JPH04158481A - Preparing method for numerical analysis for product design - Google Patents

Abstract

PURPOSE:To prepare a complicated three-dimensional shape element model in a short time by automatically preparing the three-dimensional shape element model from a two-dimensional shape element model. CONSTITUTION:A three-dimensional shape element model preparation processing part 15 takes out each data stored in a two-dimensional shape element data storage part 14 and prepares, for example, four planes parallel with the planes of element models E1 - E4. The apexes t1 - t6 of original two-dimensional shape element models E1 - E4 are projected on prepared parallel planes. Each projected apex is converted to numeric data at a numeric value conversion processing part 13. The data representing each apex number of 16 three- dimensional shape element models prepared in such way is stored in a three- dimensional element data storage part 16, and stored apex number data is developed to the three-dimensional shape element model displayable on a display part 20 at an output processing part 19, and is displayed on the display part 20 as a three-dimensional stereoscopic model. Threby, the three-dimensional shape element model can be prepared.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention relates to a numerical analysis shape model for product design that creates a three-dimensional shape element model for product design using numerical analysis methods such as the finite element method. Regarding the creation method.

(Prior art) Conventionally, as a method for creating a three-dimensional shape element model for numerical analysis such as the finite element method, a two-dimensional shape element model is simply swept and the sweep amount or the sweep amount is calculated. 3 with a thickness equal to one integer
There was a method for creating a dimensional shape element model.

(Problem to be Solved by the Invention) However, with the method for creating a three-dimensional shape element model described above, there is no problem when creating a three-dimensional shape element model of a simple shape, but when designing a product etc. In order to create a complex three-dimensional shape element model such as the case, complicated operations are required.

In other words, in the conventional method of creating a 3D shape element model, 3D shape element models can be created by simply sweeping a 2D shape element model.
An operation had to be performed for each part where a dimensional shape element model could be created, and a special operation had to be performed for each joint between the created three-dimensional shape element models.

The present invention has been made in view of the above circumstances, and its purpose is to provide a method for creating a numerical analysis shape model for product design, which allows creation of a three-dimensional shape element model without performing such special operations. There is a particular thing.

(Means for Solving the Problems) In order to solve the above problems, the method for creating a numerical analysis shape model for product design according to the present invention involves creating a two-dimensional shape model of a product to be designed, and also creating a two-dimensional shape model of the product to be designed. The model is further divided into multiple two-dimensional shape element models whose basic elements are triangles, and each vertex of each divided two-dimensional shape element model is converted into numerical data.
A dimensional shape element model is represented by three vertex numbers indicated by this converted numerical data, and thickness data indicating the thickness of each 2D shape element model is added to these three vertex numbers to create each 2D shape element. Based on the shape data of the model, and the thickness data of each two-dimensional shape element model,
Create a plane parallel to the plane of the dimensional shape element model, project each vertex of the original 2D shape element model onto this created parallel plane, and each projected vertex will be connected to multiple 2D shape elements. When shared by models, each vertex is projected onto the intersection line or point of intersection of multiple two-dimensional shape element models, and each vertex of the projected new two-dimensional shape element model is converted into numerical data. A three-dimensional shape element model is developed on the screen using the vertex numbers of the three projected vertices and the vertex numbers of the original three vertices.

(Operation) A two-dimensional shape model of the product to be designed is created on the display screen, and this two-dimensional shape model is further divided into a plurality of two-dimensional shape element models having triangles as basic elements. That is, the shape model is divided into triangular basic elements.

Then, each vertex of each divided two-dimensional shape element model is converted into numerical data. Numerical data is expressed by defining a reference point on a two-dimensional shape model and by distances from this reference point in each direction of the X coordinate, Y coordinate, and X coordinate.

Then, each two-dimensional shape element model is represented by three vertex numbers indicated by this converted numerical data,
Thickness data (indicated by numerical values) indicating the thickness of each two-dimensional shape element model is added to this vertex number to obtain shape data of each two-dimensional shape element model. That is,
Shape data of one two-dimensional shape element model is composed of four pieces of data: three vertex numbers and one thickness data.

Next, based on the thickness data of this shape data,
2 indicated by the vertex number included in the shape data
A plane parallel to the plane of the dimensional shape element model is created, and each vertex of the original two-dimensional shape element model is projected onto the created parallel plane. At this time, if each projected vertex is shared by multiple 2D shape element models, simply projecting each vertex to be shared on a parallel plane will not allow the vertices to be shared by multiple 2D shape element models. Since the positions of the vertices do not match, in this case, the vertices are projected onto the intersection line or point of intersection of the plurality of two-dimensional shape element models.

