Geotechnical material cutting and crushing simulation method considering coordination number and particle shape

Abstract

The invention discloses a geotechnical material cutting and crushing simulation method and device considering coordination number and particle shape. The method comprises the following steps: acquiring particle space data, carrying out geometric simplification, and constructing an irregular particle shape library containing point-surface information; generating a DEM sample for numerical simulation based on the irregular particle shape library; determining a crushing triggering threshold value; determining octahedral shear stress q of the particles, and triggering particle crushing when q is greater than a crushing triggering threshold value; the particle cutting times are distributed with the coordination number as a dominant variable; a main fracture surface is determined, and crushing operation is executed; the orientation of the main fracture surface is consistent with the maximum main stress direction, and the main fracture surface passes through the maximum contact force point; and determining a secondary fracture surface, and executing secondary or multiple crushing operations according to the number of times of cutting until simulation is completed. According to the method, the calculation overhead is remarkably reduced while the irregular geometry and the controllable crushing degree are kept, and the influence of the shape effect and the scale effect on the strength and particle size distribution evolution can be reflected.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of geotechnical engineering and particle mechanics model simulation and computer-aided calculation, in particular to a simulation method for cutting and crushing of rock-soil materials considering coordination number and particle shape. BACKGROUND

[0002] Coarse-grained soils are prone to particle crushing under high stress and shear conditions, leading to significant evolution of strength, deformation and seepage properties. The methods for simulating particle crushing based on DEM can be mainly divided into three categories: the first category is the cemented cluster method, which forms a cluster by cementing multiple small particles, and when a large amount of cementing in the cluster is destroyed, the particle is crushed. This method can simulate the irregular crushing process and irregular particle shape, but the calculation cost is high, and the crushing degree is limited; the second category is the fragment replacement method, which replaces the original particle with a group of small particles without bonding when the particle stress condition meets the preset crushing criterion. The fragment replacement method has high calculation efficiency and controllable crushing degree, but it still has limitations in simulating complex-shaped particles, such as the determination of the fragment template of irregular particles. The third category is the splitting crushing method proposed in recent years, which determines the fracture surface to achieve crushing by considering the contact force state when the particle stress condition meets the preset crushing criterion. This method avoids the generation of mass and volume non-conservation and artificial local stress, and can reflect the complexity of the particle crushing mode to a certain extent. However, the existing schemes usually ignore the influence of coordination number and contact curvature / shape on the crushing threshold and fracture surface.

[0003] In addition, most methods use ideal spheres or regular shapes, which are difficult to reflect the influence of real irregular geometry on crushing behavior. Therefore, there is an urgent need for an efficient DEM crushing simulation method that can consider the crushing degree driven by coordination number and multi-factor triggering criterion under real shape conditions. SUMMARY

[0004] In order to solve the problems of high calculation cost, lack of constraints on crushing degree and fracture surface determination, and difficulty in reflecting real irregular shape by ideal spheres / regular geometry in existing DEM particle crushing simulation, the present application provides a simulation method for cutting and crushing of rock-soil materials considering coordination number and particle shape. This method introduces coordination number to modify the crushing threshold and fracture surface determination mechanism, combines real particle geometry to construct the crushing criterion, realizes efficient simulation of particle crushing degree and mode, and provides a reliable numerical simulation means for the mechanical property research of coarse-grained soils under high stress and shear conditions.

[0005] In the first aspect, the present application provides a simulation method for cutting and crushing of rock-soil materials considering coordination number and particle shape, comprising the following steps: Obtain particle spatial data, perform geometric simplification, and construct an irregular particle shape library containing point and surface information; Generate DEM sample for numerical simulation based on irregular particle shape library; Determine the breakage trigger threshold; Determine the particle octahedral shear stress q, when q is greater than the breakage trigger threshold, then trigger particle breakage; Assign the particle cutting frequency with coordination number as the dominant variable; Determine the main fracture surface and perform the breakage operation; The main fracture surface is oriented in the direction of the maximum principal stress and passes through the maximum contact force point; Determine the secondary fracture surface and perform the secondary or multiple breakage operations according to the cutting frequency until the simulation is completed. In a possible implementation manner, the particle space data is obtained by using structured light or laser scanning rock-soil particles.

