Mesh mapping and data transfer method for coupled calculation of casting and structural simulation

Abstract

The invention discloses a mesh mapping and data transmission method for coupled calculation of casting and structural simulation, which relates to the technical field of material calculation, and is used for reflecting the influence of casting process on structural analysis of casting products. The specific steps include: establishing a finite element mesh, and discretizing the casting simulation model and the structural simulation model respectively; realizing mesh mapping between the two simulation models according to the coordinate information of the finite element nodes; realizing data processing in the mesh and data transmission between the mapped meshes according to the physical information of the finite element nodes; the invention can provide technical support for coupled calculation and analysis of casting simulation and structural simulation with differences in mesh size and quantity, and realize coupled calculation and analysis of the two simulation models with high precision and high efficiency.

Description

Technical Field

[0001] The invention relates to the technical field of material calculation, and in particular to a grid mapping and data transmission method for casting and structural simulation coupling calculation. Background Art

[0002] Casting aluminum alloy has the advantages of light weight, excellent mechanical properties, high corrosion resistance and good thermal conductivity. It has been widely used in many industrial fields and has become one of the indispensable materials in modern manufacturing. In the automotive industry, it is used to manufacture engine parts, body structures, suspension systems, etc. to improve the fuel efficiency and performance of automobiles; in the aerospace industry, it is used to manufacture aircraft structures, engine parts, avionics equipment, etc. to reduce the weight of aircraft and improve fuel efficiency; in the electronics industry, it is used to manufacture radiators, electronic housings, power transmission lines, etc. to provide good thermal conductivity and corrosion resistance; in the construction industry, it is used to manufacture building structures, doors and windows, curtain walls, etc. to provide light weight, durability and good appearance; in the shipbuilding industry, it is used to manufacture hull structures, marine equipment, etc. to provide light weight and corrosion resistance. In short, aluminum alloy casting has continuously improved its position in industrial materials due to its excellent performance and wide application fields.

[0003] However, changes in the alloy cooling rate during the casting process and the resulting shrinkage and porosity will have a significant impact on the mechanical properties and fatigue life of the aluminum alloy. In addition, the cooling rate and shrinkage and porosity of different parts of the aluminum alloy model are slightly different.

[0004] At present, when performing casting and structural simulation, it is difficult to effectively transfer data between them due to the different software used. Structural simulation software does not have the ability to consider a series of casting process issues such as cooling rate, shrinkage, and shrinkage. Therefore, it is particularly urgent to realize an efficient and accurate mesh mapping and data transfer method for coupled calculation of casting simulation and structural simulation. Summary of the invention

[0005] In order to solve the above technical problems, the present invention proposes an automatic identification and quality evaluation method for aluminum alloy melt inclusions, comprising:

[0006] A mesh mapping and data transfer method for casting and structural simulation coupling calculation, characterized in that it includes the following steps:

[0007] S1: Divide the casting simulation model into grids, establish index numbers for the grids and nodes, and output the index number of the grid where each node is located and the coordinate information of each node;

[0008] S2: According to the boundary of the casting simulation model mesh, the vertex coordinate information of the cuboid containing all the meshes of the model is obtained; according to the position information of the cuboid, the cuboid is divided into a series of cubes with equal side lengths; and a hash table is established with the coordinate information of each cube and the index number information of all the nodes contained therein;

[0009] S3: Divide the structural simulation model into grids, establish index numbers for the grids and nodes, and output the node index numbers contained in each grid and the coordinate information of each node;

[0010] S4: mapping the grid of the structural simulation model to the grid of the casting simulation model according to the spatial position information and the hash table, completing the correspondence between the node index number of the structural simulation model and the grid index number of the casting simulation model, and ensuring that a node of the structural simulation model corresponds to only one grid of the casting simulation model;

[0011] S5: Transfer parameters from casting simulation model to structural simulation model ,Parameter transfer is based on the mesh mapping of the two simulation models, that is, any mesh data of the casting simulation model is transferred to the node of the structural simulation model mapped with the mesh, and finally the mapping to the mesh of the structural simulation model is realized.

