JPH05290015A - Mesh generator - Google Patents

Abstract

PURPOSE:To automatically generate the mesh of a desired model by generating data structure in conformity with an alteration designation table for every combination of the designated variable items (value) of a model mesh. CONSTITUTION:A model mesh file 12 and the alteration designation table to store procedure to calculate the value of the predetermined variable item among the items of the mesh of the model mesh file 12 and generate the data structure of the mesh are provided, and the predetermined variable item of the model mesh selected from the model mesh file 12 and its default value are displayed, and the data structure of the mesh is generated by calculating the value of the variable item in accordance with the alteration of the default value of the variable item or the designation of changing an area in conformity with the alteration designation table 13, and substituting it for the item value of the model mesh.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mesh generator for generating a model mesh.

[0002]

2. Description of the Related Art In recent years, the role of simulation in product development has increased. Structural analysis and magnetic field analysis are examples. The work of mesh division is absolutely necessary as a pre-analysis step. The mesh division is to divide the model to be analyzed into fine elements. In the analysis, a predetermined formula is applied to each of the divided elements (mesh) and calculation is performed. The analysis result greatly differs depending on the method of mesh division, and the work of mesh division in analysis occupies a very important position. Therefore, the analyst is required to be skilled in mesh division.

Even if the model can be divided into meshes,
If this mesh cannot be input to the computer system, it cannot be analyzed. To input the mesh into the computer system, the coordinates of the points (nodes) are input, and further the sequence of the node numbers is input. The array of node numbers represents a mesh, which is formed by connecting the previously input nodes to form a hexahedron, for example, (a) of FIG.
The meshes 1 and 2 in (b). Here, the meshes 1 and 2 in (a) and (b) of FIG. 24 represent the XZ plane among the three dimensions as shown in the figure.

Now, as two models, for example, a mesh 1 in FIG. 24 (a) and a mesh 2 in FIG. 24 (b).
Take as an example. These two models have almost the same shape, but the dimensions are slightly different in the parts in the figure. Even if the dimensions are slightly different in this part, the method of dividing the mesh is the same, but the coordinates of the nodes are different, so the analyst can input the meshes of the two models individually,
I was copying and correcting different parts by manual input.

[0005]

As described above, conventionally, the analyst manually inputs the mesh data of the model to be simulated (node coordinates, arrangement of node numbers, etc.) by hand. There was a problem that when creating a model mesh when the shape is almost the same but the dimensions are changed slightly, it is necessary to individually input from the beginning or to copy and modify it. .. At this time, the analyst must divide the mesh considering how to divide the model to be analyzed to obtain an effective analysis result, and input the data into the computer system. If you are not familiar with both the concept of mesh division and the method of inputting to a computer system, you will not be able to input and simulate, or even if you can do it, you will need a lot of effort and you will not be able to perform simulation quickly. As a result, there was a problem that the new product development was delayed.

The present invention solves these problems.
Providing a model mesh and modification specification table, each mesh data structure is generated according to the modification specification table for each combination of variable items (values) specified for the selected model mesh, and the mesh of the desired model is automatically generated. The purpose is to

[0007]

[Means for Solving the Problems] Means for solving the problems will be described with reference to FIG. In FIG. 1, the template mesh file 12 stores in advance the data structure of the model mesh of the model.

The change designation table 13 stores a procedure for calculating the values of variable items of the template of the template mesh file 12 and generating a data structure of the mesh.

The mesh generation function 4 determines the mesh of the template selected from the template mesh file 12,
The value of the variable item whose domain is designated is calculated in accordance with the change designation table 13, a data structure of the mesh is generated, or a combination of a plurality of variable items (values) designated with the domain is generated, and the combination is calculated for each combination. It calculates values and generates a data structure of mesh.

The mesh editing function 5 finds the aspect ratio of each element in the generated data structure of the mesh, and when it does not fit within the allowable value, sets a node on the side of the long element that does not fit and divides it. When the total number of meshes after division exceeds a predetermined number, the data structure of the mesh before division is output.

