JPH1125292A - Mesh dividing device and method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a mesh dividing device and method for generating a mesh with a size to fulfill required analysis precision, and for automatically dividing each area with a shape to be analyzed in accordance with a desired type of mesh division. SOLUTION: An inputting means 1 inputs a shape to be analyzed which is preliminarily divided into plural areas with significance distribution and a division condition set for the shape to be analyzed. Based on the significance distribution, a division processing means 2 sets the significance of a mesh division designated area in a mesh division designated area set as per the division condition, and also sets a mesh division type, and the number of divisions and division node position of each side, and mesh-divides the mesh division designated area based on mesh division rule data 261 in which a correlation rule between the number of divisions and division node position and the mesh division type is preliminarily stored.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mesh dividing apparatus and a mesh dividing method for dividing a shape of an object to be analyzed when performing various analyzes of the object by applying a finite element method.

[0002]

2. Description of the Related Art When an analysis is performed using the finite element method, generally, the accuracy decreases when the mesh, that is, the element is made coarser, and the accuracy improves when the element is made finer. There is a problem that the capacity and the analysis time increase, and the calculation cost increases.

[0003] Therefore, when an analyst manually creates a mesh, the area where high accuracy is required is made smaller and more elements, and the area where low accuracy is required is made larger and less elements. To solve the above problems.

For example, as described in Japanese Patent Application Laid-Open No. 9-6994, an analysis shape with a configuration importance is input and an area importance is assigned to each region of the analysis shape. The degree is set and the density division is performed according to the density division rule.

[0005]

When an analyst creates a mesh by hand and efficiently performs element roughening, an area that requires high accuracy is equally divided into small elements, and low accuracy is required. Is divided into large elements unequally.
Furthermore, in the case of a two-dimensional shape or a three-dimensional shell shape, the number of divisions between opposite sides of a quadrilateral region is changed between a region where high accuracy is required and a region where low accuracy is required. In this case, a mesh called a junction is used to change the number of divisions between facing faces of the hexahedral region. Also, the change in mesh size is made to change over the entire analysis shape, so that the overall analysis accuracy is ensured.

However, Japanese Patent Application Laid-Open No. 9-6994 describes the above.
In the system described in Japanese Patent Application Laid-Open Publication No. H10-157, since the area importance uses discrete values set in the manner of 1, 2, and 3, it is difficult to achieve a change in mesh size that matches the required analysis accuracy. There is a problem that it is difficult to generate an uneven mesh and a junction mesh in a desired area.

An object of the present invention is to generate a mesh of a shape to be analyzed when performing analysis using the finite element method.
It is an object of the present invention to provide a mesh dividing device and a dividing method which can generate a mesh having a mesh size satisfying a required analysis accuracy, and which automatically automates each region of a shape to be analyzed with a mesh of a desired division type.

[0008]

In order to achieve the above object, the present invention relates to an analysis target shape divided in advance into a plurality of regions, and a significance distribution and a division condition set for the analysis target shape. An input unit for inputting the analysis target shape, a division processing unit for performing a mesh division process on the analysis target shape based on the importance distribution and the division condition, and an output unit for displaying the analysis target shape obtained by the mesh division. In the mesh division device, the division processing unit may include a designated region selection unit that selects a mesh division designated region from the plurality of regions based on a region designation condition in the input division condition. Importance area setting means for comparing the importance distribution with the selected mesh division designated area and setting the importance of the mesh division designated area; and the input division condition Division type setting means for setting a mesh division type in a mesh division designated region in which the importance is set based on a condition of a mesh division type in the inside, and division of each side of the mesh division designated region in which the mesh division type is set The division number / division node position setting means for setting the number and division node position, and the division number / division based on mesh division rule data in which a correlation rule between the division number / division node position and the mesh division type is stored in advance. A mesh division unit configured to perform mesh division on a mesh division designated area in which a node position is set.

In another aspect of the present invention, the division type setting means sets at least one of uniform mesh division, non-uniform mesh division, and junction mesh division based on the condition of the mesh division type. It is in.

