shaft of the servo motor is connected to one end of the output shaft of the planetary reducer, and the other end of the output shaft of the planetary reducer is connected to the lead screw via a coupling. The two ends of the lead screw are respectively connected to the lead screw support side seat and the lead screw fixed side seat. Both the lead screw support side seat and the lead screw fixed side seat are fixedly connected to the enclosure. The nut pusher block is movably connected to the lead screw. The two ends of the push plate are respectively fixedly connected to the nut pusher blocks in the two power assemblies. The servo motor is used to drive the lead screw to rotate through the planetary reducer, thereby realizing the forward and backward movement of the nut pusher block and the push plate through the lead screw.

[0010] The extrusion deformation device also includes a laser displacement sensor, a magnetic grating ruler, and a camera. The front ends of the two enclosures are equipped with magnetic grating rulers, and the front end of one enclosure is equipped with a laser displacement sensor. The laser displacement sensor and the magnetic grating ruler are used to measure the displacement of the push plate. An observation window for observing the extrusion model is opened in the middle of the enclosure. The camera is mounted on the base plate and is used to monitor the extrusion model in the extrusion chamber in real time.

[0011] The central axis of the curved platform coincides with the rotation axis of the centrifuge. The device has two working modes: a vertical extrusion mode and a tangential extrusion mode. When the device is in the vertical extrusion mode, the extension direction of the curved platform is parallel to the axis of the power component, and the curvature of the lower surface of the push plate is consistent with the curvature of the cross-section of the curved platform. When the device is in the tangential extrusion mode, the extension direction of the curved platform is perpendicular to the axis of the power component, and the lower surface of the push plate is flat.

[0012] The planetary reducer and servo motor in the power assembly are connected to an external control system. The control system precisely controls the speed of the servo motor, thereby achieving precise control of the extrusion speed of the extrusion model.

[0013] The space between the push plate and the curved platform is filled with polyetheretherketone as a sealant.

[0014] II. A method for testing the deformation of the extrusion structure of a long-arm centrifuge, comprising the following steps:

[0015] Step S1: First, evenly spread the extrusion mold into the extrusion chamber, let it stand to allow the extrusion mold material to flow level and vent the air;

[0016] Step S2: Next, the entire device is hoisted into a centrifuge to conduct a centrifugal compression simulation test under hypergravity conditions.

[0017] Step S3: In the centrifugal extrusion simulation test, the extrusion model in the extrusion chamber is observed to obtain the deformation characteristics of the extrusion model, and then the extrusion deformation characteristics of the real geological prototype under the action of geodynamics are restored.

[0018] The centrifugal compression simulation test under hypergravity environment in step S2 is specifically as follows:

[0019] First, the entire device is hoisted into the centrifuge basket and fixed. The centrifuge is then started, and the centrifugal acceleration of the geotextile centrifuge is gradually increased to a preset value of Ng and maintained for a preset time. Under Ng hypergravity, the power component is activated through the control system, causing the pusher plate to compress the extrusion model under the push of the power component. During the centrifugal extrusion simulation test, the displacement of the pusher plate is monitored in real time through the laser displacement sensor and magnetic grating ruler in the device. At the same time, the deformation characteristics of the extrusion model under hypergravity environment are monitored in real time using a camera.

[0020] In step S1, based on the stratigraphic composition of the geological prototype, the material used in the extrusion model is one of brittle materials, ductile materials, or a combination of brittle and ductile materials. Brittle materials are used to simulate the brittle deformation behavior of the upper crust (such as fracture and crack propagation), while ductile materials are used to simulate the ductile deformation behavior of the middle and lower crust (such as plastic flow and slip). The combination of brittle and ductile materials can simulate the complex deformation behavior of the entire crust. The selection methods for brittle and ductile materials are as follows:

[0021] For brittle materials, whose deformation characteristics follow the Mohr-Coulomb criterion, and based on similarity requirements, length scale and gravitational acceleration scale are typically set. Combined with the rock properties of the geological prototype, appropriate simulation materials are selected. The selection of brittle materials is obtained using the following formula:

[0022] E r = ρ r × l r × g r

[0023] in, E rIt is the ratio of the uniaxial compressive strength of the extrusion model material to that of the prototype material; ρ r This is the ratio of the density of the extrusion model material to the density of the prototype material; l r The ratio of the length of the extruded model material to the length of the prototype material; g r The ratio of the gravitational acceleration of the extrusion model material to that of the prototype material;

