Mine fan-shaped medium-length hole rock blasting numerical simulation method based on Lsdyna and Hypermesh

Abstract

The invention discloses a mining fan-shaped medium-length hole rock blasting numerical simulation method based on Lsdyna and Hypermesh, and the method comprises the steps: firstly building a three-dimensional numerical model through CAD and SOLIDWORKS software, then carrying out the grid division and optimization through HYPERMESH software, and finally setting a material constitutive, a fluid-solid coupling algorithm and boundary conditions in LSDYNA software, and completing the numerical simulation. According to the method, through multi-software cooperation, the problems of complex model construction and grid division are solved, the simulation efficiency and accuracy are improved, and theoretical support is provided for mine blasting parameter optimization.

Description

Technical Field

[0001] This invention relates to the field of mining technology, specifically to a numerical simulation method for deep-hole rock blasting in a mining sector based on Lsdyna and Hypermesh. Background Technology

[0002] With the increasing global demand for strategic mineral resources, the development and utilization of mineral resources has gradually become an important issue for energy security, economic development, and environmental protection in various countries. Blasting has been widely used in the mining industry for centuries and remains a primary method for breaking rocks and excavating tunnels. However, with increasing mining depth and stage height, the requirements for precision blasting technology are becoming increasingly stringent in order to reduce the proportion of large blocks and minimize over- and under-excavation. Numerical simulation technology for rock blasting, as an important tool for theoretical research in mine blasting, faces severe challenges.

[0003] In recent years, the development of numerical simulation software has provided various technical means for numerical simulation of rock blasting in mines. ANSYS / LSDYNA is an excellent numerical simulation software for blasting and has been used by many scholars for numerical simulation of slopes, numerical simulation of smooth blasting, and numerical simulation of deep-hole blasting in fan-shaped areas. However, LSDYNA software is relatively weak in model building and mesh generation, and its operation is difficult, especially when dealing with complex models (such as deep-hole models in fan-shaped areas), where creating numerical models is time-consuming and prone to errors. For example, when constructing boreholes with different inclination angles and arc-shaped regions, using LSDYNA's built-in coordinate modeling method is very difficult, and distorted meshes are prone to occur during mesh generation, affecting computational efficiency and accuracy.

[0004] Therefore, there is an urgent need for a more efficient and accurate numerical simulation technique to address the shortcomings of existing technologies. Summary of the Invention

[0005] The main objective of this invention is to address the problems existing in the prior art by providing a numerical simulation method for deep-hole rock blasting in a mining sector based on Lsdyna and Hypermesh, optimizing model construction, mesh generation, and calculation processes to improve simulation efficiency and accuracy.

[0006] The technical solution of the present invention is as follows: a numerical simulation method for deep-hole rock blasting in a sector shape in mines based on Lsdyna and Hypermesh, characterized by the following steps: S1, using CAD software to draw a plan view of deep-hole blasting in a sector shape, and importing it into SOLIDWORKS software to construct a three-dimensional numerical model, including an explosive model and a rock model;

[0007] S2. Import the three-dimensional numerical model using Hypermesh software, perform model cutting, Boolean operations, and mesh generation to produce a symmetric mesh model.

[0008] S3. Import the mesh model using Lsdyna software, set the material constitutive model, fluid-structure interaction algorithm, boundary conditions and output control, and complete the numerical simulation calculation.

[0009] Furthermore, the construction of the three-dimensional numerical model specifically includes:

[0010] Explosive model construction: Generate a solid by rotating the inner side of the borehole around the center line, and use the stretch cut function to trim the excess part;

[0011] Rock model construction: Generate solids by extrude planar regions with bosses and integrate the models using the combo function.

[0012] Furthermore, the mesh division specifically includes:

[0013] The explosive and blocking areas are divided into surface and volume grids, and the grid density is controlled to avoid distorted grids.