[0006] In a possible implementation manner, the breakage trigger threshold The calculation formula is as follows:

[0007] In the formula: is the breakage strength of the particle, P s is the survival probability of the particle, denotes the particle size of the broken particle, denotes the survival probability of the broken particle with the particle size d, m is the Weibull modulus of the particle breakage strength, denotes the characteristic breakage strength of the particle, d 0 denotes the particle size corresponding to the characteristic breakage strength of the particle, n d characterizes the geometric similarity of the mechanical problem, n d / m determines the strength degree of the size effect of the particle strength, f CN denotes the influence coefficient of the coordination number on the breakage mechanism, f d denotes the influence coefficient of the contact surface curvature on the breakage mechanism.

[0008] In a possible implementation manner, the particle cutting frequency is assigned with the coordination number as the dominant variable, including: The mapping relationship between the coordination number Z and the particle breakage level and the cutting frequency is as follows: Z=2, 100% of all particles are grade I; Z=3, 40% of all particles are grade I and 60% are grade II; Z=4, 30% of all particles are grade I and 70% are grade II; Z=5: 20% of all particles are grade I and 80% are grade II; Z≥6: 100% of all particles are grade III; Wherein, the I-grade particle is cut once, the II-grade particle is cut twice, and the III-grade particle is cut three times.

[0009] In one possible implementation, the determining the main breakage surface and performing the breaking operation includes: obtaining a maximum contact force vector of the particle under the force state F max , a maximum principal stress direction vector σ 1 and a point of action of the maximum contact force p 1. calculating F max the cross product of the maximum contact force σ 1 and the maximum principal stress direction vector n , to obtain a normal vector of the main breakage surface of the particle n ; and generating the main breakage surface of the particle according to the normal vector p and the point of action of the maximum contact force 1, and performing the breaking operation.

[0010] In one possible implementation, the determining the secondary breakage surface and performing the secondary or multiple breaking operations according to the number of times of cutting includes: F obtaining a lateral contact force vector of the particle under the force state i , a centroid of the particle P o and a contact point of the lateral contact force P i ; i represents the i-th breaking operation, and i≥2; calculating P o a vector connecting the centroid of the particle P i P o P i ; calculating F i the cross product of the lateral contact force P o and the vector connecting the centroid of the particle P i , to obtain a normal vector of the secondary breakage surface of the particle n i ; generating the secondary breakage surface of the particle according to the normal vector n i and the contact point of the lateral contact force P i , and performing the breaking operation.

[0011] In one possible implementation, the rock-soil material cutting and crushing simulation method restricts volume and mass conservation during cutting and performs de-overlapping and contact smoothing on the new-born fragments. The volume and mass conservation restriction adopts a relative error threshold ε, and the de-overlapping and contact smoothing includes geometric extrapolation, minimum distance restriction and contact normal smoothing.

[0012] In a second aspect, a rock-soil material cutting and crushing simulation device considering coordination number and particle shape is provided, including: An acquisition module is configured to acquire particle spatial data, perform geometric simplification, and construct an irregular particle shape library containing point and surface information; A generation module is configured to generate a DEM sample for numerical simulation based on the irregular particle shape library; A determination module is configured to determine a crushing trigger threshold, determine an octahedral shear stress q of a particle, trigger particle crushing when the q is greater than the crushing trigger threshold, and assign a particle cutting frequency based on the coordination number as a dominant variable; A primary crushing module is configured to determine a primary fracture surface and perform a crushing operation, wherein the primary fracture surface is oriented in the same direction as the maximum principal stress and passes through a maximum contact force point; A secondary crushing module is configured to determine a secondary fracture surface and perform a secondary or multiple crushing operations according to the cutting frequency until the simulation is completed. In a third aspect, an electronic device is provided, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the rock-soil material cutting and crushing simulation method considering coordination number and particle shape according to the first aspect when executing the program.