[0024] For tough materials, length scale, time scale, and gravitational acceleration scale are typically set. Combined with the rock properties (viscosity, density) of the geological prototype, appropriate simulation materials are selected. The selection of tough materials is obtained according to the following formula:

[0025] ƞ r = ρ r × l r × g r × t r

[0026] in, η r This is the viscosity ratio of the extrusion mold material to the prototype material; ρ r This is the ratio of the density of the extrusion model material to the density of the prototype material; l r The ratio of the length of the extruded model material to the length of the prototype material; g r The ratio of the gravitational acceleration of the extrusion model material to that of the prototype material; t r This is the ratio of the motion time of the extrusion model material to that of the prototype material.

[0027] In the brittle-tough material combination, the thickness ratio of the brittle material to the tough material is 1:1 to 1:5.

[0028] The pusher plate of this invention is made of aerospace-grade aluminum alloy. Its function is to transfer the thrust of the power unit to the test model. The pusher plate adopts a double-layer design to ensure machining accuracy while facilitating disassembly and replacement of the sealing strip. Depending on the space of the centrifuge basket and the internal dimensions of the device, the bottom of the pusher plate can be curved or flat, applying thrust to the test model in the vertical / tangential direction.

[0029] The curved stage of this invention is made of high-strength aluminum alloy and is formed in one step using a wire drawing process. The bottom of the curved surface of the stage is located at the center, and the central axis of the curved stage coincides with the rotation axis of the centrifuge during operation. The curved surface design of the stage provides an equipotential surface for the test material under the action of a hypergravity field, thereby preventing the test material from being subjected to inertial forces such as centrifugal force and Coriolis force during centrifuge rotation, which could introduce certain errors into the experimental results.

[0030] The method of this invention first determines the scope of the study area and relevant geological parameters based on the prototype problem of tectonic deformation. Then, based on the three basic criteria of geometric similarity, kinematic similarity, and dynamic similarity, corresponding experimental parameters are designed, including the three-dimensional dimensions of the experimental model, the selection of heterogeneous similarity experimental materials, and the control velocity of the device under specified hypergravity. In the experimental method of this invention, the extrusion model uses one of the following materials: brittle materials, ductile materials, or a combination of brittle and ductile materials. Brittle materials are mainly used to simulate brittle deformation in the upper crust, while ductile materials are mainly used to simulate ductile strata in the upper crust, the weak lower crust, and the deformation of the asthenosphere. The descriptions of brittle and ductile materials in terms of dynamic similarity differ. The dynamic similarity of brittle materials usually only considers the ratio of the material's gravity to its cohesion (…). S m For ductile materials, the kinetic similarity is usually considered in terms of the ratio of the material's gravity to the pressure gradient force. R m Under ideal conditions, a physical model and a geological prototype that satisfy dynamic similarity are obtained. S m Number and sum R m The numbers should be the same or on the same order of magnitude.

[0031] The device provided by this invention uses high-load, high-strength motors, high-precision sensors, and other high-pressure resistant components. It employs a special output mode combining a planetary reducer, servo motor, and ball screw to achieve stable, long-stroke, low-speed drive of the motor under hypergravity. High-performance PEEK material is used to seal the device, ensuring no leakage of model material during the experiment. Observation windows are provided on both sides of the device's enclosure, and a full-frame camera is attached to the outside for large-format real-time recording of the experiment. Sensors monitor the synchronicity of the pusher's movements in real time, eliminating simulation errors. The method of this invention first places the device on a long-arm centrifuge basket, designs a similar experimental model based on the experimental target, lays the model on a curved platform, starts the centrifuge and servo motor, and completes the hypergravity experiment on the extrusion deformation structure. During the experiment, a full-frame camera and sensors record the experimental process in real time. Finally, the experimental results are analyzed and an experimental report is generated. The apparatus and method of this invention overcome the shortcomings of existing tectonic deformation hypergravity physical simulation experiments. The apparatus has a simple structure, reliable performance, and high precision. The experimental method is simple and easy to implement, with a clear operation process, covering steps such as similar model design, preparation, installation, driving loading, observation and analysis, and experimental report compilation, with comprehensive overall consideration. The experimental results can effectively invert the state of crustal movement and the compression deformation process, providing a reference for revealing the crustal deformation rate, influence range, and long-term evolution characteristics.

