Two-dimensional sbfem-fem coupling numerical grid identification method and system based on human-computer interaction

Abstract

The application belongs to the technical field of computer numerical simulation modeling, and particularly relates to a two-dimensional SBFEM-FEM coupling numerical grid identification method and system based on human-computer interaction, which obtains and stores effective nodes and effective line segments by reading a two-dimensional grid pattern of a model, identifying and cutting the two-dimensional grid pattern line segments in the model; obtains the topological relationship between the effective nodes and the line segments according to the effective nodes and the effective line segments, and constructs a node relationship matrix, a node connection vector, a node number vector, a node ordering vector and a line segment angle vector according to the topological relationship; generates a polygonal proportional boundary finite element of the effective nodes by using the topological relationship of the nodes and the line segments and a closed domain structure; assembles the effective node and the polygonal proportional boundary finite element information, and generates a two-dimensional proportional boundary finite element-finite element coupling grid. The application can identify and generate a proportional boundary finite element-finite element two-dimensional coupling numerical grid based on human-computer interaction, is controllable and efficient, and can meet the application requirement of structural model numerical simulation.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of computer numerical simulation modeling, and particularly relates to a two-dimensional SBFEM-FEM coupling numerical grid identification method and system based on human-computer interaction. BACKGROUND

[0002] With the development of computer technology, numerical simulation methods are becoming more and more mature, and have become one of the mainstream research methods in the engineering field. An important step in modeling in numerical simulation is to discretize the continuum into a finite number of element grids. For the same model, the calculation results are quite different when different sizes of element grids are used for discretization. As the basis of numerical analysis, the selection of numerical grid size has a great impact on the reliability and accuracy of the calculation results. Especially for structures with complex stress states, it is difficult to maintain linear elastic stress-strain relationship under stress state, and more detailed grids are needed to reflect the stress-strain state. There are often large-scale structural systems in engineering. If the structure is finely divided in one size, the number of generated grids will be large, which is difficult to bear the calculation amount. If the conventional large-scale grid is used to meet the calculation requirements, it is difficult to achieve fine analysis for the core complex parts.

[0003] For the problem of large-scale structural system, the traditional method often uses quadtree method for discretization. The circumscribed square of the simulated two-dimensional object is divided into four small squares, and the small squares are recursively divided to form a two-dimensional SBFEM-FEM coupling grid which gradually transitions from large-scale elements to small-scale elements. The coupling grid has polygonal elements and conventional triangular and quadrilateral finite elements. The SBFEM-FEM coupling method is used to solve the grid, and SBFEM is used to solve the polygonal elements, and FEM is used to solve the conventional finite elements. However, the quadtree method also has some disadvantages. When discretizing a large-scale structural system, it is necessary to gradually transition from large-scale elements to small-scale elements, which increases the workload and the number of grids, and it is difficult to arbitrarily add local grids according to human needs, and the human controllability is low. In order to enhance the human control during the grid division of the structure, CAD software is often used to divide the grid. However, the grid divided based on the CAD drawing software is mostly limited to the identification and generation of conventional triangular and quadrilateral elements, and the types of elements that can be identified and generated are relatively single. It is not possible to simultaneously identify and generate conventional finite elements such as triangular and quadrilateral elements and polygonal elements. Only single finite elements or single polygonal boundary finite elements can be generated. How to quickly and efficiently generate numerical grids to meet the numerical simulation calculation has become a problem to be solved. SUMMARY

[0004] To this end, the application provides a two-dimensional SBFEM-FEM coupling numerical grid identification method and system based on human-computer interaction, which can identify and generate a two-dimensional coupling numerical grid of proportional boundary finite elements and finite elements based on human-computer interaction, is controllable, efficient, and can meet the application requirements of structural model numerical simulation.