[0014] The surface of the rock region is divided into simple quadrilateral regions, and a volume mesh is generated after dividing the surface mesh.

[0015] Use mirroring to ensure the mesh model is symmetrical from front to back.

[0016] Furthermore, the material constitutive model includes:

[0017] The rock constitutive model uses the *MAT-RHT material model;

[0018] The explosive material is modeled using the *MAT_HIGH_EXPLOSIVE_BURN model and the JWL equation of state, which is as follows: In the formula: P is the detonation pressure; V is the relative volume; ω is the initial specific internal energy; A, B, R1, R2, and ω are material constants.

[0019] Furthermore, the air material adopts the *MAT_NULL model and a linear polynomial state equation, which is: , where μ=1 / V−1, and C0 to C6 are equation parameters.

[0020] Furthermore, the fluid-structure interaction algorithm settings include:

[0021] Use the *CONTROL_ALE keyword to set ALE algorithm parameters;

[0022] Implement the Lagrange and ALE algorithms using the *SECTION_SOLID keyword;

[0023] Use SET_PART_LIST to group fluid and solid domains, ALE_MULTI-MATERIAL_GROUP to manage multi-material groups, and *CONSTRAINED_LAGRANGE_IN_SOLID to achieve coupling.

[0024] Furthermore, the boundary condition settings include:

[0025] Use SET_SEGMENT and BOUNDARY_NON_REFLECTING to set the transmission boundary;

[0026] Displacement constraints are applied using SET_NODE and BOUNDARY_SPC_SET.

[0027] Furthermore, the output control includes:

[0028] Define the status output frequency using *DATABASE_BINARY_D3PLOT;

[0029] Use *DATABASE_EXTENT_BINARY to define the damage parameter output;

[0030] Use *DATABASE_BINARY_D3THDT to define the time history output.

[0031] Compared with the prior art, the present invention has the following advantages: 1. By working collaboratively with multiple software programs, it solves the limitations of LSDYNA in complex model construction and mesh generation; 2. It improves the efficiency of model production, reduces errors, and provides a new means for theoretical analysis of deep blasting in mines; 3. It supports the design of optimized deep hole blasting parameters in the sector of mines, improving production efficiency and safety. Attached Figure Description

[0032] Figure 1 This is a flowchart of the present invention;

[0033] Figure 2 This is a schematic diagram of borehole parameters according to an embodiment of the present invention; Figure 3 This is a front view of the numerical model according to an embodiment of the present invention; Figure 4 for Figure 3 A magnified view of a portion of the document; Figure 5 for Figure 3 The left view. Detailed Implementation

[0034] like Figure 1-5 As shown, this embodiment presents a numerical simulation method for deep-hole rock blasting in a mining sector based on Lsdyna and Hypermesh, including the following steps: Step 1, Numerical model construction:

[0035] Based on the actual blasting parameters in the mine (such as borehole diameter, depth, and spacing), a fan-shaped borehole blasting plan is drawn using CAD software and saved as a DWG file.

[0036] Import the DWG file into SOLIDWORKS software and use functions such as extrusion, rotation, and combination to build a 3D model:

[0037] Explosive model construction: Select a top-down view. Use the rotation function to select the inner side of the boreholes and rotate it around the centerline to create a solid. There are 14 boreholes in total. During rotation, disable the merge result option. Use the stretch cut function to cut off the solids that extend beyond the fan-shaped borehole frame. Save the model in STEP AP203 format.

[0038] Rock Model Construction: Select a top-down view, hide the explosive entity, and use the boss extrusion function to extrude all areas within the plane to generate a solid. Use the group function, select all solids, delete the boss extrusion entity from the solids to be grouped, select the boss extrusion entity as the main solid, confirm the grouping to generate a rock solid, and save it as a STEP AP203 format.

