JP2003337836A - Method and device for preparing model for analysis - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a device for preparing a model for analysis for allowing a system user to easily and quickly prepare his or her desired model for analysis by reducing any complicate pre-processing or manual operation while there is possibility that any mode for analysis unintended by the system user is prepared, or much labor and time is required for the pre-processing or the preparation of a model for analysis in a conventional manner. <P>SOLUTION: This device is provided with a shape characteristic recognizing means 102 for recognizing shape characteristics being the candidate of modeling execution from a shape model, a modeling presenting means 103 for presenting a modeling method 1405 applicable to each of the recognized shape characteristics, and a modeling executing means 104 for modeling the shape characteristics by a modeling method 1406 selected by a system user. The system user is able to generate his or her desired model for analysis only by selecting the modeling method displayed corresponding to the shape characteristics. Therefore, it is possible to sharply reduce any labor and time required for preparing a model for analysis. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a C which streamlines design work by numerical analysis simulation using a computer.
The present invention relates to an analytical model creating method and an analytical model creating apparatus in AE (Computer Aided Engineering), and in particular,
The present invention relates to a technique for increasing the efficiency of modeling work when creating a model for analysis from a shape model to be analyzed.

[0002]

2. Description of the Related Art First of all, in the present specification and drawings, modeling a shape model means deleting holes and fillets in a shape model to be analyzed for the purpose of shortening the execution time of numerical simulation. Replacing the joints between the models with an approximate model.

The shape feature is a partial shape in the shape model such as a hole, a fillet, or a shape joint which is an object of modeling and is a partial shape which can be interpreted in a specific meaning.

It is known that the modeling work of the shape model is conventionally performed by a person skilled in numerical analysis simulation by manual operation, which is labor-intensive and time-consuming.

The following method has been proposed as a conventional method for creating a model for analysis.

The first method is, for example, Japanese Patent Laid-Open No. 2000-3.
As described in Japanese Patent No. 31194, for a keyword having a name of a shape feature belonging to a shape model and attribute values such as a dimension value, an area, and a volume of the shape feature,
A threshold parameter is set for each keyword of the name of the shape feature, and when the attribute value of the shape feature falls below the threshold parameter, the shape feature is removed and the shape model is modeled.

The second method is, for example, Japanese Patent Laid-Open No. 06-25.
As described in Japanese Patent No. 9505, when a user specifies a modeling type and a shape feature portion to be modeled, an analysis modeling process is executed to create an analysis model.

[0008]

The conventional analytical model creating method and analytical model creating apparatus have the following problems.

In the first method, the threshold parameter is set for each keyword of the name of the shape feature and the shape feature is removed when the attribute value of the shape feature falls below the threshold parameter. There is a risk that an analysis model will be created. Further, the above-mentioned publication describes a function capable of setting an arbitrary shape feature outside the removal target in advance. However, it is difficult for the system user to judge whether or not to be removed before the modeling process is executed. Further, the work of creating the analysis model requires a lot of labor and time.

In the second method, it is necessary to previously input the type of modeling performed by the system user and the shape element to be the target. For system users who are unfamiliar with analytical modeling, it is difficult to determine which modeling method can be applied to which shape feature. Further, since the type of modeling and the shape element to be the target are input, the work takes time.

An object of the present invention is to create an analysis model having a procedure and means for reducing a complicated preprocessing and manual work so that a system user can easily create a desired analysis model in a short time. A method and an apparatus for creating a model for analysis.

[0012]

In order to achieve the above object, the present invention recognizes a shape feature from a shape model to be analyzed and registers at least one of the recognized shape feature and the shape feature in association with each other. We propose an analysis model creation method that presents two modeling methods to a system user, executes a modeling process selected by the system user from the presented modeling methods, and creates an analysis model.

In the present invention, a shape feature that is a candidate for modeling execution is recognized from a shape model, a modeling method applicable to each recognized shape feature is presented, and selected by the system user. Since the shape feature is modeled by the modeling method, the system user can generate a desired analysis model by simply selecting the modeling method that is displayed in association with the recognized shape feature. The labor and time required to create an analytical model can be significantly reduced.

