A method and system for simulating the crushing of irregular particles based on discrete element method

Abstract

The present invention relates to the fields of geotechnical engineering and powder technology, and specifically to a method and system for simulating the crushing of irregular particles based on a discrete element method. The method comprises the following steps: using a rigid cluster model to obtain an irregular particle model; according to the irregular particle model, obtaining the stress state of particles and sub-particles; based on the stress state, obtaining the failure criterion and failure strength of the particles and sub-particles, the failure criterion includes an octahedral shear stress criterion and an improved Brazilian splitting strength criterion; marking a failure area according to the failure criterion and the failure strength; based on the failure area, combining a three-dimensional Voronoi decomposition method, splitting the particles. The present invention greatly improves the simulation accuracy and significantly reduces the calculation cost by comprehensively considering the stress state and crushing process of irregular particles, and effectively solves the problem of the difficulty in balancing the accuracy and calculation efficiency of the simulation of the crushing of irregular-shaped particles in the prior art.

Description

Technical Field

[0001] The invention relates to the fields of geotechnical engineering and powder technology, and in particular to a method and system for simulating the crushing of irregular particles based on a discrete element method. Background Art

[0002] As a powerful numerical simulation tool, the discrete element method can simulate the interaction between particles and the overall behavior of the particle system, so it has significant advantages in studying particle breakage. With the advancement of science and technology and the improvement of engineering needs, higher requirements are placed on the accuracy and efficiency of particle breakage simulation, especially when dealing with irregularly shaped particles.

[0003] In the prior art, the commonly used discrete element methods mainly include the bonded particle model method and the fragment replacement method. The bonded particle model method simulates the crushing behavior by decomposing particles into bonded sub-particles, which can truly reproduce crack propagation and stress distribution, but the shape of the factor particles is mostly spherical, which makes it difficult to accurately describe irregular particles, and the calculation cost is relatively high; the fragment replacement method replaces the broken particles with smaller fragments, which can effectively capture the changes in particle size distribution and generate irregular fragments, but ignores the actual stress state and lacks a mechanical explanation of the crushing mode. Therefore, the main problem of the existing method is that it is difficult to take into account both the accuracy and computational efficiency of the crushing of irregular particles; the bonded particle model method affects the simulation accuracy due to geometric simplification, and the crushing mode preset by the fragment replacement method is difficult to adapt to complex loading conditions, which limits its breadth of application in engineering.

[0004] Currently, there is not enough research work on the simulation of irregular particle crushing, and there is no specific method for simulating the crushing of irregular particles that comprehensively considers the stress state and crushing process of irregular particles. Summary of the invention

[0005] In view of the defects in the prior art, the present invention provides a method and system for simulating the crushing of irregular-shaped particles based on the discrete element method, aiming to solve the problem in the prior art that it is difficult to balance the accuracy and computational efficiency of the simulation of the crushing of irregular-shaped particles.

[0006] In a first aspect, the present invention provides a method for simulating the crushing of irregular particles based on a discrete element method, comprising the following steps: using a rigid cluster model to obtain an irregular particle model; obtaining the stress state of particles and sub-particles based on the irregular particle model; based on the stress state, obtaining the failure criterion and failure strength of the particles and sub-particles, the failure criterion including an octahedral shear stress criterion and an improved Brazilian splitting strength criterion; marking a failure area based on the failure criterion and the failure strength; splitting the particles based on the failure area in combination with a three-dimensional Voronoi decomposition method. The present invention utilizes a rigid cluster model to accurately obtain an irregular particle model, thereby greatly improving the accuracy and authenticity of the simulation, making the study of the crushing behavior of special-shaped particles more in-depth and reliable; by obtaining the stress state of particles and sub-particles, combined with the octahedral shear stress criterion and the improved Brazilian splitting strength criterion, the damage of particles and sub-particles is comprehensively and accurately judged, providing a solid theoretical basis for particle crushing simulation; by marking the failure area and combining the three-dimensional Voronoi decomposition method, effective splitting of particles is achieved, which not only improves the simulation accuracy, but also significantly reduces the calculation cost, effectively solving the problem of difficult balance between accuracy and calculation efficiency in the prior art of irregular shaped particle crushing simulation.