[0005] According to the design scheme provided by the application, a two-dimensional SBFEM-FEM coupling numerical grid identification method based on human-computer interaction is provided, which includes the following contents:

[0006] The two-dimensional grid pattern of the model is read, and the effective nodes and effective line segments are obtained and stored by identifying and cutting the line segments of the two-dimensional grid pattern in the model;

[0007] The topological relationship between the effective nodes and the line segments is obtained according to the effective nodes and the effective line segments, and the node relationship matrix, the node connection vector, the node number vector, the node ordering vector, and the line segment angle vector are constructed according to the topological relationship;

[0008] The polygonal proportional boundary finite element of the effective node is generated by using the topological relationship of the node and the line segment and the closed domain structure;

[0009] The effective node and the polygonal proportional boundary finite element information are assembled, and the two-dimensional proportional boundary finite element-finite element coupling grid is generated.

[0010] As the two-dimensional SBFEM-FEM coupling numerical grid identification method based on human-computer interaction in the application, further, the effective nodes and effective line segments are obtained and stored by identifying and cutting the line segments of the two-dimensional grid pattern in the model, which includes: first, identifying the key points and line segments in the two-dimensional grid pattern, positioning the key point coordinates and solving the intersection points in the original line segments, and cutting each original line segment into a plurality of sub-line segments at the intersection points; then, solving the node common times, and identifying the effective nodes and effective line segments by comparing the common times with the preset threshold.

[0011] As the two-dimensional SBFEM-FEM coupling numerical grid identification method based on human-computer interaction in the application, further, the effective nodes and effective line segments are identified by comparing the common times with the preset threshold, the nodes with the common times greater than the preset threshold are determined as invalid nodes, the line segments to which the invalid nodes belong are regarded as invalid line segments, and the remaining nodes and line segments are regarded as effective nodes and effective line segments.

[0012] As the two-dimensional SBFEM-FEM coupling numerical grid identification method based on human-computer interaction in the application, further, the topological relationship between the effective nodes and the line segments is obtained according to the effective nodes and the effective line segments, containing: first, the grid is generated by reordering the effective nodes and the effective line segments, then, the node class for storing the effective node number and coordinate information and the line segment class for storing the effective line segment number and the node number information of the effective line segment are created.

[0013] As the two-dimensional SBFEM-FEM coupling numerical grid identification method based on human-computer interaction in the application, further, the node relationship matrix, the node connection vector, the node number vector, the node ordering vector and the line segment angle vector are constructed according to the topological relationship, containing: first, the node relationship matrix is created according to the connection relationship between the effective nodes; then, the node connection vector is created according to the upper triangular matrix in the node relationship matrix; then, all the line segments of the shared node are processed, and the node number vector for storing the number information of the line segment of the shared node in the entire grid, the node ordering vector for storing the ordering information of the node in the corresponding shared line segment, and the line segment angle vector for storing the line segment and X-axis positive direction angle information based on the shared node are created.

[0014] As the two-dimensional SBFEM-FEM coupling numerical grid identification method based on human-computer interaction in the application, further, the polygonal proportional boundary finite element of the effective node is generated by using the topological relationship of the node and the line segment and the closed domain structure, containing: first, whether the effective node can generate a new unit of the polygonal proportional boundary finite element is identified in sequence; then, for the effective node that can generate a new unit, the line segments of the shared node are identified, and adjacent line segments are grouped into a group two by two, and the terminal edge, the starting edge, and the terminal node and the transition node are set for each group of line segments; then, the connection relationship of the terminal node and the transition node of each group of line segments is solved, if the connection relationship solving result is that the terminal node and the transition node can be connected into a line segment, a new unit is generated, otherwise the next transition point is identified, until the transition point can be connected with the terminal node into a line segment, until all the effective nodes that can generate a new unit are identified.

[0015] As the two-dimensional SBFEM-FEM coupling numerical grid identification method based on human-computer interaction in the application, further, whether the effective node can generate a new unit of the polygonal proportional boundary finite element is identified, containing: whether the node connection vector of the effective node meets the preset numerical value is judged, if yes, it is determined that the effective node can generate a new unit, otherwise, it is determined that the effective node cannot generate a new unit.