The present invention also recognizes a shape feature from a shape model to be analyzed, displays either or both of the recognized shape feature and the type of the shape feature on the shape model, and recognizes the recognized shape feature or shape. The type of feature and at least one modeling method registered in association with the shape feature are presented to the system user, and the system user uses the presented modeling method for each shape feature or for each type of shape feature. We propose an analysis model creation method that creates the analysis model by executing the selected modeling process.

In the present invention, a shape feature that is a candidate for modeling is recognized from the shape model, and either or both of the recognized shape feature and the type of the shape feature are displayed on the shape model, and the recognized shape is displayed. For each feature, a modeling method applicable to the shape feature is presented, and the system user models the shape feature according to the modeling method selected for each shape feature or each type of shape feature. For the recognized shape features, a desired analysis model can be generated for each shape feature or each type of shape features by simply selecting a modeling method that is displayed in association with the shape feature. The labor and time can be reduced significantly.

In order to achieve the above object, the present invention comprises a shape model input means for inputting a shape model to be analyzed,
Presents a shape feature recognition unit that recognizes shape features from the shape model to be analyzed and identifies the type, and at least one analysis modeling method registered in association with each recognized shape feature type. An analysis including a modeling presentation means for allowing a system user to select a modeling method and a modeling execution means for performing a modeling process on a shape feature by the selected modeling method to create an analysis model We propose a model creation device for use in computer.

In the present invention, a shape feature recognition means for recognizing a shape feature which is a candidate for execution of modeling from a shape model, and a modeling method for presenting each recognized shape feature a modeling method applicable to the shape feature. Since the presenting means and the modeling execution means for modeling the shape feature by the modeling method selected by the system user are provided, the system user displays the recognized shape feature in association with the shape feature. A desired analysis model can be generated simply by selecting a modeling method, and the labor and time for creating the analysis model can be significantly reduced.

The present invention further includes a shape model input means for inputting a shape model to be analyzed, a shape feature recognition means for recognizing shape features from the shape model to be analyzed and specifying a type, and the recognized shape features or shapes. One or both of the feature types are displayed on the shape model, and at least one analysis modeling method registered in association with each recognized shape feature type is presented to the system user. Modeling presentation means for selecting a modeling method for each shape feature or for each type of shape feature, and modeling for performing a modeling process on the shape feature by the selected modeling method to create an analysis model An analysis model creating apparatus including an executing means is proposed.

In the present invention, the shape feature recognition means for recognizing a shape feature that is a candidate for modeling execution from the shape model, and either or both of the recognized shape feature and the type of the shape feature are displayed on the shape model. Then, for each recognized shape feature, the modeling feature that presents a modeling method applicable to the shape feature and the modeling feature selected by the system user for each shape feature or each type of shape feature are used. Since the system user is provided with a modeling execution means for modeling, the system user can select, for each recognized shape feature, a modeling method displayed in association with the shape feature. A desired analysis model can be generated for each type of, and the labor and time for creating the analysis model can be reduced significantly.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION Next, referring to FIGS.
An embodiment of an analysis model creation method and an analysis model creation device according to the present invention will be described. 1. Configuration of Analytical Model Creating Apparatus FIG. 1 is a block diagram showing the overall configuration of an embodiment of an analytical model creating apparatus according to the present invention. The analysis model creation apparatus of this embodiment includes an input / output device 100, a shape model input unit 101, a shape feature recognition unit 102, a modeling presentation unit 103, a modeling execution unit 104, and an analysis condition input unit 105. , Analysis mesh generation means 106,
Model database 107 and modeling database 1
And 08.

The input / output device 100 inputs a geometric model to be analyzed and inputs / outputs analysis model information. The shape model input means 101 inputs the shape model to be analyzed into the model database 107. Shape feature recognition means 102
Recognizes the shape feature from the shape model registered in the model database 107 based on the identification criterion of each shape feature registered in the modeling database 108, and registers the shape feature in the model database 107 in association with each other. .

The modeling presentation means 103 outputs the shape feature registered in the model database 107, the type thereof, and the modeling method registered in association with the type of the shape feature registered in the modeling database 108. The information is displayed on the device 101a, the system user is prompted to select the modeling method using the input / output device, and the modeling method selected for each shape feature is registered in association with the model database 107.

