JP2002082996A - Method and apparatus for analyzing structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and an apparatus for analyzing structure, by which setting of a boundary condition and display of an analysis result can easily and accurately conducted even if an actual structure shape differs from a micro element used for analysis, and to provide a manufacturing method for a structure and a storage medium with a computer program realizing the method stored therein. SOLUTION: In analysis calculation in the design of a structure, the surface of the structure is divided into surface elements being micro flat elements. The boundary condition of analysis is set for the surface elements, and the whole structure is divided into micro total elements. The boundary condition which is set is transferred to the total elements and the total elements are analyzed by using the boundary condition. The analysis result of the surface elements is calculated based on the obtained analysis result.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for analyzing a structure, an analyzer, a manufacturing method, and a storage medium.

[0002]

2. Description of the Related Art In product design of a structure, when predicting deformation or stress due to a load applied to a product, or pressure or defective molding that occurs again in molding a product by a molding method such as injection molding, a finite number is required. Numerical analysis methods such as the element method, the difference method, and the boundary element method have been used. These methods divide the shape of the structure, which is the analysis area, into planar microelements such as triangles and quadrilaterals, and three-dimensional microelements such as hexahedrons and tetrahedrons. By setting boundary conditions such as an inflow flow rate and a temperature, and performing analysis using a computer, it is possible to obtain a displacement amount and a stress in the microelement, a filling time, a pressure, a velocity, and the like. The designer predicts the defective parts of the product from the analysis results in advance and repeats the analysis again for the design change shape with countermeasures, so that the design that satisfies the specifications such as strength, rigidity, formability, etc. Obtainable.

[0003] For analysis of such a structure design, CAD data is being used to simplify the creation of input data, and the boundary conditions are directly set for the surface shape defined by the CAD data. Then, a system for automatically dividing the microelements and displaying the analysis results of the microelements is commercially available.

[0004] On the other hand, a method of automatically creating microelements from CAD data is described in, for example, the “Delaty knee division method” described in “Lattice formation method and computer graphics” (published by the University of Tokyo). Applying the method of creating small triangular elements that connect the point cloud dispersed in the area, the method of generating triangular elements on the center plane in the thickness direction called the neutral plane, and the similar method are extended three-dimensionally. A method of generating a triangular pyramid-shaped minute element, or a method of generating a hexahedral element inside a surface surrounded by CAD as disclosed in Japanese Patent Application Laid-Open No. 10-255077 is known.

According to another prior art, Japanese Patent Application Laid-Open No.
As in the invention described in Japanese Patent No. 305651, a display mesh data composed of a small number of coarse minute elements is created separately from the analysis mesh data, and the analysis result obtained using the analysis mesh data is displayed on the display mesh data. There is known a method of speeding up the display by mapping and displaying the data. However, according to this method, the display mesh data is not used for setting the boundary conditions, and the analysis result obtained from the analysis mesh data is directly mapped to the minute element position of the display mesh data. .

[0006]

When a small element is generated by automatic element division from CAD data composed of a curved surface, generally, a plane such as a hexahedral element having high accuracy or a triangle which can represent a shape with a small number of elements is used. Although it is desirable to use a mold element, for example,
In the case of using a method of approximating the shape of a structure called a voxel method in a stepwise manner using a small cube, or a flat type such as a triangle on the neutral plane in the thickness direction When the method of creating the element is used, the minute element does not match the actual surface shape of the structure.
Therefore, in setting the boundary condition, it is necessary to replace the constraint condition and load condition on the surface of the structure with the surface of the minute element, and this depends on the experience and knowledge of the designer. In the display of analysis results, for example, in the case of hexahedron approximation, since the smooth surface is approximated in a stepwise manner, stress concentrations that do not actually occur at corners are displayed, such as minute element shapes Unnatural analysis results will be obtained due to the difference from the structure shape of.

In view of the above problems, the present invention provides a method of analyzing a structure that can easily and accurately set boundary conditions and display analysis results even when an actual structure shape and a microelement used for analysis are different. An object of the present invention is to provide an analyzer, a manufacturing method, and a storage medium storing a computer program for realizing the method.

[0008]

According to the present invention, in order to achieve the above-mentioned object, a step of dividing the surface of a structure into surface elements, which are minute plane elements, is performed by analyzing the surface elements. Setting a boundary condition, dividing the whole structure into minute whole elements, transferring the boundary condition set to the surface elements to the whole elements, and transferring the transferred boundary conditions A method of analyzing the entire element using the method, and a step of calculating an analysis result of the surface element based on the obtained analysis result of the entire element. You.