[0007] Optionally, the use of a rigid cluster model to obtain an irregular particle model includes: preliminarily generating model particles through a bubble filling algorithm, wherein the model particles are composed of a plurality of spheres; optimizing the shape of the model particles by adjusting ratio and distance parameters to obtain irregular model particles that conform to the shape of real particles, wherein the ratio parameter represents the ratio of the minimum and maximum radius of the sphere, and the distance parameter represents the average degree of separation between the spheres. The present invention preliminarily generates model particles composed of a plurality of spheres through a bubble filling algorithm, which not only simplifies the construction process of the model particles, but also improves the diversity and flexibility of the particle shapes, and provides a solid foundation for particle shape optimization; by adjusting the ratio parameters, the shape characteristics of the model particles are precisely controlled to make them closer to the morphology of real particles, thereby greatly improving the accuracy and authenticity of the simulation; by adjusting the distance parameters, the internal structure of the model particles is further optimized, so that it not only conforms to the shape characteristics of real particles, but also has higher stability and reliability.

[0008] Optionally, the step of obtaining the stress state of particles and sub-particles according to the irregular particle model includes: calculating the average stress tensor of particles according to the irregular particle model using the contact force between particles and the position vector; calculating the stress tensor of sub-particles according to the irregular particle model using the virtual force balance method, wherein the virtual force balance method eliminates the force imbalance between sub-particles by introducing virtual force and torque. The present invention calculates the average stress tensor of particles by using the contact force between particles and the position vector, accurately reflects the stress state of particles under complex stress environments, provides an important basis for the mechanical behavior analysis of particles, and greatly improves the accuracy and reliability of stress calculation; by introducing the virtual force balance method to calculate the stress tensor of sub-particles, the problem of force imbalance between sub-particles is effectively solved, making the calculation of the stress state of sub-particles more accurate and stable, and providing a powerful tool for in-depth research on the stress distribution inside particles; by combining the characteristics of the irregular particle model, a comprehensive and accurate calculation of the stress state of particles and sub-particles is achieved, which not only improves the accuracy and depth of stress analysis, but also provides a scientific basis for the evaluation and optimization of particle mechanical properties.

[0009] Optionally, the average stress tensor of the particles satisfies the following relationship:

[0010] ,

[0011] in, is the average stress tensor of the particle, is the particle volume, is the contact force, For the The vector from the force point to the particle center, is the total number of force application points; the stress tensor calculation expression of the sub-particle is as follows:

[0012] ,

[0013] in, is the average stress tensor of the sub-particles, is the sub-particle volume, is the contact force, For the The vector from the force point to the center of the sub-particle, is the total number of force application points; the formula of the virtual force balance method is as follows:

[0014] ,

[0015] in, For unbalanced external forces, is the unbalanced external torque, is the normal virtual force, , are different tangential virtual forces, is the distance from the tangent point to the center of the sub-particle, is the normal vector of the external force. The present invention introduces the average stress tensor relationship of the particles to accurately calculate the overall stress state of the particles under a complex stress environment, fully considers the influence of the contact force and the position of the point of action on the particle stress, and improves the accuracy and scientificity of the stress calculation; by constructing a virtual force balance system, including normal virtual force and tangential virtual force, the problem of force imbalance between sub-particles is effectively solved, making the calculation of the stress state of sub-particles more accurate and reliable, providing strong support for in-depth analysis of the internal stress distribution of particles; by combining the geometric and mechanical properties of particles and sub-particles, a comprehensive and accurate description of the stress state is achieved, which not only improves the accuracy of the evaluation of the mechanical properties of the particles, but also provides a scientific basis for the design and optimization of the particle model.