[0016] As the two-dimensional SBFEM-FEM coupling numerical grid identification method based on human-computer interaction of the present application, further, for the effective node that can generate a new element, the line segment that shares the node is identified, and adjacent line segments are grouped two by two, and the terminal edge, the starting edge, and the terminal node and the transition node are set for each group of line segments, containing: first, set the new element generated by the effective node a has n nodes, and the effective node a is the first node; then, identify all line segments that share the node a, group every two adjacent line segments into a group, if the next line segment has a larger included angle vector than the current line segment, then set the next line segment as the terminal edge and the other node of the line segment as the terminal node b, and set the current line segment as the starting edge and the other node of the line segment as the transition node m.

[0017] As the two-dimensional SBFEM-FEM coupling numerical grid identification method based on human-computer interaction of the present application, further, the connection relationship of the terminal node and the transition node of each group of line segments is solved, if the connection relationship solving result is that the terminal node and the transition node can be connected into a line segment, then a new element is generated, and further containing: if the terminal node and the transition node cannot be connected into a line segment, then take the transition node as an intermediate node m1, identify all line segments that share the intermediate node m1, determine the order j of NLN(i) in all line segments that share the intermediate node m1, locate the line segment NLN(j-1) based on the counterclockwise ordering principle of all nodes of the composed element, and the other node of the line segment NLN(j-1) that shares the intermediate node m1 is the current transition node m, if A(b,m)=1, then a new element is generated, otherwise, take the node as an intermediate node m2, and then continue to find the next transition node, until a line segment that can be connected with the terminal node to generate a new element is found, wherein NLN(i) represents the line segment with the counterclockwise ordering number i in all line segments that share the intermediate node m1; NLN(j-1) represents the line segment with the counterclockwise ordering number j-1 in all line segments that share the intermediate node m1; A(b,m) represents the node relationship matrix, and the element value equal to 1 represents that the node b is connected with the node m.

[0018] Further, the present application also provides a two-dimensional SBFEM-FEM coupling numerical grid identification system based on human-computer interaction, containing: a node line segment acquisition module, a node line segment processing module and a numerical grid generation module, wherein,

[0019] The node line segment acquisition module is used for reading the two-dimensional grid graphics of the model, and acquiring and storing the effective nodes and effective line segments by identifying and cutting the line segments of the two-dimensional grid graphics in the model;

[0020] The node line segment processing module is used for acquiring the topological relationship between the effective nodes and the line segments according to the effective nodes and the effective line segments, and constructing the node relationship matrix, the node connection vector, the node number vector, the node ordering vector and the line segment included angle vector according to the topological relationship;

[0021] A numerical mesh generation module is configured to generate a polygonal scaled boundary finite element of an effective node by using a topological relationship of the node and the line segment and a closed domain configuration; and assemble information of the effective node and the polygonal scaled boundary finite element, and generate a two-dimensional scaled boundary finite element-finite element coupling mesh.

[0022] The present application has the following advantages:

[0023] The present application can be connected to computer-aided design software, and can refine the mesh in a local encryption part according to human requirements to achieve the desired effect, without worrying about the mesh transition between the scaled boundary finite element and the finite element, effectively reducing the pre-processing time; in terms of automatic identification and generation of a calculation model of an arbitrary complex coupling SBFEM-FEM mesh, the mesh identification efficiency and accuracy are greatly improved, and the present application can be used for numerical simulation of a complex large-scale engineering model. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 A two-dimensional SBFEM-FEM coupling numerical mesh identification process based on human-computer interaction in the embodiment is shown in the figure;

[0025] Figure 2 A two-dimensional graph in the embodiment is shown in the figure;

[0026] Figure 3 All node line segments in the embodiment are shown in the figure;

[0027] Figure 4 The effective node and the line segment are rearranged in the embodiment, as shown in the figure;

[0028] Figure 5 A node connection relationship matrix A in the embodiment is shown in the figure;

[0029] Figure 6 A node connection number vector in the embodiment is shown in the figure;

[0030] Figure 7 A new element generation process in the embodiment is shown in the figure;

[0031] Figure 8 A new element generation diagram in the embodiment is shown in the figure;

[0032] Figure 9 A numerical mesh generation result in the embodiment is shown in the figure. DETAILED DESCRIPTION

[0033] To make the purpose, technical solutions and advantages of the present application clearer and more apparent, the present application will be further described in detail below with reference to the figures and technical solutions.