Each vertex of the new two-dimensional shape element model projected in this way is converted into numerical data, and a three-dimensional shape element model is created using the vertex numbers of the three projected vertices and the vertex numbers of the original three vertices. Expand on the screen.

(Example) Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing the electrical configuration of a three-dimensional shape element model creation device to which the creation method of the present invention is applied.

In the figure, the three-dimensional shape element model creation device of the present invention includes an input section 11, a two-dimensional shape element model creation processing section 12
, numerical conversion processing section 13. two-dimensional element data storage section 14.
Three-dimensional shape element model creation processing section J5. Consists of a three-dimensional element data storage section 16, a numerical analysis processing section 17, an analysis data storage section 8, an output processing section 19, and a display section 2° for displaying the shape model, etc. There is. The output of the input section 11 is led to a two-dimensional shape element model creation processing section 12, and the output of the two-dimensional shape element model creation processing section 12 is led to a two-dimensional element data storage section]4. . Also,
The two-dimensional shape element model creation processing unit 12 and the numerical conversion processing unit 3 are bidirectionally connected, and the numerical conversion processing unit 13 converts the two-dimensional shape given from the two-dimensional shape element model creation processing unit 12. The data indicating each vertex of the element model is converted into numerical data and then provided again to the two-dimensional shape element model creation processing section 12.

Further, the output of the two-dimensional element data storage section 14 is led to the three-dimensional shape element model creation processing section 5, and the output of the three-dimensional shape element model creation processing section 15 is sent to the three-dimensional element data storage section 16. being guided. Furthermore, the three-dimensional shape element model creation processing unit 15 and the numerical conversion processing unit 13 are bidirectionally connected, and the numerical conversion processing unit 13 receives the three-dimensional The data indicating each vertex of the shape element model is converted into numerical data and then provided again to the three-dimensional shape element model creation processing section 15.

The output of the two-dimensional element data storage section 14 and the output of the three-dimensional element data storage section 16 are led to the display section 20 via the output processing section 19, and the numerical analysis processing section 17
guided by. The output of the numerical analysis processing section 17 is led to the analysis data storage section 18, and the output of the analysis data storage section 18 is sent to the display section 2o via the output processing section 19.
The structure is guided by.

Input unit 1 is comprised of a keyboard, digitizer, etc., and inputs only the outline of the two-dimensional shape model.

Based on the outline of the two-dimensional shape model input from the input unit 11, the two-dimensional shape element model creation processing unit 12 further divides the outline into a plurality of two-dimensional shape element models having triangles as basic elements. At the same time, thickness data indicating the thickness of the divided two-dimensional shape element model is added to the three vertex numbers indicated by the numerical data given from the numerical conversion processing unit 13 to form shape data, and the two-dimensional element data is stored. It is stored in the section 14. That is, the two-dimensional shape element model is represented by three vertex numbers indicated by numerical data converted by the numerical conversion processing section 13.

The numerical conversion processing unit 3 converts each vertex of each two-dimensional shape element model given from the two-dimensional shape element model creation processing unit 12 into numerical data, and provides it again to the two-dimensional shape element model creation processing unit 12. , each vertex of the projected three-dimensional shape element model provided by the three-dimensional shape element model creation processing unit 15 is converted into numerical data, and the data is again provided to the three-dimensional shape element model creation processing unit 15.

The three-dimensional shape element model creation processing unit 15 creates a surface parallel to the surface of the two-dimensional shape element model based on the thickness data of the two-dimensional shape element model stored in the two-dimensional element data storage unit 14, Each vertex of the original two-dimensional shape element model is projected onto this created parallel plane. At this time, if each projected vertex is shared by a plurality of two-dimensional shape element models, each vertex is projected onto the intersection line or point of intersection of the plurality of two-dimensional shape element models. Then, data indicating each vertex of the new two-dimensional shape element model projected in this way is given to the numerical conversion processing section 13, and the projected 3 vertices indicated by the numerical data provided from the numerical conversion processing section 13 are The two vertex numbers and the original three vertex numbers are stored in the three-dimensional element data storage unit 16 as shape data of the three-dimensional shape element model.

Based on the shape data stored in the two-dimensional element data storage unit 14, the numerical analysis processing unit 17 performs analysis (flow analysis, cooling analysis, etc.) for investigating defects in injection molding, or simple structural analysis. to do things. Also, based on the shape data stored in the three-dimensional element data storage unit 16,
For example, we examine and analyze temperature distribution, sink marks, and deformation during injection molding, and perform detailed structural analysis to examine product shape, wall thickness, etc. Then, such analysis results are stored in the analysis data storage section 18.