[0016] Optionally, obtaining the destruction criterion and destruction strength of the particle and the sub-particle based on the stress state includes: based on the stress state, using the octahedral shear stress criterion as the overall destruction criterion of the particle; based on the overall destruction criterion, using the improved Brazilian splitting strength criterion as the local destruction criterion of the sub-particle, and the improved Brazilian splitting strength criterion modifies the standard Brazilian splitting strength criterion by introducing the minimum principal stress; based on the overall destruction criterion and the local destruction criterion, combining the Weibull distribution and the size effect, calculating the destruction strength of the particle and the sub-particle. The present invention adopts the octahedral shear stress criterion as the overall destruction criterion of the particle, comprehensively considers the stress conditions of the particle under complex stress state, accurately judges the overall destruction state of the particle, and provides a scientific basis for the analysis of the destruction behavior of the particle; by introducing the improved Brazilian splitting strength criterion as the local destruction criterion of the sub-particle, the destruction problem of the sub-particle under local stress is effectively solved, the accuracy and applicability of the sub-particle destruction criterion are improved, and a powerful tool is provided for in-depth analysis of the destruction mechanism inside the particle; by combining the Weibull distribution with the size effect, the destruction strength of the particle and the sub-particle is calculated, which not only considers the mechanical properties and size characteristics of the particle, but also fully considers the randomness and statistical laws of the particle destruction, so that the calculation of the destruction strength is more accurate and reliable, and provides an important reference for the performance evaluation and design of the particle model.

[0017] Optionally, the breaking strength of the particles satisfies the following expression:

[0018] ,

[0019] in, is the breaking strength of the particle, Particle size The corresponding characteristic crushing strength, is the particle size, is the exponential weight parameter, The present invention introduces the relationship between particle size and characteristic crushing strength, accurately reflects the effect of particle size on its destructive strength, and provides a scientific basis for the evaluation of mechanical properties of particles; by introducing the particle inhomogeneity parameter, the effect of the internal material inhomogeneity of the particle on its destructive strength is fully considered, providing a powerful tool for the in-depth analysis of particle destructive behavior, and also providing an important reference for the design of particle models and performance optimization.

[0020] Optionally, the destructive strength of the sub-particles satisfies the following expression:

[0021] ,

[0022] in, is the destructive strength of the sub-particle, The particle size is The corresponding characteristic crushing strength is is the size of the sub-particle, is the exponential weight parameter, The present invention provides a scientific basis for evaluating the mechanical properties of sub-particles by accurately expressing the relationship between sub-particle size and destructive strength, effectively improving the accuracy and reliability of sub-particle destructive strength prediction; by comprehensively considering the weights of different factors affecting the destructive strength of sub-particles, the calculation of destructive strength is more comprehensive and precise, and the flexibility and applicability of the model are enhanced; by deeply analyzing the influence of the internal material inhomogeneity of sub-particles on their destructive strength, it provides strong support for the exploration of sub-particle destruction mechanisms, and also provides an important reference for the microstructure design and performance optimization of particle models.

[0023] Optionally, the marking of the failure area according to the failure criterion and the failure strength includes: when the stress on the sub-particles in the cluster is greater than the failure strength, marking the position of the sub-particle as a crack initiation point; marking the area formed by the crack initiation point as a failure area. The present invention accurately determines whether the stress on the sub-particle exceeds its failure strength and accurately identifies the initial position of crack initiation, thereby providing key information for the analysis of the failure behavior of the particle model; by marking the area formed by the crack initiation point as a failure area, the internal destruction of the particle material is intuitively displayed, providing a visualization means for in-depth exploration of the failure mechanism, and enhancing the scientificity and intuitiveness of the failure analysis.

[0024] Optionally, the method of splitting particles according to the failure region in combination with the three-dimensional Voronoi dissection method includes: according to the failure region, using the three-dimensional Voronoi dissection method, dividing the particles into a plurality of fragment particles to form a spatial segmentation region; generating new fragment particles according to the spatial segmentation region; replacing the initial particles with the new fragment particles to obtain a replacement result; and splitting the particles through the replacement result. The present invention simulates the actual damage of particles in the process of being subjected to force by accurately identifying the failure region and using the three-dimensional Voronoi dissection method to split the particles, so that the generated fragment particles are more in line with the actual situation, thereby improving the accuracy and credibility of the simulation results; generating new fragment particles through the spatial segmentation region, retaining the microstructural characteristics of the particle model after destruction, and providing more detailed and accurate data support for the analysis of the destruction mechanism and performance evaluation of the particle model; and splitting the particles by replacing the initial particles with new fragment particles, which not only enriches the means of particle simulation, but also provides a powerful tool for predicting the destruction behavior and optimizing the performance of the particle model.

