Extrusion structure deformation test device and method suitable for long-arm centrifugal machine

Abstract

The invention discloses an extrusion structure deformation test device and method suitable for a long-arm centrifugal machine. The fences are installed on the bottom plate, the curved table is located between the two fences, the push plate is movably installed on the fences, the lower surface of the push plate is in sealing contact with the curved table, the curved table, the push plate, the baffle and the fences define an extrusion cavity used for containing an extrusion model, and the power assembly is fixedly connected to the push plate and pushes the push plate to move to extrude the extrusion model; the method comprises the following steps: uniformly laying extrusion models in an extrusion chamber; hoisting the whole device into a centrifugal machine, and carrying out a centrifugal extrusion simulation test in a supergravity environment; and observing the extrusion model to obtain deformation characteristics of the extrusion model. By adopting the transmission mode of the servo motor, the speed reducer and the ball screw, the large-stroke, low-speed and stable driving of the driving part in the supergravity environment can be realized, the extrusion structure deformation process of the model can be observed in real time, and the large-temporal-spatial-scale geological extrusion structure deformation phenomenon can be simulated.

Description

Technical Field

[0001] The invention belongs to the technical field of structural physical simulation, and in particular relates to an extrusion structural deformation test device and method suitable for a long-arm centrifuge. Background Art

[0002] Tectonic physical simulation is an effective means to study the characteristics, genetic mechanisms and dynamic processes of tectonic deformation on a large temporal and spatial scale. Among them, compressional tectonic deformation is one of the important manifestations of crustal movement, which usually occurs in the process of plate collision and the formation of folded mountains. Studying the problem of compressional tectonic deformation is important for understanding and responding to geological phenomena caused by crustal stress, designing safe engineering structures, and predicting geological disasters.

[0003] When conducting compression tectonic deformation simulation experiments under normal gravity, low-strength materials are usually used to meet the similarity criteria. However, these materials are greatly affected by factors such as the experimental environment and operation mode, resulting in large random errors in the results. With the help of the hypergravity environment created by the ultragravity centrifuge equipment, geological structure physical simulation experiments can be carried out to achieve the tectonic movement process of hundreds of kilometers and millions of years, reproduce the formation and evolution process of large-scale earth sphere compression fractures and their development mechanism, and lay a solid foundation for analyzing the tectonic deformation and topographic features under the simulated regional tectonic environment and historical tectonic movement periods. However, the hypergravity environment (up to 300g) will significantly affect the shape and performance of each component of the tectonic deformation device. The material bearing capacity of the conventional test compression tectonic deformation device often does not meet the requirements, and the existing driving equipment cannot achieve large-stroke low-speed stable driving under hypergravity. In addition, there is a lack of hypergravity experimental methods related to large-scale temporal and spatial scale compression tectonic deformation. Therefore, it is urgent to design a set of supergravity model experimental devices and experimental methods for compression tectonic deformation to study the characteristics, causal mechanisms and dynamic processes of large-scale temporal and spatial scale compression tectonic deformation.

[0004] The existing three-dimensional extrusion and stretching devices usually have low driving accuracy and poor dynamic stability; the experimental device for tectonic geomorphology physics simulation has low experimental accuracy and poor stability, and the experimental results are unreliable; the geological structure physics simulation experimental device under the hypergravity field of a large centrifuge can only simulate under low centrifugal acceleration, and the time and space range that can be simulated are limited. Therefore, the existing technology lacks a device for extrusion and deformation of structures under hypergravity. Summary of the invention

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

[0006] The technical solution adopted by the present invention is as follows: 1. An extrusion structure deformation test device suitable for a long-arm centrifuge, characterized in that: It includes a push plate, a power assembly, a base plate, a baffle, a curved table and an enclosure; the two enclosures are fixedly installed on both sides of the base plate, the curved table 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 table, the lower surface of the push plate is in contact with the curved table, the curved table, the push plate, the baffle and the two enclosures form an extrusion chamber for placing the extrusion model, the two power assemblies are fixedly connected to the two ends of the push plate, and the power assembly is used to push the push plate to move forward and backward to extrude the extrusion model.