[0032] This invention enables large-stroke, low-speed, and stable driving of the drive component under hypergravity conditions, allowing real-time observation of the extrusion deformation process of the model and simulating large-scale spatiotemporal geological extrusion deformation phenomena. The device has a simple structure, reliable performance, and convenient operation.

[0033] The beneficial effects of this invention are as follows:

[0034] 1. This invention adopts a power output mode that combines planetary reducer, servo motor and ball screw. The servo axis synchronously adopts a two-servo master-slave axis control method, which can achieve large stroke and low speed stable drive in hypergravity environment.

[0035] 2. The curved stage of the device of the present invention is formed in one step by wire drawing process to ensure processing accuracy. The bottom of the curved surface is located at the center, which can provide an equipotential surface for experimental materials under hypergravity environment and reduce experimental simulation error.

[0036] 3. The device of the present invention uses high-strength PEEK material as the sealing filler, which has self-lubricating properties and an extremely low coefficient of friction. It can maintain dimensional stability under long-term high load conditions, and can prevent the sealing material from falling off or failing under hypergravity.

[0037] 4. The device of the present invention is equipped with a human-machine interface. It accurately feeds back displacement data through a high-precision ranging laser sensor and a large-range magnetostrictive magnetic grating sensor. The device has strong anti-interference ability in hypergravity environment and can provide high-precision and stable drive control feedback in real time.

[0038] 5. This invention features an observation window and is equipped with a full-frame camera with strong anti-interference capabilities, enabling real-time large-format monitoring under hypergravity conditions. This accurately captures the deformation of the experimental model, significantly improving the reliability and intuitiveness of the simulation results. Attached Figure Description

[0039] Figure 1 This is a schematic diagram of the structure of the device of the present invention;

[0040] Figure 2 This is a schematic diagram of the power component of the present invention;

[0041] Figure 3 This is a schematic diagram of the curved surface stage of the present invention;

[0042] Figure 4 This is a flowchart of the supergravity test method for extrusion structure deformation according to the present invention;

[0043] Figure 5 This is a schematic diagram of the thrust and compression direction of the device of the present invention under different working conditions.

[0044] In the diagram: 1. Laser displacement sensor; 2. Push plate; 3. Magnetic scale; 4. Camera; 5. Observation window; 6. Power assembly; 7. Base plate; 8. Lifting ring; 9. Baffle; 10. Curved table; 11. Lead screw support side seat; 12. First mounting plate; 13. Nut push block; 14. Lead screw; 15. Lead screw fixed side seat; 16. Coupling; 17. Reducer mounting base; 18. Second mounting plate; 19. Planetary reducer; 20. Servo motor. Detailed Implementation

[0045] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. The following embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, it should be understood that after reading the teachings of this invention, those skilled in the art can make various alterations or modifications to the invention, and these equivalent forms also fall within the scope defined by the appended claims.

[0046] like Figure 1As shown, the device includes a push plate 2, two power components 6, a base plate 7, a baffle 9, a curved platform 10, and two enclosures. The two rectangular strip-shaped enclosures are fixedly installed on the left and right sides of the base plate 7, respectively. The curved platform 10 is located in the middle of the two enclosures and is fixedly installed in the middle of the base plate 7. The left and right ends of the push plate 2 are respectively installed on the two enclosures by sliding blocks. The baffle 9 is fixedly installed on the upper surface of the rear end of the curved platform 10. The lower surface of the push plate 2 and the curved platform 10 are in sealed contact. The curved platform 10, the push plate 2, the baffle 9, and the two enclosures form an extrusion chamber for placing the extrusion model. The extrusion chamber is a sealed box structure with only an opening at the top. The two power components 6 are fixedly connected to the left and right ends of the upper surface of the push plate 2, respectively. The power components 6 are used to push the push plate 2 to move back and forth, thereby extruding the extrusion model.

[0047] The power assembly 6 is parallel to the axis of the enclosure, the push plate 2 and the baffle 9 are arranged parallel to each other, and the two power assemblies 6 are arranged parallel to each other and perpendicular to each other. The front-back direction of the device is parallel to the axis of the power assembly 6, and the left-right direction of the device is perpendicular to the axis of the power assembly 6. A slide rail is fixedly installed on the enclosure, and the push plate 2 moves back and forth along the track direction of the slide rail by a slider to realize the movement of the push plate 2 on the enclosure.