[0034] For the case of dam dynamic large deformation caused by seismic load, the embodiment of the present application, see Figure 1As shown, a two-dimensional SBFEM-FEM coupling numerical grid identification method based on human-computer interaction is provided, comprising:

[0035] S1, read the two-dimensional grid pattern of the model, obtain and store the effective nodes and effective line segments by identifying and cutting the two-dimensional grid pattern line segments in the model;

[0036] S2, obtain the topological relationship between the effective nodes and the line segments according to the effective nodes and the effective line segments, and construct the node relationship matrix, the node connection vector, the node number vector, the node ordering vector and the line segment angle vector according to the topological relationship;

[0037] S3, generating the polygonal proportional boundary finite element of the effective nodes by using the topological relationship of the nodes and the line segments and the closed domain construction;

[0038] S4, assembling the effective nodes and the polygonal proportional boundary finite element information, and generating the two-dimensional proportional boundary finite element-finite element coupling grid.

[0039] The two-dimensional grid pattern of the model can be drawn using computer-aided design software, and the effective nodes and line segments can be generated by processing the key point and line segment information in the grid. The effective nodes and line segments are preprocessed to generate the node relationship matrix, the node connection vector, the node number vector, the node ordering vector and the line segment angle vector. Further, the new element, i.e. the proportional boundary finite element or the finite element, is generated by using the topological relationship between the effective nodes and the line segments and the closed domain construction. The two-dimensional proportional boundary finite element-finite element coupling grid is generated by arranging the node and element information.

[0040] The two-dimensional grid pattern information is derived from computer-aided design software. On the software operation interface, the model pattern can be divided by line segments. In the specific implementation, there is no need to pay attention to the transition problem between different grid sizes, and local grid encryption can be performed at any position by increasing line segments as needed. The pattern drawn in this embodiment is composed of 12 nodes and 6 line segments, as shown in the accompanying drawings. Figure 2 As shown, the polygonal proportional boundary finite element or the finite element can be generated by full coverage identification of triangles, quadrilaterals and polygons, breaking through the limitation of traditional methods which are limited to identification of conventional triangular, quadrilateral and other finite elements. There is no need to consider the transition problem between different scale elements, and local grid encryption can be performed at any position as needed. The two-dimensional proportional boundary finite element-finite element coupling numerical grid can be efficiently and controllably generated with high quality, which is convenient for numerical simulation application in structural models.

[0041] As a preferred embodiment, further, the valid nodes and the valid line segments are acquired and stored by identifying and cutting the two-dimensional grid figure line segments in the model, containing: first, identifying the key points and the line segments in the two-dimensional grid figure, positioning the key point coordinates and solving the intersection points in the original line segments, cutting each original line segment into multiple sub-line segments at the intersection points; then, solving the node common times, and identifying the valid nodes and the valid line segments by comparing the common times with the preset threshold.

[0042] The nodes with the common times greater than the preset threshold can be determined as invalid nodes, and the line segments to which the invalid nodes belong are regarded as invalid line segments, and the remaining nodes and line segments are regarded as valid nodes and valid line segments. For example, the nodes with the common times greater than one are regarded as invalid nodes, and the line segments to which the invalid nodes belong are regarded as invalid line segments, and the remaining nodes and line segments are regarded as valid.

[0043] Further, in the embodiments of the present case, the topological relationship between the valid nodes and the line segments is acquired according to the valid nodes and the valid line segments, containing: first, generating a grid by reordering the valid nodes and the valid line segments, then creating a node class for storing the valid node numbers and coordinate information and a line segment class for storing the valid line segment numbers and the node numbers constituting the valid line segments.