Another feature of the present invention is an input step of inputting an analysis target shape divided in advance into a plurality of regions, together with an importance distribution and a division condition set for the analysis target shape. A division processing step of performing a mesh division processing of the analysis target shape based on the importance distribution and the division condition; and an output step of displaying the analysis target shape obtained by the mesh division, wherein the division processing is performed. A step of selecting a mesh division designated area from the plurality of areas based on an area designation condition in the input division condition, a step of selecting a mesh division designated area, the input importance distribution and the selected An importance area setting step of collating with a mesh division designation area and setting the importance of the mesh division designation area; and A division type setting step of setting a mesh division type in a mesh division designated area in which the importance is set based on the condition of the mesh division type; and a mesh size and an aspect ratio condition in the input division condition. And a division number / division node position setting step of setting a division number and a division node position of each side of the mesh division designated area in which the mesh division type is set, in an order based on the set importance, A mesh division step of mesh-dividing a mesh division designated area in which the number of divisions and division node positions are set based on mesh division rule data in which a correlation rule between the number and division node positions and the mesh division type is stored. It is in.

According to the present invention, the designated area selecting means selects a mesh division designated area from the plurality of areas based on an area designation condition among the division conditions input from the input means. The importance area setting means compares the input importance distribution with the selected mesh division designated area and sets the importance of the mesh division designated area. The division type setting means sets the mesh division type in the mesh division designation area in which the importance is set based on the mesh division type condition in the input division conditions. The division number / division node position setting means sets the division number and division node position of each side of the mesh division designated area in which the mesh division type is set. The mesh dividing means mesh-divides a mesh division designated area in which the number of divisions and the positions of the division nodes are set, based on mesh division rule data in which a correlation rule between the number of divisions and the positions of the division nodes and the mesh division type is stored in advance. .

The division type setting means sets at least one of uniform mesh division, non-uniform mesh division and junction mesh division based on the condition of the mesh division type.

Thus, a mesh having a mesh size that satisfies the required analysis accuracy can be generated in the mesh division designated area of the shape to be analyzed, and each area of the shape to be analyzed can be equally divided, unequally divided, and junction divided. A desired mesh combined can be automatically generated.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A mesh dividing apparatus and a mesh dividing method according to one embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows a functional configuration of a mesh dividing apparatus according to one embodiment of the present invention. An input means 1 for inputting a shape to be analyzed previously divided into a plurality of regions, together with a distribution of importance set for the shape to be analyzed and a condition for dividing the shape to be analyzed. When,
It is composed of a division processing unit 2 for performing a mesh division process on the analysis target shape based on the importance distribution and the division condition, and an output unit 3 for displaying the analysis target shape obtained by the mesh division.

The input means 1 is a means for inputting an area-divided analysis target shape, an importance distribution preset for the analysis target shape, and a division condition for dividing an area of the analysis target shape. It is.

The importance distribution indicates the degree to which the region divided in the analysis target shape is to be analyzed with high accuracy.
The region to be analyzed with the highest accuracy is represented as the region with the highest importance, and thereafter, the importance gradually decreases in accordance with the accuracy requirement.

The division conditions include an instruction of an area to be mesh-divided in the region-divided analysis target shape, a type of mesh division (equal division, non-uniform division, junction division), a mesh size indicating a mesh area, It refers to an aspect ratio or the like indicating the ratio of the length and width of the mesh.

The analysis target shape obtained by the region division, the predetermined importance distribution, and the division condition can be inputted by an analyst, that is, an operator using a keyboard, a mouse, or the like.

Alternatively, the analysis target shape, the importance distribution, and the division condition obtained by dividing the region may be stored in a data file in advance, and the data file may be input by the input unit 1.

The division processing means 2 designates, based on the area designation conditions in the division conditions input from the input means 1, a plurality of mesh division designated areas from among the divided areas of the analysis target shape. Region selecting means 21, importance area setting means 22 for comparing the importance distribution inputted from the input means 1 with each selected mesh division designated area and setting the importance of each mesh division designated area, and input means The division type setting means 23 sets the mesh division type in each mesh division designated area for which importance is set based on the condition of the mesh division type in the division conditions input from 1 and the input from the input means 1. Based on the mesh size and aspect ratio conditions in the division conditions, set the number of divisions and the position of the division nodes on each side of each mesh division designated area where the mesh division type is set. The division number and division node position are set based on the division number / division node position setting means 24 and the mesh division rule data 261 storing the correlation rule between the division number and division node position and the mesh division type in advance. Mesh dividing means 25 for dividing each designated mesh dividing area into meshes; and storage means 2 for storing mesh division rule data 261 and data necessary for various processes.
6.

