Device and method for measuring dynamic shear characteristics of mechanical-soil interface

Abstract

The invention provides a device and a method for measuring dynamic shear characteristics of a mechanical-soil interface. The mechanical-soil interface dynamic shear characteristic measuring device comprises a chain type test model, a test framework, a loading and control system and a data acquisition system. The chain type test model comprises a chain, a shear plate to be tested, a gear rotating shaft, a driving gear, a driven gear, a suspension plate, a middle partition plate, a test base and a high-strength bolt. The loading and control system comprises a linear servo electric cylinder, a servo motor, a planetary reducer and a servo motor driving device. The data acquisition system comprises a torque sensor, a rotating speed sensor, a film pressure sensor, a linear displacement sensor and a vertical force sensor. By adopting the measuring device and the measuring method disclosed by the invention, the dynamic linear shearing characteristics of the mechanical-soil interface under different conditions can be tested, and the defects of bulldozing effect or uneven stress distribution and the like in the traditional test are improved.

Description

Technical Field

[0001] The invention relates to a device and method for measuring dynamic shearing characteristics of a machine-soil interface. Background Art

[0002] The interaction between mechanical excavation tools or traction components and soil includes the extrusion deformation and shear behavior of soil. In order to explore this complex problem, it is necessary to conduct a comprehensive and in-depth experimental study on the physical and mechanical properties of soil. The bearing characteristics of soil involve the vertical deformation behavior of soil under normal pressure, and the shear characteristics of soil involve the tangential slip deformation behavior of soil under the combined action of normal and tangential stresses. In the field of ground mechanics, the dynamic interaction between mechanical excavation tools such as scrapers, cutters, cutting teeth and traction components such as tracks and wheels and the soil interface is quite different from the quasi-static shear loading conditions in classical soil mechanics tests. The soil shear rate of excavation or traction behavior is at least 2-3 orders of magnitude higher than the shear rate in classical soil mechanics tests. Therefore, it is necessary to redesign the test plan to conduct an in-depth study on the dynamic shear characteristics of the mechanical-soil interface, thereby optimizing the soil cutting capacity and soil transportation efficiency of mechanical excavation tools and improving the ground passing performance of traction components.

[0003] The direction of external force loading is one of the important factors affecting the dynamic shear characteristic parameters of soil. On-site soil usually presents stratification characteristics, that is, soil parameters such as water content and porosity change rapidly with increasing burial depth, which makes the soil anisotropic. Therefore, it is necessary to test it in the shear plane that may actually occur. Existing soil shear strength test methods include circumferential shear, linear direct shear, uniaxial compression test, etc. Among them, the ring shear test method can measure the shear characteristics of soil under large strain conditions, and can partially simulate the shear effect of wheels or tracks on soil in the field of ground mechanics, so it is widely used. However, due to the different shear speeds inside and outside the shear ring in the ring shear test, the stress and displacement distribution on the ring radius is uneven. At the same time, the soft soil between the ring blades is pulled out of the ring due to centrifugal force, so that the space below the shear ring cannot be completely filled with shear soil. The above factors may lead to an underestimate of the shear strength results. The linear direct shear test can improve some defects of the ring shear test to a certain extent. However, the "bulldozer effect" is very likely to occur in most linear direct shear tests, that is, when the soil in front of the shear device continues to accumulate and is pushed away, the measured horizontal force is the combined force of the shear force and the thrust force, which makes the dynamic shear strength of the soil likely to be overestimated and it is difficult to accurately control the shear rate. In addition, the linear direct shear test has high requirements for the site and space and is not suitable for a narrow laboratory environment. Therefore, it is necessary to develop a new soil dynamic shear property measurement device to improve the defects of existing tests and devices. Summary of the invention

[0004] In view of the problems existing in the prior art, the present invention is proposed.

[0005] In order to solve the above technical problems, the present invention provides the following technical solutions: a device for measuring dynamic shear characteristics of a machine-soil interface, comprising a chain test model, a test frame, a loading and control system and a data acquisition system;

[0006] The chain test model includes a chain, a shear plate to be tested, a gear shaft, a driving gear, a driven gear, a suspension plate, a middle partition, a test base and high-strength bolts; the driving gear and the driven gear are arranged in an isosceles triangle; the gear shaft is fixed to the suspension plates on both sides of the chain through seat bearings and bolts; the chain is installed on the driving gear and the driven gear, and bolt holes are reserved on the outside of the chain; the shear plate to be tested is fixed to the chain through the reserved bolt holes and bolts on the chain; the suspension plates are located on both sides of the chain and are connected and fixed by high-strength bolts; the middle partition is arranged between the suspension plates; the test base is located between the two driven gears, a chain guide is installed and fixed at the bottom of the test base, and the test base and the suspension plate are connected by high-strength bolts.