According to another aspect of the present invention, a step of defining a shape of a structure by CAD data, a step of setting a boundary condition for analysis on the CAD data, and Splitting into surface elements that are planar elements;
A step of dividing the entire structure into small whole elements, a step of transferring the set boundary conditions to the whole elements, a step of performing analysis on the whole elements using the transferred boundary conditions, and an analysis of the whole elements A method for analyzing a structure, comprising the step of calculating an analysis result of a surface element from a result is provided.

According to yet another aspect of the present invention,
A step of dividing the surface of the structure into surface elements that are minute plane elements, a step of dividing the entire structure into minute whole elements, and a step of performing analysis on the whole elements;
A method for analyzing a structure is provided, comprising a step of calculating an analysis result of the surface element based on the obtained analysis result of the entire element.

Further, according to a preferred embodiment of the present invention,
A step of dividing the surface of the structure into surface elements that are minute plane elements, a step of dividing the entire structure into minute whole elements, and a step of performing analysis on the whole elements;
A step of calculating the primary analysis result of the surface element by transferring the analysis result of the obtained whole element, and a step of calculating a secondary analysis result of the surface element based on the primary analysis result And a method for analyzing a structure characterized by the following.

According to another preferred aspect of the present invention, a step of dividing the surface of the structure into surface elements, which are minute plane elements, and a step of setting a boundary condition for analysis with respect to the surface elements. Dividing the whole structure into small whole elements, transferring the boundary conditions set to the surface elements to the whole elements, and analyzing the whole elements using the transferred boundary conditions. The steps to be performed;
A step of calculating the primary analysis result of the surface element by transferring the analysis result of the obtained whole element, and a step of calculating a secondary analysis result of the surface element based on the primary analysis result And a method for analyzing a structure characterized by the following.

According to another preferred embodiment of the present invention, a step of defining the shape of the structure by CAD data, a step of setting a boundary condition for analysis on the CAD data, Dividing the whole structure into minute whole elements, transferring the set boundary condition to the whole elements, and transferring the transferred boundary elements to the whole elements. Performing the analysis of the entire element using boundary conditions, calculating the primary analysis result of the surface element by transferring the analysis result of the overall element, and calculating the surface based on the primary analysis result. There is provided a method for analyzing a structure, comprising a step of calculating a secondary analysis result of an element.

[0014] In particular, according to a preferred aspect of the present invention, the primary analysis result of the surface element is a displacement amount of each surface element generated when a load is applied to the structure, and the secondary analysis result is obtained. Provides a method for analyzing a structure characterized by distortion or stress of each surface element.

For example, if the primary analysis result is the deformation amount obtained by using the voxel element as the whole element, the voxel element is a stepped cube, and the stress on the surface of the whole element is displayed. A stress value that cannot actually occur, such as stress concentration, is displayed. On the other hand, if the stress value of the surface is recalculated from the primary analysis result for the surface element having the same shape as the actual structure surface by the analysis method, a smooth stress distribution along the surface can be displayed, The analysis result can be evaluated with high accuracy.

According to another preferred aspect of the present invention, the structure is a molded article formed by injection molding, and a primary analysis result of the surface element is obtained when the structure is injection-molded. A method for analyzing a structure is provided, wherein the filling time of each surface element is described, and the secondary analysis result is a weld angle of each surface element.

Further, according to another aspect of the present invention, there are provided means for dividing a surface of a structure into surface elements which are minute plane elements, means for setting boundary conditions for analysis with respect to the surface elements, Means for dividing the entire structure into small whole elements, means for transferring the boundary conditions set for the surface elements to the whole elements, and analysis of the whole elements using the transferred boundary conditions. There is provided an apparatus for analyzing a structure, comprising: means for executing; and means for calculating an analysis result of the surface element based on the obtained analysis result of the entire element.

According to another aspect of the present invention, a means for defining the shape of a structure by CAD data, a means for setting a boundary condition for analysis with respect to the CAD data, Means for dividing into surface elements that are planar elements;
A means for dividing the entire structure into small whole elements, a means for transferring the set boundary conditions to the whole elements, a means for performing an analysis on the whole elements using the transferred boundary conditions, and an analysis of the whole elements An apparatus for analyzing a structure, comprising means for calculating an analysis result of a surface element from a result is provided.