[0007] The power assembly includes a nut push block, a 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 screw through a coupling, and the two ends of the screw are respectively connected to the screw support side seat and the screw fixed side seat, and the screw support side seat and the screw fixed side seat are both fixedly connected to the enclosure, and the nut push block is connected to the screw so as to be movably forward and backward, and the two ends of the push plate are respectively fixedly connected to the nut push blocks in the two power assemblies, and the servo motor is used to drive the screw to rotate through the planetary reducer, and then realize the forward and backward movement of the nut push block and the push plate through the screw.

[0008] The extrusion structure deformation device also includes a laser displacement sensor, a magnetic scale and a camera. The front ends of the two enclosures are each provided with a magnetic scale. The front end of one of the enclosures is provided with a laser displacement sensor. The laser displacement sensor and the magnetic scale 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 installed on the bottom plate. The camera is used to monitor the extrusion model in the extrusion chamber in real time.

[0009] The central axis of the curved table coincides with the rotation axis of the centrifuge; the device is provided with two working modes, namely, the celestial extrusion mode and the tangential extrusion mode. When the device is in the celestial extrusion mode, the extension direction of the curved table is parallel to the axial direction 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 table; when the device is in the tangential extrusion mode, the extension direction of the curved table is perpendicular to the axial direction of the power component, and the lower surface of the push plate is a plane.

[0010] The planetary reducer and servo motor in the power assembly are externally connected to a control system, and the rotation speed of the servo motor is precisely controlled by the control system, thereby achieving precise regulation of the extrusion speed of the extrusion model.

[0011] Polyetheretherketone is filled between the push plate and the curved table as a sealing filler.

[0012] 2. A method for testing the deformation of an extrusion structure of a long-arm centrifuge, comprising the following steps: Step S1, first, evenly lay the extrusion model in the extrusion chamber, and let it stand to allow the extrusion model material to level and exhaust; Step S2: Next, the entire device is hoisted into a centrifuge to perform a centrifugal extrusion simulation test under a high gravity environment; Step S3: Observe the extrusion model in the extrusion chamber in the centrifugal extrusion simulation test 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.

[0013] The centrifugal extrusion simulation test under the supergravity environment in step S2 is specifically as follows: Firstly, the whole device is hoisted into the hanging basket of the centrifuge and fixed, and the centrifuge is started. The centrifugal acceleration of the geotechnical centrifuge is gradually increased to the preset Ng and maintained for the preset time. The power assembly is started through the control system under Ng hypergravity, so that the push plate extrude the extrusion model under the push of the power assembly. During the centrifugal extrusion simulation test, the displacement of the push plate is monitored in real time by the laser displacement sensor and magnetic scale in the device, and the deformation characteristics of the extrusion model in the hypergravity environment are monitored in real time by the camera.

[0014] In step S1, according to the formation composition of the geological prototype, the material used in the extrusion model is one of brittle material, ductile material, and a combination of brittle material and ductile material, wherein the brittle material is used to simulate the brittle deformation behavior of the upper crust (such as fracture, crack propagation, etc.), and the ductile material is used to simulate the ductile deformation behavior of the middle and lower crust (such as plastic flow, slip, etc.). The brittle material-ductile material combination can simulate the complex deformation behavior of the entire crust. The brittle material and the ductile material are selected as follows: For brittle materials, the deformation characteristics of brittle materials follow the Mohr-Coulomb criterion. According to the similarity requirements, the length scale and gravity acceleration scale are usually set. Combined with the rock properties of the geological prototype, the appropriate simulation material is selected. The selection method of brittle materials is obtained according to the following formula: E r = ρ r × l r × g r in, E r is the ratio of the uniaxial compressive strength of the extruded model material to that of the prototype material; ρ r is the ratio of the density of the extruded model material to the density of the prototype material; l r g is the ratio of the length of the extruded model material to the length of the prototype material; rIt is the ratio of gravitational acceleration between the extruded model material and the prototype material; For tough materials, the length scale, time scale, and gravity acceleration scale are usually 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: ƞ r = ρ r × l r × g r × t r in, η r is the ratio of the viscosity of the extruded model material to the prototype material; ρ r is the ratio of the density of the extruded model material to the density of the prototype material; l r g is the ratio of the length of the extruded model material to the length of the prototype material; r It is the ratio of gravitational acceleration between the extruded model material and the prototype material; t r It is the motion time ratio of the extruded model material and the prototype material.