The division processing means 2, designated area selection means 21, importance area setting means 22, division type setting means 2
3, the number of divisions / divided node position setting means 24, the mesh dividing means 25, and the storage means 26 are, for example, a CPU, a ROM,
(A program for performing a predetermined process is stored in advance), and can be executed by an electronic device such as a RAM or various CMOSs.

When a series of processing is completed, the output means 3
This is a means for outputting a division state of the analysis target shape obtained by mesh division, and can be realized by, for example, a display means such as a CRT, an EL display, a liquid crystal display, or a printing means such as a laser printer, a dot printer, or an XY plotter.

FIG. 2 shows a flowchart of the mesh dividing process according to one embodiment of the present invention. First, Step 1
At 00, input processing of the analysis target shape divided into regions, the importance distribution set in advance for the analysis target shape, and the division condition is performed.

Next, the division processing means 2 generates a mesh shape for each region of the analysis target shape. That is, it is stored in advance in the storage unit 26 as mesh division rule data 261 based on the analysis target shape input and divided into regions in step 100 and the importance distribution and the division condition preset for the analysis target shape. A region is mesh-divided from a plurality of mesh division rules according to a rule that meets the application condition (110).

Next, the output means 3 outputs a mesh of the analysis target shape obtained by dividing the mesh (120).

FIG. 3 is a detailed flowchart of the dividing process in step 110 of FIG. First, step 20
At 0, a plurality of mesh division designated regions are selected from the region of the analysis target shape divided into regions based on the region designation conditions in the input division conditions. Next, the selected mesh division designated areas are collated with the input importance distribution to set the importance of each mesh division designated area (210). Next, a mesh division type is set in each mesh division designated area for which importance has been set, based on the condition of the mesh division type in the input division conditions (22).
0). Next, based on the mesh size and aspect ratio conditions in the input division conditions, and in the order based on the set importance, the number of divisions of each side of each mesh division designated area in which the mesh division type is set. And the position of the dividing node is set (230). Next, based on mesh division rule data in which a correlation rule between the number of divisions and the positions of the division nodes and the mesh division type is stored in advance, each mesh division designated area in which the number of divisions and the positions of the division nodes are set is divided into meshes ( 240).

FIGS. 4, 5, and 7 show steps 22 in FIG.
It is a flowchart which shows the specific process by the mesh division | segmentation type set by 0. Here, step 11 in FIG.
The implementation of 0 may use only one of FIG. 4, FIG. 5, and FIG. 7, or a combination of a plurality of them.

FIG. 4 is a flowchart showing a uniform or non-uniform mesh division process. First, an area having the highest importance in the designated area group is set as a target area (step 300). Next, it is determined whether or not the entire designated region group has been divided into meshes (310), and the process is terminated if the mesh division of all the designated region groups has been performed.

If the mesh division of all designated area groups has not been completed in step 310, the target area is divided into equal or unequal meshes (320), and the same is applied to the undivided designated area group in the vertical and horizontal directions of the target area. The number of divisions in the direction and the positions of the division nodes are set (330).

Next, it is determined whether or not there is an area in the designated area group in which only the number of divisions in the vertical and horizontal directions and the positions of the division nodes are set (340). An area having a high importance is set as a target area (35).
0), returning to step 310; If there is no area in the designated area group in which only the number of divisions in the vertical and horizontal directions and the division node position are set in step 340, the area having the highest importance in the undivided designated area group is set as the target area. (3
60), returning to step 310;

FIG. 5 is a flowchart showing the junction mesh dividing process. First, a region having the highest importance in the designated region group is set as a target region (step 400), and it is determined whether or not all designated region groups are divided into meshes (410). If divided, the process ends.

If the mesh division of all designated area groups is not completed in step 410, the target area is divided into junction meshes (420), and the area having the highest importance in the undivided designated area group is set as the target area. Set (43
0), and return to step 410.

FIG. 6 is a detailed flowchart showing the process of dividing the target area into a junction mesh in step 420 of FIG. First, the number of divisions and the positions of the nodes on each side of the target area are determined based on the division condition, the degree of importance, the number of divisions of the adjacent area, and the positions of the division nodes (step 5).
00). Next, the target area is divided by the division number for which the sub direction has been determined (510), and the divided partial area on the main direction main division side is set as the target partial area (520).

The sub-direction and the main direction main split side will be described later in detail.