[0007] As a preferred solution of the device for measuring the dynamic shear characteristics of the mechanical-soil interface of the present invention, the test frame includes a steel frame, a support base, an acrylic transparent plate and a horizontal linear guide rail; a support base is installed at the bottom of the steel frame, an acrylic transparent plate is installed on the front side of the steel frame, and the soil to be tested is placed inside the steel frame; the chain test model is placed on the soil to be tested; and the horizontal linear guide rail is installed on the top of the steel frame to control the horizontal position of the chain test model.

[0008] As a preferred solution of the device for measuring the dynamic shear characteristics of the mechanical-soil interface described in the present invention, wherein: the loading and control system includes a linear servo electric cylinder, a servo motor, a planetary reducer and a servo motor drive device; the servo motor power output shaft is connected to the power input end of the planetary reducer through a rigid coupling, and the servo motor and the planetary reducer housing are connected through a flange fixed by bolts; the bottom of the linear servo electric cylinder is fixed to the horizontal linear guide rail through a threaded connection, and the sliding block of the linear servo electric cylinder is connected to one side of the suspension plate through high-strength bolts; the servo motor drive device is installed on the top of the steel frame, and the servo motor drive device is respectively connected to the linear servo electric cylinder and the servo motor through wires, and is used for closed-loop control of the position, speed and gear torque of the chain test model.

[0009] As a preferred solution of the device for measuring the dynamic shear characteristics of the mechanical-soil interface of the present invention, the data acquisition system includes a torque sensor, a speed sensor, a thin film pressure sensor, a linear displacement sensor, a vertical force sensor, a traction force sensor, a micro soil pressure box, a data acquisition module, a computer module and a power module; the torque sensor is installed on the gear shaft of the driving gear, the power input end of the torque sensor is connected to the power output shaft of the planetary reducer through a key, and the power output shaft of the torque sensor is connected to the driving gear shaft through a sleeve to detect the driving torque of the servo motor; the speed sensor is respectively installed at the ends of the driving gear and the driven gear shaft to detect the speed of the gear; the thin film pressure sensor is pasted or Embedded in the bottom and side surfaces of the shear plate to be tested that may contact the soil to be tested, it is used to detect the actual normal pressure on the shear plate to be tested and the movement resistance of the soil on the plate side; the linear displacement sensor is installed at one end of the linear servo electric cylinder to detect the vertical distance between the chain test model and the soil to be tested; the vertical force sensor is installed on the sliding block of the linear servo electric cylinder to detect the normal pressure applied to the soil to be tested by the chain test model as a whole; the traction force sensor is installed on the upper part of the horizontal linear guide rail to detect the horizontal traction force exerted on the chain test model when the chain rotates; the miniature soil pressure boxes are placed at equal intervals in the soil to be tested at different depths to test the distribution and change law of the soil pressure of the chain test model in the soil to be tested under different settlement depths.

[0010] As a preferred solution of the device for measuring the dynamic shear characteristics of the mechanical-soil interface described in the present invention, the input port of the data acquisition module is respectively connected to each sensor; the output port of the data acquisition module is connected to the computer module; the computer module receives the real-time data of each sensor and performs automatic visualization processing; the power supply module respectively supplies power to the torque sensor, the speed sensor, the thin film pressure sensor, the linear displacement sensor, the vertical force sensor, the traction force sensor, the micro soil pressure box, the data acquisition module, the computer module, the linear servo electric cylinder, the servo motor, the planetary reducer and the servo motor drive device.

[0011] As a preferred solution of the device for measuring the dynamic shear characteristics of the mechanical-soil interface described in the present invention, the measuring device can carry out dynamic shear characteristic parameter tests of the mechanical-soil interface in indoor soil troughs, outdoor construction sites, etc., to study the influence of soil parameters, mechanical parameters, and driving conditions on the dynamic shear characteristics of the mechanical-soil contact interface (maximum shear stress, residual shear stress, shear stress-slip displacement curve).

[0012] As a preferred solution of the device for measuring the dynamic shear characteristics of the machine-soil interface of the present invention, the shear plate to be tested has different forms and can be flexibly adjusted according to the test requirements. When testing the dynamic shear characteristics of the soil, the size and shape of the shear plate to be tested is consistent with the mechanical structure to be studied or proportionally reduced.