[0012] Furthermore, step S1 is specifically as follows:

[0013] S101: After dividing the casting simulation model into grids, four files are output from the casting simulation model: file n1, node index number + node coordinate information; file e1, grid index number + index number of the node contained in the grid; file ne1, node index number + index number of all grids containing the node; file na1, node index number + parameters transferred from the casting simulation model to the structural simulation model ; and store the information of file n1, file e1, file ne1 and file na1 respectively as list n1, list e1, list ne1 and list na1 for subsequent calls.

[0014] Furthermore, step S2 is specifically as follows:

[0015] S201: using the data of the list n1 obtained in S1 as input, obtaining the coordinate information of the eight vertices of the smallest cuboid containing all the grids;

[0016] S202: Use the vertex coordinate information obtained in S201 and the side length of the small cube as input, divide the cuboid, obtain a series of small cubes and number them, traverse the list n1, determine which small cube the node is in, and make a hash table.

[0017] Furthermore, step S3 is specifically as follows:

[0018] S301: After dividing the structural simulation model into grids, two files are output from the structural simulation model: file n2, node index number + node coordinate information; file e2, grid index number + index number of the nodes contained in the grid; and the information of file n2 and file e2 are stored respectively as list n2 and list e2 for subsequent calls.

[0019] Further, step S4 is specifically as follows:

[0020] S401: traverse the list n2, combine with the hash table, determine the number of the small cube where the node of the structure simulation model is located, and read the corresponding node index number of the casting simulation model;

[0021] S402: Read the list ne1 according to the node index number in the hash table to obtain all grid number information that may intersect with the small cube;

[0022] S403: Traverse the obtained grid number information, combine it with the list n2, use the volume method to determine whether the node of the structure simulation model is in the grid of the casting simulation model, and store the obtained result as a list L.

[0023] Furthermore, step S5 is specifically as follows:

[0024] S501: traverse the list L in S4, and map the mesh data of the casting simulation model to the nodes of the structural simulation model by interpolation method;

[0025] S502: traverse the list e2 and map the data on the nodes of the structural simulation model to the grid by interpolation method.

[0026] Furthermore, each part of the hash table includes: the number of the small cube, the range of the small cube x coordinate, the range of the small cube y coordinate, the range of the small cube z coordinate, and the node index number of the included casting simulation model.

[0027] Furthermore, each portion of data stored in the list L includes: a node index number of the structural simulation model, a ratio of four node data of the casting simulation model adopted by the nodes of the structural simulation model, and index numbers of the four nodes of the casting simulation model.

[0028] Furthermore, the nodes of the structural simulation model adopt the ratio of the four node data of the casting simulation model, using V represents the volume of the tetrahedron, 1, 2, 3, and 4 are the node numbers of the four nodes of the casting simulation model grid, and the data ratio of node p of the structural simulation model to node 1 of the casting simulation model is expressed as: .

[0029] Further, the mesh data of the casting simulation model is mapped to the nodes of the structural simulation model by interpolation. Taking a four-node tetrahedron mesh as an example, 1, 2, 3, and 4 are the node numbers of the four nodes of the casting simulation model mesh, and the data of the nodes of the casting simulation model are used to represent the nodes of the structure simulation model. Indicates that the data of the nodes of the structural simulation model are expressed as Represented as: The data mapped to the node p of the structural simulation model is represented as: .

[0030] Furthermore, the data on the nodes of the structural simulation model are mapped to the grid by the interpolation method. Taking a ten-node tetrahedral grid as an example, 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10 are the node numbers of the ten nodes of the structural simulation model grid, respectively. Then, the data on the grid p of the structural simulation model is expressed as: .

[0031] The beneficial effects of the present invention are as follows:

[0032] 1. The grid-based information transmission of the present invention can accurately reflect the specific impact of the casting process on the mechanical properties, and assign different grids and different material properties according to different locations and casting processes.

[0033] 2. The present invention can efficiently complete grid mapping and information transmission based on hash tables, greatly shortening the overall calculation time and improving the operation efficiency of the algorithm. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 The figure is a flow chart of a method according to an embodiment of the present invention.

[0035] Figure 2 This is a tetrahedral mesh model of a casting in casting simulation software according to an embodiment of the present invention.