[0025] In the second aspect, the present invention provides a system for simulating the crushing of shaped particles based on the discrete element method, including an input device, a processor, an output device and a memory, wherein the input device, the processor, the output device and the memory are interconnected, wherein the memory is used to store a computer program, the computer program includes program instructions, the processor is configured to call the program instructions, and the system uses the method for simulating the crushing of shaped particles based on the discrete element method. The present invention accurately simulates the crushing process of shaped particles under complex stress environments by integrating multiple technologies such as bubble filling algorithm, rigid cluster model, stress state calculation and failure criterion, and provides a powerful tool for performance evaluation and design optimization of particle models, significantly improving the accuracy and practicality of simulation; by using three-dimensional Voronoi dissection technology to split particles, the microstructure characteristics of particles after destruction are truly reflected, providing rich data support for in-depth analysis of particle crushing mechanism and performance changes, and enhancing the scientificity and depth of simulation. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a flow chart of a method for simulating crushing of irregular particles based on discrete element method according to an embodiment of the present invention;

[0027] Figure 2 A shape diagram of a rigid cluster simulation particle according to an embodiment of the present invention;

[0028] Figure 3 A schematic diagram of sub-particle stress calculation according to an embodiment of the present invention;

[0029] Figure 4 A schematic diagram of particle segmentation according to an embodiment of the present invention;

[0030] Figure 5 A schematic diagram of a particle segmentation result and newly generated fragment particles according to an embodiment of the present invention;

[0031] Figure 6 Schematic diagram of the structure of a system for simulating the crushing of irregular particles based on a discrete element method according to an embodiment of the present invention;

[0032] Figure 7 The present invention is a flowchart of an algorithm for executing a system for simulating the crushing of irregular particles based on a discrete element method according to an embodiment of the present invention. DETAILED DESCRIPTION

[0033] The specific embodiments of the present invention will be described in detail below. It should be noted that the embodiments described herein are only for illustration and are not intended to limit the present invention. In the following description, a large number of specific details are set forth in order to provide a thorough understanding of the present invention. However, it is obvious to those of ordinary skill in the art that these specific details do not need to be adopted to implement the present invention. In other examples, in order to avoid confusing the present invention, known circuits, software or methods are not specifically described.

[0034] Throughout the specification, references to "one embodiment," "an embodiment," "an example," or "an example" mean that a particular feature, structure, or characteristic described in conjunction with the embodiment or example is included in at least one embodiment of the present invention. Therefore, the phrases "in one embodiment," "in an embodiment," "an example," or "an example" appearing in various places throughout the specification do not necessarily all refer to the same embodiment or example. In addition, particular features, structures, or characteristics may be combined in one or more embodiments or examples in any suitable combination and / or subcombination. In addition, it should be understood by those of ordinary skill in the art that the figures provided herein are for illustrative purposes and that the figures are not necessarily drawn to scale.

[0035] See also Figure 1 The embodiment of the present invention provides a method for simulating the crushing of irregular particles based on a discrete element method, the method comprising the following steps:

[0036] S1. Using the rigid cluster model, obtain the irregular particle model.

[0037] In one embodiment, a rigid cluster model is used to model irregular particles to obtain an irregular particle model, such as Figure 2 As shown. The rigid cluster model is a commonly used model in numerical simulation, mainly used to simulate and represent particles or objects with complex shapes and surface characteristics; the model of particles or objects is constructed by combining a series of rigid, non-deformable basic units. The basic units include spheres and ellipsoids, which are closely arranged in the model without mutual penetration or deformation, thereby maintaining the overall rigidity.

[0038] Specifically, firstly, an efficient bubble filling algorithm is selected, such as a random sequence adsorption algorithm; the bubble filling algorithm can simulate the process of spheres being arranged randomly and without overlapping in space.