According to another aspect of the present invention, there is provided means for dividing a surface of a structure into surface elements which are minute plane elements, means for dividing the entire structure into minute whole elements, An apparatus for analyzing a structure, comprising: means for executing an analysis on an entire element; and means for calculating an analysis result on the surface element based on the obtained analysis result on the entire element.

Further, according to another preferred aspect of the present invention, means for dividing the surface of the structure into surface elements which are minute plane elements, means for dividing the entire structure into minute whole elements, Means for performing analysis on the whole element, means for calculating the primary analysis result of the surface element by transferring the obtained analysis result of the whole element, and the surface element based on the primary analysis result An apparatus for analyzing a structure, comprising means for calculating a secondary analysis result is provided.

According to another preferred embodiment of the present invention, there are provided means for dividing the surface of the structure into surface elements which are minute plane elements, and means for setting boundary conditions for analysis with respect to the surface elements. Means for dividing the entire structure into small whole elements, means for transferring the boundary conditions set for the surface elements to the whole elements, and analysis of the whole elements using the transferred boundary conditions. Means to perform;
Means for calculating the primary analysis result of the surface element by transferring the obtained analysis result of the entire element, and means for calculating the secondary analysis result of the surface element based on the primary analysis result An apparatus for analyzing a structure is provided.

According to another preferred embodiment of the present invention, means for defining the shape of the structure by CAD data, means for setting a boundary condition for analysis on the CAD data, Means for dividing the structure into surface elements that are minute plane elements, means for dividing the entire structure into minute whole elements, means for transferring the set boundary conditions to the whole elements, Means for performing analysis of the entire element using boundary conditions, means for transferring the analysis result of the entire element to calculate a primary analysis result of the surface element, and the surface based on the primary analysis result An apparatus for analyzing a structure, comprising means for calculating a secondary analysis result of an element is provided.

According to another aspect of the present invention, the primary analysis result of the surface element is a displacement amount of each surface element generated when a load is applied to the structure, and a secondary analysis result is provided. The result is a distortion or a stress of each surface element, and an apparatus for analyzing a structure is provided.

According to another aspect of the present invention, the structure is a molded product formed by injection molding, and a primary analysis result of the surface element is obtained by the injection molding of the structure at the time of injection molding. An apparatus for analyzing a structure is provided, wherein a filling time of each surface element is provided, and the secondary analysis result is a weld angle of each surface element.

According to another aspect of the present invention, a step of dividing the surface of the structure into surface elements that are minute plane elements, a step of dividing the entire structure into minute whole elements, There is provided a computer-readable storage medium storing a program for executing a step of performing an analysis on the entire element and a step of calculating the analysis result of the surface element based on the analysis result of the entire element.

Further, according to another aspect of the present invention, a step of dividing a surface of the structure into surface elements, which are minute plane elements, in an analytical calculation in a design for manufacturing the structure; A structure for manufacturing an article designed by dividing the whole into minute whole elements, executing the analysis of the entire elements, and calculating the analysis results of the surface elements based on the analysis results of the entire elements An article manufacturing method is provided.

The structures such as products in the present invention include structures in all fields to which numerical analysis is applied, such as mechanical parts and molded products, architectural structures, electronic and electrical products, automobiles, production equipment, and the like.

The analysis in the present invention means a numerical analysis using a computer. For example, analysis of the response of a structure to the amount of displacement, strain, stress, strain energy, etc. that occurs in the structure due to the difference between the load applied to the structure including external force, forced displacement, heat, vibration, shock, electromagnetic waves, sound pressure, etc. Fluid analysis to analyze the pressure, temperature, velocity, stress, etc. of the fluid in the injection molding process where the fluid flows inside the mold, the fluid flow process inside the device, the fluid flow process around the object, etc.

The surface element in the present invention is a minute element created to smoothly approximate the surface of a structure with a planar minute element such as a triangle or a quadrangle, and is a higher-order element such as a secondary element. And a combination of elements used in a numerical analysis method such as a normal finite element method, such as a combination of triangles and rectangles, can be used.

Further, the whole element in the present invention means a micro element or a micro element constituting an analysis model of the entire structure (only a part included in the range to be analyzed) for analyzing the structure. Refers to a set. For example, planar elements such as triangles and squares used as microelements created when analyzing ordinary finite element structures,
Including three-dimensional elements such as hexahedrons and combinations thereof, the order expressing the accuracy of the internal function of each element can be a first to higher order.