[0036] Figure 3 This is a tetrahedral mesh model of a casting in a structural simulation software according to an embodiment of the present invention.

[0037] Figure 4 This is a model of a casting according to an embodiment of the present invention after meshing in casting simulation software.

[0038] Figure 5 This is a model of a casting according to an embodiment of the present invention after meshing in structural simulation software.

[0039] Figure 6 This is a model of a casting according to an embodiment of the present invention after material assignment is completed in structural simulation software. DETAILED DESCRIPTION

[0040] In order to more clearly understand the above-mentioned purpose, features and advantages of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that the embodiments of the present application and the features in the embodiments can be combined with each other without conflict.

[0041] The mesh mapping and data transfer method for casting and structural simulation coupling calculation includes the following steps:

[0042] S1: Divide the casting simulation model into grids, establish index numbers for the grids and nodes, and output the index number of the grid where each node is located and the coordinate information of each node;

[0043] S2: According to the boundary of the casting simulation model mesh, the vertex coordinate information of the cuboid containing all the meshes of the model is obtained; according to the position information of the cuboid, the cuboid is divided into a series of cubes with equal side lengths; and a hash table is established with the coordinate information of each cube and the index number information of all the nodes contained therein;

[0044] S3: Divide the structural simulation model into grids, establish index numbers for the grids and nodes, and output the node index numbers contained in each grid and the coordinate information of each node;

[0045] S4: mapping the grid of the structural simulation model to the grid of the casting simulation model according to the spatial position information and the hash table, completing the correspondence between the node index number of the structural simulation model and the grid index number of the casting simulation model, and ensuring that a node of the structural simulation model corresponds to only one grid of the casting simulation model;

[0046] S5: Transfer parameters from casting simulation model to structural simulation model ,Parameter transfer is based on the mesh mapping of the two simulation models, that is, any mesh data of the casting simulation model is transferred to the node of the structural simulation model mapped with the mesh, and finally the mapping to the mesh of the structural simulation model is realized.

[0047] As a specific implementation of this embodiment, Figure 1 As shown, a specific implementation manner of the mesh mapping and data transfer method for coupled calculation of casting and structural simulation of the present invention is shown. Taking aluminum alloy wheel hub casting as an example, the mesh mapping and information transfer between the two simulation models are completed by the mesh mapping and data transfer method for coupled calculation of casting and structural simulation of the present invention, and the mapping of the influence of the casting process on the mechanical properties is completed.

[0048] The specific steps include:

[0049] S101: Figure 4As shown in the figure, the Pro cast software is used to divide the mesh for the casting simulation model. The first-order tetrahedral unit is selected, and the mesh size is 6mm. The division result is: 433640 tetrahedral meshes and 98656 nodes on the casting. Four files are output from the casting simulation model: file n1, node index number + node coordinate information; file e1, mesh index number + index number of the node contained in the mesh; file ne1, node index number + index number of all meshes containing the node; file na1, node index number + parameters transferred from the casting simulation model to the structural simulation model. ; and store the information of file n1, file e1, file ne1 and file na1 respectively as list n1, list e1, list ne1 and list na1 for subsequent calls.

[0050] S201: using the data in the list n1 obtained in S101 as input, obtaining the coordinate information of the eight vertices of the smallest cuboid containing all the grids;

[0051] S202: using the vertex coordinate information obtained in S201 and the side length of the small cube (the side length of the small cube is 8 mm) as input, dividing the cuboid to obtain a series of small cubes and numbering them, traversing the list n1, determining in which small cube the node is located, and making a hash table; the structure of the hash table in this embodiment is: the number of the small cube (starting from 1 and increasing in sequence), the range of the x coordinate of the small cube, the range of the y coordinate of the small cube, the range of the z coordinate of the small cube, and the node index number of the casting simulation model included; for example {1:{"x_range":(-5,0),"y_range":(-5,0),"z_range":(-5,0),"nodes":[3,6,22,23,25,26,35,36,45,56,57,70, 74]},…}.