[0011]

According to the present invention, as shown in FIG. 1, predetermined variable items of the template mesh selected from the template mesh file 12 and their default values are displayed, and the variable range is selected from these displayed variable items. Based on the value of the designated variable item, and the default value (or the designated value) of the others, the value of the variable item is calculated according to the change designation table 13 to generate the mesh data structure. There is.

At this time, a combination of variable items is generated corresponding to the designation of the variable region and the number of divisions.
The change designation table 13 for each of these generated combinations
The value of the variable item is calculated according to the above, and the data structure of the mesh is generated respectively.

With respect to the data structures of the generated meshes, the mesh editing function 5 obtains the aspect ratio of each element and, when the mesh ratio is not within the allowable value, sets a node on the side of the long element that does not fit. I am trying to divide it.

Further, when the total number of meshes after division so that the aspect ratio of each element falls within the allowable value exceeds a predetermined number, the data structure of the mesh before division is output.

Therefore, the template mesh file 12 and the change designation table 13 are provided, and the data structure of the mesh is generated in accordance with the change designation table 13 for each combination of variable items designated for the selected mesh of the template. Furthermore, by generating the data structure of the divided mesh when the aspect ratio does not fall within the allowable value, or by outputting the data structure of the mesh before the division when the number of meshes after the division exceeds a predetermined number,
You can automatically generate the mesh of the desired model, automatically generate the data structure of all combinations of meshes according to the domain specification, or divide the automatically generated mesh aspect ratio to be within the allowable value. Further, it becomes possible to keep the total number of meshes below a predetermined number.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the configuration and operation of an embodiment of the present invention will be described in detail with reference to FIGS.

FIG. 1 shows a block diagram of an embodiment of the present invention.
In FIG. 1, an analysis condition input 1 is a condition of a mesh of a model to be analyzed (for example, material characteristics, boundary conditions, etc.) and is input to the solver 14.

The mesh generator 2 is for automatically generating a mesh for simulating a model, and here is for generating a mesh data structure that can be input to a computer system. The mesh generator 2 includes an input unit 3, a mesh generation function 4,
It comprises a mesh editing function 5, an input data file 6, a data structure 7, and the like.

The input unit 3 is for inputting various data, and here, it is selected from a screen (screen 1, screen 2, screen 3 and the like, which will be described later) and input, or in an input field on the screen. It is for inputting data.

The mesh generation function 4 calculates the template mesh selected from the template mesh file 12 as follows.
According to the change specification table 13, the value of the variable item with the domain specified is calculated to generate the data structure of the mesh, or the combination of the plurality of variable items with the field specified is generated, and the value is calculated for each combination. Then, the data structure of the mesh is generated (described later with reference to the flowchart of FIG. 7).

The mesh editing function 5 obtains the aspect ratio of each element in the generated data structure of the mesh, and when it is found that the element does not fit within the allowable value, a node is set on the side of the longer element that does not fit to divide it. Or outputting the data structure of the mesh before division when the total number of meshes after division exceeds a predetermined number (described later with reference to the flowchart of FIG. 15).

The input data file 6 stores the data input from the screen, which is the input unit 3,
It stores data such as shapes and dimensions, shape member names, and variable item dimension values.

The data structure 7 is the data structure of the mesh generated by the mesh generation function 4, and is the data describing the method of mesh division of the shape of the size to be analyzed (see FIG. 14). This data structure 7 is stored in a file.

The shape database 8 is a database relating to the shape of the model. Here, the shape classification file 9, the variable item file 10 and the graphic file 1 are used.
1, a template mesh file 12, a change designation table 13, and the like.

The shape classification file 9 stores the shapes registered in the template mesh file 12, and here, as shown in FIG. 2A, a shape code, a shape name, and a shape member. It stores the name. When the analyst looks at the list of shape names and selects the model to be analyzed and inputs the code, the shape member name corresponding to it is recorded. In the subsequent processing after the recording, a file such as the template mesh file 12 is referred to by the recorded member name.

The variable item file 10 is a file in which each side of the shape is given a name and is stored as a variable item. For example, the height of a shape is named variable item name H and width W (definition)
Then, clarify where the input dimensions are in the shape of the model. Further, the variable item file 10 stores typical dimension values (default values) of the shape of the model to assist in inputting the dimension of the model to be analyzed (see FIG. 6). (See (a)).