Also, the visibility can be improved by transferring the primary analysis result or the secondary analysis result of the whole element as it is to the surface element and displaying the analysis result in the same shape as the actual structure. .

[0032]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a flow chart showing a schematic procedure of an embodiment when the present invention is applied to a numerical analysis in designing a structure.

The numerical analysis method according to this embodiment mainly includes a pre-analysis processing step (steps 1 to 5), an analysis step (step 6), and a post-analysis processing step (steps 7 to 9).

Further, the analysis apparatus used in the present embodiment includes computations for performing computation processing before and after analysis, such as execution of analysis and division of surface elements, division of whole elements, transfer of boundary conditions, calculation of primary and secondary analysis results, and the like. A device 100, a data storage device 200 including a memory or a hard disk for storing analysis data and software, a keyboard, a mouse, a digitizer,
There are a CAD input device 300 such as a three-dimensional shape measuring device and a boundary condition input device 400, and an output device 500 such as a display, a printer, and an optical shaping device.
FIG. 2 shows the configuration of the apparatus.

As a first embodiment, an example of an embodiment in which the present invention is applied to a structural analysis will be described by taking the design of a mechanical component product shown in FIG. 3 as an example.

First, the analyst uses general CAD software or the like in step 1 of FIG.
At 00, product shape data is input. FIG. 4 shows stereolithography shape data created using CAD, in which the product shape is represented by a triangle covering the surface, and is constituted by coordinate values of three points forming the triangle. In addition,
As the shape data, CAD data composed of point coordinates for expressing a curved surface such as a spline or NURBS used in general CAD, a curve number, and connection relation data between the curved surfaces can also be used. Also,
A finite element data format expression consisting of the node coordinates of the finite element method and the node numbers constituting the elements can also be used. The created shape data is stored in the data storage device.

Next, the analyst sets the boundary conditions on the CAD data using the boundary condition input device 400 in step 2 of FIG. As an example, FIG. 4 shows a state in which the constraint condition 2 and the load condition 3 are set in the stereolithography shape data relating to the structure 1 having the shape as shown in FIG. Although a concentrated load is set here as the load condition, any other load condition that can be generally considered in structural analysis, such as pressure, heat, and vibration, can be set. Regarding the constraint condition, not only the complete constraint,
It is also possible to set conditions such as contact conditions, slip, and spring instructions. Further, the analyst sets required physical property values such as an elastic coefficient, a Poisson's ratio, and a coefficient of linear expansion. The boundary conditions and physical property values are stored in the data storage device 200.

Subsequently, at step 3, the data storage device 2
00, CAD data is loaded into the arithmetic unit 100,
A surface element covering the structure is generated by the surface element dividing means 101 of the arithmetic unit. FIG. 5 shows an example in which a triangular surface element 4 is generated, and the surface of the structure has a smoothly approximated shape. The generated surface element data is stored in the data storage device 200 again.

When CAD data is not created,
The analyst may create surface elements using shape definition software called a preprocessor and set boundary conditions on the surface elements in the same manner as in ordinary finite element method analysis according to steps 1 'and 2' in FIG. .

Subsequently, in steps 4 and 5, the CAD data,
Alternatively, the surface element data is loaded from the data storage device 200 to the arithmetic unit 100, the entire element 7 is generated by the entire element dividing unit 102 of the arithmetic unit, and the boundary condition of the surface element 4 is transferred to the entire element 7 by the boundary condition transfer unit 103. Transcribed. FIG. 6 shows an example of the overall element shape and the transferred boundary conditions. Here, the generation of the entire element is described in
No. 077, and the boundary condition is transferred to the entire element vertex closest to the set point of the boundary condition of the surface element. For the transfer of the boundary condition, other methods such as weighting and averaging the load according to the distance from the set point on the surface element may be used. The generated entire elements and boundary conditions are stored in the data storage device 200.

Subsequently, at step 6, the data storage device 2
From 00, the whole element 7 and the boundary condition are loaded into the arithmetic unit 100, the analysis is executed by the analysis execution unit 104 of the arithmetic unit, and the primary analysis result on the entire element is stored in the data storage device 200.