[0044] When the figure in Figure 2 is identified, it can be identified that the figure has 20 key points and 6 line segments, wherein 8 key points are line segment intersection points, the line segments are cut at the intersection points, and a total of 22 sub-line segments are cut, as shown in the attached Figure 3 The common times of the 20 nodes in Figure 3 are solved, and the valid nodes and the line segments after solving are reordered, and the grid result is as shown in Figure 4 .

[0045] As a preferred embodiment, further, the node relationship matrix, the node connection vector, the node number vector, the node ordering vector and the line segment angle vector are constructed according to the topological relationship, containing: first, creating the node relationship matrix according to the connection relationship between the valid nodes; then, creating the node connection vector according to the upper triangular matrix in the node relationship matrix; then, processing all the line segments of the common nodes, and creating the node number vector for storing the number information of the line segments of the common nodes in the entire grid, creating the node ordering vector for storing the ordering information of the nodes in the corresponding common line segments, and creating the line segment angle vector for storing the line segment and X-axis positive direction angle information with the common nodes as the reference. For example, the node relationship matrix, the node connection vector, the node number vector, the node ordering vector and the line segment angle vector can be acquired by identifying Figure 4The connection relationship of each effective node is identified, and a node relationship matrix A is constructed, as shown in the following table.

[0046] Figure 4 The connection relationship of each effective node in the grid is identified, and a node relationship matrix A is constructed, as shown in the following table. Figure 5 The connection relationship of each effective node in the grid is identified, and a node relationship matrix A is constructed, as shown in the following table. Figure 6 The connection relationship of each effective node in the grid is identified, and a node relationship matrix A is constructed, as shown in the following table.

[0047] Further, the polygonal proportional boundary finite element of the effective node is generated by using the topological relationship of the node and the line segment and the closed domain structure, which includes: first, identifying whether the effective node can generate a new element of the polygonal proportional boundary finite element; then, for the effective node that can generate a new element, identifying the line segments shared by the node, and grouping the adjacent line segments two by two, and setting the terminal edge, the starting edge, and the terminal point and the transition point for each group of line segments; then, solving the connection relationship of the terminal point and the transition point of each group of line segments, if the connection relationship solving result is that the terminal point and the transition point can be connected into a line segment, a new element is generated, otherwise the next transition point is identified until the transition point can be connected with the terminal point into a line segment, until all the effective nodes that can generate a new element are identified.

[0048] The information of the effective node and the line segment is preprocessed, and a new element, i.e. a proportional boundary finite element or a finite element, is generated according to the topological relationship between the effective node and the line segment and the closed domain structure. Figure 7As shown, the node whether can generate new unit is identified in turn according to the numbering order of the effective node, if the node cannot generate new unit is identified, the next node is continuously identified; the line segment of the node which can generate new unit is identified, the adjacent line segments are classified into a group two by two, the terminal edge and the starting edge are defined, and the terminal point and the transition point are defined; the connection relationship of the terminal point and the transition point of each group of line segments is solved, if the solving result is that the terminal point and the transition point can be connected into a line segment, new unit is generated, if the terminal point and the transition point cannot be connected into a line segment, the next transition point is identified until the terminal point and the transition point can be connected into a line segment; after new unit is generated, the next node which can generate unit is identified again until all effective nodes are identified.

[0049] In specific operation, the effective node which can generate new unit, the terminal edge, the terminal point, the starting edge, the transition point and the connection relationship of the terminal point and the transition point need to be determined. The specific implementation algorithm can be designed as follows: whether VNL(a) of the node numbered a is greater than or equal to 2 is judged, if VNL(a)≥2, the node can generate new unit, otherwise, the next node is entered for judgment. If the node a can generate new unit and the finally generated new unit has n nodes, the node a is the first node, all line segments which share the node a are identified, and every adjacent two line segments (NLN(i+1), NLN(i)) are classified into a group, wherein NLA(i+1)>NLA(i) is necessary, the line segment NLN(i+1) is defined as the terminal edge and the other node of the line segment is defined as the terminal point b, and the terminal point is the nth node, the line segment NLN(i) is defined as the starting edge and the other node of the line segment is defined as the transition point m.