[0039] Step 2, Mesh generation for the numerical model:

[0040] Import the STEP format file using HYPERMESH software and perform the following operations:

[0041] Model Classification, Naming, and Cutting: Use the Materials function to create materials (such as explosives or blockages), and move entities to the corresponding materials using "tool→organize". Use "Geom→quick edit→spilt surf node" to select the centerline point on the side of the model for cutting, and then use "Solid edit→trim with lines" to cut the model into symmetrical front and back parts along the axis. Create a new material dd, and move the front part into dd.

[0042] Boolean operations: Use "Geom→Solid edit→boolean", set operation type to advanced, operation to A+B, combine through to none, and calculate after hiding dd.

[0043] Grid generation:

[0044] For explosives and blockages: Hide the rocks, use F12 to switch the mesh generation function, set Geometry Color Mode to By 2D Type, select the top area of ​​the explosives, set the element size and mesh type (square mesh), and control the boundary point density to generate the mesh. Use "3D→Solid map one volume→solid" to set the along size value to generate the volume mesh.

[0045] For rocks: Hide explosives and block, use "Geom→quick edit→split surf line→node" to divide the surface area into simple quadrilaterals, and after dividing the surface mesh, use "3D→Solid map one volume→solid" to divide the volume mesh.

[0046] Hide the solids, show all the meshes, and use "tool→reflect" to mirror the meshes to the other side to ensure symmetry. Save the model as a K file.

[0047] Step 3: Improve the numerical model:

[0048] Open the K file using LSDYNA software:

[0049] Delete irrelevant parts, and rename and number the boreholes for each part.

[0050] Use "element tools→move" to merge the front and back parts, and use "element tools→duplicatenodes" to merge duplicate nodes.

[0051] Use "element and mesh→element generation→solid" to stretch the rock entity to meet the blasting parameters. Stretch a ring of the entity around the explosive and the plug and name it air.

[0052] To set a non-reflective boundary: Click "Model and part → create entity → set date → *SET-SEGM" and select the face to create.

[0053] Step 4, Setting up the material constitutive model:

[0054] Rock constitutive model: The *MAT-RHT (No. 272) material model was used to characterize the tensile-compression damage evolution, strain rate effect, hardening-softening characteristics and failure behavior of rock mass under dynamic load.

[0055] Explosive material: The *MAT_HIGH_EXPLOSIVE_BURN model and JWL equations of state are used, and the expression is: In the formula: P is the detonation pressure; V is the relative volume; ω is the initial specific internal energy; A, B, R1, R2, and ω are material constants;

[0056] Air material: Using the MAT_NULL model and the EOS_LINER_POLYNOMIAL equation of state, the expression is: , where μ=1 / V−1, and C0 to C6 are equation parameters.

[0057] Step 5: Fluid-structure interaction algorithm parameter settings:

[0058] Basic control keywords: set CONTROL_TERMINATION (calculation termination time), CONTROL_TIMESTEP (time step parameter), *CONTROL_ALE (ALE algorithm control parameters, such as loop count NALEMAX, smoothing algorithm METHOD, and mesh re-division frequency AFAC).

[0059] Fluid-structure interaction settings: The Lagrange algorithm is used for rock, while the ALE algorithm is used for explosives, plugging, and air. The algorithm settings are implemented using the SECTION_SOLID keyword, SET_PART_LIST groups the fluid and solid domains, ALE_MULTI-MATERIAL_GROUP sets up multi-material groups, and CONSTRAINED_LAGRANGE_IN_SOLID implements the coupling.

[0060] Boundary settings: Use SET_SEGMENT and BOUNDARY_NON_REFLECTING to set the transmission boundary, and SET_NODE and BOUNDARY_SPC_SET to apply displacement constraints.

[0061] Initial conditions and output control: Use INITIAL_DETONATION to set the detonation point and detonation time, DATABASE_BINARY_D3PLOT to define the output frequency, DATABASE_EXTENT_BINARY to define the damage parameter output, and DATABASE_BINARY_D3THDT to define the time history output.