Subsequently, at step 7, the displacement of the vertices, which is the analysis result of the entire element, is transferred to the surface element by the primary analysis result transfer means 105 of the arithmetic unit. Here, the value of the entire element vertex closest to the surface element vertex is transferred. FIG. 7 is a deformation diagram showing the analysis result of the entire element, and FIG. 8 shows a deformation diagram of the surface element 4 as a result of transferring the deformation amount. The deformation amount data of the surface element is stored in the data storage device 200.

Further, the secondary analysis result calculating means 106 of the arithmetic unit calculates the strain and stress value of the surface element 4. First, the shape data and physical property data of the surface element and the displacement amount data of the surface element 4 are loaded from the data storage device 200 to the arithmetic device 100. The arithmetic unit 100 uses a general finite element method based on the shape data of the surface element 4 (for example, as a reference, for example, a “matrix finite element method” (Baifukan)).
Generates a B matrix and a D matrix of membrane elements for each surface element 4. The B matrix is a transformation matrix to the gradient in the element 4 determined by the coordinate values of the element vertices, and is obtained from the displacement amount of the vertex for each surface element 4 according to {distortion} = [B] {vertex displacement amount}. A distortion amount is calculated. The D matrix is an elastic coefficient matrix determined by physical property values, and a stress value in each surface element 4 is calculated by {stress} = [D] {strain}. The strain and stress values calculated by the above procedure are stored in the data storage device 200.

Further, at step 9, the data output device 5
00, the analysis result on the surface element 4 is
It is output by a method such as a contour display diagram of distortion, numerical data output, graph output, and vector display. FIG. 9 shows a stress distribution diagram of a surface element as an example. The analyst checks the strength and rigidity of the structure from the output diagram, and if necessary, makes design changes such as shape modification. When you finally get a satisfactory result,
The manufacturing specification may be finally determined based on this and manufactured.

As Embodiment 2, an embodiment in which the present invention is applied to injection molding analysis will be described with reference to an injection molded product shown in FIG. 10 as an example.

First, the analyst uses the general CAD software or the like in step 1 of FIG.
At 00, the shape data of the injection molded product is input. FIG. 11 shows stereolithography shape data as an example of shape data created using CAD. The created CAD data is stored in the data storage device 200.

Next, the analyst sets boundary conditions on the CAD data using the boundary condition input device 400 in step 2 of FIG. As an example, FIG. 11 shows a state in which the gate position 15 at the time of injection molding is set in the optical molding shape data. Further, the analyst sets necessary physical property values such as viscosity and thermophysical property of the material. The boundary conditions and physical property values are stored in the data storage device 200.

Subsequently, at step 3, the data storage device 2
00, CAD data is loaded into the arithmetic unit 100,
A surface element that covers the structure is generated by the surface element dividing unit 101 of the arithmetic device 100. FIG. 12 shows an example in which a triangular surface element 16 is generated, and the surface of the structure has a smoothly approximated shape. The generated surface element data is stored in the data storage device 200 again.

Subsequently, in steps 4 and 5, the CAD data,
Alternatively, the surface element data is loaded from the data storage device 200 to the arithmetic unit 100, the entire element 17 is generated by the entire element dividing unit 102 of the arithmetic unit, and the boundary condition of the surface element 16 is set by the boundary condition transfer unit 103.
Is transferred to FIG. 13 shows an example of the whole element shape and the transferred boundary condition (gate position). Generated overall element 1
7 and the boundary condition are stored in the data storage device 200.

Subsequently, at step 6, the data storage device 2
From 00, the entire element 17 and the boundary condition are loaded into the arithmetic unit 100, the analysis is executed by the analysis execution unit 104 of the arithmetic unit, and the primary analysis result on the entire element 17 is stored in the data storage device 200.

Subsequently, at step 7, the primary analysis result transfer means 105 of the arithmetic unit starts the injection at the time when the pressure value at the vertex and the flow front at the time of injection pass the vertex, which are the analysis results for the entire element 17. The filling time, which is the time from the transfer to the surface element, is transferred. Here, the value of the entire element vertex closest to the surface element vertex is transferred. FIG. 14 shows a filling pattern obtained by displaying the filling time, which is the analysis result of the entire element, on a contour line. FIG. 1 shows a filling pattern diagram of the surface element obtained as a result of transferring the filling time value to the surface element.
It is shown in FIG. Surface element pressure and fill time data is stored in data storage 200.