The modeling execution means 104 executes analysis modeling processing on the shape features registered in the model database 107 according to the modeling method selected by the system user. The analysis condition input means 105 prompts the system user to input analysis conditions such as materials and boundary conditions, and registers the input analysis conditions in the model database 107. The analysis mesh generation means 106 generates an analysis mesh for the shape model registered in the model database 107.

The model database 107 stores the shape model to be analyzed, the shape feature information belonging to the shape model, the analysis conditions, and the analysis mesh in association with each other. The modeling database 108 stores the types of shape features, their identification criteria, and the modeling method in association with each other.

The analysis model creating apparatus of the present embodiment recognizes the shape feature that is a candidate for modeling execution from the shape model, displays the modeling method for each recognized shape feature on the screen, and informs the system user. A modeling presentation means for selecting a modeling method is provided so that the analysis modeling process can be executed efficiently. 2. Database Structure 2.1 Model Database 107 FIG. 2 is a conceptual diagram showing the model database 107 in the present invention. The model database 107 manages model data by assigning a unique identifier to each analysis target. As the identifier, for example, a model number or a model name may be used.

In the model database 107, shape model data, shape feature data,
Analysis condition data and analysis mesh data can be registered in association with each other.

As a representation of the shape model data, for example, a boundary representation may be used. In the boundary representation, a solid is represented by a boundary surface that divides the outside and the inside. The shape model data is represented by topological (topology) data indicating the connection of boundaries and geometric data (geometry) indicating the shape of the boundaries.

FIG. 3 is a conceptual diagram showing a phase data expression method by boundary expression in the present invention. In boundary representation,
A solid is a set of at least one continuous face belonging to it
It has a data structure that owns a (shell), a surface owns at least one group of line segments (loop) belonging to it, and a line segment owns its start and end points. Of these, the shell and the loop have an outline or a hole as an attribute thereof.

Here, a solid, a shell, a surface, a loop, a line segment, and a point in the shape data expression method based on the boundary expression are called shape elements. Each shape element has a unique identifier in one shape model.

An example of the geometric data by the boundary expression is shown below. A point has a three-dimensional coordinate value as its geometric data. There are various types of geometrical data representation methods for lines and surfaces, and any of them may be used.

Here, the NURBS function widely used for shape representation in three-dimensional CAD is used. NUR
The defining function of the surface of K × L order by BS is represented by Expression 1.

[0032]

[Equation 1] In Equation 1, the number of control points is (n + 1) × (m + 1), and N
i, K (u), Mj, L (v) are basis functions in the u and v parameter directions, and wij is the weight of each control point. The knot vector is [x0x1 ... xp] [y0y1 ... yq], and p = n + K +
1, q = m + L + 1.

For details of the representation method of the shape data,
"Basics and applications of three-dimensional CAD": Hiroshi Toriya, Hiroaki Chiyokura ed .: Kyoritsu Shuppan Co., Ltd.

As a representation of the shape feature data, a unique identifier such as a shape feature number is given to each shape feature,
Corresponding to this, type of shape feature, attribute value of shape feature,
The shape element group of the shape model related to the shape feature and the flag indicating the presence / absence of modeling execution are associated and registered.

FIG. 4 is a diagram showing an example of the data structure of the shape feature data according to the present invention. The attribute value of the shape feature and the shape element group of the shape model to be registered differ depending on the type of the shape feature. Details of the shape element group will be described in the description of the simplified database 108.

As the analysis condition data, materials, loads, constraint conditions, etc. are registered in association with the shape elements of the analysis target shape model.

FIG. 5 is a diagram showing an example of the data structure of analysis mesh data. As analysis mesh data,
Node data (total number of nodes, coordinate value of node), element data (total number of elements, number of nodes forming element, node number) are registered. 2.2 Modeling Database 108 FIG. 6 is a diagram showing an example of the data structure of the modeling database 108 in the present invention. The modeling database 108 includes an identification criterion for recognizing a shape feature from a shape model according to the type of the shape feature, a rule for selecting a shape element group forming the shape feature, and at least one applicable modeling method. Are registered in association with each other.