[0015] In the brittle material-tough material combination, the thickness ratio of the brittle material to the tough material is 1:1 to 1:5.

[0016] The push plate of the present invention is made of aviation aluminum alloy, and its function is to transfer the thrust of the power assembly to the test model. The push plate adopts a double-layer design to ensure processing accuracy and facilitate the removal and replacement of the sealing strip. According to the space of the centrifuge basket and the internal size of the device, the bottom of the push plate can be in a curved or flat form to apply thrust to the test model in the lateral / tangential direction.

[0017] The curved table of the present invention is made of high-strength aluminum alloy material and is formed by one-step wire drawing. The bottom of the curved surface of the curved table is located at the center. When the centrifuge rotates, the central axis of the curved table coincides with the rotation axis of the centrifuge. The curved surface design of the curved table can provide a curved equipotential surface for the test material under the action of the hypergravity field, thereby preventing the test material from being subjected to inertial forces such as centrifugal force and Coriolis force when the centrifuge rotates, which causes a certain error in the experimental results.

[0018] The method of the present invention first determines the scope of the research area and related geological parameters based on the prototype problem of structural deformation, designs corresponding test parameters based on the three basic principles of geometric similarity, motion similarity and dynamic similarity, and determines the three-dimensional size of the test model, the selection of heterogeneous similar experimental materials, the control speed of the device under specified hypergravity and other parameters. The material of the extrusion model in the test method of the present invention adopts one of brittle materials, ductile materials and a combination of brittle materials 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 expressions of dynamic similarity between brittle materials and ductile materials are different. The dynamic similarity of brittle materials usually only considers the ratio of the material's gravity to cohesion ( S m ), while for ductile materials, the dynamic similarity usually considers the ratio of the material's gravity to the pressure gradient force ( R m ), under ideal conditions, the physical model and geological prototype that meet the dynamic similarity S m Number and sum R m The numbers should be the same or in the same order of magnitude.

[0019] The device provided by the present invention uses high-pressure resistant devices such as large-load, high-strength motors, and high-precision sensors; a special output mode of a coordinated combination of a planetary reducer, a servo motor, and a ball screw is used to achieve a large-stroke, low-speed, stable drive of the motor under supergravity; the device is sealed with the help of high-performance PEEK materials to ensure that the model material does not leak during the test; observation windows are provided on the enclosures on both sides of the device, and a full-frame camera is attached to the outside to achieve large-format real-time recording of the test process. The synchronization of the movements on both sides of the push plate is monitored in real time by sensors to eliminate test simulation errors. The method of the present invention first places the device on the hanging basket of a long-arm centrifuge, designs a similar test model according to the test objectives, lays the model on a curved table, starts the centrifuge and the servo motor, completes the supergravity test of extrusion structure deformation, and uses a full-frame camera and a sensor to record the experimental process in real time during the test. Finally, the test results are analyzed and a test report is obtained. The device and method of the present invention overcome the shortcomings of existing structural deformation supergravity physical simulation experiments. The device has a simple structure, reliable performance, high precision, simple and easy test methods, clear operation procedures, and covers similar model design, preparation, installation, drive loading, observation analysis, and experimental report compilation. The overall consideration is comprehensive. The test results can effectively invert the state of crust movement and the compression deformation process, providing a reference for revealing the crust deformation rate, impact range, and long-term evolution characteristics.