[0048] like Figure 2 As shown, the power assembly 6 includes a nut pusher 13, a lead screw 14, a planetary reducer 19, and a servo motor 20. The output shaft of the servo motor 20 is connected to one end of the output shaft of the planetary reducer 19, and the other end of the output shaft of the planetary reducer 19 is connected to one end of the lead screw 14 through a coupling 16. The two ends of the lead screw 14 are respectively connected to the lead screw support side seat 11 and the lead screw fixed side seat 15. The lead screw support side seat 11 and the lead screw fixed side seat 15 are both fixedly connected to the enclosure. The nut pusher 13 is movably connected to the lead screw 14. The left and right ends of the push plate 2 are respectively fixedly connected to the nut pushers 13 in the two power assemblies 6. The servo motor 20 is used to drive the lead screw 14 to rotate through the planetary reducer 19, and at the same time, precisely control the rotation speed of the lead screw 14, thereby realizing the precise forward and backward movement of the nut pusher 13 and the push plate 2 through the lead screw 14.

[0049] Two power components 6 are located directly above the two fences respectively. The lead screw support side seat 11 is connected to the front end of the fence through the first mounting plate 12. The planetary reducer 19 is mounted on the reducer mounting seat 17. The reducer mounting seat 17 and the lead screw fixed side seat 15 are both fixedly connected to the fence through the second mounting plate 18.

[0050] The extrusion deformation device also includes a laser displacement sensor 1, a magnetic grating ruler 3, and a camera 4. Magnetic grating ruler 3 is installed at the front end of both enclosures, and a laser displacement sensor 1 is installed at the front end of one of the enclosures. The laser displacement sensor 1 and the magnetic grating ruler 3 are used to measure the displacement of the push plate 2, and then measure the amount of extrusion of the extrusion model by the push plate 2. An observation window 5 for observing the extrusion model is opened in the middle of the enclosure. The camera 4 is installed on the base plate 7 and is used to monitor the extrusion model in the extrusion chamber in real time.

[0051] A lifting ring 8 for the hoisting device is also fixedly installed on the base plate 7. The base plate 7 is placed on the basket of the long-arm centrifuge basket. The observation window 5 is made of transparent material, and can be combined with, but is not limited to, the following materials: acrylic or tempered glass, to ensure the compressive strength it can withstand during the extrusion test, while ensuring transparency to meet the needs and observation effects of real-time observation. The observation window is 1000×200 mm in size and is equipped with a professional camera 4 to realize real-time large-format monitoring of the structural deformation process under hypergravity.

[0052] like Figure 3 As shown, during the experiment, the central axis of the curved stage 10 coincides with the rotation axis of the centrifuge. The device has two working modes: the vertical extrusion mode and the tangential extrusion mode. When the device is in the vertical extrusion mode, the extension direction of the curved stage 10 is parallel to the axis of the lead screw 14 in the power assembly 6, and the curvature of the lower surface of the push plate 2 is consistent with the curvature of the cross section of the curved stage 10. When the device is in the tangential extrusion mode, the extension direction of the curved stage 10 is perpendicular to the axis of the lead screw 14 in the power assembly 6, and the lower surface of the push plate 2 is flat.

[0053] The curved stage 10 is made of high-strength aluminum alloy and is formed in one piece using a wire drawing process to ensure machining accuracy. The bottom of the curved stage 10 is located at the center, and when the centrifuge rotates, the central axis of the curved stage 10 coincides with the rotation axis of the centrifuge, providing an equipotential surface for the test material. The radius of curvature of the curved stage cross-section is 4380mm. The push plate 2 is made of aerospace-grade aluminum alloy with a double-layer design to ensure machining accuracy and facilitate disassembly. The bottom of the push plate 2 can be curved or flat depending on the test requirements. In the axial extrusion mode, a curved form is used, and the radius of curvature of the push plate 2 surface is the same as that of the curved stage 10; in the tangential extrusion mode, a flat form is used to accommodate the curvature changes of the curved stage. The curved stage 10 is a strip structure with a cross-section that is always consistent in its extension direction. Specifically, the cross-section of the curved stage 10 is a curved surface perpendicular to its own extension direction.

[0054] The planetary reducer 19 and servo motor 20 in the power assembly 6 are connected to an external control system. The control system precisely controls the speed of the servo motor 20, thereby achieving precise control of the extrusion speed of the extrusion model.

[0055] Laser displacement sensor 1, magnetic grating ruler 3 and camera 4 are all connected to the control system to realize real-time monitoring of the displacement of push plate 2 and the changes of extrusion model during the test.