[0013] In order to solve the above technical problems, the present invention provides the following technical solutions: a method for measuring the dynamic shear characteristics of a machine-soil interface,

[0014] S1: Before the test, the size and shape of the shear plate to be tested are customized according to the type of machinery to be studied, and fixed on the chain by bolts in a certain arrangement;

[0015] S2: Start the linear servo electric cylinder through the loading and control system to slowly and accurately adjust the vertical position of the chain test model so that its bottom is in horizontal contact with the surface of the soil to be tested. The vertical force sensor on the sliding block of the linear servo electric cylinder continuously records the vertical force applied by the chain test model as a whole to the soil to be tested until it reaches a predetermined value and controls it to remain unchanged;

[0016] S3: The servo motor is started through the loading and control system to drive the gear shaft to rotate. The torque sensor continuously records the driving torque of the servo motor, the speed sensor continuously records the speed of the gear, the film pressure sensor continuously outputs the plate side soil movement resistance of the shear plate to be tested, and the vertical force sensor continuously records the total normal pressure applied by the chain test model to the soil to be tested;

[0017] S4: The data acquisition module and computer module comprehensively organize and summarize all the test data received, and calculate the parameters related to the dynamic shear characteristics of the machine-soil interface.

[0018] As a preferred embodiment of the method for measuring the dynamic shear characteristics of the mechanical-soil interface of the present invention, the mechanical-soil interface dynamic shear characteristics measuring device can measure the parameters related to the dynamic shear characteristics of the mechanical-soil contact interface: according to the measured data recorded by the torque sensor, the rotation speed sensor, the thin film pressure sensor, and the vertical force sensor, the dynamic shear characteristics of the mechanical-soil contact interface under different conditions can be obtained by using the first formula, and the first formula is:

[0019]

[0020] where τ d is the dynamic shear stress at the machine-soil interface, τ max is the dynamic maximum shear stress of the soil, τ0 is the quasi-static shear stress of the soil, v is the dynamic shear rate, and k is the dynamic shear deformation coefficient;

[0021] When studying the dynamic shear characteristics of the machine-soil contact interface, τ in the first formulad The calculation can be performed by the second formula, which is:

[0022]

[0023] Where T m is the servo motor driving torque, r0 is the driving gear radius, m is the number of shear plates to be tested in contact with the soil to be tested, A is the area of ​​the shear plate to be tested, τ f is the unit soil movement resistance on the shear plate side to be measured;

[0024] τ0 in the first formula can be calculated by a third formula, and the third formula is:

[0025]

[0026] Where c is the soil cohesion, N is the unit normal pressure of the shear plate to be tested, is the friction angle within the soil;

[0027] In the first formula, v can be calculated by the fourth formula, which is:

[0028] v=2πnr0

[0029] Where n is the driving gear speed;

[0030] In the third formula, N can be calculated by the fifth formula, which is:

[0031]

[0032] Where N w is the total normal pressure on the shear plate to be tested;

[0033] In the first formula, τ max The maximum torque T of the servo motor (32) that causes the soil to slip at the moment of starting can be measured by the chain test model 1 and measured by the torque sensor (41). max,0 , then let T m =T max,0 , we can obtain τ by the second formula max .

[0034] As a preferred solution of the method for measuring the dynamic shear characteristics of the machine-soil interface described in the present invention, wherein: the linear displacement sensor can record the vertical deformation of the soil to be tested, so as to analyze the bearing pressure mechanical characteristics of the soil to be tested; the traction force sensor can record the horizontal traction force generated when the chain rotates, so as to analyze the movement trend of the chain test model and optimize the chain transmission parameters; the micro soil pressure box can record the distribution and changes of the soil pressure in the soil to be tested, and can analyze the disturbance of the surrounding soil when the actual traction components or excavation machinery are working and optimize the corresponding structural parameters.

[0035] Beneficial effects of the present invention: 1. The chain test model provided by the present invention is placed in an isosceles triangle, the overall structure is stable, the space occupied is small, and it is suitable for laboratory environment. Through the servo motor and linear servo electric cylinder device, high-precision controllable dynamic linear shear behavior of the machine-soil interface can be achieved.

[0036] 2. The introduction of the chain transmission mode greatly improves the bulldozing effect that is prone to occur in traditional long-distance linear shear tests. It also avoids the problems of shear velocity differences inside and outside the shear ring and uneven stress on the ring radius in traditional ring shear tests.

[0037] 3. The shape, size and material of the shear plate to be tested can be flexibly customized according to the test type and machine type, and it has strong applicability. The bolt holes set on the chain are conducive to the assembly and disassembly of the shear plate to be tested. Shear plates of different types and groups can simulate various usage scenarios such as tracks, wheels, and excavators.