When the shape feature has an attribute value that defines the feature, if the threshold value parameter of the attribute value is also registered, the threshold value parameter and the attribute value of the shape feature are compared. , Can also be presented as a modeling target.

Next, the identification criteria for recognition, the shape element selection rules, the applicable modeling method, and the attribute values that define the characteristics are shown for each type of shape characteristics. << Hole, Protrusion >> FIG. 7 is a diagram showing an example of modeling a hole shape according to the present invention. Modeling holes and protrusions means deleting holes and protrusions that do not significantly affect the accuracy of analysis calculation for the purpose of shortening the analysis time.

FIG. 7 (a) is a shape model having a shape feature that should be recognized as a hole shape, and FIG. 7 (b) is shown in FIG. 7 (a).
It is the figure which wire-displayed the shape model of.

The hole identification standard, shape element selection rule, modeling method, and attribute value are shown below. Identification Criteria: Loops whose attributes are holes (hole loops). Shape element selection rule: All the line groups (line group 1) that are in contact with the loop whose attribute is a hole, and the surface group (the surface group that includes all the constituent lines of the outer shape loop among the shape model constituent surfaces) 1), all the point groups (point group 1) belonging to the line group 1 are holes. Modeling method: Deletion (face group 1 selected by the selection rule, line group 1, face corresponding to point group 1,
(Lines and points are deleted, and the hole loop belonging to line group 1 is deleted from the data of the surface to which the hole loop belongs). Attribute value: The maximum value of the area of the hole loop contour to which the shape feature belongs.

In the case of the shape model of FIG. 7, since the line groups 701 and 702 are hole loops, the hole identification criteria are satisfied. Then, the shape elements forming the hole are selected based on the selection rule.

In the shape model of FIG. 7, line segment 70
5, 706, 707, the surface 708 corresponding to the side surface of the hole, the points 709, 7010 are selected, and the model database 10 is selected.
Registered in 7.

At this time, the areas of the contours of the hole loops 701 and 702 are obtained, and the larger area is registered together with the model database 107 as the attribute value of the hole.

Next, the modeling of holes will be described.
The modeling database 108 describes the keyword “delete” as a modeling method and the operation when “delete” is executed.

In the shape model of FIG. 7, the shape elements 705 to 7010 forming the holes are deleted, and the faces 703 and 704 to which the hole loops 701 and 702 belong.
The hole loops 701 and 702 are deleted from the constituent loop of FIG.

FIG. 7C shows the shape model after execution of "delete".

Although the modeling of the hole shape is shown here, the projection can also be modeled by the same process. << Fillet >> FIG. 8 is a diagram showing an example of modeling a fillet according to the present invention. A fillet is a shape that is characterized by being composed of at least one continuous surface group of a cylindrical surface, a torus surface, or a spherical surface.Modeling a fillet refers to the accuracy of analysis calculation for the purpose of shortening the analysis time. It is to delete the fillet that does not affect so much.

FIG. 8A shows a shape model having shape features to be recognized as a fillet.

Fillet identification criteria, shape element selection rules, modeling method, and attribute values are shown below. Identification criteria: A cylindrical surface or torus surface in which lines other than arcs are continuous with a flat surface. Shape element selection rule: A line segment and a point belonging to a cylindrical surface, a spherical surface, and a surface shape that are in contact with a cylindrical surface that is a reference retrieved by the identification reference by a line are set as fillets. Modeling method: Deletion (extend the surfaces that are in line with each cylindrical surface selected by the selection rule to the position of the intersection line). Attribute value: radius of fillet.

In the case of the shape model of FIG. 8, the surface 801 or 802 or 803 satisfies the identification criterion. Then, based on the selection rule, the shape elements forming the hole shape are selected.

In the shape model of FIG. 7, surfaces 801,
802, 803, lines and points belonging to these surfaces are selected and registered in the model database 107.

Also, the cylindrical surfaces 801, 802, 803
Is calculated, and the maximum radius is also registered in the model database 107 as an attribute value of the fillet.

Next, modeling of the fillet will be described. The modeling database 108 describes the keyword “delete” as a modeling method and the operation when “delete” is executed.