[0013] In a fourth aspect, a non-transitory computer readable storage medium is provided, which stores a computer program executable by a processor to implement the rock-soil material cutting and crushing simulation method considering coordination number and particle shape according to the first aspect.

[0014] Compared with the prior art, the present application has the following beneficial effects: 1. The method provided by the present application adopts three-dimensional scanning and geometric simplification technology to construct an irregular particle shape library, solves the problem that ideal spheres / regular shapes in the prior art cannot reflect the actual particle geometry, makes the DEM simulation more consistent with the actual particle morphology of coarse-grained soil, and significantly improves the authenticity and reliability of the simulation.

[0015] 2. The method provided by the application effectively solves the problem of ignoring the influence of coordination number and contact curvature on the breakage threshold in the prior art by introducing a coordination number dominant breakage threshold correction and a breakage surface determination mechanism, combining with the real particle geometry to construct a breakage criterion, realizing efficient and accurate simulation of the degree and mode of particle breakage, and breaking through the bottleneck of lack of constraints on the degree of breakage in the prior art.

[0016] 3. The method provided by the application optimizes the control logic of the breakage process by combining the coordination number driven cutting frequency allocation with the multi-factor trigger criterion, avoids the defects of high calculation cost of the cemented cluster method and limited breakage degree of the fragment replacement method in the prior art, and realizes efficient and controllable particle breakage simulation. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 A flowchart of a rock-soil material cutting and breakage simulation method considering coordination number and particle shape is provided for the embodiments of the application.

[0018] Figure 2 A breakage surface determination schematic diagram of a rock-soil material cutting and breakage simulation method considering coordination number and particle shape is provided for the embodiments of the application. Figure 2 (a) is a main breakage surface breakage simulation schematic diagram, Figure 2 (b) is a secondary breakage surface breakage simulation schematic diagram.

[0019] Figure 3 A triaxial numerical shear flowchart of a rock-soil material cutting and breakage simulation method considering coordination number and particle shape is provided for the embodiments of the application.

[0020] Figure 4 A scanning and simplified particle shape schematic diagram of a rock-soil material cutting and breakage simulation method considering coordination number and particle shape is provided for the embodiments of the application.

[0021] Figure 5 A numerical simulation sample schematic diagram of different sizes of a rock-soil material cutting and breakage simulation method considering coordination number and particle shape is provided for the embodiments of the application.

[0022] Figure 6 A particle breakage simulation effect diagram of a rock-soil material cutting and breakage simulation method considering coordination number and particle shape is provided for the embodiments of the application.

[0023] Figure 7 A structure schematic diagram of a rock-soil material cutting and breakage simulation device considering coordination number and particle shape is provided for the embodiments of the application.

[0024] Figure 8 A structure schematic diagram of an electronic device is provided for the embodiments of the application. DETAILED DESCRIPTION

[0025] The terms "comprise" and "have" and any variations thereof in the specification and claims of the present application and the above drawings are intended to cover a non-exclusive inclusion, for example, a process, method, system, product or device that includes a series of steps or model structure updates, model parameter updates, and is not necessarily limited to which steps or units are clearly listed, but can include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0026] In order to make the purpose, technical solutions and advantages of the present application clearer, the technical solutions in the present application will be described clearly and completely in the following with reference to the drawings and embodiments. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application. In addition, the technical features in each embodiment or single embodiment provided by the present application can be combined with each other arbitrarily to form a feasible technical solution, which is not restricted by the order of steps and / or structure composition mode, but must be based on the implementation by those skilled in the art. When the combination of technical solutions appears contradictory or unfeasible, it should be considered that the combination of technical solutions does not exist and is not within the scope of protection claimed by the present application.

