Numerical simulation method and system for whole process of ore rock fracture based on FDEM impact load

Abstract

The invention relates to the technical field of numerical simulation of rock dynamics, in particular to a numerical simulation method and system for the whole process of ore rock fracture based on FDEM impact loads.The method comprises the steps that a continuous medium structure is discretized into a finite element network composed of triangular units through FDEM, and an ore rock impact test model is constructed; setting material parameters and impact speed boundary conditions according to the ore rock impact test model; a normal contact force calculation model and a tangential contact force calculation model are established according to material parameters and impact speed boundary conditions, and coordinates and speed updating results of triangular unit nodes are obtained in combination with the Newton second law and the calculation models; and performing visual analysis based on the coordinate and speed updating result, and outputting crack propagation, stress field and energy evolution results under the impact load. The method can accurately simulate the crack propagation, the fracture mode and the energy evolution law of the ore rock under the impact load, quantitatively researches the crushing characteristics and the energy evolution law of the ore rock, and provides a calculation method for the research of the crushing mechanism of the ore rock.

Description

Technical Field

[0001] This invention relates to the field of numerical simulation technology of rock dynamics, specifically to a numerical simulation method and system for the entire process of rock and ore fracture under FDEM impact loading. Background Technology

[0002] In the fields of mining engineering and rock mechanics, the dynamic fracturing process of ore and rock under impact load is a key research topic. Traditional experimental methods, such as the split Hopkinson bar (SHPB) test, can present the dynamic mechanical properties of materials, but they are difficult to fully capture the entire process of crack initiation, expansion, and energy evolution.

[0003] Numerical simulation, as the third major method in rock mechanics research after theory and experiment, can be divided into several types: continuous, discontinuous, and continuous-discontinuous coupled. Among them, the continuous method is represented by the finite element method (FEM), while the discontinuous method is mainly represented by the discrete element method (DEM). The finite element method (FEM) is based on the assumption of continuous medium and performs well in simulating the stress-strain behavior of minerals and rocks. However, it has insurmountable limitations when simulating discontinuous phenomena such as crack propagation and block separation. The discrete element method (DEM) can simulate the motion and interaction of blocks, but its accuracy is somewhat lacking when describing the stress propagation and deformation behavior of continuous media.

[0004] To overcome the limitations of single-method approaches, a finite-discrete element coupled method (FDEM) was proposed. This method can simulate the stress-strain behavior of continuous media as well as handle the contact and separation problems of discontinuous bodies. However, some problems still exist when using numerical simulation to solve the rock and ore fracturing process under impact loads: First, the computational load is huge due to the shared node elements in traditional numerical simulation of continuous media structures; second, the numerical simulation results are extremely sensitive to the values ​​of joint element penalty parameters, and the parameter calibration process is cumbersome and complex; third, the crack propagation path is highly dependent on the mesh generation method.

[0005] To address the problem of accurately simulating crack propagation, fracture modes, and energy evolution in rocks under impact loads, a more precise numerical simulation method is needed. Summary of the Invention

[0006] To address the shortcomings of existing methods and their limitations in practical applications, the following issues urgently need to be resolved when using numerical simulation to solve the rock fracturing process under impact loading: First, traditional numerical simulations employ continuous medium structures and solve using shared node elements, resulting in an extremely large computational load and increasing computational costs and time. Second, the numerical simulation results are highly sensitive to the values ​​of joint element penalty parameters; even small changes in these parameters can significantly affect the results, leading to a complex and cumbersome parameter calibration process. Third, the crack propagation path is largely constrained by the mesh generation method; different mesh generation methods yield drastically different crack propagation paths, affecting the accuracy and reliability of the simulation results.