The graphic file 11 stores data necessary for displaying the shape registered in the template mesh file 12 in graphic form. This graphic file 11 is not related to mesh division at all, but stores data necessary for confirming what shape the shape selected from the shape classification file 9 is. Further, along with the shape of the model, variable items are also stored with data necessary for displaying them as shown in FIGS. 6 (a) and 6 (b).

The model mesh file 12 stores in advance the data structure of the mesh serving as the model for each shape, and stores the data structure of the model mesh when an expert actually divides the mesh. It was done.

The change specification file 13 stores the rewriting method (procedure) of the template mesh file 12, and when a specific dimension is given, the data structure of the template mesh is rewritten according to the dimension. It stores a place and a procedure for calculating a numerical value to be rewritten (FIG. 13).
reference).

The solver 14 is the mesh generator 2
For the data structure of the mesh automatically generated by, under the condition given by the analysis condition input 1,
The value (for example, magnetic flux density) of each part of the mesh is calculated according to the flowchart of FIG. The calculated analysis contents are printed on paper or displayed graphically as two-dimensional or three-dimensional information (Fig. 2).
2, see FIG. 23).

FIG. 2 shows an example of the file of the present invention. Figure 2
(A) shows an example of the shape classification file. This is
3 is an example of the shape classification file 9 that forms the shape database 8 of FIG. 1, in which the shape code, the shape name, and the shape member name of those registered in advance in the template mesh file 12 are registered as a pair. Therefore, the analyst
As described above, when the shape name list is extracted from the shape classification file 9 and displayed, and the corresponding shape code is input, the shape member name corresponding to this shape code is recorded, and this is recorded in the subsequent processing. Files such as the template mesh file 12 are referred to by the shape member name.

FIG. 2B shows an example of a variable item file. This is an example of the variable item file 13 forming the shape database 8 of FIG. 1, and the variable items that are variable in the shape dimensions correspond to the shape name of the shape classification file 9 of FIG. In addition, typical dimension values (represented by basic dimension code, basic dimension name, parameter name, and parameter dimension) are registered in advance (see FIG. 6).

Next, the procedure for inputting the data of the shape of the model will be specifically described according to the order shown in the flowchart of FIG. In FIG. 3, in S1, the shape code is input. This is to display the contents read from the shape classification file 9 of FIG. 2A as shown in the screen 1 of FIG. 4, and from this screen 1, input “1” of “core shape to be analyzed” here. Fill in the fields. As a result, the core shape of the model to be analyzed is "EI center chip gap".
Has been entered as.

In S2, the basic size code is input. This displays the contents read from the variable item file 10 of FIG. 2B as shown in the screen 2 of FIG.
Therefore, here, "11" of "basic dimension code" is input in the input field. As a result, the basic dimension code of the core shape of the model to be analyzed is input as "11".

In step S3, the default value of the variable item is determined using the basic size code as a key. This is performed by extracting the default values (default values) of the variable items of the basic dimension code "11" in the core shape "EI center chip gap", which are input in S1 and S2, respectively. a),
It is displayed as shown in (b).

In S4, the dimensions of the analytical model are input. For example, among the variable items displayed as shown in screen 3 of FIG. 6 in S3, the initial values in the figure are rewritten to the dimensions of the model to be analyzed, and the MIN (minimum value) MAX (maximum value) and the number of times (the number of times of division) are arbitrarily input (see the explanation of FIG. 6 for the range of variation). These input data are stored in the input data file 6.

As described above, the omitted values (initial values, default values) of the variable items corresponding to the shape code and the basic dimension code are displayed on the screen 3 of FIG. MAX, MI in the range
By inputting N and the number of divisions, the data necessary for creating the mesh of the model can be input by a simple operation, and it is also shown which of the model shapes the variable items correspond to in FIG. It is displayed graphically as shown in (b).

FIG. 4 shows an example (screen 1) of the shape code selection screen of the present invention. This is a list of shape names of the shape classification file 9 shown in FIG. Here, a list of core shapes is displayed. From this list, enter the shape code "1" in the input field and click "E".
Select "I Center Gap".