[0027] In order to solve the problems of high calculation cost, lack of constraints in breaking degree and fracture surface determination, and difficulty in reflecting real irregular shape by ideal sphere / regular geometry in existing DEM particle crushing simulation, the present application provides a rock-soil material cutting and crushing simulation method considering coordination number and particle shape.

[0028] Referring to Figure 1 A rock-soil material cutting and crushing simulation method considering coordination number and particle shape, comprising: S101, obtaining particle spatial data, performing geometric simplification, and constructing an irregular particle shape library containing point and surface information.

[0029] In a possible implementation manner, the particle spatial data is obtained by using structured light or laser scanning rock-soil to draw particles. For example, EinScan-SP is used, and the single-scan accuracy is not less than 0.05 mm.

[0030] In a possible implementation manner, the geometric simplification uses MeshLab software to simplify the particles on the basis of retaining typical characteristic information of the particles, and the simplified three-dimensional information contains information of several hundred points and surfaces.

[0031] S102, generating a DEM sample for numerical simulation based on the irregular particle shape library.

[0032] In one possible implementation, the generation of the DEM specimen includes: loading the specimen according to the target gradation curve and relative density, using loading algorithms such as the rain method, particle size expansion method, and layered underpressure method, setting flexible membrane conditions and top / bottom loading boundaries; and optionally using rigid wall or FDM-DEM coupled simulation to achieve confining pressure servo.

[0033] S103. Determine the crushing trigger threshold; determine the octahedral shear stress q of the particle, and trigger particle crushing when q is greater than the crushing trigger threshold; allocate the number of particle cuttings with coordination number as the dominant variable.

[0034] It should be noted that the coordination number refers to the number of contacts contained in a single particle, and typically requires that the normal contact force of each contact is greater than zero. For example, if particles B, C, and D have a normal contact force greater than zero with particle A, then the coordination number is 3. The particle cutting number b refers to the number of cuts required for a single particle to generate the final fracture surface. The correspondence between the particle fragmentation level and the number of cuts b is as follows: Level I (splitting), b=1, producing 2 fragments; Level II (low-intensity fragmentation), b=2, producing 4 fragments; Level III (high-intensity fragmentation), b=3, producing 8 fragments.

[0035] Understandably, there is a correlation between the number of low-intensity fractures and cuts and the number of fragments. For example, a cutting situation where b=1 produces 2 fragments is defined as low-intensity fracture. High-intensity fracture is similar.

[0036] In one possible implementation, S103 includes: S103a, Determine the breakage trigger threshold .

[0037] In one possible implementation, the breakage trigger threshold The calculation formula is as follows: (1) In the formula: The crushing strength of the particles. P s It is the probability of particle survival. Refers to the particle size of the crushed particles. This represents the survival probability of a broken particle with a particle size of d (no breakage indicates survival). m The Weibull modulus is the particle crushing strength. The characteristic crushing strength of particles. d 0 refers to the particle size corresponding to the characteristic crushing strength of the particles. n d Characterizing the geometric similarity of mechanical problems, nd / m determines the strength of the size effect of particle strength, f CN determines the influence coefficient of coordination number on the breakage mechanism, f d determines the influence coefficient of contact surface curvature on the breakage mechanism.

[0038] (2) (3) In the formula, d denotes the particle size in contact with the broken particle, d denotes the coordination number of the particle. CN

[0039] Breakage trigger threshold In the formula, the size effect of particle breakage strength is embodied by characteristic breakage strength , Weibull modulus m and n d The particle size and peak breakage force are determined by single-particle breakage physical tests.

[0040] S103b, determine the octahedral shear stress q of the particle, and when q is greater than the breakage trigger threshold, the particle breakage is triggered.

[0041] In one possible implementation manner, the formula of the octahedral shear stress q is as follows: (4) In the formula, σ1, σ2 and σ3 respectively denote the first, second and third principal stresses. , ,

[0042] In the discrete element method, the stress tensor σ acting on a particle with a volume of V is defined as: (5) In the formula, σx, σy and σz denote the Cartesian coordinate components, N denotes the total number of contacts of the particle, V denotes the volume of the particle, F denotes the component of the contact force in the direction of ,and denotes the branch vector of the contact center. The principal stresses σ1, σ2 and σ3 are calculated by using the calculation formula of the stress tensor σ. ​​​​​​​​​

[0043] S103c, Determine the mapping relationship between coordination number and crushing grade and number of cuts.