[0007] To address the aforementioned problems, the present invention provides a numerical simulation method for the entire process of rock and ore fracture under impact loading based on FDEM. The method includes the following steps: discretizing the continuous medium structure into a finite element network composed of triangular elements using FDEM; constructing a rock and ore impact test model based on the finite element network; setting material parameters and impact velocity boundary conditions based on the rock and ore impact test model; establishing a normal contact force calculation model and a tangential contact force calculation model based on the material parameters and the impact velocity boundary conditions; obtaining the coordinates and velocity update results of the triangular element nodes by combining Newton's second law, the normal contact force calculation model, and the tangential contact force calculation model; and performing visualization analysis based on the coordinates and velocity update results to output the crack propagation, stress field, and energy evolution results under impact loading.

[0008] The method of this invention is a complete and systematic simulation process. From model construction to parameter setting, mechanical calculation and result analysis, each link is closely connected and cooperates with each other, which helps to improve simulation efficiency and accuracy, reduce errors caused by incoordination between links, and obtain various response results of ore and rock under impact load more quickly and accurately.

[0009] Optionally, the discretization of the continuous medium structure into a finite element network composed of triangular elements using FDEM, and the construction of a rock impact test model based on the finite element network, includes: introducing a three-dimensional finite element mesh generator Gmsh; constructing a rock impact test model using the three-dimensional finite element mesh generator Gmsh and the finite element network; and dividing the rock impact test model into a mesh using an unstructured Delauney triangulation algorithm, inserting joint elements in the boundaries of adjacent elements to simulate crack initiation and propagation in the rock impact test model.

[0010] The three-dimensional finite element mesh generator of this invention can generate high-quality three-dimensional finite element meshes, providing a foundation for subsequent simulation analysis and helping to improve the accuracy of simulation results.

[0011] Optionally, setting material parameters and impact velocity boundary conditions based on the rock impact test model includes: acquiring indoor experimental data; setting mechanical parameters of triangular elements based on the indoor experimental data, the mechanical parameters of triangular elements including elastic modulus, Poisson's ratio, and density; setting microscopic parameters of joint elements based on the indoor experimental data, the microscopic parameters of joint elements including tensile strength, cohesion, internal friction angle, and joint element fracture energy release rate; and setting penalty parameters with reference to the indoor experimental data, the penalty parameters including normal penalty parameters, tangential penalty parameters of triangular elements, and penalty parameters of joint elements.

[0012] This invention rationally sets material parameters and penalty parameters, providing reasonable initial conditions and parameter ranges for numerical calculations, which helps to optimize the calculation process, improve calculation convergence, and ensure that the simulation can be completed smoothly and obtain reliable results.

[0013] Optionally, establishing the normal contact force calculation model and the tangential contact force calculation model based on the material parameters and the impact velocity boundary conditions includes: calibrating the fracture energy based on the material parameters and the impact velocity boundary conditions, wherein the fracture energy includes the type I fracture energy release rate. and Type II fracture energy release rate The fracture energy of this invention can describe the key parameter of energy dissipation in materials during crack propagation, which is consistent with the physical nature of material fracture mechanics and enhances the physical rationality of the model.

[0014] Optionally, establishing the normal contact force calculation model and the tangential contact force calculation model based on the material parameters and the impact velocity boundary conditions includes: introducing MultiFracS software and the NBS contact algorithm; performing contact judgment based on the MultiFracS software, the NBS contact algorithm, the fracture energy, the material parameters, and the impact velocity boundary conditions to obtain the contact situation of triangular elements in adjacent meshes; and establishing a contact force calculation model based on the contact situation, wherein the contact force calculation model includes a normal contact force calculation model and a tangential contact force calculation model.

[0015] The software of this invention can make full use of computer hardware resources, improve calculation speed, reduce calculation time, and improve simulation efficiency.

[0016] Optionally, the normal contact force calculation model satisfies the following relationship: , in, For normal contact force, For normal penalty parameters, One of two adjacent triangular units It is the other one of two adjacent triangular units. For gradient, for Dot at The momentum, For overlapping regions and At a point within the intersection, for Dot at The momentum, For overlapping regions and At a point within the intersection, Let be the area of ​​the overlapping portion of the triangular units. Let be the vector representing the direction of the outward normal to the overlapping portion. For contact triangle The outer boundary of the overlapping portion, For unit Potential function on, For unit Potential function on.