FIG. 5 shows an example (screen 2) of the basic dimension code selection screen of the present invention. This is “1” on screen 1 in FIG.
In response to the selection of, the list of the basic dimension codes of the variable item file 10 of FIG. 2B is displayed. Here, the basic dimension code “11” is input from this list and “EI30 / 26K” is selected.

FIG. 6 shows a default value (initial value) of variable items of the model of the present invention and a screen example (screen 3) of the variable range.
This corresponds to the selection of the shape code “1” on the screen 1 of FIG. 4 and the basic dimension code “11” on the screen 2 of FIG. 5 from the variable item file 10 of FIG. 2B. Initial value (default value) of basic item dimensions to be displayed on screen 3
Shown above.

FIG. 6A shows variable items and variable areas.
This is as shown in the parameter input table shown.
Parameters (variable items) W1, W2, W3, WG, H1,
H2, H3, H, D, EGP, BG1, BH1, BL1
The total of 13 initial values (default values) are displayed. The positions of these variable items in the model are shown in FIG.

Further, the variable region sets MIN (minimum value) and MAX (maximum value) to be divided, and the interval is divided by the number of times. For example, in the case of the parameter initial value MIN of the domain, MAX number of the domain WG 5.000 4.000 6.000 3, it means that the value of MAX from MIN of the WG is divided into three, and in this example, WG = There are three types, 4.000 5.000 6.0000. The same applies to other variable items for which a variable range is set.

Next, the procedure for generating the data structure of the model mesh based on the input data input in the description of FIGS. 3 to 6 will be specifically described according to the order shown in the flowchart of FIG.

In FIG. 7, in step S11, input data (shape member name, variable item) is read. this is,
The input data input in the description of FIGS. 3 to 6 is read, for example, as shown in FIG.

In step S12, a template mesh is selected using the shape member name as a key. This is done by selecting a template mesh from the template mesh file 12 using the shape member name as a key, for example, as shown in FIG.

In step S13, the number N of variable item sets is calculated. This is the input data example of FIG. 8 read in S11, and the number N of sets of variable items having a division number of 1 or more is calculated. In the case of FIG. 8, variable items with a division number of 1 or more are There are two. Since the values of WG and H are three in each of WG 4 5 6 H 1 1.5 2, it is clear that there are 9 combinations in total as shown in FIG. 9. Therefore, N = 9.

In S14, I = 0 is initialized. S15
Is I = I + 1. In S16, a set of variable items is determined.

In S17, variables are defined. These S16,
In S17, for example, it is determined that the set is the head of the set of variable items in FIG. 9, and the value of the variable (variable item) at that time is WG = 4, H = 1.
It is defined as.

In step S18, two records are read from the change item. This is to read two records in order from the beginning of the change item record of the change instruction table 13 of FIG. 13 having the same shape member name. Here, the first two records GRID 2 8.25 0.0 0.0 <representing a location record ... GRID 2 <G2> 0.0 0.0 <representing a change record ... Read.

A step S19 finds a template mesh record that matches the location record. For this, for example, with respect to the above-mentioned location record extracted in S18, a matching record is found from the template mesh file 12 having the same shape member name, for example, from FIG.

In step S20, it is determined whether or not it has been found. Here, since it was found as in FIG. 12, the template mesh record is rewritten with the change record in S21 and written in the data structure. In this example, the record of FIG. 12 is rewritten as the change record of FIG. 13 and is written in the mesh data structure of FIG. At this time, <G2
> Substitutes the variable item values W1 = 30 and W2 = 20 of FIG. 8 into SET G2 = (W1-W2) /2.0 of the variable definition record of FIG. 13, and G2 = (30-20) / 2 = 5 is obtained, and this value is set at the position of <G2>. Then, the process proceeds to S22. On the other hand, in the case of NO in S20, it was not found, so an error (unchangeable) occurs in S24, and the location record is output as a mesh data structure in S25.

A step S22 decides whether or not there is a record of the changed item. If there is, S18 and the subsequent steps are repeated until no more. On the other hand, if there is none, the process proceeds to S23.

In S23, it is determined whether N = I, that is, the number N of variable item pairs obtained in S13 has been repeated. In the case of YES, since the mesh data structure has been generated by the number N of variable item sets, the process ends. On the other hand, in the case of NO,
I = I + 1 is set in S15, and S1 is set for the next variable item set.
Repeat from 6 onward.