In the shape model of FIG. 8, planes 801, 802, 803 forming the fillet are deleted, and lines and points belonging to these planes are deleted, and planes 806 and 807, 807 and 808 which are in line with each cylindrical surface. , 808 and 806
Extend each to the position of the intersection line.

FIG. 8B shows the shape model after the execution of "delete". << Thin Plate >> FIG. 9 is a diagram showing an example of modeling a thin plate according to the present invention. Modeling a thin plate is to convert a solid into a surface shape for the purpose of reducing the analysis scale.

FIG. 9A is a shape model having a shape feature that should be recognized as a thin plate, and FIG. 9B is a diagram in which the shape of FIG. 9A is displayed by wires.

The thin plate identification criteria, shape element selection rules, modeling method, and attribute values are shown below. Discrimination Criteria: Face groups that face each other within a standard dimension value set in the system (for example, 1/20 of the side length of a cube that completely encloses a solid). Shape element selection rule: Faces searched by the identification criteria and lines and points belonging to the faces. Modeling method: Neutral surface creation (create and extend a surface at the center of each facing surface, join at the intersection line position, and delete the facing surface group). Outer surface extraction (deleting the surface groups other than the surface group to which the surface selected by the system user among the facing surface groups and the lines and points belonging to the surface group). Attribute value: The average value of the distances between the facing surface groups.

In the case of the shape model of FIG. 9, the reference dimension value is 1
When the distance is 0 mm, the faces 901 and 903 face each other at a distance of 5 mm, and the faces 902 and 904 face each other at a distance of 8 mm, which satisfies the identification criterion.

Subsequently, the shape elements forming the hole shape are selected based on the selection rule.

In the shape model of FIG. 7, surfaces 901,
902, 903, 904 and lines and points belonging to these surfaces are selected and registered in the model database 107.

The average value of two pairs of facing distances is 4 m.
m is also registered as an attribute value in the model database 107.

Next, modeling of the fillet will be described. The modeling database 108 includes the keywords “neutral plane creation” and “outer surface extraction” as modeling methods,
The operation when "neutral surface creation" and "outer surface extraction" are executed is described.

In the shape model of FIG. 9, when "neutral surface creation" is selected, new surfaces 905 and 906 are created at the positions of the center distances of the surfaces 901 and 903 and the surfaces 902 and 904, and thin plates are created. Delete all shape elements selected as.

When "external surface extraction" is selected, a message "Select a surface to be used as an external surface" is displayed on the screen to prompt the system user to select the surface.
FIG. 9D is a surface group created when the system user selects the surface 903 or 904, and FIG. 9E is a surface group created when the system 901 or 902 is selected. is there.

For easy understanding of the differences between FIG. 9 (c), FIG. 9 (d) and FIG. 9 (e), the shape elements belonging to the shape model before execution of modeling are shown by broken lines. The broken line shape element is deleted by the modeling process. << Fastening portion >> The fastening portion is a joint portion between three-dimensional objects, and includes, for example, adhesive fastening (complete joining), welding fastening (boundary joining),
Different modeling methods are used, such as contact and bolt fastening.

In addition, in adhesive fastening, welding fastening, and contact, two solid bodies contact each other at their surfaces, whereas in bolt fastening, a hole having the same center exists in the two solid bodies, and the identification criteria of the shape model are different. .

Here, modeling in the case where two solids are in contact with each other on a surface will be described. Discrimination Criteria: Two solids are in contact with each other.

Shape element selection rule: A surface where two solids contact. Modeling method: Bonding (splitting the faces of each solid so as to coincide with the contacting parts of the two solids, and joining the lines and points of the joining face and the boundary to form shared faces, shared lines, and shared points). Welding (dividing the faces of each solid so that they coincide with the joining faces of the two solids, and joining the boundary lines of the joining faces and their endpoints as shared lines and shared points). Contact (gives the attribute that a contact element is created on the part of the contact surface of two solids). Attribute value: None.

FIG. 10 is a diagram showing an example of modeling of adhesion, welding and contact according to the present invention. FIG. 10 is a diagram for explaining modeling by adhesion, welding, and contact.
In (a), the solid 1002 is arranged on the surface of the solid 1001.