[0017] This invention calculates the normal contact force using a potential function and a normal penalty parameter, which can effectively analyze the energy state of an object in a force field and reflect the interaction energy between two contacting bodies. This combination makes the calculation process of the normal contact force clearer and can more accurately reflect the nature of the force during the contact process.

[0018] Optionally, the step of establishing a contact force calculation model based on the contact situation, wherein the contact force calculation model includes a normal contact force calculation model and a tangential contact force calculation model, includes: setting the relative misalignment condition between two adjacent triangular units according to Coulomb's friction law; and establishing a tangential contact force calculation model by combining the contact situation and the relative misalignment condition. The relative misalignment condition satisfies the following relationship: , in, for Tangential contact force at moment, For normal contact force, The relevant friction angle; The tangential contact force calculation model satisfies the following relationship: , in, for Tangential contact force at moment, For the damping of the element node, It is the normal contact force.

[0019] The model of this invention takes into account the generation and change mechanism of tangential force during the contact process, and can realistically reflect the interaction between two contacting bodies in the tangential direction, and can more accurately simulate the tangential mechanical behavior in the actual contact process.

[0020] Optionally, the step of combining Newton's second law, the normal contact force calculation model, and the tangential contact force calculation model to obtain the coordinate and velocity update results of the triangular element node includes: introducing Newton's second law; and obtaining the coordinate and velocity update results of the triangular element node based on Newton's second law, the normal contact force calculation model, and the tangential contact force calculation model.

[0021] This invention uses Newton's second law to accurately analyze how normal and tangential contact forces affect the acceleration of triangular unit nodes, and thus their velocity and coordinates, which helps to deepen the understanding of the mechanical behavior of objects during contact.

[0022] Optionally, the step of obtaining the coordinate and velocity update results of the triangular element nodes based on Newton's second law, the normal contact force calculation model, and the tangential contact force calculation model includes: The coordinate and velocity update results satisfy the following relationship: , in, for The speed of time, for The speed of time, For total nodal force, For time step, For the quality of the node, for The distance of time, for The distance of time.

[0023] The normal contact force calculation model and the tangential contact force calculation model of this invention describe the force action during the contact process from different directions, so that this method can more comprehensively and accurately reflect the influence of contact on the motion of the triangular element nodes, thereby more realistically simulating actual contact mechanics.

[0024] Secondly, this invention also provides a numerical simulation system for the entire process of rock and ore fracture under FDEM impact loading. This system can efficiently execute the numerical simulation method for the entire process of rock and ore fracture under FDEM impact loading provided by this invention. The system includes an input device, a processor, an output device, and a memory, wherein the input device, processor, output device, and memory are interconnected. The memory includes a computer-readable storage medium as described in the first aspect of this invention. The memory is used to store a computer program, which includes program instructions. The processor is configured to call the program instructions. The numerical simulation system for the entire process of rock and ore fracture under FDEM impact loading provided by this invention has a compact structure, strong applicability, and greatly improves operating efficiency. Attached Figure Description

[0025] Figure 1 This is a flowchart of the numerical simulation method for the entire process of rock and ore fracture under FDEM impact loading according to the present invention. Figure 2 This is a schematic diagram illustrating the basic principle of FDEM in this invention; Figure 3 This is a schematic diagram of the SHPB impact model of the present invention; Figure 4 This is a schematic diagram of the joint element fracture constitutive model of the present invention; Figure 5 This is a schematic diagram of the contact forces between the triangular units of the present invention; Figure 6 This is a cloud map showing the displacement changes during the rock and ore fracturing process under impact load, as presented in this invention. Figure 7 This is a schematic diagram illustrating the crack rose diagram of the present invention, showing the characteristics of crack direction distribution. Figure 8 This is a schematic diagram of the numerical simulation system for the entire process of rock and ore fracture under FDEM impact loading, based on the present invention. Detailed Implementation

[0026] Specific embodiments of the present invention will now be described in detail. It should be noted that the embodiments described herein are for illustrative purposes only and are not intended to limit the invention. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the invention. However, it will be apparent to those skilled in the art that these specific details are not necessary to practice the invention. In other instances, well-known circuits, software, or methods have not been specifically described to avoid obscuring the invention.