As described above, the data structures of the mesh shown in FIG. 14 corresponding to the number N of sets of variable items calculated in S13 are automatically generated. Here, the number of sets of variable items in FIG. 9 and the data structure of nine meshes are automatically generated.

FIG. 8 shows an example of input data of the present invention. This is an example of input data input according to the flowchart of FIG. 3, in which there are 13 variable items, and the variable range is set as shown.

FIG. 9 shows an example of a set of variable items according to the present invention. This is about the input data example of the variable items in FIG.
With respect to two variable items WG and H having a division number of 2 or more, nine sets are arranged as a combination thereof. These nine sets have variable items WG = 4, 5, 6 H = 1, 1.5, 2 and are thus combined in a non-overlapping form.

FIG. 10 shows a specific example of the data structure of the template mesh of the present invention. Here, for the record having the GRID of the node designation record, the node number 1 is created at the coordinate (0, 0, 0) as described on the right side. Also,
The record having the GCIR of the node designation record has a radius of 1 with the node number 11 as the center, as described on the right side.
0, the angle with the X axis is 45 °, and the Z coordinate is 0. In addition, for the record having MOVE of the node designation record, as described on the right side, the Z coordinates of the node numbers 1 to 22 are incremented by 10, and the node numbers 101 to 122 are added.
Create and turn.

The element designation record indicates designation of hexahedral elements or pentahedral elements, as shown in the figure. As described in the lower part, the first identifier of the node designation record is GRID: coordinate value input GCIR: intersection of a circle and a straight line passing through the center of the circle MOVE: movement and copying of defined node The identifier at the beginning of the designated record represents an ELE8: 6 face element.

ELE6: Represents a pentahedral element. FIG. 11 shows a mesh diagram of the present invention. This is shown in FIG.
2 schematically shows the data structure of the stationery mesh. For example, 1 represents the node "1" and corresponds to the first record GRID 1 of the node designation record in FIG. Similarly, 2, 11, 12, and 22 are the same as in FIG.
It corresponds to the second to fifth records of the node designation record of.

The hexahedron of element number 1 corresponds to the first record ELE81 of the element designation record of FIG.
The pentahedron of element number 2 is 2 in the element designation record of FIG.
It corresponds to the th record ELE62.

FIG. 12 shows an example of a template mesh file of the present invention. This is extracted from the template mesh file 12 using the shape member name as a key (FIG. 7).
See S12). This template mesh file 12 is
The data structure of a model mesh having a shape and dimensions preset by the expert is registered.

FIG. 13 shows an example of the change designation table of the present invention. The change specification table 13 includes variable definition records and
It consists of change item record and. The variable definition record defines a calculation formula for obtaining the value of the variable (variable item) in the variable item record.

The change item record is a pair of the location record and the change record, and replaces the corresponding record in the data structure of the template mesh to change its value. Specifically, when a record that matches the location record is found in the data structure of the template mesh, the record of the template mesh is replaced with the change record, and the data structure of the desired mesh is automatically generated. At this time, variables (variable items) in the change record
For example, when there is <G2>, the corresponding calculation formula SET G2 = (W1-W2) /2.0 of the variable definition record is calculated and replaced with this value.

FIG. 14 shows an example of the data structure of the mesh of the present invention. This is a data structure of a mesh that is automatically generated by modifying the template mesh file of FIG. 12 according to the modification designation table 13 of FIG. The data structure of the mesh in FIG. 14 will be automatically generated according to the flowchart in FIG. 7 for the number of sets of variable items in FIG.

FIG. 15 shows a mesh editing flowchart of the present invention. This is about the data structure of the mesh of FIG. 14 that is automatically generated by the description of FIG. 7 to FIG.
The aspect ratio of each element is calculated and divided so as to be within the allowable value, and the analysis accuracy is automatically improved. At this time, when the total number of meshes after division exceeds the computational capacity of the computer system, the total number of meshes within the limit is automatically suppressed, and the simulation analysis is performed with the maximum accuracy using limited resources. .. This will be described below.