[0020] The invention can realize the large stroke, low speed and stable driving of the driving components in the hypergravity environment, can observe the extrusion structure deformation process of the model in real time, and can simulate the large-scale geological extrusion structure deformation phenomenon. The device has a simple structure, reliable performance and convenient operation.

[0021] The beneficial effects of the present invention are as follows: 1. The present invention adopts a planetary reducer, a servo motor and a ball screw in a coordinated combination output mode, and the servo axis synchronously adopts a two-servo master-slave axis control mode, which can achieve a large stroke and low-speed stable drive in a hypergravity environment.

[0022] 2. The curved surface table 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 in the center, which can provide a curved equipotential surface for experimental materials in a hypergravity environment and reduce experimental simulation errors.

[0023] 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 friction coefficient. It can still maintain dimensional stability under long-term high-load conditions and can prevent the sealing material from falling off or failing under a hypergravity field.

[0024] 4. The device of the present invention is equipped with a human-computer interaction interface, which 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 a hypergravity environment and can provide high-precision and stable drive control feedback in real time.

[0025] 5. The present invention is provided with an observation window and equipped with a full-frame camera with strong anti-interference ability, which can perform large-scale monitoring in real time under a hypergravity environment, accurately capture the deformation of the experimental model, and significantly improve the reliability and intuitiveness of the simulation results. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a schematic diagram of the structure of the device of the present invention; Figure 2 It is a schematic diagram of the structure of the power assembly of the present invention; Figure 3 It is a structural schematic diagram of the curved table of the present invention; Figure 4 It is a flow chart of the supergravity test method for extrusion structure deformation of the present invention; Figure 5 It is a schematic diagram of the thrust extrusion direction of the device of the present invention under different working conditions.

[0027] In the figure: 1. laser displacement sensor; 2. push plate; 3. magnetic scale; 4. camera; 5. observation window; 6. power assembly; 7. bottom plate; 8. lifting ring; 9. baffle; 10. curved table; 11. side seat for supporting screw; 12. first mounting plate; 13. nut push block; 14. screw; 15. side seat for fixing screw; 16. coupling; 17. reducer mounting seat; 18. second mounting plate; 19. planetary reducer; 20. servo motor. DETAILED DESCRIPTION

[0028] The present invention will be further described below in conjunction with the accompanying drawings and specific implementation cases. The following implementation cases are only used to illustrate the present invention and are not intended to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms also fall within the scope limited by the appended claims of the application.

[0029] like Figure 1 As shown, the device includes a push plate 2, two power components 6, a base plate 7, a baffle 9, a curved table 10 and two enclosures; the two rectangular long strip enclosures are respectively fixedly mounted on the left and right sides of the base plate 7, the curved table 10 is located in the middle of the two enclosures, and the curved table 10 is fixedly mounted in the middle of the base plate 7, the left and right ends of the push plate 2 are respectively mounted on the two enclosures by sliders and can be moved forward and backward, the baffle 9 is fixedly mounted on the upper surface of the rear end of the curved table 10, and the lower surface of the push plate 2 is in sealed contact with the curved table 10. The curved table 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 upper end open. The two power components 6 are respectively fixedly connected to the left and right ends of the upper surface of the push plate 2, and the power component 6 is used to push the push plate 2 to move forward and backward to extrude the extrusion model.

[0030] The power assembly 6 and the axial direction of the enclosure are parallel, the push plate 2 and the baffle 9 are arranged in parallel and spaced apart, the two power assemblies 6 are arranged in parallel and spaced apart, and the push plate 2 and the power assembly 6 are perpendicular. The front-to-back direction of the device of the present invention is parallel to the axial direction of the power assembly 6, and the left-to-right direction of the device is perpendicular to the axial direction of the power assembly 6. A slide rail is fixedly installed on the enclosure, and the push plate 2 moves forward and backward along the track direction of the slide rail through a slider to realize the movement of the push plate 2 on the enclosure.