[0044] The mapping relationship between the coordination number Z and the particle crushing grade and the number of cuts is as follows: Z=2: 100% of all particles are Grade I; Z=3: 40% of all particles are Grade I and 60% are Grade II; Z=4: 30% of all particles are Grade I and 70% are Grade II; Z=5: 20% of all particles are Grade I and 80% are Grade II; Z≥6: 100% of all particles are Grade III. Among them, Class I particles are cut once, Class II particles are cut twice, and Class III particles are cut three times.

[0045] Furthermore, when the number of cutting operations is b, the final number of fragments is preferably 2. b After each cut, the contact topology is updated and the upper limits of velocity and angular velocity of the new fragments are initialized to control numerical oscillations.

[0046] S104. Determine the main fracture surface and perform the crushing operation; the orientation of the main fracture surface is consistent with the direction of the maximum principal stress and passes through the point of maximum contact force.

[0047] See Figure 2 (a) In one possible implementation, S104 includes: S104a, Obtain the maximum contact force vector of the particle under stress. F max , Maximum principal stress direction vector σ 1 and the point of application of the maximum contact force p 1; S104b, Calculation F max and σ The cross product of 1 yields the normal vector of the main fracture surface of the particle. n According to the normal vector n and the point of application of the maximum contact force p 1. Generate the main fracture surface of the particle and perform the crushing operation.

[0048] It should be noted that the maximum contact force vector F max This refers to the force vector corresponding to the contact with the largest normal force modulus among all contact forces of the particle, and the direction vector of the maximum principal stress. σ 1 refers to the direction of the maximum principal stress and the point of application of the maximum contact force. p 1 refers to the point where the maximum contact force is applied to the particle.

[0049] S105, determining a secondary fracture surface, performing secondary or multiple breakage operations according to the number of cutting operations until the simulation is completed.

[0050] Referring to Figure 2 (b), in one possible implementation, S105 comprises: S105a, obtaining a lateral contact force vector of the particle under the force state F i , the centroid of the particle P o , and the contact point of the lateral contact force P i ; i represents the i-th breakage operation, i≥2; S105b, calculating P o connected to P i vector P o P i ; S105c, calculating F i and P o P i cross product of the vectors, obtaining the normal vector of the secondary fracture surface of the particle n i ; S105d, generating the secondary fracture surface of the particle according to the n i and the P i , and performing the breakage operation.

[0051] It should be noted that the lateral contact force vector F i refers to the force vector corresponding to the contact pair with the second largest normal force module value among all contact forces of the particle, the contact point of the lateral contact force P i refers to the force point of the lateral contact force acting on the particle.

[0052] In one possible implementation, the rock-soil material cutting breakage simulation method constrains the conservation of volume and mass during the cutting process, and performs de-overlapping and contact smoothing on the newly generated fragments; wherein the volume and mass conservation constraint adopts a relative error threshold ε, preferably ε ≤1×10 -4 ; the de-overlapping and contact smoothing includes geometric extrapolation, minimum distance constraint, and contact normal smoothing.

[0053] It can be understood that the method provided by the embodiments of the present application is applicable to numerical test scenes such as triaxial compression, direct shear, true triaxial, and impact loading, and can be used in combination with confining pressure servo control, loading rate control, and boundary friction control.

[0054] The application will be described in more detail with reference to the more detailed embodiments.

[0055] Referring to Figure 3 , the embodiments of the present application simulate and analyze the triaxial numerical shear process of a certain core rockfill dam based on the aforementioned cutting and crushing numerical simulation method, including: S1: Obtain particle spatial data, perform geometric simplification, and construct an irregular particle shape library containing point and surface information.