[0052] S301: Figure 5 As shown, Abaqus software is used to divide the mesh for the structural simulation model, and the second-order tetrahedral mesh: C3D10 is selected with a mesh size of 7 mm. The division result is: 278934 tetrahedral meshes and 453164 nodes on the casting. Two files are output from the structural simulation model: file n2, node index number + node coordinate information; file e2, mesh index number + index number of the nodes contained in the mesh; and the information of file n2 and file e2 are stored respectively as list n2 and list e2 for subsequent calls.

[0053] S401: traverse the list n2, combine with the hash table, determine the number of the small cube where the node of the structure simulation model is located, and read the corresponding node index number of the casting simulation model;

[0054] S402: According to the node index number in the hash table, the list ne1 is read to obtain all grid number information that may intersect with the small cube;

[0055] S403: Traverse the obtained mesh number information, combine it with list n2, and use the volume method (if a point is inside a tetrahedron or on its boundary, then the sum of the volumes of four new small tetrahedrons formed by the point and any vertex of the tetrahedron should be equal to the volume of the original tetrahedron) to determine whether the node of the structural simulation model is in the mesh of the casting simulation model, and store the obtained results as a list L.

[0056] In this embodiment, the structure of list L is: the node index number of the structural simulation model, the ratio of the four node data of the casting simulation model adopted by the nodes of the structural simulation model, and the index numbers of the four nodes of the casting simulation model, for example: [[1,0.2,0.3,0.2,0.3,50,63,72,48],…].

[0057] In the list L of this embodiment, the proportion of the four node data of the casting simulation model used by the nodes of the structural simulation model is Indicates that Figure 2 As shown, V represents the volume of the tetrahedron, 1, 2, 3, and 4 are the node numbers of the four nodes of the casting simulation model grid, and the data ratio of the node p of the structural simulation model to the node 1 of the casting simulation model can be expressed as: .

[0058] S501: traverse the list L and map the mesh data of the casting simulation model to the nodes of the structural simulation model by interpolation method, such as Figure 2 As shown, taking a four-node tetrahedron mesh as an example, 1, 2, 3, and 4 are the node numbers of the four nodes of the casting simulation model mesh, and the data of the nodes of the casting simulation model are Indicates that the data of the nodes of the structural simulation model are expressed as Represented as: The data mapped to the node p of the structural simulation model can be expressed as: ;

[0059] S502: traverse the list e2 and map the data on the nodes of the structural simulation model to the grid by interpolation. Figure 3 As shown, taking a ten-node tetrahedron grid as an example, 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10 are the node numbers of the ten nodes of the structural simulation model grid, and the data on the grid p of the structural simulation model can be expressed as: .

[0060] The method provided in the above embodiment effectively realizes the accurate mapping of the influence of the casting process on the mechanical properties of the aluminum alloy wheel casting. Figure 6 As shown, a total of more than 70,000 different material properties were assigned. The entire process took 26.8 hours, of which 26 hours were spent on material assignment, and the efficiency of the mapping algorithm took less than 1 hour.

[0061] The method provided in the above embodiment transfers data through a grid mapping algorithm, takes into account the influence of a series of casting simulation results on the mechanical properties and fatigue properties of aluminum alloy, and further improves the accuracy of mechanical property simulation results.

[0062] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art who is familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A mesh mapping and data transfer method for coupled calculation of casting and structural simulation, characterized in that: The following steps are involved: S1: Divide the casting simulation model into grids, establish index numbers for the grids and nodes, and output the index number of the grid where each node is located and the coordinate information of each node; S2: according to the boundary of the casting simulation model mesh, the vertex coordinate information of the cuboid containing all the meshes of the model is obtained; according to the position information of the cuboid, the cuboid is divided into a series of cubes with equal sides; a hash table is established with the coordinate information of each cube and the index number information of all the nodes contained therein; each part of the hash table includes: the number of the small cube, the range of the x-coordinate of the small cube, the range of the y-coordinate of the small cube, the range of the z-coordinate of the small cube, and the node index number of the casting simulation model contained therein; S3: Divide the structural simulation model into grids, establish index numbers for the grids and nodes, and output the node index numbers contained in each grid and the coordinate information of each node; S4: mapping the grid of the structural simulation model to the grid of the casting simulation model according to the spatial position information and the hash table, completing the correspondence between the node index number of the structural simulation model and the grid index number of the casting simulation model, and ensuring that a node of the structural simulation model corresponds to only one grid of the casting simulation model; S5: Transfer parameters from casting simulation model to structural simulation model ,Parameter transfer is based on the mesh mapping of the two simulation models, that is, any mesh data of the casting simulation model is transferred to the node of the structural simulation model mapped with the mesh, and finally the mapping to the mesh of the structural simulation model is realized.