FIG. 10B shows the solid 10
It is the figure which divided 01 and the solid 1002, and was displayed by the wire frame.

The solids 1001 and 1002 are the plane 1003.
And the surface 1004 are in contact with each other, and are selected as the shape element forming the shape feature according to the shape element selection rule of the surfaces 1003 and 1004.

In the case of welding and fastening, the surfaces of the solid body are divided so that the solid body 1001 and the solid body 1002 are in contact with each other.

Since the surface 1004 of the solid 1002 corresponds here, the surface 1004 divides the surface 1003 of the solid 1001 into the surfaces 1005 and 1006.

Further, in the case of adhesion, the surfaces 1004 and 1005 are joined so that the joining surfaces of the two solids have the same behavior.

In the case of welding, the boundary line segments of the joint surfaces 1004 and 1005 are joined so that the boundary portions of the joint surfaces have the same behavior.

In the case of contact, since the behaviors of the two solids do not match, the surfaces 1003 and 1004 where the two solids contact each other.
Set the attribute to generate a contact element for.

Here, as the shape feature, << hole,
The modeling of the projections ≫ << fillet >><< thin plate >><< fastening part >> was explained, but for the types of shape features, the identification criteria for extracting the shape features from the shape model and the shape features that meet the identification criteria are configured. Any type of shape feature can be registered in the modeling database 108 as long as the rule for selecting a shape element to be associated with the modeling method is associated.

For example, in creating a hexahedral mesh by the mapping method, it is necessary to divide a cylindrical surface or fillet as a pre-process for mesh generation. It is described in the collection of papers p44 to p47.

Here, a cylindrical surface having an angle of 360 degrees between both ends of the arc and the center of the arc is divided into four cylindrical surfaces having the same angle of 90 degrees.

Therefore, regarding this processing, the shape feature: the cylindrical surface of 360 degrees, the identification criterion: the cylindrical surface whose angle between the end points of the arc and the center of the arc is 360 degrees, and the shape element selection rule: the identification criteria are satisfied. Cylindrical surface, modeling processing: It can be registered in the modeling database 108 by dividing into four cylindrical surfaces having an angle of 90 degrees. 3. Operation of Components in Analytical Model Creating Apparatus FIG. 11 is a diagram showing an example of a screen display of the analytical model creating apparatus according to the present invention. FIG. 11A is a diagram showing an example in which the shape model 1101 to be analyzed by the analysis model generation device is displayed on the screen. FIG. 11B shows the shape model 11
11C is a wireframe display model of 01, and FIG. 11C shows solids 1107 and 110 of the shape model 1101.
It is the figure which separated and displayed 8. 3.1 Shape Model Input Means 101 When the system user selects the “shape model input” button 1102 in FIG. 11A, the shape model input means 101
Prompts the system user to input the shape model to be analyzed.

The system user is required to input the input device 101b or 1
The shape model created using 01c is registered in the model database 107.

The system user can read the shape model data created by another system and designated by using the input / output device and register it in the model database 107. 3.2 Shape Feature Recognizing Means 102 When the system user selects the “shape feature recognizing” button 1103 in FIG. 11A, the shape feature recognizing means 102 makes a model for the shape model registered in the model database 107. The partial shape (shape feature) matching the type of shape feature registered in the optimization database 108 is searched.

FIG. 12 is a flow chart showing the processing procedure for shape feature recognition in the present invention. ST1 of FIG.
201 to ST1205 are the recognition registration processing of the fastening portion, ST1206 to ST1210 are the recognition registration processing of the fillet, ST1211 to ST1215 are the holes,
It is the recognition registration processing of the protrusion.

Here, it is assumed that << shape, protrusion >><< fillet >><< fastening >> described in the section of the modeling database 108 is registered as the shape feature in the modeling database 108.

The recognized shape feature is registered in the model database 107 with the data structure shown in FIG.