[0050] In the identification of the connection relationship of the terminal point and the transition point, if the line segment can be connected, that is, A(b,m)=1, new unit is generated, if the line segment cannot be connected, the transition point is taken as the intermediate point m1, all line segments which share the intermediate point m1 are identified, the order j of the line segment NLN(i) in all line segments which share the intermediate point m1 is determined, based on the principle that all nodes constituting the unit must be sorted counterclockwise, the line segment NLN(j-1) is located, and the other node of the line segment NLN(j-1) which is composed of the intermediate point m1 is the transition node m at this time, if A(b,m)=1, the unit is generated, otherwise, the node is taken as the intermediate point m2, and then the next transition point is continuously searched until the terminal point can be connected to generate new unit.

[0051] After the above steps, the polygonal proportional boundary finite element (1-2-4-7-6) and the finite element (2-3-5-4, 4-5-8-7) are finally generated. The node and unit information are arranged, and the two-dimensional proportional boundary finite element-finite element coupling numerical grid which can be used for numerical analysis is output, as shown in the accompanying drawings. Figure 9

[0052] ​Since the grid pattern of the model is drawn in the computer-aided design software, and then the effective nodes and line segment information is obtained by identifying the key points and line segments of the pattern, the meshing is more controllable, and the transition problem between different size meshes does not need to be considered, the local mesh encryption can be carried out at any position according to the needs, and the cross-scale fine meshing of the mesh can be realized. Further, the effective nodes and line segments are preprocessed, so as to obtain the related information between the nodes and the nodes, the line segments and the line segments, and the nodes and the line segments, and the related information is stored in advance for the next step, so as to realize the rapid generation of the unit. Further, the unit is generated through the topological relationship of the effective nodes and line segments and the construction of the closed domain, the rapid generation of the proportional boundary finite element and the finite element is realized, and finally the node and unit information is arranged to complete the generation of the two-dimensional coupled mesh. Therefore, through the scheme in the embodiment, the cross-scale fine meshing of the mesh can be realized, and the high-quality two-dimensional proportional boundary finite element-finite element coupled numerical mesh can be generated, wherein the mesh refinement of the part needing local encryption can be carried out, so that the expected effect can be achieved, and the mesh transition between the proportional boundary finite element and the finite element does not need to be concerned, the pre-processing time is effectively reduced, the mesh recognition efficiency, speed and accuracy can be greatly improved, and the system can be used for the identification and generation of the calculation model of the complex large-scale engineering model.

[0053] Further, based on the above method, the embodiment of the present application also provides a two-dimensional SBFEM-FEM coupled numerical mesh identification system based on human-computer interaction, comprising: a node line segment acquisition module, a node line segment processing module and a numerical mesh generation module, wherein,

[0054] The node line segment acquisition module is used to read the two-dimensional mesh pattern of the model, and the effective nodes and effective line segments are obtained and stored by identifying and cutting the line segments of the two-dimensional mesh pattern of the model;

[0055] The node line segment processing module is used to obtain the topological relationship between the effective nodes and the line segments according to the effective nodes and the effective line segments, and construct the node relationship matrix, the node connection vector, the node number vector, the node ordering vector and the line segment angle vector according to the topological relationship;

[0056] The numerical mesh generation module is used to generate the polygon proportional boundary finite element of the effective node by using the topological relationship of the node and the line segment and the closed domain construction; and assemble the effective node and the polygon proportional boundary finite element information, and generate the two-dimensional proportional boundary finite element-finite element coupled mesh.

[0057] Unless otherwise specifically stated, the relative steps, numerical expressions and numerical values of the components and steps set forth in these embodiments do not limit the scope of the present application.

[0058] The various embodiments are described in the specification in a progressive manner, each embodiment focusing on the differences from other embodiments, and the same or similar parts between embodiments can be mutually referred to. For the system disclosed in the embodiments, since it corresponds to the method disclosed in the embodiments, the description is relatively simple, and the relevant parts can be referred to the description of the method.