[0027] Throughout this specification, references to "an embodiment," "an embodiment," "an example," or "an example" mean that a particular feature, structure, or characteristic described in connection with that embodiment or example is included in at least one embodiment of the invention. Therefore, the phrases "in an embodiment," "in an embodiment," "an example," or "an example" appearing in various places throughout the specification do not necessarily refer to the same embodiment or example. Furthermore, specific features, structures, or characteristics can be combined in one or more embodiments or examples in any suitable combination and / or sub-combination. Moreover, those skilled in the art will understand that the illustrations provided herein are for illustrative purposes and are not necessarily drawn to scale.

[0028] Please see Figure 1 To accurately simulate the crack propagation path, fracture mode characteristics, and energy evolution over time in ore and rock under impact loads, and to provide an information foundation for understanding key issues such as ore and rock fracture mechanisms and optimizing mine mining and protection design, this invention provides a numerical simulation method for the entire process of ore and rock fracture under FDEM impact loads. The method includes the following steps: S1. Discretize the continuous medium structure into a finite element network composed of triangular elements using FDEM. Construct a rock impact test model based on the finite element network. The implementation details are as follows: A three-dimensional finite element mesh generator, Gmsh, was introduced, and a rock impact test model was constructed using Gmsh and finite element networks.

[0029] The core idea of ​​FDEM is to discretize the continuous medium structure into a finite element network composed of triangular elements. For a schematic diagram of the basic principle of FDEM, please refer to [link to schematic diagram]. Figure 2 ,based on Figure 2 As can be seen, the FDEM includes a topological structure of triangular elements and joint elements to simulate the dynamic response and fracture failure process of rock and ore under impact loading. To achieve the above objectives, a three-dimensional finite element mesh generator, Gmsh, was introduced in this embodiment. Its mesh generation function was used to initially construct the basic model framework for the Rock and Ore Impact Test (SHPB). For the SHPB impact model, please refer to [link to relevant documentation]. Figure 3 Where H is the height of the simulated specimen, The length of the rod, The diameter is the rod diameter.

[0030] The unstructured Delauney triangulation algorithm was used to divide the mesh in the rock impact test model, and joint elements were inserted in the boundaries of adjacent elements to simulate crack initiation and propagation in the rock impact test model.

[0031] To ensure that the model can accurately simulate the actual characteristics of the ore and rock, this embodiment uses the unstructured Delauney triangulation algorithm to mesh the ore and rock impact test model. The unstructured mesh has better adaptability and can better fit the complex shape and internal structure of the ore and rock, thereby improving the accuracy of the simulation results.

[0032] After mesh generation, joint elements are inserted at the boundaries of adjacent elements. The introduction of joint elements is a crucial step in simulating discontinuities in ore and rock using the FDEM method. Ore and rock inherently contain various natural joints and fractures, and these discontinuities become the starting points for crack initiation and propagation under impact loading. Inserting joint elements effectively simulates the mechanical behavior of these discontinuities in ore and rock, allowing the ore and rock impact test model to accurately demonstrate the dynamic evolution of cracks, including key information such as crack initiation location, propagation direction, and propagation velocity.

[0033] S2. Based on the rock impact test model, set the material parameters and impact velocity boundary conditions, the specific contents of which are as follows: Acquire indoor experimental data. Based on a series of indoor experiments, key data for setting model parameters were obtained. The aforementioned indoor experimental data includes, but is not limited to, various mechanical parameters of triangular elements and joint elements, providing a basis for subsequent model parameter settings.

[0034] I. Setting the mechanical parameters of the triangular element Relevant mechanical parameters were extracted from indoor experimental data to set the parameters of the triangular element. The main mechanical parameters of the triangular element include elastic modulus, Poisson's ratio, and density, which are respectively represented by... , and By accurately inputting the corresponding experimental data during the model setup process, it can be ensured that the mechanical properties of the triangular unit are consistent with the continuous medium part of the actual ore and rock.