[0038] 4. Since the hanging plate does not close the chain and the outer space of the shear plate to be tested, the film pressure sensor can be directly pasted or embedded on the shear plate to be tested and rotate with the chain without being stuck. It can most intuitively and accurately test the dynamic shear mechanical properties of the mechanical and soil contact interface under different shear rates and time conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work. Among them:

[0040] Figure 1 It is a schematic diagram of the overall structure of the device for measuring the dynamic shear characteristics of the machine-soil interface of the present invention.

[0041] Figure 2 for Figure 1 An enlarged schematic diagram of the interior of the chain test model.

[0042] Figure 3 for Figure 1 A magnified front view of the test frame in Figure 2.

[0043] Figure 4 for Figure 1 A magnified side view of the chain test model in .

[0044] Figure 5 for Figure 1 Schematic diagram of two different types of shear plates to be tested.

[0045] Figure 6 for Figure 1 An enlarged side view of the chain and gears in Figure 1.

[0046] In the figure, 1. chain test model; 2. test frame; 3. loading and control system; 4. data acquisition system; 11. chain; 12. shear plate to be tested; 13. gear shaft; 14. driving gear; 15. driven gear; 16. suspension plate; 17. middle partition; 18. test base; 19. high-strength bolts; 21. steel frame; 22. support base; 23. acrylic transparent plate; 24. horizontal linear guide; 31. linear servo electric cylinder; 32. servo motor; 33. planetary reducer; 34. servo motor drive device; 41. torque sensor; 42. speed sensor; 43. film pressure sensor; 44. linear displacement sensor; 45. vertical force sensor; 46. traction sensor; 47. micro soil pressure box; 48. data acquisition module; 49. computer module; 50. power module. DETAILED DESCRIPTION

[0047] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the accompanying drawings.

[0048] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0049] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor does it refer to a separate or selective embodiment that is mutually exclusive with other embodiments.

[0050] like Figure 1As shown, the present invention is a device for measuring dynamic shear characteristics of a machine-soil interface, which mainly includes a chain test model 1, a test frame 2, a loading and control system 3 and a data acquisition system 4.

[0051] refer to Figure 2 and Figure 4 The chain test model 1 is placed in an isosceles triangle, with a stable overall structure and small space occupation. It mainly includes a chain 11, a shear plate 12 to be tested, a gear shaft 13, a driving gear 14, a driven gear 15, a suspension plate 16, a middle partition 17, a test base 18 and a high-strength bolt 19. The driving gear 14 and the driven gear 15 are arranged in an isosceles triangle; the gear shaft 13 is fixed to the suspension plate 16 on both sides of the chain through a seat bearing and bolts; the chain 11 is installed on the driving gear 14 and the driven gear 15, and bolt holes are reserved on the outer side of the chain 11; the shear plate 12 to be tested is fixed to the chain 11 through the reserved bolt holes and bolts on the chain, and the reserved bolt holes are conducive to the assembly and disassembly of the shear plate 12 to be tested; the shape, size and material of the shear plate 12 to be tested can also be flexibly customized according to the difference in test type and mechanical type, and the applicability is strong. Shear plates to be tested of different types and groups can simulate various usage scenarios such as crawlers, wheels, and excavators. In addition, the introduction of the chain transmission mode greatly improves the bulldozing effect that is prone to occur in traditional long-distance linear shear tests, while also avoiding problems such as the shear velocity difference inside and outside the shear ring and uneven stress on the ring radius in traditional ring shear tests.

[0052] The suspension plates 16 are located on both sides of the chain 11 and are connected and fixed by high-strength bolts 19; the middle partition plate 17 is arranged between the suspension plates 16 to further reinforce the chain test model 1 and also serve as a fender; the test base 18 is located between the two driven gears 15, and a chain guide is installed and fixed at the bottom of the test base 18, and the test base 18 and the suspension plate 16 are connected by high-strength bolts 19.

[0053] refer to Figure 3 The test frame 2 includes a steel frame 21, a support base 22, an acrylic transparent plate 23 and a horizontal linear guide rail 24. The support base 22 is installed at the bottom of the steel frame 21, the acrylic transparent plate 23 is installed at the front side of the steel frame 21, and the soil to be tested is placed inside the steel frame 21; the chain test model 1 is placed on the soil to be tested; the horizontal linear guide rail 24 is installed on the top of the steel frame 21 to control the horizontal position of the chain test model 1.