Further, the velocity and the weld angle of the surface element are calculated by the secondary analysis result calculating means 106 of the arithmetic unit. First, the shape data and physical property data of the surface element, the pressure data of the surface element, and the filling time data are loaded from the data storage device 200 to the arithmetic device 100. Arithmetic unit 10
At 0, a B matrix of membrane elements is generated for each surface element from the shape data of the surface element by a general finite element method. The B matrix is a transformation matrix to the gradient in the element determined by the coordinate value of the element vertex, and the velocity in the element is calculated from the pressure of the vertex for each surface element by {velocity} = conductance x [B] {vertex pressure} Is done. Here, the conductance is a coefficient determined by the material viscosity and the wall thickness as described in Japanese Patent No. 2998596, and is an index indicating the ease of flow. Furthermore, by using the B matrix, the {front flow vector} =
[B] The front flow vector is calculated for each surface element by [vertex filling time], and the weld angle, which is the angle at which the flow front hits, is calculated from the angle between the front flow vectors between adjacent surface elements as shown in FIG. Is calculated. The speed and weld angle calculated by the above procedure are stored in the data storage device 200.

Further, in step 9, the data output device 5
As a result, the analysis results such as pressure and velocity on the surface element are output by a method such as a contour display diagram, numerical data output, graph output, and vector display. FIG. 17 shows an example in which the surface element has a weld angle of 100 degrees. In the region where the weld angle is small, the flow front is likely to collide, causing poor appearance and poor strength.The analyst checks the weld occurrence from the output diagram, and if necessary, changes the design such as changing the gate position. Do.

[0054]

According to a preferred embodiment of the method and the apparatus for analyzing a structure according to the present invention, the boundary condition is directly set on the CAD data, or the surface element on which the surface shape of the structure is correctly expressed is obtained. By setting the boundary conditions in the analysis, the boundary conditions are automatically transcribed to the whole elements used in the analysis, so that the analyst can set the conditions without being conscious of the whole elements. It is possible to prevent a difference in the setting accuracy of the boundary condition from occurring due to the knowledge and knowledge.

According to a preferred embodiment of the present invention, 1
By transferring the next analysis result to the surface element or calculating the second analysis result, the analysis result can be output with higher accuracy than when the analysis result is directly output with the whole element used for the analysis. In addition to this, the analyst can execute the entire analysis only on the surface elements without being conscious of the entire elements. Therefore, even a designer who is not familiar with the numerical analysis such as the finite element method can easily execute the analysis, and can improve the efficiency of design development.

[Brief description of the drawings]

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

FIG. 2 is an analysis apparatus used in an example of an embodiment of the present invention.

FIG. 3 is a shape view of a mechanical component used in Embodiment 1 of the present invention.

FIG. 4 is an example showing a state in which a boundary condition is set in the data diagram for stereolithography of the mechanical component of FIG. 3;

FIG. 5 is an example showing a state in which the surface of the mechanical component of FIG. 3 is divided into triangular surface elements and boundary conditions are set.

FIG. 6 is an example showing a state in which the surface of the machine component of FIG. 3 is divided into whole hexahedral elements and boundary conditions are set.

FIG. 7 is a diagram showing a deformed state of an entire element generated under the boundary condition of FIG. 6;

8 is a diagram showing a deformed state of the surface element obtained as a result of transferring the deformed state of FIG. 7 to the surface element of FIG. 5;

9 is a stress distribution diagram of a surface element calculated from the deformation state of FIG.

FIG. 10 is a shape diagram of an injection-molded product used in Example 2 of the present invention.

FIG. 11 is an example showing a state in which boundary conditions are set in the data diagram for stereolithography of the injection molded article of FIG. 10;

FIG. 12 is an example showing a state in which the surface of the injection molded article of FIG. 10 is divided into triangular surface elements and boundary conditions are set.

FIG. 13 is an example showing a state in which the surface of the injection molded article of FIG. 10 is divided into hexahedral elements and boundary conditions are set.

FIG. 14 is a filling pattern diagram in which the filling time of microelements obtained as a result of performing injection molding analysis using the whole elements of FIG. 13 is displayed in a contour line.

FIG. 15 is a filling pattern diagram in which the filling time of FIG. 14 is transferred to the surface element of FIG. 12 and contour lines are displayed.

FIG. 16 is a conceptual diagram showing a method of calculating a weld angle.

17 is a weld diagram in which a weld angle is calculated from the filling time in FIG. 15 and a portion at an angle of 100 degrees is displayed.