[0062] Step 6, Calculation Results:

[0063] Save the K file and click "file→run" to perform the calculation. Analyze the numerical simulation results by observing parameters such as effective stress and damage variables.

[0064] Through the above steps, this invention achieves efficient and accurate numerical simulation of deep-hole rock blasting in a mining sector, providing reliable theoretical support for mine blasting design.

Claims

1. A numerical simulation method for deep-hole rock blasting in a sector-shaped mine based on Lsdyna and Hypermesh, characterized in that, Includes the following steps: S1. Use CAD software to draw the plan view of the deep hole blasting in the sector and import it into SOLIDWORKS software to build a three-dimensional numerical model, including the explosive model and the rock model. S2. Import the three-dimensional numerical model using Hypermesh software, perform model cutting, Boolean operations, and mesh generation to generate a symmetric mesh model; S3. Import the mesh model using Lsdyna software, set the material constitutive model, fluid-structure interaction algorithm, boundary conditions and output control, and complete the numerical simulation calculation.

2. The numerical simulation method for deep-hole rock blasting in a mining sector based on Lsdyna and Hypermesh according to claim 1, characterized in that, The construction of the three-dimensional numerical model specifically includes: Explosive model construction: Generate a solid by rotating the inner side of the borehole around the center line, and use the stretch cut function to trim the excess part; Rock model construction: Generate solids by extrude planar regions with bosses and integrate the models using the combo function.

3. The numerical simulation method for deep-hole rock blasting in a mining sector based on Lsdyna and Hypermesh according to claim 1, characterized in that, The grid division specifically includes: The explosive and blocking areas are divided into surface and volume grids, and the grid density is controlled to avoid distorted grids. The surface of the rock region is divided into simple quadrilateral regions, and a volume mesh is generated after dividing the surface mesh. Use mirroring to ensure the mesh model is symmetrical from front to back.

4. The numerical simulation method for deep-hole rock blasting in a mining sector based on Lsdyna and Hypermesh as described in claim 1, characterized in that, The material constitutive model includes: The rock constitutive model uses the *MAT-RHT material model; The explosive material is modeled using the *MAT_HIGH_EXPLOSIVE_BURN model and the JWL equation of state, which is as follows: In the formula: P is the detonation pressure; V is the relative volume; ω is the initial specific internal energy; A, B, R1, R2, and ω are material constants.

5. The numerical simulation method for deep-hole rock blasting in a mining sector based on Lsdyna and Hypermesh according to claim 4, characterized in that, The air material is modeled using *MAT_NULL and a linear polynomial state equation, which is as follows: , where μ=1 / V−1, and C0 to C6 are equation parameters.

6. The numerical simulation method for deep-hole rock blasting in a mining sector based on Lsdyna and Hypermesh according to claim 1, characterized in that, The fluid-structure interaction algorithm settings include: Use the *CONTROL_ALE keyword to set ALE algorithm parameters; Implement the Lagrange and ALE algorithms using the *SECTION_SOLID keyword; Use SET_PART_LIST to group fluid and solid domains, ALE_MULTI-MATERIAL_GROUP to manage multi-material groups, and *CONSTRAINED_LAGRANGE_IN_SOLID to achieve coupling.

7. The numerical simulation method for deep-hole rock blasting in a mining sector based on Lsdyna and Hypermesh according to claim 1, characterized in that, The boundary condition settings include: Use SET_SEGMENT and BOUNDARY_NON_REFLECTING to set the transmission boundary; Displacement constraints are applied using SET_NODE and BOUNDARY_SPC_SET.

8. The numerical simulation method for deep-hole rock blasting in a mining sector based on Lsdyna and Hypermesh according to claim 1, characterized in that, The output control includes: Define the status output frequency using *DATABASE_BINARY_D3PLOT; Use *DATABASE_EXTENT_BINARY to define the damage parameter output; Use *DATABASE_BINARY_D3THDT to define the time history output.

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