[0059] The units and method steps of each example described in combination with the embodiments disclosed herein can be realized in electronic hardware, computer software or a combination of both. In order to clearly illustrate the interchangeability of hardware and software, the composition and steps of each example have been described in the above description in general terms. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation does not exceed the scope of the present application.

[0060] Those skilled in the art can understand that all or part of the steps in the above method can be instructed by a program to complete the relevant hardware, and the program can be stored in a computer readable storage medium, such as a read-only memory, a magnetic disk or an optical disk. Alternatively, all or part of the steps of the above embodiments can also be implemented using one or more integrated circuits, and accordingly, each module / unit in the above embodiments can be implemented in the form of hardware or in the form of a software function module. The present application is not limited to any specific form of combination of hardware and software.

[0061] Finally, it should be noted that the above-described embodiments are merely specific implementations of the present application, which are used to illustrate the technical solutions of the present application, and are not limiting. The protection scope of the present application is not limited thereto, although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that any person skilled in the art can modify or easily think of changes to the technical solutions described in the foregoing embodiments within the technical scope disclosed by the present application, or make equivalent replacements to some of the technical features; and these modifications, changes or replacements do not cause the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A two-dimensional SBFEM-FEM coupling numerical grid identification method based on human-computer interaction, characterized in that, The application relates to a method for reading a two-dimensional grid pattern of a model, acquiring and storing effective nodes and effective line segments by identifying and cutting the two-dimensional grid pattern line segments in the model, which comprises the following steps. First, key points and line segments in the two-dimensional grid pattern are identified, the key point coordinates are located, and intersection points in original line segments are solved and acquired, and each original line segment is cut into multiple sub-line segments at the intersection points. Then, the node common times are solved, and the effective nodes and effective line segments are identified by comparing the common times with a preset threshold value. The topological relationship between the effective nodes and the line segments is acquired according to the effective nodes and the effective line segments, and a node relationship matrix, a node connection vector, a node number vector, a node ordering vector and a line segment angle vector are constructed according to the topological relationship. The polygonal proportional boundary finite elements of the effective nodes are generated by using the topological relationship between the nodes and the line segments and the closed domain structure. The effective nodes and the polygonal proportional boundary finite element information are assembled, and a two-dimensional proportional boundary finite element-finite element coupling grid is generated.

2. The human-computer interaction based two-dimensional SBFEM-FEM coupling numerical mesh recognition method according to claim 1, characterized in that, In the identification of the effective nodes and the effective line segments by comparing the common times with the preset threshold value, the nodes with the common times greater than the preset threshold value are determined as invalid nodes, the line segments to which the invalid nodes belong are regarded as invalid line segments, and the remaining nodes and line segments are regarded as the effective nodes and the effective line segments.

3. The human-computer interaction based two-dimensional SBFEM-FEM coupling numerical mesh recognition method according to claim 1, characterized in that, The topological relationship between the effective nodes and the line segments is acquired according to the effective nodes and the effective line segments, which comprises the following steps.

4. The human-computer interaction based two-dimensional SBFEM-FEM coupling numerical mesh recognition method according to claim 1 or 3, characterized in that, First, the grid is generated by reordering the effective nodes and the effective line segments, then, a node class for storing the effective node number and coordinate information and a line segment class for storing the effective line segment number and the node number information of the effective line segment are created.