In FIG. 15, S31 rewrites the data structure into a format for mesh editing. In S32, the aspect ratio of each element is calculated. Where the aspect ratio is
For example, taking the element number 606 of the data structure (mesh editing format) of FIG. 16 as an example, this one element number 606
Which is a combination of all sides, one of which is: aspect ratio = [edge (606-706)] / [edge (606-607)] = 0.1 / 0.335 ((( See a) mesh figure 1). Similarly, length ratios are calculated for other combinations of sides.

In step S33, it is determined whether all aspect ratios are within the allowable values. For example, when the allowable value of the aspect ratio is 1/2 ≦ aspect ratio ≦ 2, the side (606-706) = 0.1 in FIG. 16 and the side (606-607) = 0.335. The side (706-707) = 0.335, which is too long, and it is found that the ratio between the two is not within the allowable value (the allowable value between 1/2 and 2) (see the mesh diagram 1 in FIG. 18A). ). If it does not fit, the process proceeds to the division after S34. On the other hand, if it fits, the mesh diagram is graphically output in S40 and the process proceeds to S39.

In S34, a node is set on the side of the longest side of the element that does not fall within the allowable value, and is set on the side of the side related to this side. This is to set the node such that the long side is divided into equal parts, for example, so that the aspect ratio falls within the allowable value in the element found to have the aspect ratio not falling within the allowable value in S33. Specifically, FIG.
As shown in (b) of FIG. 8, the longest that does not fit in the allowable value is the node 1001 on the side (606-607), the node 1002 on the side (626-627), and the node 1002 on the side (706-707). The node 1004 is set on the 1003st side (726-727) (see FIG. 18B). here,
The elements are also changed from the old 506 to the new 506 and 1001. And these new 1001 to 1004
Since the number of nodes has increased, nodes are also set (1005 and 1006) on the edges related to them (see FIG. 18).
(B) of the mesh (point indicated by x on the mesh diagram 2), and the element is also changed (new 606, 1002).

In S35, the mesh is added and deleted using the new node. By setting and changing the nodes as described above, the final stage is reached as shown in the mesh diagram of FIG. FIG. 17 shows the data structure after editing (mesh editing format) at this time. In FIG. 17, in GRID 606 1.365 0 2.03 GRID 1001 1.5325 0 2.03 GRID 607 1.700 0 2.03, GRID 1001 is the side (606-607).
This is a node that is set by equally dividing the space. Similarly, GR
The above-mentioned values are similarly set for the IDs 1002 to GRID 1006.

In step S36, the total number of meshes is counted. S37
Determines whether the total number of meshes is within the solver capacity. If it fits, S32 and subsequent steps are repeated. On the other hand, if it does not fit, the mesh before subdivision is graphically output in S38. Then, the process proceeds to S39.

At S39, the analyst determines whether or not this mesh is acceptable. If it is good, the series of mesh division editing processing is terminated. If it is bad, use another template mesh or cut a new mesh.

By the above, for example, based on the data structure of the mesh of FIG. 16 (see the mesh diagram 1 of FIG. 18A), the aspect ratio of each element is calculated, and the allowable value is set for the side that does not fall within the allowable value. The nodes are set so that they fit within the area and the mesh is divided, and the data structure of the mesh in FIG.
9 mesh figure 3) is automatically generated. As a result, it is possible to automatically generate an appropriate mesh data structure by setting a node on the side where the aspect ratio does not fall within the allowable value and dividing the data structure of a mesh with slightly different dimensions automatically generated from the template mesh. It will be possible.

FIG. 16 shows an example of the data structure (mesh editing format) of the present invention. This is a data structure of a mesh that is automatically generated according to the flowchart of FIG. 7 and according to the description of FIGS. 8 to 14, and is an example of a data structure to be a mesh edit target. Here, for example, the first record GRID 506 1.365 0.0 1.775 has the element number of the node 506, and its position is the coordinate value of X, Y, and Z that follows it. Others are the same. A schematic representation of these is the mesh diagram 1 in FIG. 18 (a).

FIG. 17 shows an example of a data structure (mesh editing format) after editing according to the present invention. This is a data structure after nodes are set in equal division for the sides where the aspect ratio of each element of the data structure of the mesh in FIG. 16 does not fall within the allowable value. Here, nodes 1001 to 1006, which are indicated as split by the arrow, are newly set. A schematic representation of these is the mesh diagram 3 of FIG.