[0056] High-strength polyetheretherketone (PEEK) is used as a sealing filler between push plate 2 and curved platform 10, between enclosure and curved platform 10, and between baffle 9 and curved platform 10. PEEK has self-lubricating properties and an extremely low coefficient of friction, and can maintain dimensional stability under long-term high load conditions. This can prevent the sealing material from falling off or failing under hypergravity. Conventional rubber sealing methods are prone to causing push plate jamming or model material leakage under high pressure, and cannot effectively seal.

[0057] The curved stage 10 is made of rigid material and is used to support the push plate 2 and the test materials. The output shaft of the planetary reducer 19 is arranged parallel to the base plate 7. The nut push block 13 and the lead screw 14 constitute a ball screw. This invention adopts a power output mode of planetary reducer 19, servo motor 20 and ball screw working together. The ball screw can also be replaced by a roller screw. This power output mode has a maximum stroke of 400 mm and a minimum operating speed of 0.001 mm / s. It does not exhibit "creeping" phenomenon under hypergravity. The speed fluctuation under 150 g hypergravity is less than 10%. The servo axis synchronization adopts a master-slave axis control method of two servo motors 20, with a synchronization drive error of less than 0.01 mm, which can realize large stroke, low speed and stable drive under hypergravity. The servo motor 20 is connected to the programmable logic controller (PLC) system and communicates with the ground interactive machine through an external fiber optic slip ring to realize real-time transmission and feedback of parameters such as speed and torque. The PLC system is equipped with a human-machine interface, capable of displaying the motion curve of the device in real time and supporting control over the device's start / stop, displacement, and speed. It can also monitor equipment status and adjust experimental parameters in real time. Simultaneously, displacement data is fed back through a high-precision laser displacement sensor 1 and a large-range magnetic scale 3. The symmetrical mounting structure of the magnetic scale 3 effectively monitors the synchronicity of the left and right ends of the push plate 2 during its movement, ensuring synchronous control of the servo motor 20 during the experiment. The laser displacement sensor 1 has strong anti-interference capabilities in hypergravity environments and can provide high-precision, stable drive control feedback in real time.

[0058] This invention's method can simulate large-scale spatiotemporal scale compressional tectonic deformation phenomena, achieving high-precision quantitative simulation of compressional tectonic deformation under hypergravity, overcoming the shortcomings of traditional hypergravity physical simulation techniques for compressional tectonic deformation. The embodiments of this invention include the following steps: Figure 4 As shown:

[0059] Step S1: First, evenly spread the extrusion mold into the extrusion chamber and let it stand for a period of time to allow the extrusion mold material to flow and level. The material used for the extrusion mold is one of the following: brittle material, tough material, and a combination of brittle and tough materials.

[0060] Step S2: Next, the entire device is hoisted into a centrifuge to conduct a centrifugal compression simulation test under hypergravity conditions.

[0061] Step S3: In the centrifugal extrusion simulation test, observe the extrusion model in the extrusion chamber, scan and photograph the surface morphology of the extrusion model to obtain the deformation characteristics of the extrusion model, and then restore the extrusion deformation characteristics of the real geological prototype under the action of geodynamics.

[0062] The centrifugal extrusion simulation test under hypergravity environment in step S2 is as follows:

[0063] First, the entire device is hoisted into the centrifuge basket and secured. The centrifuge is then started, and the centrifugal acceleration of the geotextile centrifuge is gradually increased to a preset value of Ng and maintained for a preset time. Under Ng of hypergravity, the power component 6 is activated via the control system, causing the pusher plate 2 to compress the extrusion model under the push of the nut pusher block 13 in the power component 6. Figure 5 As shown, during the centrifugal extrusion simulation test, the displacement of the push plate 2 is monitored in real time by the laser displacement sensor 1 and the magnetic grating ruler 3 in the device, while the deformation characteristics of the extrusion model under hypergravity environment are observed in real time by the camera 4.

[0064] Specifically, the laser displacement sensor 1 and the magnetic grating ruler 3 provide real-time feedback on the loading process and motion curve of the device, controlling its start and stop at any time. The experimental process is observed in real time through the camera 4, recording the physical phenomena such as the flow, deformation, and fracture of the extruded model material under a specified gravitational field. After the experiment is completed, the centrifuge is stopped, and after the centrifuge basket stops rotating, the experimental results are analyzed and an experimental report is generated.