[0039] Furthermore, the bubble filling algorithm is used to generate irregular particles composed of multiple spheres; for each irregular particle, it is preset to be composed of about 100 spheres; the initial radius of the sphere can be randomly assigned, but it should be ensured that the overall shape can approximate the surface characteristics of the real particle, such as Figure 2 As shown in (c) in .

[0040] For further information, see Figure 2 In (a), the particle shape is optimized by adjusting the ratio and distance parameters, where the ratio parameter represents the ratio of the minimum and maximum values ​​of the sphere radius, and the distance parameter represents the average separation between the spheres. The ratio parameter is used to control the roughness and uniformity of the particle shape; a smaller ratio means that the sphere radius is closer and the resulting particle shape is more uniform; a larger ratio will produce a rougher and irregular shape. The distance parameter is used to control the smoothness of the particle surface; a smaller distance parameter value will make the particle surface more compact and smoother, while a larger distance parameter value will produce a looser and rougher surface. Figure 2 In (a), Ratio means ratio, and Distance means distance, which is indirectly measured by angle. represents the maximum value of the sphere radius, represents the minimum value of the sphere radius, , They all represent the angle between the tangent lines of the two related spheres. It represents the average value of the angles between all the tangent lines of two spheres.

[0041] Further, a scanned image of the optimized particle shape is generated and compared with the actual particle surface for verification. Figure 2 As shown in (b), after comparison, the geometric accuracy of the scanned image is relatively high.

[0042] S2. According to the irregular particle model, the stress state of the particle and the sub-particle is obtained.

[0043] Among them, S2 includes the following steps:

[0044] S21. According to the irregular particle model, the average stress tensor of the particles is calculated using the contact force between the particles and the position vector.

[0045] In one embodiment, based on the condition that the particles are subjected to external loads, the average stress tensor of the particles is calculated using the contact force between the particles and the position vector, and the average stress tensor satisfies the following relationship:

[0046] ,

[0047] in, is the stress tensor of the particle, is the particle volume, is the contact force, For the The vector from the force point to the particle center, is the total number of force application points.

[0048] Furthermore, by analyzing the average stress tensor, the overall stress state of the particle is obtained.

[0049] S22. According to the irregular particle model, the stress tensor of the sub-particle is calculated using the virtual force balance method.

[0050] In one embodiment, for each sub-particle in the cluster, a virtual force and torque are introduced through a virtual force balance method to eliminate the force imbalance between the sub-particles and ensure the accuracy of the stress tensor calculation. It should be noted that when the sub-particles in the rigid cluster are analyzed independently, the interaction forces between the sub-particles are not considered, so the stress tensor is calculated under the condition of unbalanced external forces. Therefore, it is necessary to introduce virtual forces to balance the stress state of the sub-particles.

[0051] Specifically, see Figure 3 , Figure 3 (a) in the figure shows the radial cross section of the sub-particles in the cluster, and the gray area shows the radial cross section of sub-particles of different sizes. Figure 3 (b) in the figure shows the force diagram of the sub-particles in the cluster. First, we simplify the unbalanced external force on the sub-particles as Straight line and an unbalanced external torque .

[0052] Furthermore, by adding a normal virtual force Effect on balance and add tangential virtual force , At point and Balance , so that the sub-particles are in equilibrium.

[0053] Specifically, the formula of the virtual force balance method is as follows:

[0054] ,

[0055] in, For unbalanced external forces, is the unbalanced external torque, is the normal virtual force, , are different tangential virtual forces, is the distance from the tangent point to the center of the sub-particle, is the external force normal vector.

[0056] Furthermore, when the sub-particles are in a state of equilibrium, the average stress tensor of each sub-particle is calculated, and the specific calculation expression is as follows:

[0057] ,

[0058] in, is the average stress tensor of the sub-particles, is the sub-particle volume, is the contact force, For the The vector from the force point to the center of the sub-particle, is the total number of force application points;

[0059] Furthermore, by analyzing the average stress tensor of the sub-particles, the stress state of the sub-particles is obtained.

[0060] S3. Based on the stress state, the failure criterion and failure strength of the particle and the sub-particle are obtained, wherein the failure criterion includes an octahedral shear stress criterion and an improved Brazilian splitting strength criterion.