FIG. 18 shows an example of mesh editing according to the present invention. FIG. 18A shows the state before the editing. This is a schematic display (graphic output) of the data structure of FIG. 16 which is the target of mesh editing. The node number “506” described in this mesh diagram 1
"507", "606", "607", "706", "7"
07 "indicates GRID 506 and GRID 50 in FIG.
7, GRID 606, GRID 607, GRID
706 and GRID 707 are displayed based on the coordinate values.

FIG. 18B shows a state in the middle of editing. This is because the node numbers “1001”, “1003”, and “100” in the mesh diagram 1 of FIG.
After setting 5 ″ equally divided, a node is set at the associated x position.

FIG. 19 shows an example of mesh editing (final stage of editing) according to the present invention. As shown in (b) of FIG. 18, this is the final step after mesh division is performed by repeatedly setting the node to the long side and the related side so that the aspect ratio falls within the allowable value. Is a schematic representation of the data structure of. At this final stage, mesh division is automatically performed so that the aspect ratio when paying attention to each element is below the allowable value.

FIG. 20 shows a solver flowchart of the present invention. This is because the solver 14 of FIG. 1 gives analysis conditions (material characteristics, boundary conditions, etc.) to the data structure of the mesh of the model automatically generated by the mesh generator 2, for example, the data structure of the mesh of FIG.
This is an operation when a predetermined formula is calculated for the mesh and the result is obtained. This will be described below.

In FIG. 20, in S51, data is read. This is the condition for analysis (boundary condition,
Material properties, etc.) and the data structure of the edited mesh of FIG. 17 (see the mesh diagram of FIG. 19).

In step S52, the coefficient matrix K is created. This creates the coefficient matrix K shown in FIG. 21, for example, for solving the simultaneous linear equations in S54. S5
3 creates the right side vector f. This creates the right side vector f shown in FIG. 21, for example, for solving the simultaneous linear equations in S54.

In S54, the simultaneous linear equations are solved (K · U
= F). This solves the simultaneous linear equations K · U = f shown in FIG. 21, for example, when performing static magnetic field analysis. S55 outputs the result. As a result, as shown in FIG. 22, the magnetic flux density distribution chart is graphically output. Further, as shown in FIG. 23, the magnetic flux distribution density is graphically output in a perspective view.

By the above, the template mesh file 1
Based on the domain specified by the analyst as a variable item for the template mesh selected from 2, the data structures of all combinations of meshes are automatically generated according to the change specification table 13 created in advance, and the aspect ratio of each element is further generated. Mesh division is performed automatically so that is within the allowable range, and a mesh data structure is generated. Regarding the generated mesh data structure (for example, the data structure of FIG. 17), analysis conditions (boundary conditions, material characteristics, etc.) ) Is given to automatically analyze the magnetic flux density of each mesh. Then, the result can be displayed graphically so that the analyst can easily view the result.

FIG. 21 shows an example of simultaneous linear equations. This is an example of simultaneous linear equations that are applied to the data structure of an automatically generated mesh and used when performing static magnetic field analysis. Here, • K is a coefficient matrix, which is determined by the shape of the magnetic material, boundary conditions (symmetry), and material properties.

F is a magnetic field matrix, which is determined by the magnetic substance, the shape of the current element, the current value, and the like. U is the magnetization matrix, unknown
This is for obtaining this and calculating the magnetic flux density and the like from the value of U.

FIG. 22 shows an analysis example of the present invention. For the data structure of the mesh in FIG. 17, the solver 14 solves simultaneous linear equations according to the flowchart in FIG. 20, finds the magnetic flux density for each mesh, and calculates the vector (magnitude and direction of the magnetic flux density on each mesh of the model). It has been displayed with an arrow. The figure shows the appearance of the XZ plane.

FIG. 23 shows an analysis example of the present invention. This is a graphical representation of the magnetic flux density distribution similar to that shown in FIG. 22 with a perspective view giving a stereoscopic effect.