[0065] In step S1, based on the stratigraphic composition of the geological prototype, the material used in the extrusion model is one of the following: brittle material, ductile material, or a combination of brittle and ductile materials. The brittle material is used to simulate the brittle deformation behavior of the upper crust (such as fracture and crack propagation), the ductile material is used to simulate the ductile deformation behavior of the middle and lower crust (such as plastic flow and slip), and the combination of brittle and ductile materials can simulate the complex deformation behavior of the entire crust. The selection methods for brittle and ductile materials are as follows:

[0066] For brittle materials, whose deformation characteristics follow the Mohr-Coulomb criterion, and based on similarity requirements, length scale and gravitational acceleration scale are typically set. Combined with the rock properties of the geological prototype, appropriate simulation materials are selected. The selection of brittle materials is obtained using the following formula:

[0067] E r = ρ r × l r × g r

[0068] in, E r It is the ratio of the uniaxial compressive strength of the extrusion model material to that of the prototype material; ρ r This is the ratio of the density of the extrusion model material to the density of the prototype material; l r The ratio of the length of the extruded model material to the length of the prototype material; g r The ratio of the gravitational acceleration of the extrusion model material to that of the prototype material;

[0069] For tough materials, length scale, time scale, and gravitational acceleration scale are typically set. Combined with the rock properties (viscosity, density) of the geological prototype, appropriate simulation materials are selected. The selection of tough materials is obtained according to the following formula:

[0070] ƞ r = ρ r × l r × g r × t r

[0071] in, η r This is the viscosity ratio of the extrusion mold material to the prototype material; ρ r This is the ratio of the density of the extrusion model material to the density of the prototype material; l r The ratio of the length of the extruded model material to the length of the prototype material; g r The ratio of the gravitational acceleration of the extrusion model material to that of the prototype material; t r This is the ratio of the motion time of the extrusion model material to that of the prototype material.

[0072] In the combination of brittle and tough materials, the thickness ratio of brittle material to tough material is 1:1 to 1:5.

[0073] Brittle materials include quartz sand, gypsum, barite powder, etc., while tough materials include silica gel, paraffin wax, modeling clay, glycerin, etc.