[0061] Among them, S3 includes the following steps:

[0062] S31. Based on the stress state, obtain the failure criterion and failure strength of the particle.

[0063] In one embodiment, the octahedral shear stress criterion is used as the failure criterion of the entire particle, and its calculation formula is as follows:

[0064]

[0065] in, is the octahedral shear stress, , , is the principal stress value corresponding to the stress tensor of different particles; when the octahedral shear stress Exceeding the breaking strength of particles When the particle is completely destroyed, the particle is destroyed. The calculation process is as follows:

[0066] First, consider the heterogeneity of particles:

[0067]

[0068] in, The particle size is The inhomogeneity parameter at , which is used to measure the inhomogeneity of particles, is the characteristic crushing strength of the particle, is the exponential weight parameter, is the stress on the particle.

[0069] Furthermore, the size effect of particles is considered:

[0070]

[0071] in, The particle size is The stress on The particle size is Characteristic crushing strength.

[0072] Furthermore, combining the above expressions considering the heterogeneity and size effect of particles, the expression of the particle's destructive strength is obtained, which is as follows:

[0073] ,

[0074] in, is the breaking strength of the particle, Particle size The corresponding characteristic crushing strength, is the particle size, is the exponential weight parameter, is the particle inhomogeneity parameter.

[0075] S32. Based on the stress state, obtain the destruction criterion and destruction strength of the sub-particle.

[0076] In one embodiment, firstly, based on step S22, the sub-particle stress is calculated. .

[0077] Furthermore, the improved Brazilian splitting strength criterion is used as the local destruction criterion of the sub-particles to calculate the maximum tensile stress of the sub-particles. It should be noted that when considering the actual stress state of the sub-particles, the simple Brazilian splitting test may underestimate the destruction stress. Therefore, it is necessary to modify the standard criterion by introducing the minimum principal stress to make it more applicable to the actual particle crushing problem. Therefore, the maximum tensile stress satisfies the following relationship:

[0078]

[0079] in, is the maximum tensile stress of the sub-particle, , are the maximum principal stress and minimum principal stress of the sub-particles, respectively. Exceeding its breaking strength When the particle size is smaller than 0.05 mm, the particle size will be partially failed.

[0080] Further, based on the above expression of maximum tensile stress, combined with the expression considering the particle heterogeneity and size effect in step S31, the expression of sub-particle destructive strength is obtained, which is as follows:

[0081] ,

[0082] in, is the destructive strength of the sub-particle, The particle size is The corresponding characteristic crushing strength is is the size of the sub-particle, is the exponential weight parameter, is the inhomogeneity parameter of the sub-particles.

[0083] S4. Mark the failure area according to the failure criterion and the failure strength.

[0084] In one embodiment, firstly, based on step S3, particles or sub-particles satisfying the destruction condition are determined, and then the particles are split in combination with the three-dimensional Voronoi decomposition method.

[0085] Specifically, the sub-particles in the cluster that exceed the failure strength are determined by stress state evaluation, and their positions are marked as crack initiation points, i.e., seed points. The marking of their local failure areas is shown in the figure below. Figure 4 As shown in (a) in the figure. Among them, the seed point , , Located at the center of the connecting fracture area O and the sub-particle mass center respectively , , The straight lines intersect with the particle edges at points , , , the seed point , , are set as line segments , , The midpoint of the particle is ensured to be located inside the particle and consistent with the direction of crack propagation.

[0086] Furthermore, according to the above marking process, the marking results of the local failure area are obtained, such as Figure 4 As shown in (b) in .

[0087] S5. Splitting the particles based on the failure region in combination with the three-dimensional Voronoi decomposition method.

[0088] In one embodiment, a three-dimensional Voronoi decomposition technique is used to generate a crushing surface and divide the particle into multiple fragments. Specifically, the Voronoi decomposition method is used to generate a spatial segmentation region, and the fragment shape is determined by geometric calculation, such as Figure 5 As shown, Figure 5 (a) in the figure represents the whole particle before segmentation. Figure 5 (b) in the figure shows the fragmented particles after dissection.