[0031] like Figure 2As shown, the power assembly 6 includes a nut push block 13, a 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 screw 14 through a coupling 16, and the two ends of the screw 14 are respectively connected to the screw support side seat 11 and the screw fixed side seat 15, and the screw support side seat 11 and the screw fixed side seat 15 are both fixedly connected to the enclosure, and the nut push block 13 is connected to the screw 14 so as to be movable forward and backward, and the left and right ends of the push plate 2 are respectively fixedly connected to the nut push blocks 13 in the two power assemblies 6, and the servo motor 20 is used to drive the screw 14 to rotate through the planetary reducer 19, and at the same time accurately control the rotation speed of the screw 14, thereby realizing the accurate forward and backward movement of the nut push block 13 and the push plate 2 through the screw 14.

[0032] The two power assemblies 6 are respectively located directly above the two enclosures. The screw support side seat 11 is connected to the front end of the enclosure through the first mounting plate 12. The planetary reducer 19 is installed on the reducer mounting seat 17. The reducer mounting seat 17 and the screw fixed side seat 15 are both fixedly connected to the enclosure through the second mounting plate 18.

[0033] The extrusion structure deformation device also includes a laser displacement sensor 1, a magnetic scale 3 and a camera 4. The front ends of the two enclosures are provided with a magnetic scale 3. The front end of one of the enclosures is provided with a laser displacement sensor 1. The laser displacement sensor 1 and the magnetic scale 3 are used to measure the displacement of the push plate 2, and then measure the extrusion amount of the push plate 2 on the extrusion model. An observation window 5 for observing the extrusion model is opened in the middle of the enclosure. The camera 4 is installed on the bottom plate 7. The camera 4 is used to monitor the extrusion model in the extrusion chamber in real time.

[0034] A lifting ring 8 for the lifting device is also fixedly mounted on the bottom plate 7. The bottom plate 7 is placed on the basket of the long-arm centrifuge basket. The observation window 5 is made of transparent material, which can be matched with but not limited to the following materials, acrylic or tempered glass, to ensure the extrusion strength during the extrusion test, while ensuring transparency, meeting the needs and observation effects of real-time observation. The observation window size is 1000×200 mm, and a professional camera 4 is attached to realize real-time large-scale monitoring of the structural deformation process under hypergravity.

[0035] like Figure 3 As shown, during the test, the central axis of the curved table 10 coincides with the rotation axis of the centrifuge; the device is provided with two working modes, namely, the celestial extrusion mode and the tangential extrusion mode. When the device is in the celestial extrusion mode, the extension direction of the curved table 10 is parallel to the axial direction 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 table 10; when the device is in the tangential extrusion mode, the extension direction of the curved table 10 is perpendicular to the axial direction of the lead screw 14 in the power assembly 6, and the lower surface of the push plate 2 is a plane.

[0036] The curved table 10 is made of high-strength aluminum alloy material and is formed in one step by a wire drawing process to ensure processing accuracy. The bottom of the curved table 10 is located in the center. When the centrifuge rotates, the central axis of the curved table 10 coincides with the rotation axis of the centrifuge, providing a curved equipotential surface for the test material. The curvature radius of the cross section of the curved table is 4380mm. The push plate 2 is made of aviation aluminum alloy material and has a double-layer design to ensure processing accuracy and facilitate disassembly. The bottom of the push plate 2 can be in a curved or flat form according to test needs. In the sky-to-earth extrusion mode, a curved form is adopted, and the curvature radius of the push plate 2 curved surface is the same as the curvature radius of the curved table 10; in the tangential extrusion mode, a flat form is adopted to adapt to the arc change of the curved table. Among them, the curved table 10 is a strip structure whose cross section is always consistent in its own extension direction, and the cross section of the curved table 10 is specifically a curved surface perpendicular to the extension direction of the curved table 10 itself.