Next, it is determined whether or not all the partial areas have been divided into meshes (530). If all the partial areas have been divided into meshes, the process is terminated. If the mesh division of all the partial areas is not completed in step 530, the target partial area is divided into junction meshes (540), and an undivided partial area adjacent to the target partial area is set as the target partial area (55).
0), and return to step 530.

FIG. 7 is a detailed flowchart showing a composite mesh division process for sequentially performing uniform, junction, and non-uniform mesh division. First, a group of regions where uniform mesh division is performed is set as a specified region group (step 60).
0), the designated area group is divided into uniform meshes using the processing described with reference to FIG. 4 (610).

Next, an area group to be subjected to junction mesh division is set as a designated area group (620), and the designated area group is divided into junction meshes using the processing described with reference to FIG. 5 (630). Next, all remaining area groups to be subjected to uneven mesh division are set as designated area groups (640),
The specified area group is divided into non-uniform meshes using the processing described in FIG. 4 (650).

Next, with reference to FIGS. 13 and 14, the importance distribution, the main / sub direction of the area, and the main / sub division will be described.

FIG. 13 is a diagram showing an example of the importance distribution when the maximum value of the importance is 1.0 and the minimum value is 0. The importance distribution of the present example is an example in which the importance decreases as the distance from the location of the highest importance increases.

FIG. 14 shows sides 1200, 1210, and 1
220, one region composed of a side 1230 is shown;
The importance on side 1200 is 0.6, the importance on side 1210 is 0.4, the importance on side 1220 is 0.5,
The example in which the importance on the side 1230 is 0.8 is shown.

The main direction refers to the direction in which the difference in importance between the opposite sides is larger, and the main direction is from side 1230 to side 1210. The sub-direction refers to the direction in which the difference in importance between the opposite sides is smaller, and the side from the side 1200 to the side 1220 is the sub-direction.

The main division side refers to the side of the opposite side with high importance, and in the case of the sides 1230 and 1210, the side 123
0 is the main division side, and the side 1210 is the sub division side. Side 120
In the case of 0 and the side 1220, the side 1200 is the main division side and the side 1220 is the sub division side.

Next, examples of the uniform mesh division rule, the uneven mesh division rule, and the junction mesh division rule will be described with reference to FIG. As shown in (a), when the number of opposite sides of the region 1100 is equal, the uniform mesh division rule determines the position of a dividing node so that each side is divided into equal lengths by the number of divisions, and performs mesh division. This is a rule, and after division, it becomes a division shape 1110.

As shown in (b), the non-uniform mesh division rule is such that when the number of divisions on the opposite side of the region 1120 is equal,
This is a rule that determines the position of the dividing node so that each side is divided into unequal lengths by the number of divisions so that the mesh gradually increases from the side with higher importance to the lower side,
After the division, a divided shape 1130 is obtained.

The junction mesh division rule is as follows:
As shown in (c) and (d), the area 1140 and the area 11
When the number of divisions on the opposite side of 60 is different, the rule is to determine the division node position so that the region is composed of a plurality of rectangles and perform mesh division. After division, a division shape 1150 and a division shape 1170 are obtained.

Although the mesh division rules shown here are merely examples, a number of mesh division rules can be considered in practice, and are stored in the storage means 26 as mesh division rule data 261.

Next, an example of the operation of uniform mesh division will be specifically described with reference to FIG. 8 based on the flowchart of FIG. FIG. 8A shows an analysis target shape 700 that is divided into a plurality of regions in advance, and regions a, b, c, and d are specified as a specified region group. FIG. 8B
Is an importance distribution diagram 710 in which the importance distribution when the upper left corner P point of the analysis target shape 700 is set to the highest importance is shown by contour lines.

First, in step 300, a region a having the highest importance in the designated region group is set as a target region. Next, since all the specified area groups are not divided into meshes (310), the process proceeds to step 320. In step 320, the target area a is determined based on the importance distribution, mesh size, aspect ratio, and other conditions based on the analysis target shape 7 shown in FIG.
As shown in 20, a uniform mesh division is performed.

In step 330, the designated area group (area b, area c) which is not divided in the vertical and horizontal directions of the target area a is
The number of divisions in the same direction and division node positions are set. The numbers written in the area b and the area c of the analysis target shape 720 are the number of divisions in the same direction. In addition, the division node positions corresponding to the number of divisions are set on the sides of the region, and in the region c, the two S points on the side adjacent to the region a are the division node positions.