[0056] The blasting rock materials from a certain rockfill dam project are subjected to particle screening treatment, which are divided into five particle size groups with particle sizes of 10-20 mm, 20-30 mm, 30-40 mm, 40-50 mm, and 50-60 mm. An EinScan-SP scanner is used for particle scanning. EinScan-SP is a high-precision white light desktop 3D scanner that uses grating structured light technology, with a single-scan accuracy of 0.05 mm. It is suitable for high-quality three-dimensional data acquisition of small to medium-sized objects, and can output complete STL models and seamlessly connect 3D printing. The spatial data obtained by scanning each particle contains nearly hundreds of thousands of point and surface information. Considering the limitation of calculation amount, the three-dimensional point cloud data of the particles is sparsely simplified by using MeshLab software. The scanned and mesh-simplified graphics are shown in Figure 4 .

[0057] S2: Based on the irregular particle shape library, generate a DEM sample for numerical simulation.

[0058] To ensure the reasonableness of the numerical test results, the numerical sample preparation, rubber film simulation, and triaxial compression test simulation are all carried out in accordance with the requirements of physical tests. The numerical sample sizes are 300 mm (diameter) x 600 mm (height), 450 mm x 900 mm, 600 mm x 1200 mm, and 750 mm x 1500 mm, as shown in Figure 5 .

[0059] S3: Determine the breakage trigger threshold; determine the octahedral shear stress q of the particle, and when q is greater than the breakage trigger threshold, the particle breakage is triggered; and assign the particle cutting frequency based on the coordination number as the dominant variable.

[0060] Specifically, S3 includes: S3.1: Determine the breakage trigger threshold ; S3.2: Determine the octahedral shear stress q of the particle, and when q is greater than the breakage trigger threshold, the particle breakage is triggered.

[0061] S3.3: Determine the mapping relationship between coordination number and fragmentation level and cutting times, and the simulation effect is shown in Figure 6

[0062] S4: Calculate the cross product of the maximum contact force vector (F F max ) and the maximum principal stress direction vector (n σ 1), to determine the normal vector (n n ) of the main fracture surface of the particle; according to the normal vector (n n ) and the point of action (P p 1) of the maximum contact force, generate the main fracture surface of the particle, and perform the fragmentation operation; S5: Calculate the cross product of the lateral contact force vector (F F i ) and the vector connecting the centroid (C P o ) of the particle and the contact point (P P i ) of the lateral contact force, to determine the normal vector (n n i ) of the secondary fragmentation surface of the particle; according to the normal vector (n n i ) and the contact point (P P i ) of the lateral contact force, generate the secondary fracture surface of the particle, and perform the fragmentation operation.

[0063] In the cutting process, the volume and mass conservation are constrained, and the de-overlapping and contact smoothing of the newly generated fragments are performed to ensure numerical stability; In the embodiment, the fragmented sample is recorded and analyzed systematically, and the stress-strain curve, volume strain curve, fragmentation particle size distribution curve (gradation evolution) and fragmentation rate of the sample are obtained and saved, which are key indicators for quantifying the influence of fragmentation on mechanical behavior and particle size distribution and serving as an experimental basis for numerical model calibration.

[0064] The coordination number and particle shape considering rock-soil material cutting fragmentation simulation device provided in the present application is described below, and the coordination number and particle shape considering rock-soil material cutting fragmentation simulation device described below can be correspondingly referred to the coordination number and particle shape considering rock-soil material cutting fragmentation simulation method described above.