5. The human-computer interaction based two-dimensional SBFEM-FEM coupling numerical mesh recognition method according to claim 1, characterized in that, The node relationship matrix, the node connection vector, the node number vector, the node ordering vector and the line segment angle vector are constructed according to the topological relationship, which comprises the following steps. First, the node relationship matrix is created according to the connection relationship between the effective nodes; then, the node connection vector is created according to the upper triangular matrix in the node relationship matrix; then, all the line segments of the common nodes are processed, and the node number vector for storing the number information of the line segments of the common nodes in the entire grid, the node ordering vector for storing the ordering information of the nodes in the corresponding common line segments and the line segment angle vector for storing the line segment and X-axis positive direction angle information based on the common nodes are created. The polygonal proportional boundary finite elements of the effective nodes are generated by using the topological relationship between the nodes and the line segments and the closed domain structure, which comprises the following steps. First, whether the effective nodes can generate new units of the polygonal proportional boundary finite elements is identified; then, for the effective nodes capable of generating new units, the line segments of the common nodes are identified, and adjacent line segments are grouped into a group, and the terminal edge, the starting edge and the terminal point and the transition point of each group of line segments are set; then, the connection relationship of the terminal point and the transition point of each group of line segments is solved, if the connection relationship solving result is that the terminal point and the transition point can be connected into a line segment, a new unit is generated, otherwise the next transition point is identified, until the transition point can be connected into a line segment with the terminal point, and until all the effective nodes capable of generating new units are identified.

6. The human-computer interaction based two-dimensional SBFEM-FEM coupling numerical mesh recognition method according to claim 5, characterized in that, The method comprises: judging whether the node connection vector of the effective node satisfies a preset value, and if yes, determining that the effective node can generate a new element, otherwise, determining that the effective node cannot generate a new element.

7. The human-computer interaction based two-dimensional SBFEM-FEM coupling numerical mesh recognition method according to claim 5, characterized in that, For the effective node that can generate a new element, line segments sharing the node are identified, and adjacent line segments are grouped into a group, and a terminal edge, a starting edge, a terminal node and a transition node are set for each group of line segments, comprising: first, setting that the new element generated by the effective node a has n nodes, and the effective node a is the first node; then, identifying all line segments sharing the node a, and grouping each adjacent two line segments into a group, and if the included angle vector of the next line segment is greater than that of the current line segment, setting the next line segment as the terminal edge and the other node of the line segment as the terminal node b, and setting the current line segment as the starting edge and the other node of the line segment as the transition node m.

8. The human-computer interaction based two-dimensional SBFEM-FEM coupling numerical mesh recognition method according to claim 7, characterized in that, The connection relationship of the terminal node and the transition node of each group of line segments is solved, and if the connection relationship solving result is that the terminal node and the transition node can be connected into a line segment, a new element is generated, and further comprising: if the terminal node and the transition node cannot be connected into a line segment, taking the transition node as an intermediate node m1, identifying all line segments sharing the intermediate node m1, determining the order j of NLN(i) in all line segments sharing the intermediate node m1, positioning the line segment NLN(j-1) based on the counterclockwise ordering principle of all nodes constituting the element, and the other node of the line segment NLN(j-1) together with the intermediate node m1 is the current transition node m, if A(b,m)=1, a new element is generated, otherwise, the node is taken as an intermediate node m2, and then the next transition node is searched, until the terminal node can be connected into a line segment to generate a new element, wherein, NLN(i) represents the line segment with the counterclockwise ordering number i in all line segments sharing the intermediate node m1; NLN(j-1) represents the line segment with the counterclockwise ordering number j-1 in all line segments sharing the intermediate node m1; A(b,m) represents the node relationship matrix element value of the node b and the node m.

9. A two-dimensional SBFEM-FEM coupling numerical grid identification system based on human-computer interaction, characterized in that, The method comprises: a node line segment acquisition module, a node line segment processing module and a numerical grid generation module, wherein, The node line segment acquisition module is used for reading a two-dimensional grid pattern of a model, acquiring and storing effective nodes and effective line segments by identifying and cutting the two-dimensional grid pattern line segments in the model; The node line segment processing module is used for acquiring the topological relationship between the effective nodes and the line segments according to the effective nodes and the effective line segments, and constructing a node relationship matrix, a node connection vector, a node number vector, a node ordering vector and a line segment included angle vector according to the topological relationship; The numerical grid generation module is used for generating a polygonal proportional boundary finite element of the effective node by using the topological relationship of the nodes and the line segments and the closed domain structure, assembling the effective node and the polygonal proportional boundary finite element information, and generating a two-dimensional proportional boundary finite element-finite element coupling grid.

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