Next, it is determined whether or not there is an area in the designated area group in which only the number of divisions in the vertical and horizontal directions and the positions of the division nodes are set (340). Since only the number of divisions and the positions of the division nodes are set, the region c having the highest importance among those regions is set as the target region (350), and the routine proceeds to step 310.

Since the mesh division of all the specified area groups has not been completed in step 310, the target area c is assigned the importance distribution,
FIG. 8 based on conditions such as mesh size and aspect ratio.
The uniform mesh division is performed as shown in the analysis target shape 730 of (d) (320).

In step 330, the number of divisions and the positions of the division nodes in the same direction are set for the undivided designated region group (region d) in the vertical and horizontal directions of the target region c.

Next, it is determined whether or not there is an area in the designated area group in which only the number of divisions in the vertical and horizontal directions and the division node positions are set (340). Since only the number of divisions and the positions of the division nodes are set, the region b having the highest importance among those regions is set as the target region (350), and the routine proceeds to step 310.

In step 310, since the mesh division of all the designated area groups has not been completed, the target area b is assigned the importance distribution,
FIG. 8 based on conditions such as mesh size and aspect ratio.
The uniform mesh division is performed as shown in the analysis target shape 740 of (e) (320).

In step 330, since there is no undivided designated area group in the vertical and horizontal directions of the target area b, the flow advances to step 340. It is determined whether or not there is an area in the designated area group in which only the number of divisions in the vertical and horizontal directions and the positions of the division nodes are set (340), and in the area d, only the number of divisions and the positions of the division nodes in the one direction are set. Therefore, the area d is set as the target area (350), and the process proceeds to step 310.

Since the mesh division of all the specified area groups has not been completed in step 310, the target area d is assigned the importance distribution,
FIG. 8 based on conditions such as mesh size and aspect ratio.
The uniform mesh division is performed as shown in the analysis target shape 750 of (f) (320).

In step 330, since there is no undivided designated area group in the vertical and horizontal directions of the target area d, the flow advances to step 340. It is determined whether or not there is an area in the designated area group in which only the number of divisions in the vertical and horizontal directions and the division node positions are set (340).

At step 360, since there is no undivided designated area group, the target area is undecided and the routine proceeds to step 310.
In step 310, since all the specified area groups are divided into meshes, the process ends.

Next, an operation example of the non-uniform mesh division will be specifically described with reference to FIG. 9 based on the flowchart of FIG. FIG. 9A shows an analysis target shape 800 that is divided into a plurality of regions in advance, and regions a, b, c, and d are specified as a specified region group. FIG. 9B
Is an importance distribution diagram 810 in which the importance distribution when the upper left corner P point of the analysis target shape 800 is set to the highest importance is shown by contour lines.

First, in step 300, a region a having the highest importance in the designated region group is set as a target region. Next, since all the specified area groups are not divided into meshes (310), the process proceeds to step 320.

In step 320, as shown in the analysis target shape 820 in FIG. 9C, the target area a is determined by determining the unequal division ratio based on the conditions such as the importance distribution, the mesh size, and the aspect ratio. The non-uniform mesh division is performed so that the mesh size gradually increases from the division side to the sub division side.

In step 330, the designated area group (area b, area c) which is not divided in the vertical and horizontal directions of the target area a is
The number of divisions in the same direction and division node positions are set. 830
The numbers written in the areas b and c indicate the number of divisions in the same direction. In the area c, five S points on the side adjacent to the area a are division node positions.

Next, it is determined whether there is an area in the designated area group in which only the number of divisions in the vertical and horizontal directions and the positions of the division nodes are set (340), and the areas b and c are determined in one direction. Since only the number of divisions and the positions of the division nodes are set, the region c having the highest importance among those regions is set as the target region (350), and the routine proceeds to step 310.

Since the mesh division of all the specified area groups has not been completed in step 310, the target area c is assigned the importance distribution,
FIG. 9 based on conditions such as mesh size and aspect ratio.
Uneven mesh division is performed as shown in the analysis target shape 830 of (d) (320).

In step 330, the number of divisions and the positions of the division nodes in the same direction are set for the designated area group (area d) in the vertical and horizontal directions of the target area c.

Next, it is determined whether or not there is an area in the designated area group in which only the number of divisions in the vertical and horizontal directions and the positions of the division nodes are set (340). Since only the number of divisions and the positions of the division nodes are set, the region b having the highest importance among those regions is set as the target region (350), and the routine proceeds to step 310.