[0035] II. Setting the micro-parameters of joint elements The microscopic parameters of the joint element were set based on indoor experimental data. These parameters included tensile strength, cohesion, internal friction angle, and fracture energy release rate. These parameters were determined using [methods not specified in the original text]. , , , and This indicates that the relevant parameters can accurately describe the mechanical behavior of joint elements, especially in simulating the propagation and fracture process of joints and fissures in ore under impact loads. This allows the model to realistically reflect the discontinuous characteristics of ore. The embodiment constructs a joint element fracture constitutive model; please refer to the details for further information. Figure 4 Where xyz is the Cartesian three-dimensional coordinate system, Figure 4The paper presents a joint element fracture constitutive model that includes three failure modes: mode I is tension (I), mode II is shear (II), and mode III is mixed (III).

[0036] III. Setting Penalty Parameters The penalty parameters in the model were set based on indoor experimental data. These penalty parameters include the normal penalty parameters for the triangular elements. Tangential penalty parameters and the penalty parameters of the joint elements The aforementioned penalty parameters play a crucial role in the FDEM method. They can be used to control the contact behavior between units, ensuring that the model can reasonably handle the interaction forces between units during the simulation process, avoiding unreasonable penetration or excessive separation, thereby improving the stability and accuracy of the simulation and enabling the model to better simulate the dynamic response of ore and rock under impact loads.

[0037] IV. Setting Impact Velocity Boundary Conditions After completing the above material parameter settings, based on the actual impact scenario and referring to relevant experimental or engineering data, further set impact velocity boundary conditions for the model. It is necessary to clarify key information such as the speed, direction, and duration of the impact load, so as to ensure that the model can accurately simulate the entire process of rock fracture under impact load under the set boundary conditions.

[0038] S3. Based on material parameters and impact velocity boundary conditions, establish normal contact force calculation models and tangential contact force calculation models. Combining Newton's second law, the coordinates and velocity update results of the triangular element nodes are obtained. The specific implementation details are as follows: First, a calculation model for normal contact force and a calculation model for tangential contact force are established based on material parameters and impact velocity boundary conditions.

[0039] The first step is to calibrate the fracture energy based on material parameters and impact velocity boundary conditions. The fracture energy includes the mode I fracture energy release rate. and Type II fracture energy release rate .

[0040] This embodiment calibrates the fracture energy based on material parameters and impact velocity boundary conditions. The fracture energy includes Type I fracture energy release rate and Type II fracture energy release rate. In the adaptive FDEM method used in this invention, it is not necessary to obtain the optimal joint penalty parameter value in advance through complex calibration to achieve the same simulation effect as the optimal parameter value, which can save the joint penalty parameter calibration time.

[0041] Among them, the type I fracture energy release rate The main control joint element is the tensile failure, and the type II fracture energy release rate is... The main control joint element is shear failure, and the two work together to determine the failure mode of the entire continuum element. In this embodiment, through extensive trial and error and repeated verification, it has been found that when… and At that time, the numerical simulation results were in high agreement with the mechanical test results.

[0042] The second step involves introducing the MultiFracS software and the NBS contact algorithm. Since applying stress boundary loads requires complex reprogramming in the MultiFracS secondary development port, this embodiment uses velocity boundary loads to apply impact loads, employs MultiFracS software for FDEM solving, and uses the NBS contact algorithm for contact determination.

[0043] The third step involves determining the contact status of triangular elements within adjacent meshes using MultiFracS software, the NBS contact algorithm, fracture energy, material parameters, and the impact velocity boundary conditions.

[0044] In this embodiment, based on MultiFracS software, NBS contact algorithm, fracture energy, material parameters, and impact velocity boundary conditions, the entire solution domain is divided into triangular meshes. Only the contact situation of triangular elements within adjacent meshes is determined, thereby obtaining the contact information of triangular elements within adjacent meshes.