The output processing unit 19 stores the shape data of the two-dimensional shape element model stored in the two-dimensional element data storage unit 14, the shape data of the three-dimensional shape element model stored in the three-dimensional element data storage unit 16, and analysis data storage. The analysis data stored in the unit 18 is converted into a data format that can be displayed on the display screen of the display unit 20 and output.

Next, a procedure for creating a three-dimensional shape element model using the three-dimensional shape element model creation apparatus having the above configuration will be described using a simple three-dimensional shape element model as an example.

First, the operator inputs the outline of the product to be designed as shown in FIG. 2 by operating the input section 11, such as a keyboard or digitizer. In the two-dimensional shape element model creation processing unit 12, as shown in FIG. Divide into E4. That is, the two-dimensional shape model is divided into basic triangular elements. This divided two-dimensional shape element model E
1 to E4 are given to the output processing section 19 via the two-dimensional element data storage section 14 and displayed on the display section 20. Then, each of the vertices t1 to t6 of each of the divided two-dimensional shape element models E1 to E4 is converted into numerical data in the numerical conversion processing section 13. For the numerical data, one point a is set as a reference on the two-dimensional shape model, and the X coordinate from this reference point a is
It is expressed by the distance in each direction of the Y coordinate and the X coordinate.

Table 1 shows a list of the vertices t1 to t6 of the two-dimensional shape element models E1 to E4 converted into numerical data.

That is, the vertex t1, which is the reference point a, has the X coordinate (0,00
00000), Y coordinate (0,0000000), X coordinate (0,0000000), vertex t2 is X coordinate (0,0
000000), Y coordinate (5,0000000), X
Coordinates (0,0000000), vertex t3 has X coordinates (0,
0000000), Y coordinate (0,0000000),
The X coordinate is (5,0000000).

Each of the two-dimensional shape element models E1 to E4 is represented by three vertex numbers indicated by this converted numerical data, and the thickness data (indicated by numerical value) indicating the thickness of each two-dimensional shape element model is added to the vertex number. ) is added to form the shape data of each two-dimensional shape element model.

Table 2 shows a list of the two-dimensional shape element models E1 to E4 expressed by respective vertex numbers. That is, the shape data of one two-dimensional shape element model is composed of four data: three vertex numbers and one thickness data. For example, the two-dimensional shape element model E1 has vertex numbers t2. t
3. tl and thickness data 1.00000.

Two-dimensional shape element model E1~ created in this way
Numerical data (Table 1) of each vertex t1 to t6 of E4 and each vertex number and thickness data (Table 2) of two-dimensional shape element models E1 to E4 are stored in the two-dimensional element data storage unit 14. Further, each data stored in the two-dimensional element data storage section 14 can be taken out by the output processing section 19 if necessary, and displayed as a list on the display section 20.

The three-dimensional shape element model creation processing unit 15 retrieves each data shown in Tables 1 and 2 stored in the two-dimensional element data storage unit 14, and creates each two-dimensional shape element model E1 shown in Table 2.
~Based on the thickness data of E4, the element model E1~
Create a plane parallel to the plane of E4. In this embodiment, as shown in FIG.
2 faces with oo spacing, -X direction and -ZX direction 0.5000
Create a total of 4 pages, 2 pages at 000 intervals. Then, on each of the parallel planes created, the original two-dimensional shape element models E1 to E
Each of the vertices t1 to t6 of 4 is projected. For example, a new vertex obtained by projecting the vertex L3 of the two-dimensional shape element model E1 in the +X direction is 115. t17, and the new vertex projected in the -X direction is t16. Let it be t18.

At this time, when each projected vertex is shared by multiple two-dimensional shape element models (in this example, the vertices tl, t
2) If you simply project each vertex to be shared onto a parallel plane, the positions of the vertices to be shared by multiple 2D shape element models will not match. Project each vertex onto the intersection point (or intersection line in some cases) of the shape element model.

Each vertex projected in this way is converted into a numerical conversion processing unit 1
3, it is converted into numerical data. At this time, the number of vertices is 30, and the number of three-dimensional shape element models is 16. Table 3 lists the numerical data of each projected vertex.
Shown below.

Then, one three-dimensional shape element model is represented by three vertices representing one two-dimensional shape element model and three vertices representing one two-dimensional shape element model adjacent to this two-dimensional shape element model, and this 3 of the 6 vertices
Shape data representing a dimensional shape element model. Table 4 shows a list of each shape data of the created 3D shape element model.
Shown below.

Data indicating each vertex number of the 16 three-dimensional shape element models Ell to E26 created in this way is stored in the three-dimensional element data storage section 16.