[0065] Figure 7 is a structural schematic diagram of the coordination number and particle shape considering rock-soil material cutting fragmentation simulation device provided in the embodiment of the present application, as shown in Figure 7 ​As shown, it comprises: an acquisition module 71, a generation module 72, a determination module 73, a primary crushing module 74 and a secondary crushing module 75, wherein: The acquisition module 71 is used for acquiring particle space data, performing geometric simplification, and constructing an irregular particle shape library containing point-plane information; The generation module 72 is used for generating a DEM sample for numerical simulation based on the irregular particle shape library; The determination module 73 is used for determining a crushing trigger threshold; determining a particle octahedral shear stress q, and triggering particle crushing when the q is greater than the crushing trigger threshold; and assigning a particle cutting frequency based on a coordination number as a dominant variable; The primary crushing module 74 is used for determining a primary fracture surface and performing a crushing operation; the primary fracture surface is oriented in the same direction as the maximum principal stress and passes through the maximum contact force point; The secondary crushing module 75 is used for determining a secondary fracture surface and performing a secondary or multiple crushing operation according to the cutting frequency until the simulation is completed.

[0066] Figure 8 An example of a schematic diagram of the physical structure of an electronic device is shown as Figure 8 As shown, the electronic device can include a processor 810, a communications interface 820, a memory 830 and a communications bus 840, wherein the processor 810, the communications interface 820 and the memory 830 complete mutual communication through the communications bus 840. The processor 810 can invoke a logical instruction in the memory 830 to execute a rock-soil material cutting and crushing simulation method considering coordination number and particle shape.

[0067] In addition, the logical instruction in the memory 830 described above can be implemented in the form of a software functional unit and sold or used as an independent product, which can be stored in a computer-readable storage medium. Based on such understanding, the technical solutions of the present application essentially or say the part that contributes to the prior art or part of the technical solutions can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a plurality of instructions to make a computer device (which can be a personal computer, a server, or a network device, etc.) execute all or part of the steps of the method described in various embodiments of the present application. The aforementioned storage medium includes: a U disk, a mobile hard disk, a read-only memory (ROM, Read-Only Memory), a random access memory (RAM, Random Access Memory), a magnetic disk or an optical disk, and various media that can store program codes.

[0068] In another aspect, the application also provides a non-transitory computer readable storage medium having stored thereon a computer program, which, when executed by a processor, implements the method for simulating cutting and crushing of geotechnical materials considering coordination number and particle shape.

[0069] The device embodiments described above are merely illustrative, wherein the units described as separate components can or can not be physically separated, and the components displayed as units can or can not be physical units, i.e., can be located in one place, or can be distributed on multiple network units. Part or all of the modules can be selected to achieve the purpose of the embodiment scheme according to actual needs. Those skilled in the art can understand and implement without creative labor.

[0070] From the above description of the embodiments, those skilled in the art can clearly understand that the embodiments can be realized by means of software plus necessary general hardware platforms, and of course can also be realized by hardware. Based on such understanding, the above technical solutions, essentially or in the contribution to the prior art, can be embodied in the form of a software product. The computer software product can be stored in a computer readable storage medium, such as a ROM / RAM, a magnetic disk, an optical disk, etc., and includes a number of instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or some parts of the embodiments.

[0071] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A simulation method for cutting and crushing rock and soil materials considering coordination number and particle shape, characterized in that, Includes the following steps: Acquire particle space data, perform geometric simplification, and construct an irregular particle shape library containing point and surface information; Based on the irregular particle shape library, DEM samples are generated for numerical simulation. Determine the breakage trigger threshold; Determine the octahedral shear stress q of the particle. When q is greater than the crushing trigger threshold, particle crushing is triggered. The number of particle cuttings was assigned with coordination number as the dominant variable. Determine the main fracture surface and execute the crushing operation; The orientation of the main fracture surface is consistent with the direction of the maximum principal stress and passes through the point of maximum contact force. Determine the secondary fracture surface, and perform secondary or multiple crushing operations based on the number of cuts until the simulation is complete.

2. The simulation method for cutting and crushing rock and soil materials considering coordination number and particle shape according to claim 1, characterized in that, The particle spatial data was obtained by scanning the soil and rock with structured light or laser.