[0054] refer to Figure 4The loading and control system 3 includes a linear servo electric cylinder 31, a servo motor 32, a planetary reducer 33 and a servo motor drive device 34. The power output shaft of the servo motor 32 is connected to the power input end of the planetary reducer 33 through a rigid coupling, and the housings of the servo motor 32 and the planetary reducer 33 are connected through a flange fixed by bolts, which is used to control the chain transmission parameters; the bottom of the linear servo electric cylinder 31 is fixed to the horizontal linear guide 24 through a threaded connection, and the sliding block of the linear servo electric cylinder 31 is connected to one side of the suspension plate 16 through a high-strength bolt 19, which is used to accurately control the vertical distance between the chain test model 1 and the soil to be tested and apply the corresponding vertical force; the servo motor drive device 34 is installed on the top of the steel frame 21, and the servo motor drive device 34 is connected to the linear servo electric cylinder 31 and the servo motor 32 through wires, respectively, for closed-loop control of the position, speed, and gear torque of the chain test model 1, thereby realizing high-precision and controllable dynamic linear shear behavior of the mechanical-soil interface.

[0055] refer to Figure 2-Figure 4 The data acquisition system includes a torque sensor 41, a speed sensor 42, a film pressure sensor 43, a linear displacement sensor 44, a vertical force sensor 45, a traction force sensor 46, a micro soil pressure box 47, a data acquisition module 4, a computer module 49 and a power module 50. The torque sensor 41 is installed on the gear shaft 13 of the driving gear 14. The power input end of the torque sensor 41 is connected to the power output shaft of the planetary reducer 33 through a key. The power output shaft of the torque sensor 41 is connected to the driving gear shaft 13 through a sleeve to detect the driving torque of the servo motor; the speed sensor 42 is respectively installed at the ends of the driving gear and the driven gear shaft 13 to detect the speed of the gear; because the suspension plate 16 does not close the space outside the chain 11 and the shear plate 12 to be tested, the film pressure sensor 43 is directly pasted or embedded in the bottom and side surfaces of the shear plate 12 to be tested that may contact the soil to be tested, and rotates simultaneously with the chain 11 to detect the shear plate to be tested. 12 is subjected to the actual normal pressure and the movement resistance of the soil on the plate side; the linear displacement sensor 44 is installed at one end of the linear servo electric cylinder 31, and is used to detect the vertical distance between the chain test model 1 and the soil to be tested; the vertical force sensor 45 is installed on the sliding block of the linear servo electric cylinder 31, and is used to detect the normal pressure applied to the soil to be tested by the chain test model 1 as a whole; the traction sensor 46 is installed on the upper part of the horizontal linear guide rail 24, and is used to detect the horizontal traction force exerted on the chain test model 1 when the chain rotates; the miniature soil pressure boxes 47 are placed at equal intervals in the soil to be tested at different depths, and the distribution and change law of the soil pressure of the chain test model 1 in the soil to be tested under different settlement depths are tested.

[0056] The input port of the data acquisition module 4 is connected to each sensor respectively; the output port of the data acquisition module 4 is connected to the computer module 49; the computer module 49 receives the real-time data of each sensor and performs automatic visualization processing; the power module 50 supplies power to the torque sensor 41, the speed sensor 42, the film pressure sensor 43, the linear displacement sensor 44, the vertical force sensor 45, the traction force sensor 46, the micro soil pressure box 47, the data acquisition module 4, the computer module 49, the linear servo electric cylinder 31, the servo motor 32, the planetary reducer 33 and the servo motor drive device 34 respectively.

[0057] refer to Figure 5 Preferably, the shear plate 12 to be tested has different forms and can be flexibly adjusted according to test requirements. When testing the dynamic shear characteristics of the soil, the size and shape of the shear plate 12 to be tested is consistent with the mechanical structure to be studied or reduced in proportion.

[0058] A method for measuring dynamic shear characteristics of a machine-soil interface, characterized in that it comprises the following steps:

[0059] S1: Before the test, the size and shape of the shear plate 12 to be tested are customized according to the type of machinery to be studied, and fixed to the chain 11 by bolts in a certain arrangement;

[0060] S2: Start the linear servo electric cylinder 31 through the loading and control system 3 to slowly and accurately adjust the vertical position of the chain test model 1 so that its bottom is in horizontal contact with the surface of the soil to be tested. The vertical force sensor 45 on the sliding block of the linear servo electric cylinder 31 continuously records the vertical force applied by the chain test model 1 to the soil to be tested until it reaches a predetermined value and controls it to remain unchanged;

[0061] S3: The servo motor 32 is started by the loading and control system 3 to drive the gear shaft 13 to rotate, the torque sensor 41 continuously records the driving torque of the servo motor 32, the speed sensor 42 continuously records the speed of the gear, the film pressure sensor 43 continuously outputs the plate side soil movement resistance exerted on the shear plate 12 to be tested, and the vertical force sensor 45 continuously records the total normal pressure applied by the chain test model 1 to the soil to be tested;

[0062] S4: The data acquisition module 4 and the computer module 49 comprehensively organize and summarize all the received test data, and calculate the parameters related to the dynamic shear characteristics of the machine-soil interface.