[0045] The fourth step is to establish a contact force calculation model based on the contact conditions. This model includes both normal and tangential contact force calculation models. For details on the distribution of normal and tangential contact forces, please refer to [link to relevant documentation]. Figure 5 Among them, 1, 2, 3, , D and D are the three vertices of two adjacent triangular units, For two adjacent triangular units, Let be the overlap distance between two contact triangle elements in the normal direction. The outer boundary of the overlapping part I. Constructing a calculation model for normal contact force The normal contact force is obtained by the surface integral of the gradient of the potential function in the overlapping region. The above calculation model for the normal contact force satisfies the following relationship: , in, For normal contact force, For normal penalty parameters, One of two adjacent triangular units It is the other one of two adjacent triangular units. For gradient, for Dot at The momentum, For overlapping regions and At a point within the intersection, for Dot at The momentum, For overlapping regions and At a point within the intersection, Let be the area of ​​the overlapping portion of the triangular units. Let be the vector representing the direction of the outward normal to the overlapping portion. For contact triangle The outer boundary of the overlapping portion, For unit Potential function on, For unit Potential function on.

[0046] II. Constructing a tangential contact force calculation model In this embodiment, the relative misalignment condition between two adjacent triangular elements is set according to Coulomb's law of friction. The above relative misalignment condition satisfies the following relationship: , in, for Tangential contact force at moment, For normal contact force, The relevant friction angle.

[0047] The tangential contact force is solved using the penalty function principle. The formula for solving the tangential contact force using the penalty function principle is as follows: , in, for Tangential contact force at moment, for Tangential contact force at moment, For tangential penalty parameters, for The displacement increment within a given time period This represents the current time step.

[0048] According to Coulomb's law of friction, the relative dislocation condition must be satisfied... When two adjacent contacting triangular elements are in contact, relative misalignment will occur, resulting in relative displacement. Combining the contact conditions and the relative misalignment condition, the tangential contact force calculation model satisfies the following relationship: , in, for Tangential contact force at moment, For the damping of the element node, It is the normal contact force.

[0049] Then, by combining Newton's second law, the normal contact force calculation model, and the tangential contact force calculation model, the coordinates and velocity updates of the triangular element nodes are obtained.

[0050] The first step is to introduce Newton's second law, and the formula is as follows: , Where M is the mass of the element node. Let x be the second-order partial derivative with respect to t. Let x be the first-order partial derivative with respect to t. For the damping of the element node, For total nodal force, The total nodal force mentioned above includes the contact forces at the nodes. Nodal forces in the deformation of triangular and jointed elements Nodal forces caused by external loads The adhesive force of joint units .

[0051] The second step involves obtaining the coordinate and velocity update results of the triangular element nodes based on Newton's second law, the normal contact force calculation model, and the tangential contact force calculation model.

[0052] The coordinate and velocity update results satisfy the following relationship: , in, for The speed of time, for The speed of time, For total nodal force, For time step, For the quality of the node, for The distance of time, for The distance of time.

[0053] S4. Based on the coordinate and velocity update results, perform visualization analysis and output the crack propagation, stress field, and energy evolution results under impact loading. The specific implementation details are as follows: After completing the coordinate and velocity-based updates, visualization analysis was then performed to present the results related to crack propagation, stress field, and energy evolution under impact loading.

[0054] Import visualization analysis tools and files. In this example, ParaView software is used to import VTK result files, which are then used as the basis for subsequent visualization analysis.

[0055] This generates multi-field visualizations. Using the visualization function of ParaView software, displacement field cloud maps, stress cloud maps, and velocity vector fields are generated, which can intuitively show the distribution and changes of different physical quantities under impact loads.

[0056] In an optional embodiment, please refer to the displacement change cloud map of the rock fracturing process under impact loading. Figure 6 Please refer to the crack rose diagram for a schematic representation of the crack direction distribution characteristics. Figure 7 .