2. The grid mapping and data transfer method for casting and structural simulation coupling calculation according to claim 1, characterized in that: Step S1 is specifically as follows: S101: After dividing the casting simulation model into grids, four files are output from the casting simulation model: file n1, node index number + node coordinate information; file e1, grid index number + index number of the node contained in the grid; file ne1, node index number + index number of all grids containing the node; file na1, node index number + parameters transferred from the casting simulation model to the structural simulation model ; The information of file n1, file e1, file ne1 and file na1 are stored as list n1, list e1, list ne1 and list na1 respectively for subsequent calls.

3. The grid mapping and data transfer method for casting and structural simulation coupling calculation according to claim 2, characterized in that: Step S2 is specifically as follows: S201: using the data of the list n1 obtained in S1 as input, obtaining the coordinate information of the eight vertices of the smallest cuboid containing all the grids; S202: Use the vertex coordinate information obtained in S201 and the side length of the small cube as input, divide the cuboid, obtain a series of small cubes and number them, traverse the list n1, determine which small cube the node is in, and make a hash table.

4. The grid mapping and data transfer method for casting and structural simulation coupling calculation according to claim 3, characterized in that: Step S3 is specifically as follows: S301: After dividing the structural simulation model into grids, two files are output from the structural simulation model: file n2, node index number + node coordinate information; file e2, grid index number + index number of the nodes contained in the grid; and the information of file n2 and file e2 are stored respectively as list n2 and list e2 for subsequent calls.

5. The grid mapping and data transfer method for casting and structural simulation coupling calculation according to claim 4, characterized in that: Step S4 is specifically as follows: S401: traverse the list n2, combine with the hash table, determine the number of the small cube where the node of the structure simulation model is located, and read the corresponding node index number of the casting simulation model; S402: Read the list ne1 according to the node index number in the hash table to obtain all grid number information that may intersect with the small cube; S403: Traverse the obtained grid number information, combine it with the list n2, use the volume method to determine whether the node of the structure simulation model is in the grid of the casting simulation model, and store the obtained result as a list L.

6. The grid mapping and data transfer method for casting and structural simulation coupling calculation according to claim 5, characterized in that: Step S5 is specifically as follows: S501: traverse the list L in S4, and map the mesh data of the casting simulation model to the nodes of the structural simulation model by interpolation method; S502: traverse the list e2 and map the data on the nodes of the structural simulation model to the grid by interpolation method.

7. The grid mapping and data transfer method for casting and structural simulation coupling calculation according to claim 6, characterized in that: Each part of data stored in the list L includes: the node index number of the structural simulation model, the ratio of the four node data of the casting simulation model adopted by the nodes of the structural simulation model, and the index numbers of the four nodes of the casting simulation model.

8. The grid mapping and data transfer method for casting and structural simulation coupling calculation according to claim 7, characterized in that: The nodes of the structural simulation model adopt the ratio of the four node data of the casting simulation model, Represented by; V represents the volume of the tetrahedron, then the data ratio of node 1 of the casting simulation model used by node p of the structural simulation model is expressed as: .

9. The grid mapping and data transfer method for casting and structural simulation coupling calculation according to claim 8, characterized in that: The mesh data of the casting simulation model is mapped to the nodes of the structural simulation model by interpolation. Taking a four-node tetrahedron mesh as an example, the data of the nodes of the casting simulation model are mapped to the nodes of the structural simulation model by interpolation. Indicates that the data of the nodes of the structural simulation model are expressed as Represented as: The data mapped to the node p of the structural simulation model is represented as: .

10. The grid mapping and data transfer method for casting and structural simulation coupling calculation according to claim 6, characterized in that ,The data on the nodes of the structural simulation model are mapped to the grid by interpolation method. Taking the ten-node tetrahedron grid as an example, the data on the grid p of the structural simulation model is expressed as: .

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