[0063] The parameters related to the dynamic shear characteristics of the mechanical-soil contact interface can be calculated by the following steps: the normal pressure perpendicular to the shear plate 12 to be tested is recorded by the vertical force sensor 45, the driving torque of the servo motor 32 is recorded by the torque sensor 41, the driving gear speed is recorded by the speed sensor 42, and the soil movement resistance on the side of the shear plate 12 to be tested is recorded by the film pressure sensor 43; the dynamic shear characteristics of the mechanical-soil contact interface under different conditions are obtained by using the first formula, and the first formula is:

[0064]

[0065] where τ d is the dynamic shear stress at the machine-soil interface, τ max is the dynamic maximum shear stress of the soil, τ0 is the quasi-static shear stress of the soil, v is the dynamic shear rate, and k is the dynamic shear deformation coefficient.

[0066] In the first formula, τ d It can be calculated by the second formula, which is:

[0067]

[0068] Where T m is the servo motor driving torque, r0 is the driving gear radius, m is the number of shear plates to be tested in contact with the soil to be tested, A is the area of ​​the shear plate to be tested, τ f is the unit soil movement resistance on the shear plate side to be measured;

[0069] τ0 in the first formula can be calculated by the third formula, which is:

[0070]

[0071] Where c is the soil cohesion, N is the unit normal pressure of the shear plate to be tested, is the friction angle within the soil;

[0072] In the first formula, v can be calculated by the fourth formula, which is:

[0073] v=2πnr0

[0074] Where n is the driving gear speed;

[0075] N in the third formula can be calculated by the fifth formula, which is:

[0076]

[0077] Where N w is the total normal pressure on the shear plate to be tested;

[0078] In the first formula, τmax It can be measured by the chain test model 1, and the maximum torque T of the servo motor 32 that causes the soil to slip at the moment of starting can be measured by the torque sensor 41. max,0 , then let T m =

[0079] T max,0 , we can obtain τ by the second formula max .

[0080] The linear displacement sensor 44 can record the vertical deformation of the soil to be tested, so as to analyze the bearing pressure characteristics of the soil to be tested; the traction sensor 46 can record the horizontal traction force generated when the chain 11 rotates, so as to analyze the movement trend of the chain test model 1 and optimize the chain transmission parameters; the micro soil pressure box 47 can record the distribution and changes of the soil pressure in the soil to be tested, and can analyze the disturbance of the surrounding soil when the actual traction components or excavation machinery are working and optimize the corresponding structural parameters.

[0081] Importantly, it should be noted that the construction and arrangement of the present application shown in a plurality of different exemplary embodiments are only exemplary. Although only a few embodiments are described in detail in this disclosure, it should be readily understood by those who refer to this disclosure that many modifications are possible (e.g., the size, scale, structure, shape and proportion of various elements, and parameter values ​​(e.g., temperature, pressure, etc.), installation arrangement, use of materials, color, directional changes, etc.) without substantially departing from the novel teachings and advantages of the subject matter described in the application. For example, the element shown as integrally formed can be composed of multiple parts or elements, the position of the element can be inverted or otherwise changed, and the nature or number or position of the discrete element can be changed or changed. Therefore, all such modifications are intended to be included in the scope of the present invention. The order or sequence of any process or method steps can be changed or reordered according to alternative embodiments. In the claims, any "device plus function" clause is intended to cover the structure of performing the function described herein, and is not only structurally equivalent but also equivalent structure. Without departing from the scope of the present invention, other replacements, modifications, changes and omissions can be made in the design, operating conditions and arrangement of the exemplary embodiments. Therefore, the invention is not limited to a specific embodiment, but extends to numerous modifications still falling within the scope of the appended claims.

[0082] Additionally, in order to provide a concise description of exemplary embodiments, all features of an actual embodiment (ie, those features that are not relevant to the best mode presently contemplated for carrying out the invention or those that are not relevant to implementing the invention) may not be described.

[0083] It will be appreciated that in the development of any actual implementation, as in any engineering or design project, numerous implementation-specific decisions may be made. Such a development effort may be complex and time-consuming, but will be a routine task of design, fabrication, and production for those of ordinary skill having the benefit of this disclosure without undue experimentation.