Since the mesh division of all the specified area groups has not been completed in step 310, the target area b is assigned the importance distribution,
FIG. 9 based on conditions such as mesh size and aspect ratio.
The non-uniform mesh division is performed as shown in the analysis target shape 840 of (e) (320).

In step 330, since there is no undivided designated area group in the vertical and horizontal directions of the target area b, the flow advances to step 340. It is determined whether or not there is an area in the designated area group in which only the number of divisions in the vertical and horizontal directions and the positions of the division nodes are set (340), and in the area d, only the number of divisions and the positions of the division nodes in the one direction are set. Therefore, the area d is set as the target area (350), and the process proceeds to step 310.

Since the mesh division of all the specified area groups has not been completed in step 310, the target area d is set to the importance distribution,
FIG. 9 based on conditions such as mesh size and aspect ratio.
The uniform mesh division is performed as shown in the analysis target shape 850 of (f) (320).

At step 330, the process proceeds to step 340 because there is no undivided designated area group in the vertical and horizontal directions of the target area d. It is determined whether or not there is an area in the designated area group in which only the number of divisions in the vertical and horizontal directions and the division node positions are set (340).

At step 360, since there is no undivided designated area group, the target area is undecided and the routine proceeds to step 310.
In step 310, since all the specified area groups are divided into meshes, the process ends.

Next, an operation example of junction mesh division will be specifically described with reference to FIG. 10 based on the flowcharts of FIGS. 5 and 6. FIG. 10A shows an analysis target shape 900 that is divided into a plurality of regions in advance, and regions a and b are specified as a specified region group. FIG.
(B) is an importance distribution diagram 910 in which the importance distribution when the upper left corner P point of the analysis target shape 900 is set to the highest importance is shown by contour lines.

The analysis target shape 920 shown in FIG. 10C is the mesh shape of an area that has already been divided into meshes other than the designated area group, the number of divisions of the designated area group, and the number of divisions of the side where the dividing node position is determined. Is shown.

First, in step 400, the region a having the highest importance in the designated region group is set as a target region. Next, since all the designated area groups are not divided into meshes (410), the process proceeds to step 420.

In step 420, step 50 in FIG.
0, as shown in the analysis target shape 930 of FIG. 10D, the number of divisions and the position of the division nodes of each side of the target region based on the division condition, the importance distribution, the number of divisions of the adjacent region, and the position of the division nodes. To determine.

Next, the target area a is divided into a partial area a1 and a partial area a2 as shown in the analysis target shape 940 of FIG. .

The divided partial area a1 on the main direction main divided side
Is set as the target partial area (520), and the entire partial area is not divided into meshes (530).
The target partial area a1 is subjected to junction mesh division using the mesh division rule as shown in the analysis target shape 950 (540).

An undivided partial area a2 adjacent to the target partial area a1 is set as a target partial area (550), and the flow advances to step 530. Since the mesh division of all the partial regions has not been completed (530), the analysis target shape 96 shown in FIG.
As shown by 0, the target partial area a2 is mesh-divided using the mesh division rule (540).

Since there is no undivided partial area adjacent to the target partial area a2, the target partial area is not set (550). Since all the partial areas are mesh-divided (530), the processing ends.
Proceed to step 430 in FIG.

In step 430, the region b having the highest importance in the undivided designated region group is set as the target region, and the flow advances to step 410. Since the mesh division of all the specified area groups has not been completed (410), the process proceeds to step 500 in FIG. 6 to divide the target area b into a junction mesh (420).

In step 500, as shown in the analysis target shape 960 in FIG. 10 (g), the number of divisions and the number of divisions of each side of the target area are determined based on the division condition, the importance distribution, the division number of the adjacent area, and the position of the division node. By determining the position of the node and dividing the sub-direction by the determined number of divisions (510), FIG.
As shown in the analysis target shape 970 of (h), the target area b is divided into a partial area b1 and a partial area b2.

The divided partial area b1 on the main division side in the main direction
Is set as the target partial area (520), and the entire partial area is not divided into meshes (530).
As shown in the analysis target shape 980, the target partial area b1 is subjected to junction mesh division using the mesh division rule (540).

An undivided partial area b2 adjacent to the target partial area b1 is set as a target partial area (550), and the flow advances to step 530. Since the mesh division of all the partial regions has not been completed (530), the analysis target shape 99 shown in FIG.
As shown by 0, the target partial area b2 is mesh-divided using the mesh division rule (540).