[0037] The planetary reducer 19 and the servo motor 20 in the power assembly 6 are externally connected to a control system, and the rotation speed of the servo motor 20 is precisely controlled by the control system, thereby achieving precise regulation of the extrusion speed of the extrusion model.

[0038] The laser displacement sensor 1, the magnetic scale 3 and the camera 4 are all connected to the control system to achieve real-time monitoring of the displacement of the push plate 2 and the changes of the extrusion model during the test.

[0039] High-strength polyetheretherketone (PEEK) is filled between the push plate 2 and the curved table 10, between the enclosure and the curved table 10, and between the baffle 9 and the curved table 10 as a sealing filler. Polyetheretherketone has self-lubricating properties and an extremely low friction coefficient. It can maintain dimensional stability under long-term high-load conditions and prevent the sealing material from falling off or failing under a hypergravity field. Conventional rubber sealing methods can easily cause the push plate to get stuck or the model material to leak under high-pressure environments, and cannot be effectively sealed.

[0040] The curved table 10 is made of rigid material and is used to carry the push plate 2 and the test material. The output shaft of the planetary reducer 19 is arranged parallel to the bottom plate 7. The nut push block 13 and the lead screw 14 constitute a ball screw. The present invention adopts an output mode of a coordinated combination of a planetary reducer 19, a servo motor 20 and a ball screw, wherein the ball screw can also be replaced by a roller screw. The maximum stroke of this output mode is 400 mm, the minimum operating speed can reach 0.001 mm / s, and there is no "creeping" phenomenon in a hypergravity environment. The speed fluctuation under 150 g hypergravity is less than 10%. The servo axis synchronization adopts a master-slave axis control mode of two servo motors 20, and the synchronous drive error is less than 0.01 mm, which can realize a large stroke and low-speed stable drive under hypergravity. The servo motor 20 is connected to the programmable logic controller PLC system, and communicates data with the ground interactive machine through an external optical fiber 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, which can display the motion curve of the device in real time, and support the control of the start and stop, motion displacement and travel speed of the device. At the same time, it can monitor the equipment status and adjust the experimental parameters in real time. At the same time, through the high-precision ranging laser displacement sensor 1 and the large-range magnetic scale 3 feedback displacement data, the symmetrically installed structure of the magnetic scale 3 can effectively monitor the synchronization of the left and right ends of the push plate 2 when it moves, and ensure the synchronous control of the servo motor 20 during the experiment. The laser displacement sensor 1 has strong anti-interference ability in a hypergravity environment and can provide high-precision and stable drive control feedback in real time.

[0041] The method of the present invention can simulate the large-scale compression structure deformation phenomenon in space and time, realize the high-precision quantitative simulation of compression structure deformation under supergravity, and overcome the shortcomings of the traditional supergravity physical simulation technology of compression structure deformation. The embodiment of the present invention includes the following steps: Figure 4 As shown: Step S1, first, evenly lay an extrusion model in an extrusion chamber, and let it stand for a period of time to make the extrusion model material level, wherein the material used for the extrusion model is one of a brittle material, a tough material, and a combination of a brittle material and a tough material; Step S2: Next, the entire device is hoisted into a centrifuge to perform a centrifugal extrusion simulation test under a high gravity environment; Step S3, observing the extrusion model in the extrusion chamber in the centrifugal extrusion simulation test, scanning and photographing the surface morphology of the extrusion model to obtain the deformation characteristics of the extrusion model, and then restoring the extrusion deformation characteristics of the real geological prototype under the action of geodynamics.

[0042] The centrifugal extrusion simulation test under the supergravity environment in step S2 is specifically as follows: First, the device is hoisted into the basket of the centrifuge and fixed, the centrifuge is started, the centrifugal acceleration of the geotechnical centrifuge is gradually increased to a preset Ng and maintained for a preset time, and the power assembly 6 is started through the control system under the Ng supergravity, so that the push plate 2 is pushed by the nut push block 13 in the power assembly 6 to extrude the extrusion model, as shown in FIG. 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 scale 3 in the device, and the deformation characteristics of the extrusion model in the hypergravity environment are observed in real time by the camera 4.