[0089] See also Figure 6 , Figure 6 The structure diagram of a system for simulating the crushing of irregular particles based on the discrete element method in an embodiment of the present invention is shown in FIG. The system includes an input device, a processor, an output device, and a memory, wherein the input device, the processor, the output device, and the memory are interconnected, wherein the memory is used to store a computer program, the computer program includes program instructions, and the processor is configured to call the program instructions. The system uses the method for simulating the crushing of irregular particles based on the discrete element method, and the specific execution process is as follows: Figure 7 As shown. First, the initial particles are generated, and a destruction strength value is assigned to each particle and its sub-particles. The particle strength is calculated according to the proposed strength theory. During the simulation process, the stress state, destruction condition and contact information of the particles are monitored at regular time steps (such as 100 steps). When the particles or sub-particles meet the destruction conditions, the crushing operation is performed to generate fragments and replace the original particles, and the destruction strength value and contact information of the fragments are updated. The above process is repeated until the end of the simulation, and the particle crushing process and particle size distribution results are finally output. This process can accurately simulate the crushing behavior of irregular particles under external loads and significantly improve the calculation efficiency. It is suitable for particle crushing research and engineering applications in geotechnical engineering, powder technology and other fields.

[0090] In this embodiment, the input device includes a user interaction interface and an interface, wherein the user interaction interface includes a keyboard, a mouse and a touch screen for inputting parameters of particles or sub-particles, wherein the parameters include shape, size, quantity and material property parameters; the interface includes a USB interface and a network interface for importing particle or sub-particle related data.

[0091] The core components of the processor simulation system include high-performance computer hardware and corresponding software systems; the computer hardware includes CPU and GPU, and the software system includes discrete element simulation software; the processor is responsible for receiving parameters and data provided by the input device, and performing calculations and analyses according to the discrete element method, and can simulate the movement, deformation and fragmentation behavior of particles during force application, and calculate the interaction force and energy transfer between particles; analysis and prediction can also be performed based on the simulation results, such as calculating the fragmentation rate and energy consumption performance indicators of the particles.

[0092] The output device includes a display and a printer for displaying simulation results and outputting reports; the display is used to display in real time the particle movement, deformation and crushing during the simulation process, as well as charts and images of the simulation results; the printer is used to print out the simulation results and reports for users to archive and share.

[0093] In summary, the present invention provides a method for simulating the crushing of irregular particles based on the discrete element method. By utilizing a rigid cluster model, an irregular particle model is accurately obtained, thereby greatly improving the accuracy and authenticity of the simulation, making the study of the crushing behavior of irregular particles more in-depth and reliable; by obtaining the stress state of particles and sub-particles, combined with the octahedral shear stress criterion and the Brazilian splitting strength criterion, the damage of particles and sub-particles is comprehensively and accurately judged, providing a solid theoretical basis for particle crushing simulation; by marking the failure area and combining the three-dimensional Voronoi decomposition method, effective splitting of particles is achieved, which not only improves the simulation accuracy, but also significantly reduces the calculation cost, effectively solving the problem of difficult balance between accuracy and calculation efficiency in the prior art of irregular shaped particle crushing simulation.

[0094] The present invention provides a special-shaped particle crushing simulation system based on the discrete element method, which can accurately simulate the crushing behavior of irregular particles under external loads and significantly improve the calculation efficiency. It is suitable for particle crushing research and engineering applications in the fields of geotechnical engineering and powder technology.

[0095] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents. These modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be included in the scope of the claims and specification of the present invention.