[0074] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for testing the deformation of the extrusion structure of a long-arm centrifuge, characterized in that, The method employs a compression deformation test device suitable for a long-arm centrifuge. The device includes a push plate (2), a power assembly (6), a base plate (7), a baffle (9), a curved platform (10), and a enclosure. The two enclosures are fixedly installed on both sides of the base plate (7). The curved platform (10) is located in the middle of the two enclosures and is installed on the base plate (7). The two ends of the push plate (2) are movably installed on the two enclosures. The baffle (9) is fixedly installed on the curved platform (10). The lower surface of the push plate (2) is in contact with the curved platform (10). The curved platform (10), the push plate (2), the baffle (9), and the two enclosures form a compression chamber for placing the compression model. The two power assemblies (6) are fixedly connected to the two ends of the push plate (2). The power assembly (6) is used to push the push plate (2) to move back and forth to compress the compression model. The power assembly (6) and the enclosure are parallel to each other, the push plate (2) and the baffle (9) are set in parallel intervals, the two power assemblies (6) are set in parallel intervals, and the push plate (2) and the power assembly (6) are perpendicular to each other; a slide rail is fixedly installed on the enclosure, and the push plate (2) moves back and forth along the track direction of the slide rail by a slider; The extrusion deformation device also includes a laser displacement sensor (1), a magnetic grating ruler (3) and a camera (4). The front ends of the two enclosures are equipped with magnetic grating rulers (3), and the front end of one enclosure is equipped with a laser displacement sensor (1). The laser displacement sensor (1) and the magnetic grating ruler (3) are used to measure the displacement of the push plate (2). An observation window (5) for observing the extrusion model is opened in the middle of the enclosure. The camera (4) is installed on the base plate (7). The camera (4) is used to monitor the extrusion model in the extrusion chamber in real time. Displacement data is fed back by laser displacement sensor (1) and magnetic grating ruler (3). The symmetrical installation structure of magnetic grating ruler (3) monitors the synchronicity of the left and right ends when the push plate (2) moves, ensuring the synchronous control of servo motor (20) in the power components (6) on both sides during the experiment. The central axis of the curved platform (10) coincides with the rotation axis of the centrifuge; the device has two working modes, namely the vertical extrusion mode and the tangential extrusion mode. When the device is in the vertical extrusion mode, the extension direction of the curved platform (10) is parallel to the axis of the power component (6), and the curvature of the lower surface of the push plate (2) is consistent with the curvature of the cross section of the curved platform (10); when the device is in the tangential extrusion mode, the extension direction of the curved platform (10) is perpendicular to the axis of the power component (6), and the lower surface of the push plate (2) is flat. The power assembly (6) includes a nut pusher (13), a lead screw (14), a planetary reducer (19), and a servo motor (20). The output shaft of the servo motor (20) is connected to one end of the output shaft of the planetary reducer (19), and the other end of the output shaft of the planetary reducer (19) is connected to the lead screw (14) through a coupling (16). The two ends of the lead screw (14) are respectively connected to the lead screw support side seat (11) and the lead screw fixed side seat (15). The lead screw support side seat (11) and the lead screw fixed side seat (15) are both fixedly connected to the enclosure. The nut pusher (13) is movably connected to the lead screw (14). The two ends of the push plate (2) are respectively fixedly connected to the nut pusher (13) in the two power assemblies (6). The servo motor (20) is used to drive the lead screw (14) to rotate through the planetary reducer (19), thereby realizing the forward and backward movement of the nut pusher (13) and the push plate (2) through the lead screw (14). The method includes the following steps: Step S1: First, evenly spread the extrusion mold into the extrusion chamber, let it stand to allow the extrusion mold material to flow level and vent the air; In step S1, the material used for the extrusion mold is one of the following: brittle material, tough material, or a combination of brittle and tough materials. The selection methods for brittle and tough materials are as follows: The selection method for brittle materials is obtained by processing the following formula: E r = ρ r × l r × g r in, E r It is the ratio of the uniaxial compressive strength of the extrusion model material to that of the prototype material; ρ r This is the ratio of the density of the extrusion model material to the density of the prototype material; l r The ratio of the length of the extruded model material to the length of the prototype material; g r The ratio of the gravitational acceleration of the extrusion model material to that of the prototype material; The selection of tough materials is obtained by processing the following formula: ƞ r = ρ r × l r × g r × t r in, η r This is the viscosity ratio of the extrusion mold material to the prototype material; ρ r This is the ratio of the density of the extrusion model material to the density of the prototype material; l r The ratio of the length of the extruded model material to the length of the prototype material; g r The ratio of the gravitational acceleration of the extrusion model material to that of the prototype material; t r The ratio of the motion time of the extruded model material to that of the prototype material; Step S2: Next, the entire device is hoisted into a centrifuge to conduct a centrifugal compression simulation test under hypergravity conditions. Step S3: In the centrifugal extrusion simulation test, the extrusion model in the extrusion chamber is observed to obtain the deformation characteristics of the extrusion model, and then the extrusion deformation characteristics of the real geological prototype under the action of geodynamics are restored.

2. The method for testing the deformation of the extrusion structure of a long-arm centrifuge according to claim 1, characterized in that: The centrifugal compression simulation test under hypergravity environment in step S2 is specifically as follows: First, the entire device is hoisted into the basket of the centrifuge and fixed. The centrifuge is started, and the centrifugal acceleration of the geotechnical centrifuge is gradually increased to the preset Ng and maintained for a preset time. Under the Ng hypergravity, the power component (6) is started by the control system, so that the push plate (2) is pushed by the power component (6) to squeeze the extrusion model. During the centrifugal extrusion simulation test, the displacement of the push plate (2) is monitored in real time by the laser displacement sensor (1) and the magnetic grating ruler (3) in the device. At the same time, the deformation characteristics of the extrusion model under hypergravity environment are monitored in real time by the camera (4).

3. The method for testing the deformation of the extrusion structure of a long-arm centrifuge according to claim 1, characterized in that: In the brittle-tough material combination, the thickness ratio of the brittle material to the tough material is 1:1 to 1:

5.

4. The method for testing the deformation of the extrusion structure of a long-arm centrifuge according to claim 1, characterized in that: The planetary reducer (19) and servo motor (20) in the power assembly (6) are connected to an external control system. The speed of the servo motor (20) is precisely controlled by the control system, thereby achieving precise control of the extrusion speed of the extrusion model.

5. The method for testing the deformation of the extrusion structure of a long-arm centrifuge according to claim 1, characterized in that: The space between the push plate (2) and the curved platform (10) is filled with polyetheretherketone as a sealant.

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