[0043] Specifically, the laser displacement sensor 1 and the magnetic scale 3 provide real-time feedback on the loading process and motion curve of the device, and control the start and stop of the device at any time; the camera 4 observes the experimental process in real time, and records the physical phenomena such as flow, deformation, and fracture of the extruded model material under the specified gravity field. After the test is completed, the centrifuge is shut down, and after the centrifuge basket stops rotating, an analysis is performed based on the test results and a test report is obtained.

[0044] In step S1, according to the formation composition of the geological prototype, the material used in the extrusion model is one of brittle material, ductile material, and a combination of brittle material and ductile material, wherein the brittle material is used to simulate the brittle deformation behavior of the upper crust (such as fracture, crack propagation, etc.), and the ductile material is used to simulate the ductile deformation behavior of the middle and lower crust (such as plastic flow, slip, etc.). The brittle material-ductile material combination can simulate the complex deformation behavior of the entire crust. The selection method of brittle material and ductile material is as follows: For brittle materials, the deformation characteristics of brittle materials follow the Mohr-Coulomb criterion. According to the similarity requirements, the length scale and gravity acceleration scale are usually set. Combined with the rock properties of the geological prototype, the appropriate simulation material is selected. The selection method of brittle materials is obtained according to the following formula: E r = ρ r × l r × g r in, E r is the ratio of the uniaxial compressive strength of the extruded model material to that of the prototype material; ρ r is the ratio of the density of the extruded model material to the density of the prototype material; l r g is the ratio of the length of the extruded model material to the length of the prototype material; r It is the ratio of gravitational acceleration between the extruded model material and the prototype material; For tough materials, the length scale, time scale, and gravity acceleration scale are usually 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: ƞ r = ρ r × l r × g r × t r in, η r is the ratio of the viscosity of the extruded model material to the prototype material; ρ r is the ratio of the density of the extruded model material to the density of the prototype material; l r g is the ratio of the length of the extruded model material to the length of the prototype material; r It is the ratio of gravitational acceleration between the extruded model material and the prototype material; t r It is the motion time ratio of the extruded model material and the prototype material.

[0045] In the brittle material-ductile material combination, the ratio of the thickness of the brittle material to that of the ductile material is 1:1~1:5.

[0046] Brittle materials include quartz sand, gypsum, barite powder, etc., and tough materials include silicone, paraffin, plasticine, glycerin, etc.

[0047] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents. However, these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. An extrusion structure deformation test device suitable for a long-arm centrifuge, characterized in that: The invention comprises a push plate (2), a power assembly (6), a bottom plate (7), a baffle (9), a curved table (10) and a fence; the two fences are respectively fixedly mounted on two sides of the bottom plate (7); the curved table (10) is located between the two fences and mounted on the bottom plate (7); the two ends of the push plate (2) are movably mounted on the two fences; the baffle (9) is fixedly mounted on the curved table (10); the lower surface of the push plate (2) is in contact with the curved table (10); the curved table (10), the push plate (2), the baffle (9) and the two fences form an extrusion chamber for placing an extrusion model; the two power assemblies (6) are respectively 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 forward and backward so as to extrude the extrusion model.

2. The extrusion structure deformation test device suitable for a long-arm centrifuge according to claim 1, characterized in that: The power assembly (6) comprises a nut push block (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), 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 push block (13) is connected to the lead screw (14) so ​​as to be movable forward and backward, the two ends of the push plate (2) are respectively fixedly connected to the nut push blocks (13) in the two power assemblies (6), and 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 push block (13) and the push plate (2) through the lead screw (14).