[0057] Extract and statistically analyze crack evolution patterns. Accurately extract crack evolution patterns from visualization results, perform detailed statistics on the number of cracks, distinguish crack types (including tensile cracks and shear cracks), and analyze their directional distribution characteristics to comprehensively understand the development trend of cracks under impact loads.

[0058] Analyzing the laws of energy evolution, deeply dissecting the evolution of energy under impact loads, and exploring the trend of energy change with time or space, provides a basis for understanding the energy conversion and dissipation mechanism of the system under impact loads.

[0059] Furthermore, the numerical simulation method of the entire process of rock and ore fracture under FDEM impact loading based on the present invention is compared and analyzed with the prior art. The relevant contents are as follows: Improved computational efficiency: The method of this invention adopts an adaptive joint element insertion mechanism, which is different from the traditional FDEM method of pre-inserting joint elements globally. This effectively avoids unnecessary computational waste, significantly shortens the computation time, and improves computational efficiency.

[0060] Simplified parameter acquisition: The adaptive FDEM method does not require obtaining the optimal joint penalty parameter values ​​in advance through a complex and cumbersome calibration process, but can obtain simulation results comparable to those obtained with the optimal parameter values, thus simplifying the simulation process and reducing the difficulty of operation.

[0061] Improved simulation accuracy: By combining the improved joint element fracture constitutive model and NBS contact algorithm, the method of this invention can more accurately simulate the entire process of crack initiation, propagation and penetration, providing strong support for a deeper understanding of the failure mechanism of materials under impact load.

[0062] Comprehensive analysis capabilities: The method of this invention provides comprehensive analysis capabilities from basic physical fields such as displacement field and stress field to crack statistics and energy evolution, which can provide quantitative evidence at the microscopic level for SHPB experiments and effectively make up for the limitations of traditional indoor tests in capturing the failure process and analyzing energy evolution.

[0063] Please see Figure 8In an optional embodiment, the present invention also provides a numerical simulation system for the entire process of rock and ore fracture under FDEM impact loading. This system includes a processor, an input device, an output device, and a memory, all interconnected. The memory stores a computer program, which includes program instructions. The processor is configured to call these instructions and execute the specific steps of the numerical simulation method and related embodiments for the entire process of rock and ore fracture under FDEM impact loading provided by the present invention. The numerical simulation system for the entire process of rock and ore fracture under FDEM impact loading of the present invention is structurally complete and objectively stable.

[0064] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be covered within the scope of the claims and specification of the present invention.

Claims

1. A numerical simulation method for the entire process of rock and ore fracture under FDEM impact loading, characterized in that, Includes the following steps: The continuous medium structure is discretized into a finite element network composed of triangular elements by FDEM, and a rock impact test model is constructed based on the finite element network. Material parameters and impact velocity boundary conditions are set according to the aforementioned rock impact test model; Based on the material parameters and the impact velocity boundary conditions, a normal contact force calculation model and a tangential contact force calculation model are established. Combining Newton's second law, the normal contact force calculation model, and the tangential contact force calculation model, the coordinates and velocity update results of the triangular element nodes are obtained. Visual analysis is performed based on the coordinate and velocity update results to output the crack propagation, stress field and energy evolution results under impact load.

2. The numerical simulation method for the entire process of rock and ore fracture under FDEM impact loading as described in claim 1, characterized in that, The discretization of the continuous medium structure into a finite element network composed of triangular elements using FDEM, and the construction of a rock impact test model based on the finite element network, includes: Introducing the 3D finite element mesh generator Gmsh; A rock impact test model was constructed using the three-dimensional finite element mesh generator Gmsh and the finite element network. The unstructured Delauney triangulation algorithm was used to divide the mesh in the rock impact test model, and joint elements were inserted in the boundaries of adjacent elements to simulate crack initiation and propagation in the rock impact test model.