Claims

1. A method for simulating the crushing of irregular particles based on discrete element method, characterized in that: The method comprises the following steps: Using a rigid cluster model, an irregular particle model is obtained; Using a rigid cluster model, the irregular particle model is obtained including: preliminarily generating model particles by a bubble filling algorithm, wherein the model particles are composed of a plurality of spheres; optimizing the shape of the model particles by adjusting ratio and distance parameters to obtain irregular model particles that conform to the shape of real particles, wherein the ratio parameter represents the ratio of the minimum radius to the maximum radius of the sphere, and the distance parameter represents the average separation degree between the spheres; According to the irregular particle model, obtaining the stress state of the particle and the sub-particle; Based on the stress state, the failure criterion and failure strength of the particle and the sub-particle are obtained, and the failure criterion includes an octahedral shear stress criterion and an improved Brazilian splitting strength criterion; based on the stress state, the failure criterion and failure strength of the particle and the sub-particle are obtained, including: based on the stress state, using the octahedral shear stress criterion as the overall failure criterion of the particle; based on the overall failure criterion, using the improved Brazilian splitting strength criterion as the local failure criterion of the sub-particle, and the improved Brazilian splitting strength criterion modifies the standard Brazilian splitting strength criterion by introducing the minimum principal stress; based on the overall failure criterion and the local failure criterion, the failure strength of the particle and the sub-particle is calculated in combination with Weibull distribution and size effect; Marking a failure area according to the failure criterion and the failure intensity; According to the failure region, the particles are split in combination with the three-dimensional Voronoi decomposition method.

2. The method for simulating the crushing of irregular particles based on discrete element method according to claim 1, characterized in that: The step of obtaining the stress state of the particle and the sub-particle according to the irregular particle model includes: According to the irregular particle model, the average stress tensor of the particles is calculated using the inter-particle contact force and the position vector; According to the irregular particle model, the stress tensor of the sub-particle is calculated using a virtual force balance method, and the virtual force balance method eliminates the force imbalance between the sub-particles by introducing virtual force and torque.

3. The method for simulating the crushing of irregular particles based on discrete element method according to claim 2, characterized in that: The average stress tensor of the particles satisfies the following relationship: in, is the average stress tensor of the particle, is the particle volume, is the contact force, For the The vector from the force point to the particle center, is the total number of force application points; the stress tensor calculation expression of the sub-particle is as follows: in, is the average stress tensor of the sub-particles, is the sub-particle volume, is the contact force, For the The vector from the force point to the center of the sub-particle, is the total number of force application points; the formula of the virtual force balance method is as follows: in, For unbalanced external forces, is the unbalanced external torque, is the normal virtual force, , are different tangential virtual forces, is the distance from the tangent point to the center of the sub-particle, is the stress tensor.

4. The method for simulating the crushing of irregular particles based on discrete element method according to claim 1, characterized in that: The destructive strength of the particles satisfies the following expression: in, is the breaking strength of the particle, The initial particle size The corresponding characteristic crushing strength, is the particle size, is the exponential weight parameter, is the particle inhomogeneity parameter.

5. The method for simulating the crushing of irregular particles based on discrete element method according to claim 1, characterized in that: The destructive strength of the sub-particles satisfies the following expression: in, is the destructive strength of the sub-particle, The particle size is The corresponding characteristic crushing strength is is the size of the sub-particle, is the exponential weight parameter, is the inhomogeneity parameter of the sub-particles.

6. The method for simulating the crushing of irregular particles based on discrete element method according to claim 1, characterized in that: The marking of the failure area according to the damage criterion and the damage strength comprises: When the stress on the sub-particles in the cluster is greater than the breaking strength, the position of the sub-particles is marked as the crack initiation point; The area formed by the crack initiation point is marked as the failure area.

7. The method for simulating the crushing of irregular particles based on discrete element method according to claim 1, characterized in that: The step of splitting the particles based on the failure region and in combination with the three-dimensional Voronoi decomposition method comprises: According to the failure region, the particle is divided into a plurality of fragment particles by using a three-dimensional Voronoi decomposition method to form a spatial segmentation region; generating new fragment particles according to the spatial segmentation region; Using the new fragment particles to replace the initial particles to obtain a replacement result; As a result of the replacement, the particles are split.

8. A system for simulating the crushing of irregular particles based on discrete element method, the system using the method for simulating the crushing of irregular particles based on discrete element method according to any one of claims 1 to 7, characterized in that: The system includes an input device, a processor, an output device and a memory, wherein the input device, the processor, the output device and the memory are connected to each other, wherein the memory is used to store a computer program, the computer program includes program instructions, and the processor is configured to call the program instructions.

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