3. The extrusion structure deformation test device suitable for a long-arm centrifuge according to claim 1, characterized in that: The extrusion structure deformation device further comprises a laser displacement sensor (1), a magnetic scale (3) and a camera (4). The front ends of the two enclosures are both provided with a magnetic scale (3). The front end of one of the enclosures is provided with a laser displacement sensor (1). The laser displacement sensor (1) and the magnetic scale (3) are used to measure the displacement of the push plate (2). An observation window (5) for observing the extrusion model is provided in the middle of the enclosure. The camera (4) is mounted on the bottom plate (7). The camera (4) is used to monitor the extrusion model in the extrusion chamber in real time.

4. The extrusion structure deformation test device suitable for a long-arm centrifuge according to claim 2, characterized in that: The central axis of the curved table (10) coincides with the rotation axis of the centrifuge; the device is provided with two working modes, namely a lateral extrusion mode and a tangential extrusion mode. When the device is in the lateral extrusion mode, the extension direction of the curved table (10) is parallel to the axial direction of 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 table (10); when the device is in the tangential extrusion mode, the extension direction of the curved table (10) is perpendicular to the axial direction of the power assembly (6), and the lower surface of the push plate (2) is a plane.

5. The extrusion structure deformation test device suitable for a long-arm centrifuge according to claim 2, characterized in that: The planetary reducer (19) and the servo motor (20) in the power assembly (6) are externally connected to a control system, and the rotation 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.

6. The extrusion structure deformation test device suitable for a long-arm centrifuge according to claim 1, characterized in that: Polyetheretherketone is filled between the push plate (2) and the curved platform (10) as a sealing filler.

7. A method for testing the extrusion structure deformation of a long-arm centrifuge applied to the device according to any one of claims 1 to 6, characterized in that: The following steps are involved: Step S1, first, evenly lay the extrusion model in the extrusion chamber, and let it stand to allow the extrusion model material to level and exhaust; Step S2: Next, the entire device is hoisted into a centrifuge to perform a centrifugal extrusion simulation test under a high gravity environment; Step S3: Observe the extrusion model in the extrusion chamber in the centrifugal extrusion simulation test 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.

8. The method for testing the extrusion structure deformation of a long-arm centrifuge according to claim 7, characterized in that: The centrifugal extrusion simulation test under the supergravity 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, the centrifugal acceleration of the geotechnical centrifuge is gradually increased to a preset value Ng and maintained for a preset time, and the power assembly (6) is started through the control system under Ng hypergravity, so that the push plate (2) is pushed by the power assembly (6) to extrude the extrusion model. During the centrifugal extrusion simulation test, the displacement of the push plate (2) is monitored in real time through the laser displacement sensor (1) and the magnetic scale (3) in the device, and the deformation characteristics of the extrusion model in the hypergravity environment are monitored in real time using the camera (4).

9. The method for testing the extrusion structure deformation of a long-arm centrifuge according to claim 7, characterized in that: In step S1, the material used in the extrusion model is one of a brittle material, a tough material, and a combination of a brittle material and a tough material. The brittle material and the tough material are selected as follows: The selection method of brittle materials is obtained according to the following formula: E r = ρ r × l r × g r in, E r is the ratio of the uniaxial compressive strength of the extruded model material to that of the prototype material; ρ r is the ratio of the density of the extruded model material to the density of the prototype material; l r g is the ratio of the length of the extruded model material to the length of the prototype material; r It is the ratio of gravitational acceleration between the extruded model material and the prototype material; The selection method of ductile materials is obtained according to the following formula: ƞ r = ρ r × l r × g r × t r in, η r is the ratio of the viscosity of the extruded model material to the prototype material; ρ r is the ratio of the density of the extruded model material to the density of the prototype material; l r g is the ratio of the length of the extruded model material to the length of the prototype material; r It is the ratio of gravitational acceleration between the extruded model material and the prototype material; t r It is the motion time ratio of the extruded model material and the prototype material.

10. The method for testing the extrusion structure deformation of a long-arm centrifuge according to claim 9, characterized in that: In the brittle material-tough material combination, the thickness ratio of the brittle material to the tough material is 1:1 to 1:5.

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