Since there is no undivided partial area adjacent to the target partial area b2, the target partial area is not set (550). Since all the partial areas are mesh-divided (530), the processing is terminated.
Proceed to step 430 in FIG. In step 430, since there is no undivided designated area, the target area is not set, and the entire designated area group has been mesh-divided (410), thus ending.

Next, an operation example of the combination mesh division will be specifically described with reference to FIG. 11 based on the flowchart of FIG. FIG. 11A shows an analysis target shape 100 previously divided into a plurality of regions a, b, and c.
Indicates 0. In FIG. 11B, reference numeral 1010 denotes an analysis target shape 1
An importance distribution diagram 1010 in which the importance distribution when the center Q point on the left side of 000 is set to the highest importance is shown by contour lines.
It is.

First, in step 600, the region a is set as a designated region group as a region group for performing uniform mesh division, and the designated region a is subjected to the processing shown in FIG. 4 as shown in the analysis target shape 1020 in FIG. Then, a uniform mesh division is performed (610).

Next, in step 620, the area b is set as a specified area group as an area group to be subjected to junction mesh division, and as shown in the analysis target shape 1030 of FIG. The junction mesh is divided using the processing shown (630).

In step 640, region c is set as a designated region group as a region group for performing non-uniform mesh division.
As shown in the analysis target shape 1040 in (e), the designated area c is divided into non-uniform meshes by using the processing shown in FIG.
0), end.

FIG. 15 shows a flowchart of a process for bringing the total number of meshes of the designated area group after mesh division closer to the predetermined target number of meshes.

First, a condition for minimizing the total mesh number of the designated area group within the range of the division condition is set (step 13).
00). Next, the designated area group is divided into meshes based on the set conditions and importance distribution (1310). Next, when the total number of meshes of the designated designated area group is substantially equal to the number of target meshes (1320), the process ends.

If the designated area group total mesh number is not the same as the target mesh number (1320), the flow advances to step 1330. It is determined whether or not the designated area group total mesh number is smaller than the target mesh number (1330), and if so, the set condition is updated so that the designated area group total mesh number is increased (1340), and step 1310 Return to

If the total number of designated area group meshes is equal to or greater than the target number of meshes in the judgment at step 1330, the set conditions are updated so that the number of designated area group meshes is reduced (13).
50), and return to step 1310.

As described above, by performing the process of approaching the target number of meshes, it is possible to manage the total number of meshes of the designated area group that matches the required analysis accuracy.

Although the above embodiment has been described by taking as an example a process of dividing a two-dimensional shape, a three-dimensional solid mesh can be formed by replacing a two-dimensional line with a surface even in a three-dimensional solid shape. Division can be performed.

[0096]

According to the present invention, in the mesh division of a shape to be analyzed, a mesh of a size change satisfying required analysis accuracy can be generated, and each region of the shape to be analyzed can be equally divided, unequally divided, and junctioned. It is possible to automatically generate a desired mesh obtained by combining the divisions. Thus, it is possible to reduce the storage capacity and the analysis time in the analysis calculation, that is, to reduce the calculation cost, while securing the accuracy of the portion requiring the analysis accuracy.

[Brief description of the drawings]

FIG. 1 is a functional configuration block diagram of a mesh division device according to an embodiment of the present invention.

FIG. 2 is a flowchart of a mesh division process in the mesh division device of FIG. 1;

FIG. 3 is a detailed flowchart of the mesh division processing of FIG. 2;

FIG. 4 is a flowchart illustrating a uniform / uneven mesh division process.

FIG. 5 is a flowchart illustrating a junction mesh division process.

FIG. 6 is a detailed flowchart of a junction mesh dividing process for a target area in FIG. 5;

FIG. 7 is a detailed flowchart of a combination mesh division process.

FIG. 8 is a specific explanatory diagram of an operation example of uniform mesh division.

FIG. 9 is a specific explanatory diagram of an operation example of uneven mesh division.

FIG. 10 is a specific explanatory diagram of an operation example of junction mesh division.

FIG. 11 is a specific explanatory diagram of an operation example of combination mesh division.

FIG. 12 is a specific explanatory diagram of an example of a mesh division rule.

FIG. 13 is an explanatory diagram of an example of importance distribution.

FIG. 14 is an explanatory diagram of main and sub directions.