3. The simulation method for cutting and crushing rock and soil materials considering coordination number and particle shape according to claim 1, characterized in that, The breakage trigger threshold The calculation formula is as follows: In the formula: The crushing strength of the particles. P s It is the probability of particle survival. Refers to the particle size of the crushed particles. This represents the survival probability of a broken particle with a diameter of d. m The Weibull modulus is the particle crushing strength. The characteristic crushing strength of particles. d 0 refers to the particle size corresponding to the characteristic crushing strength of the particles. n d Characterizing the geometric similarity of mechanical problems, n d / m The size effect determines the strength of particle strength. f CN The coefficient of influence of coordination number on the crushing mechanism. f d The coefficient of influence of the curvature of the contact surface on the fracture mechanism.

4. The simulation method for cutting and crushing rock and soil materials considering coordination number and particle shape according to claim 1, characterized in that, The allocation of particle cutting times based on coordination number as the dominant variable includes: The mapping relationship between the coordination number Z and the particle crushing grade and the number of cuts is as follows: Z=2: 100% of all particles are Grade I; Z=3: 40% of all particles are Grade I and 60% are Grade II; Z=4: 30% of all particles are Grade I and 70% are Grade II; Z=5: 20% of all particles are Grade I and 80% are Grade II; Z≥6: 100% of all particles are Grade III. Among them, Class I particles are cut once, Class II particles are cut twice, and Class III particles are cut three times.

5. The simulation method for cutting and crushing rock and soil materials considering coordination number and particle shape according to claim 1, characterized in that, The process of determining the main fracture surface and performing the crushing operation includes: Obtain the maximum contact force vector of the particle under stress. F max , Maximum principal stress direction vector σ 1 and the point of application of the maximum contact force p 1; calculate F max and σ The cross product of 1 yields the normal vector of the main fracture surface of the particle. n According to the normal vector n and the point of application of the maximum contact force p 1. Generate the main fracture surface of the particle and perform the crushing operation.

6. The simulation method for cutting and crushing rock and soil materials considering coordination number and particle shape according to claim 1, characterized in that, The process of determining the secondary fracture surface and performing secondary or multiple crushing operations based on the number of cuts includes: Obtain the lateral contact force vector of the particle under stress. F i The center of mass of the particles P o Contact point with lateral contact force P i ; i represents the i-th crushing operation, i≥2; calculate P o Connected to P i vector P o P i ; calculate F i and P o P i The cross product of the two particles yields the normal vector of the secondary fracture surface of the particle. n i ; According to the above n i and stated P i A secondary fracture surface is generated for the particles, and a crushing operation is performed.

7. The simulation method for cutting and crushing rock and soil materials considering coordination number and particle shape according to claim 1, characterized in that, The simulation method for cutting and crushing soil and rock materials constrains volume and mass conservation during the cutting process and performs de-overlapping and contact smoothing on the newly formed fragments. The volume and mass conservation constraints adopt a relative error threshold ε; the deoverlapping and contact smoothing include geometric extrapolation, minimum distance constraints, and contact normal smoothing.

8. A simulation device for cutting and crushing rock and soil materials considering coordination number and particle shape, characterized in that, include: The acquisition module is used to acquire particle space data, perform geometric simplification, and build a library of irregular particle shapes containing point and surface information. The generation module is used to generate DEM samples for numerical simulation based on a library of irregular particle shapes. The determination module is used to determine the breakage trigger threshold; Determine the octahedral shear stress q of the particle. When q is greater than the crushing trigger threshold, particle crushing is triggered. The number of particle cuttings was assigned with coordination number as the dominant variable. The main crushing module is used to determine the main fracture surface and perform the crushing operation; the orientation of the main fracture surface is consistent with the direction of the maximum principal stress and passes through the point of maximum contact force. The secondary crushing module is used to determine the secondary fracture surface and perform secondary or multiple crushing operations based on the number of cuts until the simulation is complete.

9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the program, it implements the simulation method for cutting and crushing rock and soil materials considering coordination number and particle shape as described in any one of claims 1 to 7.

10. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the simulation method for cutting and crushing rock and soil materials considering coordination number and particle shape as described in any one of claims 1 to 7.

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