[Explanation of symbols]

A: CAD surface portion representing the shape of the mechanical part. 1: A triangle that approximately represents the surface shape of a mechanical part for stereolithography. 2: A symbol representing the displacement constraint portion of the mechanical component set in the stereolithography data. 3: Vector representing the load on the mechanical component set in the data for stereolithography. 4: A minute triangular surface element approximately representing the surface shape of the mechanical part. 5: Symbol indicating a displacement-constrained portion of a machine component set as a surface element. 6: Vector representing the load on the machine component set for the surface element. 7: The whole hexahedral element obtained by dividing the shape of the mechanical part. 8: Symbol representing the displacement restrained portion of the machine component transferred to the entire element. 9: Vector representing the load on the machine component transferred to the entire element. 10: The shape of the entire element before deformation. 11: Shape of the entire element after deformation. 12: Shape of surface element before deformation. 13: Surface element shape after deformation. B: CAD surface portion representing the shape of the injection molded product. 14: Triangle approximating the surface shape of the injection molded product for stereolithography. 15: Symbol indicating the gate part of injection molding set in the data for stereolithography. 16: minute triangular surface element approximately representing the surface shape of the injection molded article. 17: Entire hexahedral element obtained by dividing the shape of the injection molded product. 18: Symbol indicating the gate portion of the injection molded product transferred to the entire element. 19: Obstacle in the injection molded product cavity. 20: Tip shape of the injection molding material flowing on the left side of the obstacle 19. 21: Tip shape of the injection molding material flowing on the right side of the obstacle 19. 22:20 heading vector. 23: 21 traveling direction vector. 24: Weld angle which is an angle formed by the traveling direction vector. 25: Contour line representing a portion at a weld angle of 100 degrees. 100: arithmetic unit for performing a series of arithmetic processing. 101: Surface element dividing means in the arithmetic unit. 102: The whole element dividing means in the arithmetic unit. 103: means for transferring the boundary condition in the arithmetic unit to the whole element. 104: analysis execution means in the arithmetic unit. 105: means for transferring the primary analysis result in the arithmetic unit to the surface element. 106: A part for calculating the secondary analysis result of the surface element in the arithmetic unit. 200: Data storage device for storing data. 300: CAD input device for creating the shape of a structure. 400: Boundary condition input device for analysis. 500: Output device for analysis results.

Claims (18)