[0084] 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 preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A device for measuring dynamic shear characteristics of a machine-soil interface, characterized in that: It includes a chain test model (1), a test framework (2), a loading and control system (3) and a data acquisition system (4); The chain test model (1) comprises a chain (11), a shear plate to be tested (12), a gear shaft (13), a driving gear (14), a driven gear (15), a suspension plate (16), a middle partition plate (17), a test base (18) and a high-strength bolt (19); the driving gear (14) and the driven gear (15) are arranged in an isosceles triangle; the gear shaft (13) is fixed to the suspension plates (16) located on both sides of the chain through seat bearings and bolts; the chain (11) is installed on the driving gear (14) and the driven gear (15) ), bolt holes are reserved on the outer side of the chain (11); the shear plate (12) to be tested is fixed to the chain (11) through the reserved bolt holes and bolts on the chain; the suspension plates (16) are located on both sides of the chain (11) and are connected and fixed by high-strength bolts (19); the middle partition plate (17) is arranged between the suspension plates (16); the test base (18) is located between the two driven gears (15), a chain guide rail is installed and fixed at the bottom of the test base (18), and the test base (18) and the suspension plate (16) are connected by high-strength bolts (19).

2. The device for measuring the dynamic shear characteristics of the machine-soil interface according to claim 1, characterized in that: The test frame (2) comprises a steel frame (21), a support base (22), an acrylic transparent plate (23) and a horizontal linear guide rail (24); the support base (22) is installed at the bottom of the steel frame (21), the acrylic transparent plate (23) is installed at the front side of the steel frame (21), and the soil to be tested is placed inside the steel frame (21); the chain test model (1) is placed on the soil to be tested; and the horizontal linear guide rail (24) is installed on the top of the steel frame (21) and is used to control the horizontal position of the chain test model (1).

3. The device for measuring dynamic shear characteristics of a machine-soil interface according to claim 1, characterized in that: The loading and control system (3) comprises a linear servo electric cylinder (31), a servo motor (32), a planetary reducer (33) and a servo motor driving device (34); the power output shaft of the servo motor (32) is connected to the power input end of the planetary reducer (33) through a rigid coupling, and the housings of the servo motor (32) and the planetary reducer (33) are connected through a flange fixed by bolts; the bottom of the linear servo electric cylinder (31) is fixed to the horizontal linear guide rail (24) through a threaded connection, and the sliding block of the linear servo electric cylinder (31) is connected to one side of the suspension plate (16) through a high-strength bolt (19); the servo motor driving device (34) is installed on the top of the steel frame (21), and the servo motor driving device (34) is respectively connected to the linear servo electric cylinder (31) and the servo motor (32) through wires, and is used for closed-loop control of the position, speed and gear rotation torque of the chain test model (1).

4. The device for measuring dynamic shear characteristics of a machine-soil interface according to claim 1, characterized in that: The data acquisition system comprises a torque sensor (41), a rotation speed sensor (42), a film pressure sensor (43), a linear displacement sensor (44), a vertical force sensor (45), a traction force sensor (46), a micro soil pressure box (47), a data acquisition module (4), a computer module (49) and a power module (50); the torque sensor (41) is mounted on the gear shaft (13) of the driving gear (14); the power input end of the torque sensor (41) is connected to the power output shaft of the planetary reducer (33) through a key; the power output shaft of the torque sensor (41) is connected to the driving gear shaft (13) through a shaft sleeve, and is used to detect the driving torque of the servo motor; the rotation speed sensor (42) is respectively mounted on the ends of the driving gear and the driven gear shaft (13), and is used to detect the rotation speed of the gear; the film pressure sensor (43) is pasted or embedded in The bottom and side surfaces of the shear plate (12) to be tested, which may contact the soil to be tested, are used to detect the actual normal pressure exerted on the shear plate (12) to be tested and the soil movement resistance on the plate side; the linear displacement sensor (44) is installed at one end of the linear servo electric cylinder (31) to detect the vertical distance between the chain test model (1) and the soil to be tested; the vertical force sensor (45) is installed on the sliding block of the linear servo electric cylinder (31) to detect the normal pressure applied by the chain test model (1) as a whole to the soil to be tested; the traction force sensor (46) is installed on the upper part of the horizontal linear guide rail (24) to detect the horizontal traction force exerted on the chain test model (1) when the chain rotates; the micro soil pressure boxes (47) are placed at equal intervals in the soil to be tested at different depths to test the distribution and change law of the soil pressure of the chain test model (1) in the soil to be tested under different sinking depth conditions.

5. The device for measuring dynamic shear characteristics of a machine-soil interface according to claim 1, characterized in that: The input port of the data acquisition module (4) is connected to each sensor respectively; the output port of the data acquisition module (4) is connected to a computer module (49); the computer module (49) receives real-time data from each sensor and performs automatic visualization processing; the power supply module (50) supplies power to a torque sensor (41), a rotation speed sensor (42), a film pressure sensor (43), a linear displacement sensor (44), a vertical force sensor (45), a traction force sensor (46), a micro soil pressure box (47), a data acquisition module (4), a computer module (49), a linear servo electric cylinder (31), a servo motor (32), a planetary reducer (33) and a servo motor drive device (34).