3. The numerical simulation method for the entire process of rock and ore fracture under FDEM impact loading as described in claim 1, characterized in that, The setting of material parameters and impact velocity boundary conditions based on the rock impact test model includes: Obtain indoor experimental data; Based on the indoor experimental data, the mechanical parameters of the triangular element are set, including the elastic modulus, Poisson's ratio, and density. Based on the indoor experimental data, the micro-parameters of the joint unit are set, including tensile strength, cohesion, internal friction angle and joint unit fracture energy release rate; The penalty parameters are set with reference to the indoor experimental data. The penalty parameters include the normal penalty parameter, tangential penalty parameter, and joint penalty parameter of the triangular element.

4. The numerical simulation method for the entire process of rock and ore fracture under FDEM impact loading as described in claim 1, characterized in that, The establishment of the normal contact force calculation model and the tangential contact force calculation model based on the material parameters and the impact velocity boundary conditions includes: The fracture energy is calibrated based on the material parameters and the impact velocity boundary conditions, and the fracture energy includes the Type I fracture energy release rate. and Type II fracture energy release rate .

5. The numerical simulation method for the entire process of rock and ore fracture under FDEM impact loading according to claim 4, characterized in that, The establishment of the normal contact force calculation model and the tangential contact force calculation model based on the material parameters and the impact velocity boundary conditions includes: Introducing MultiFracS software and NBS contact algorithm; Contact determination is performed based on the MultiFracS software, the NBS contact algorithm, the fracture energy, the material parameters, and the impact velocity boundary conditions to obtain the contact situation of triangular elements within adjacent meshes; A contact force calculation model is established based on the contact conditions. The contact force calculation model includes a normal contact force calculation model and a tangential contact force calculation model.

6. The numerical simulation method for the entire process of rock and ore fracture under FDEM impact loading as described in claim 5, characterized in that, The normal contact force calculation model satisfies the following relationship: ， in, For normal contact force, For normal penalty parameters, One of two adjacent triangular units It is the other one of two adjacent triangular units. For gradient, for Dot at The momentum, For overlapping regions and At a point within the intersection, for Dot at The momentum, For overlapping regions and At a point within the intersection, Let be the area of ​​the overlapping portion of the triangular units. Let be the vector representing the direction of the outward normal to the overlapping portion. For contact triangle The outer boundary of the overlapping portion, For unit Potential function on, For unit Potential function on.

7. The numerical simulation method for the entire process of rock and ore fracture under FDEM impact loading as described in claim 5, characterized in that, The contact force calculation model is established based on the contact situation. The contact force calculation model includes a normal contact force calculation model and a tangential contact force calculation model. The relative misalignment condition between two adjacent triangular units is set according to Coulomb's law of friction. A tangential contact force calculation model is established based on the contact conditions and the relative misalignment conditions. The relative misalignment condition satisfies the following relationship: ， in, for Tangential contact force at moment, For normal contact force, The relevant friction angle; The tangential contact force calculation model satisfies the following relationship: ， in, for Tangential contact force at moment, For the damping of the element node, It is the normal contact force.

8. The numerical simulation method for the entire process of rock and ore fracture under FDEM impact loading as described in claim 1, characterized in that, The coordinate and velocity update results of the triangular element nodes obtained by combining Newton's second law, the normal contact force calculation model, and the tangential contact force calculation model include: Introduce Newton's second law; Based on Newton's second law, the normal contact force calculation model, and the tangential contact force calculation model, the coordinates and velocity updates of the triangular element nodes are obtained.

9. The numerical simulation method for the entire process of rock and ore fracture under FDEM impact loading as described in claim 8, characterized in that, The coordinate and velocity update results of the triangular element nodes obtained based on Newton's second law, the normal contact force calculation model, and the tangential contact force calculation model include: The coordinate and velocity update results satisfy the following relationship: ， in, for The speed of time for The speed of time For total nodal force, For time step, For the quality of the node, for The distance of time, for The distance of time.

10. A numerical simulation system for the entire process of rock and ore fracture under FDEM impact loading, characterized in that, The system includes a processor, an input device, an output device, and a memory, which are interconnected. The memory is used to store a computer program, which includes program instructions. The processor is configured to call the program instructions to execute the numerical simulation method for the entire process of rock and ore fracture under FDEM impact loading as described in any one of claims 1-9.

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