[Claims] A step of dividing a surface of a structure into surface elements which are minute plane elements; a step of setting a boundary condition for analysis with respect to the surface elements; Dividing, the step of transferring the boundary condition set to the surface element to the entire element, the step of performing analysis on the entire element using the transferred boundary condition, A method for analyzing a structure, comprising calculating an analysis result of the surface element based on an analysis result of the element. 2. A step of defining a shape of a structure by CAD data, a step of setting a boundary condition for analysis with respect to the CAD data, and a step of dividing the surface of the structure into surface elements which are minute plane elements. A step of dividing the entire structure into minute whole elements, a step of transferring the set boundary conditions to the whole elements, a step of performing analysis on the whole elements using the transferred boundary conditions, A method of calculating an analysis result of a surface element from the analysis result of (a). 3. A step of dividing a surface of a structure into surface elements which are minute plane elements; a step of dividing the entire structure into minute whole elements; and a step of executing analysis on the whole elements. A method for analyzing a structure, comprising calculating an analysis result of the surface element based on the obtained analysis result of the entire element. 4. A step of dividing the surface of the structure into surface elements which are minute plane elements; a step of dividing the entire structure into minute whole elements; and a step of executing analysis on the whole elements. Transferring the obtained analysis result of the entire element to calculate a primary analysis result of the surface element; and
A method for analyzing a structure, comprising calculating a secondary analysis result of the surface element based on a secondary analysis result. 5. A step of dividing a surface of a structure into surface elements which are minute plane elements; a step of setting a boundary condition for analysis with respect to the surface elements; Dividing, transferring the boundary condition set to the surface element to the entire element, performing an analysis on the entire element using the transferred boundary condition, and obtaining the obtained entire element A step of calculating a primary analysis result of the surface element by transferring the analysis result of the structure, and a step of calculating a secondary analysis result of the surface element based on the primary analysis result. Analysis method. 6. A step of defining a shape of a structure by CAD data, a step of setting a boundary condition for analysis with respect to the CAD data, and dividing the surface of the structure into surface elements which are minute plane elements. Performing the step of dividing the entire structure into small whole elements, transferring the set boundary conditions to the whole elements, and analyzing the whole elements using the transferred boundary conditions. Performing, calculating the primary analysis result of the surface element by transferring the analysis result of the entire element, and calculating the secondary analysis result of the surface element based on the primary analysis result. A method for analyzing a structure, comprising: 7. The primary analysis result of the surface element is a displacement amount of each surface element generated when a load is applied to the structure, and the secondary analysis result is distortion of each surface element or The method for analyzing a structure according to claim 4, wherein the method is a stress. 8. The structure is a molded article formed by injection molding, and a primary analysis result of the surface element is a filling time of each surface element at the time of injection molding of the structure. The structure analysis method according to any one of claims 4 to 6, wherein the secondary analysis result is a weld angle of each surface element. 9. A means for dividing the surface of a structure into surface elements, which are minute plane elements; a means for setting a boundary condition for analysis with respect to said surface elements; Means for dividing, means for transferring the boundary condition set to the surface element to the entire element, means for performing analysis on the entire element using the transferred boundary condition, and the obtained whole An apparatus for analyzing a structure, comprising: means for calculating an analysis result of the surface element based on an analysis result of an element. 10. A means for defining a shape of a structure by CAD data, a means for setting a boundary condition for analysis with respect to CAD data, and a means for dividing the surface of a structure into surface elements which are minute plane elements. Means for dividing the entire structure into small whole elements, means for transferring the set boundary conditions to the whole elements, means for performing analysis on the whole elements using the transferred boundary conditions, and An analysis apparatus for a structure, comprising: means for calculating an analysis result of a surface element from an analysis result of the above. 11. A means for dividing a surface of a structure into surface elements which are minute plane elements; a means for dividing the entire structure into minute whole elements; a means for performing analysis on the whole elements; An apparatus for analyzing a structure, comprising: means for calculating an analysis result of the surface element based on the obtained analysis result of the entire element. 12. A means for dividing a surface of a structure into surface elements which are minute plane elements; a means for dividing the whole structure into minute whole elements; a means for performing analysis on the whole elements; Means for calculating the primary analysis result of the surface element by transferring the obtained analysis result of the entire element, and means for calculating the secondary analysis result of the surface element based on the primary analysis result A structural analysis apparatus characterized by the following. 13. A means for dividing the surface of a structure into surface elements which are minute plane elements; means for setting boundary conditions for analysis with respect to said surface elements; Means for dividing, means for transferring the boundary condition set for the surface element to the whole element, means for performing analysis on the whole element using the transferred boundary condition, and the obtained whole element A structure for calculating a primary analysis result of the surface element by transferring the analysis result of the structure, and a means for calculating a secondary analysis result of the surface element based on the primary analysis result. Analysis equipment. 14. A means for defining the shape of a structure by CAD data, means for setting a boundary condition for analysis with respect to said CAD data, and dividing the surface of said structure into surface elements which are minute plane elements. Means for dividing the whole structure into small whole elements, means for transferring the set boundary conditions to the whole elements, and analysis of the whole elements using the transferred boundary conditions. Means for executing, means for calculating the primary analysis result of the surface element by transferring the analysis result of the entire element, and means for calculating the secondary analysis result of the surface element based on the primary analysis result An analysis device for a structure, comprising: 15. The primary analysis result of the surface element is a displacement amount of each surface element generated when a load is applied to the structure, and the secondary analysis result is distortion of each surface element, or The structure analyzing apparatus according to claim 12, wherein the structure is a stress. 16. The structure is a molded article formed by injection molding, and a primary analysis result of the surface element is a filling time of each of the surface elements at the time of injection molding of the structure. The structure analysis apparatus according to any one of claims 12 to 14, wherein the secondary analysis result is a weld angle of each surface element. 17. A step of dividing a surface of a structure into surface elements that are minute plane elements, a step of dividing the entire structure into minute whole elements, and a step of performing analysis on the whole elements. A computer-readable storage medium storing a program for executing a step of calculating an analysis result of the surface element based on an analysis result of the entire element. 18. A step of dividing the surface of the structure into surface elements which are minute plane elements and a step of dividing the entire structure into minute whole elements in an analytical calculation in a design for manufacturing the structure. And a method of manufacturing an article designed by the step of executing the analysis of the entire element and the step of calculating the analysis result of the surface element based on the analysis result of the entire element.