6. The device for measuring dynamic shear characteristics of a machine-soil interface according to claim 1, characterized in that: The measuring device can be used to carry out dynamic shear characteristic parameter tests of the machine-soil interface in indoor soil trenches and outdoor construction sites, etc., to study the influence of soil parameters, mechanical parameters, and driving conditions on the dynamic shear characteristics of the machine-soil contact interface (maximum shear stress, residual shear stress, shear stress-slip displacement curve).

7. The device for measuring dynamic shear characteristics of a machine-soil interface according to claim 1, characterized in that: The shear plate (12) to be tested has different forms and can be flexibly adjusted according to test requirements. When testing the dynamic shear characteristics of soil, the size and shape of the shear plate (12) to be tested is consistent with or proportionally reduced from the mechanical structure to be studied.

8. A method for determining the dynamic shear properties of a machine-soil interface, characterized in that: The device for measuring the dynamic shear characteristics of the machine-soil interface according to claim 1 comprises the following steps: S1: Before the test, the size and shape of the shear plate (12) to be tested are customized according to the type of machinery to be studied, and fixed on the chain (11) by bolts in a certain arrangement; S2: The linear servo electric cylinder (31) is started by the loading and control system (3) to slowly and accurately adjust the vertical position of the chain test model (1) so that its bottom is in horizontal contact with the surface of the soil to be tested, and the vertical force sensor (45) on the sliding block of the linear servo electric cylinder (31) continuously records the vertical force applied by the chain test model (1) as a whole to the soil to be tested until it reaches a predetermined value and controls it to remain unchanged; S3: The servo motor (32) is started by the loading and control system (3) to drive the gear shaft (13) to rotate, the torque sensor (41) continuously records the driving torque of the servo motor (32), the speed sensor (42) continuously records the speed of the gear, the film pressure sensor (43) continuously outputs the plate side soil movement resistance exerted on the shear plate (12) to be tested, and the vertical force sensor (45) continuously records the total normal pressure applied by the chain test model (1) to the soil to be tested; S4: The data acquisition module (4) and the computer module (49) comprehensively organize and summarize all received test data, and calculate the parameters related to the dynamic shear characteristics of the machine-soil interface.

9. The method for determining the dynamic shear characteristics of the machine-soil interface according to claim 8, characterized in that: The device for measuring the dynamic shear characteristics of the machine-soil interface can measure parameters related to the dynamic shear characteristics of the machine-soil contact interface: based on the measured data recorded by the torque sensor (41), the rotation speed sensor (42), the film pressure sensor (43), and the vertical force sensor (45), the dynamic shear characteristics of the machine-soil contact interface under different conditions can be obtained using a first formula, wherein the first formula is: where τ d is the dynamic shear stress at the machine-soil interface, τ max is the dynamic maximum shear stress of the soil, τ0 is the quasi-static shear stress of the soil, v is the dynamic shear rate, and k is the dynamic shear deformation coefficient; When studying the dynamic shear characteristics of the machine-soil contact interface, τ in the first formula d The calculation can be performed by the second formula, which is: Where T m is the servo motor driving torque, r0 is the driving gear radius, m is the number of shear plates to be tested in contact with the soil to be tested, A is the area of ​​the shear plate to be tested, τ f is the unit soil movement resistance on the shear plate side to be measured; τ0 in the first formula can be calculated by a third formula, and the third formula is: Where c is the soil cohesion, N is the unit normal pressure of the shear plate to be tested, is the friction angle within the soil; In the first formula, v can be calculated by the fourth formula, which is: v=2πnr0 Where n is the driving gear speed; In the third formula, N can be calculated by the fifth formula, which is: Where N w is the total normal pressure on the shear plate to be tested; In the first formula, τ max The maximum torque T of the servo motor (32) that causes the soil to slip at the moment of starting can be measured by the chain test model 1 and measured by the torque sensor (41). max,0 , then let T m =T max,0 , we can obtain τ by the second formula max .

10. The method for determining the dynamic shear characteristics of the machine-soil interface according to claim 9, characterized in that: The linear displacement sensor (44) can record the vertical deformation of the soil to be tested, thereby analyzing the bearing pressure mechanical characteristics of the soil to be tested; the traction force sensor (46) can record the horizontal traction force generated when the chain (11) rotates, thereby analyzing the movement trend of the chain test model (1) and optimizing the chain transmission parameters; the micro soil pressure box (47) can record the distribution and change of the soil pressure in the soil to be tested, and can analyze the disturbance of the surrounding soil when the actual traction component or excavator is working and optimize the corresponding structural parameters.

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