Each vertex number data stored in the three-dimensional element data storage unit 16 is expanded into a three-dimensional shape element model that can be displayed on the display unit 20 in the output processing unit 19, and displayed on the display unit 20 as a three-dimensional three-dimensional model. Ru.

On the other hand, the operator can use the shape data stored in the two-dimensional element data storage section 14 or the shape data (vertex number data) stored in the three-dimensional element data storage section 16 as necessary.
is read out to the numerical analysis processing section 17, and analyzed and examined according to the procedure shown in FIG. That is, based on the shape data read from the two-dimensional element data storage unit 14, for example, analysis (flow analysis, cooling analysis, etc.) for investigating defects in injection molding is performed, or simple structural analysis is performed.

In addition, based on the shape data read from the three-dimensional element data storage unit 16, for example, the temperature distribution of injection molding, sink marks and deformation can be examined and analyzed, and detailed structure information for examination of product shape, wall thickness, etc. Perform analysis. Such analysis results are stored in the analysis data storage section 18 and displayed on the display section 20 via the output processing section 19. The operator examines the shape, moldability, etc. of the product based on the analysis results displayed on the display section 20, and if it is found to be defective, examines the product shape, molding conditions, etc., and then runs the general-purpose mesh creation program. The two-dimensional shape element model will be created again by taking this into account. In this way, numerical analyzes such as structural analysis and heat transfer analysis are performed using the created three-dimensional shape element model, and the results are displayed on the display in the form of contour diagrams, etc., to determine the optimal wall thickness of the product, etc. This allows for consideration of the following.

In the above embodiment, the number of two-dimensional shape element models is 4.
However, it is natural that the number of two-dimensional shape element models increases depending on the shape of the product to be designed. Additionally, four parallel surfaces are created in the two-dimensional shape element model, but if the shape of the product to be designed is complex, it is natural that the number of parallel surfaces will inevitably increase. be. Furthermore, although only the outline line is input from the input unit 11, it is possible to configure the system so that a two-dimensional shape element model is directly input.

(Margins below) Table 1 Table 2 Table 3 Table 4 (Effects of the invention) The method for creating a numerical analysis shape model for product design according to the present invention automatically creates a 3D shape element model from a 2D shape element model. With this configuration, the number of man-hours for creating a three-dimensional shape element model can be significantly reduced, and a complex three-dimensional shape element model can be created in a short time. Furthermore, since the shape input by the operator is a two-dimensional shape, the figure on the graphic display is not complex, making it easier to recognize the shape and reducing errors in shape input. Furthermore, since a three-dimensional shape element model is used in product design, the accuracy of numerical simulations such as structural analysis and heat transfer analysis is improved.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the electrical configuration of a three-dimensional shape element model creation device to which the method for creating a numerical analysis shape model for product design according to the present invention is applied, and FIG. 2 shows the input 2
FIG. 3 is a diagram showing an example of the outline of a dimensional shape model, FIG. 3 is a diagram showing an example of a divided two-dimensional shape element model, FIG. 4 is a diagram showing an example of a created three-dimensional shape element model, and FIG.
The figure is a flowchart showing the procedure of numerical analysis. 11... Input unit 12... Two-dimensional shape element model creation processing unit 13...
Numerical conversion processing section 14... Two-dimensional element data storage section 15... Three-dimensional shape element model creation processing section 16...
Three-dimensional element data storage section 17...Numerical analysis processing section 18...Analysis data storage section 19...Output processing section 20...Display section Patent applicant: Sekisui Chemical Co., Ltd. Representative Hiroshi 1) Kaoru Dai Figure 2 Figure 3

Claims (1)

[Claims] 1) A method for creating a three-dimensional shape model for product design by numerical analysis such as the finite element method, which method comprises: creating a two-dimensional shape model of the product to be designed; The dimensional shape model is further divided into multiple 2D shape element models whose basic elements are triangles, each vertex of each divided 2D shape element model is converted into numerical data, and each 2D shape element The model is represented by three vertex numbers indicated by this converted numerical data, and thickness data indicating the thickness of each two-dimensional shape element model is added to these three vertex numbers, and the shape of each two-dimensional shape element model is data, and based on the thickness data of each two-dimensional shape element model,
Create a plane parallel to the plane of the dimensional shape element model, project each vertex of the original 2D shape element model onto this created parallel plane, and each projected vertex will be connected to multiple 2D shape elements. When shared by models, each vertex is projected onto the intersection line or point of intersection of multiple two-dimensional shape element models, and each vertex of the projected new two-dimensional shape element model is converted into numerical data. A method for creating a numerical analysis shape model for product design, characterized by developing a three-dimensional shape element model on a screen using the vertex numbers of the three projected vertices and the vertex numbers of the original three vertices.