FIG. 15 is a flowchart of a process for bringing the total number of meshes of a designated area group after mesh division closer to a predetermined target number of meshes.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Input means, 2 ... Division processing means, 3 ... Output means, 21
... designated area selecting means, 22 ... importance area setting means, 23
... Division type setting means, 24 ... Division number / division node position setting means, 25 ... Mesh division means, 26 ... Storage means, 26
1: Mesh division rule data

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Atsushi Suzuki 3-2-1 Sachimachi, Hitachi-shi, Ibaraki Prefecture Within Hitachi Engineering Co., Ltd. (72) Sachio Hamaguchi 3-2-2 Sachimachi, Hitachi-shi, Ibaraki No. 1 Inside Hitachi Engineering Co., Ltd.

Claims (5)

[Claims] An input means for inputting an analysis target shape previously divided into a plurality of regions together with an importance distribution and a division condition set for the analysis target shape, and inputting the importance distribution and the division In a mesh division device having division processing means for performing a mesh division process on the analysis target shape based on a condition and output means for displaying the analysis target shape obtained by the mesh division, the division processing means may include the input division A designated region selecting means for selecting a mesh division designated region from the plurality of regions based on a region designation condition among the conditions, and comparing the input importance distribution with the selected mesh division designated region. Importance area setting means for setting the importance of the mesh division designated area; and setting the importance based on a mesh division type condition in the input division conditions. Division type setting means for setting a mesh division type in the specified mesh division designated area, and a division number / divided node position for setting a division number and a divided node position of each side of the mesh division designated area in which the mesh division type is set Based on the setting unit and mesh division rule data in which a correlation rule between the number of divisions and the positions of the division nodes and the mesh division type is stored in advance, the mesh division designated area in which the number of divisions and the positions of the division nodes are set is mesh-divided. A mesh dividing apparatus comprising: a mesh dividing unit. 2. A method according to claim 1, wherein said division type setting means sets at least one of uniform mesh division, non-uniform mesh division and junction mesh division based on the condition of said mesh division type. Mesh dividing device. 3. An inputting step of inputting an analysis target shape previously divided into a plurality of regions together with an importance distribution and a division condition set for the analysis target shape, and inputting the importance distribution and the division A division processing step of performing a mesh division process on the analysis target shape based on a condition; and an output step of displaying the analysis target shape that has been subjected to the mesh division, wherein the division processing step includes a step of: A designated region selecting step of selecting a mesh division designated region from the plurality of regions based on a region designation condition in the conditions;
An importance area setting step of comparing the input importance distribution with the selected mesh division designated area to set the importance of the mesh division designated area; and a mesh division type in the inputted division condition. A division type setting step of setting a mesh division type in a mesh division designated area in which the importance is set based on the conditions of: and the setting based on conditions of a mesh size and an aspect ratio in the input division conditions. A division number / division node position setting step of setting the number of divisions and division node positions of each side of the mesh division designated area in which the mesh division type is set, in the order based on the importance, the division number and the division nodes are set in advance. The number of divisions and the positions of the division nodes are set based on the mesh division rule data storing the correlation rules between the positions and the mesh division types. Mesh division method characterized by having a mesh dividing step of mesh division mesh division designation area that is. 4. The method according to claim 3, wherein the division type setting step sets at least one of uniform mesh division, non-uniform mesh division and junction mesh division based on the condition of the mesh division type. Mesh division method. 5. A computer-readable recording medium in which a processing program for subjecting an analysis target shape divided in advance to a plurality of regions to mesh division processing based on a distribution of importance set for the analysis target shape and a division condition is recorded. The processing program causes the computer to select a mesh division designated region from among the plurality of regions based on a region designation condition in the division condition, and the importance distribution and the selected mesh division are selected. The importance of the mesh division designated area is set by collating with the designated area, and the mesh division type is assigned to the mesh division designated area whose order is set according to the importance based on the condition of the mesh division type in the division condition. Is set, and based on the mesh size and aspect ratio conditions in the division conditions, and the order of the set importance is determined. First, the number of divisions and division node positions of each side of the mesh division designated area in which the mesh division type is set are set, and a mesh in which a correlation rule between the division number and division node positions and the mesh division type is stored in advance. A computer-readable recording medium storing a mesh division processing program, wherein a mesh division designated area in which the number of divisions and the position of a division node are set based on division rule data is mesh-divided.