[0087]

As described above, according to the present invention,
Template mesh file 12 and change specification table 1
3, the mesh data structure is generated according to the change specification table 13 for each combination of variable items for the selected template mesh, or the mesh-divided data structure is generated so that the aspect ratio is within the allowable value. The data structure of the mesh before the division is output when the number of meshes after the division exceeds a predetermined value. (1) The data structure of the mesh of the desired model is automatically generated. (2) Automatically generate the data structure of the mesh of all combinations corresponding to the range and the number of divisions specified. (3) Divide the mesh so that the aspect ratio of the automatically generated mesh is within the allowable value. (4) It is also possible to keep the total number of meshes within a predetermined value so that analysis can be performed within the limited resources of the computer system. Can. As a result, even an inexperienced analyst can easily create an expert-level mesh by a simple operation and perform analysis quickly, efficiently, and accurately.

[Brief description of drawings]

FIG. 1 is a configuration diagram of an embodiment of the present invention.

FIG. 2 is an example of a file of the present invention.

FIG. 3 is an input flowchart of the present invention.

FIG. 4 is an example (screen 1) of a shape code selection screen of the present invention.

FIG. 5 is an example (screen 2) of a basic dimensional code selection screen of the present invention.

FIG. 6 is a screen example (screen 3) of default values and variable areas of variable items of the model of the present invention.

FIG. 7 is a mesh generation flowchart of the present invention.

FIG. 8 is an example of input data of the present invention.

FIG. 9 is an example of a set of variable items of the present invention.

FIG. 10 is a specific example of the data structure of the template mesh of the present invention.

FIG. 11 is an example of a mesh diagram of the present invention.

FIG. 12 is an example of a template mesh file of the present invention.

FIG. 13 is an example of a change designation table of the present invention.

FIG. 14 is an example of a data structure of a mesh of the present invention.

FIG. 15 is a mesh editing flowchart of the present invention.

FIG. 16 is a data structure of the present invention (mesh editing format)
Here is an example.

FIG. 17 is an example of a data structure (mesh editing format) after editing according to the present invention.

FIG. 18 is an example of mesh editing according to the present invention.

FIG. 19 is an example of mesh editing (final stage of editing) according to the present invention.

FIG. 20 is an example of a solver flowchart of the present invention.

FIG. 21 is an example of simultaneous linear equations according to the present invention.

FIG. 22 is an example of the analysis result of the present invention.

FIG. 23 is an example of an analysis result of the present invention.

FIG. 24 is an explanatory diagram of a conventional technique.

[Explanation of symbols]

 1: Input of analysis condition 2: Mesh generator 3: Input part 4: Mesh generation function 5: Mesh editing function 6: Input data file 7: Data structure of mesh 8: Geometry database 9: Shape classification file 10: Variable item file 11: Graphic file 12: Template mesh file 13: Change specification table 14: Solver

Claims (4)

[Claims] 1. A mesh generation device for generating a mesh of a model, a template mesh file (12) for storing a data structure of a model mesh of a model in advance, and mesh items of this template mesh file (12). Among them, a change specification table (13) for storing a procedure for calculating a value of a predetermined variable item to generate a data structure of a mesh, and selecting an arbitrary template from the template mesh file (12). In response to the selection, the preset variable items and their default values are displayed from this template, and the change designation table ( According to 13), the variable item values are calculated and the model mesh item values are replaced to generate a mesh data structure. A mesh generation device characterized by the above. 2. A combination of variable items is generated corresponding to the designation of the variable area of the variable item and the number of divisions, and the change designation table (1) is generated for each of the generated combinations.
3. The mesh generating apparatus according to claim 1, wherein the mesh generating apparatus is configured to calculate the value of the variable item and generate the data structure of the mesh in which the item value of the template mesh is replaced according to 3). 3. The data structure of the generated mesh is configured such that when the aspect ratio of each element is found and the element does not fit within the allowable value, a node is set on the side of the long element that does not fit to divide it. Claim 1 characterized by the above.
And the mesh generation device according to claim 2. 4. When the aspect ratio of each element is divided into a permissible value and the total number of meshes after division exceeds a predetermined number, the data structure of the mesh before division is output. The mesh generation device according to claim 3, which is characterized in that.