FIG. 13 is a diagram showing an example of shape features retrieved by the present invention. That is, the shape feature recognized about the shape of FIG. 11 is shown. FIG. 13A shows a <<
The lines that belong to the shape feature recognized as “holes, protrusions” are highlighted in bold. In FIG. 13B, the surface belonging to the shape feature recognized as << fillet >> is highlighted in black. In FIG. 13C, the shape feature recognized as the << fastening portion >> is highlighted by hatching. 3.3 Modeling Presenting Means 103 When the system user selects the “modeling display” button 1103 in FIG. 11A, the modeling presenting means 103 displays each shape feature registered in the model database 107 on the shape model. To display.

FIG. 14 is a diagram showing an example of the shape feature display screen according to the present invention. FIG. 14A shows an example of screen output of the modeled presentation unit.

If the system user uses the input device 101b or 10
When the shape feature is selected by 1c, the modeling presentation means 1
03 displays the modeling method associated with the type of shape feature as shown in FIG. 14B, and prompts the system user to select the modeling method. The system user is shown in Figure 14 (b).
When the modeling method is selected from the menu, the modeling presentation unit 103 registers the selected modeling method in the model database 107.

The system user can execute the modeling work only by selecting the modeling method from the menu 1406 in FIG. 14B. FIG. 14B shows the mouse pointer 14
This is a model simplification menu when the fastening portion is selected using 05, and in this case, “glue” is selected from the check boxes at the right end.

Therefore, the fastening portion is modeled by adhesion. At this time, if an arbitrary shape feature is designated after selecting the “collective selection” button 1401, a modeling method common to all shape features of the same type as the shape feature and displayed on the screen can be set. it can.

According to this embodiment, the operation of the system user can be reduced and the modeling work can be executed more efficiently.

Further, the "display control" button 1402 can be selected to limit the shape features displayed on the screen.

FIG. 15 is a diagram showing an example of a screen display when the display control button is selected in the present invention, and the display state can be controlled for each type of shape feature.

In FIG. 15, the display control is
This is a function to control the display state of shape features. For example, using a check box, "display all""hideall"
Select either "Select by threshold".

[Display all] displays all shape features of the corresponding type registered in the model database 107.

Hide all does not display all shape features of the corresponding type.

The selection by the threshold controls the display state of the shape feature based on the screen display threshold and the highlighting threshold in FIG.

The screen display threshold value is a numerical value for limiting the shape feature displayed on the screen by the attribute value (registered in the model database 107) of the shape feature of the corresponding type. Only the shape features whose attribute values registered in 107 are below the screen display threshold are displayed.

The highlighting threshold is a numerical value for controlling the display state of the shape feature on the screen, and the shape feature whose attribute value registered in the model database 107 is below the highlighting threshold. Is displayed in different colors on the screen so that the display becomes conspicuous.

When a shape feature having a small attribute value is often targeted for modeling, the display function makes it easy for the system user to identify the shape feature targeted for modeling.

Further, these thresholds often use similar values in the case of similar shapes. Therefore, FIG.
The box 1801 of (1) allows input of the model database name of the already modeled shape model and has a function of inheriting the threshold value when the shape model is modeled.

If the "collective selection" button and the "display control" button are provided, the number of times the system user determines whether or not modeling can be performed can be reduced, and modeling can be performed more efficiently.

Finally, the modeling presentation means 103 registers the modeling method selected by the system user in the shape feature data section of the model database 107 for each shape feature.

Here, it is assumed that the modeling process as shown in FIG. 16 is set for each shape feature. 3.4 Modeling Execution Unit 104 The system user uses the modeling execution button 140 shown in FIG.
When 3 is selected, the modeling execution means 104 registers the model registered in the modeling database 108 according to the modeling set by the modeling presentation means 103 for each shape feature registered in the shape feature data of the model database 107. Apply the optimization method to change the shape of the shape model.

FIG. 17 is a diagram showing an example of the analysis model created by the present invention. Regarding the analysis model after modeling each shape feature by the modeling method shown in FIG. 16, FIG. 17 (a) is a diagram showing a wire model display, and FIG. 17 (b) is FIG. 11 (c). To show the difference with
It is the figure which separated and displayed two solids.

When the system user selects the modeling part display button 1407 in FIG. 14, the shape element deleted by the modeling execution can be displayed and the changed portion can be confirmed.

FIG. 18 is a diagram showing an example of a screen display when the modeled partial display button is selected in the present invention. Figure 1
As shown in FIG. 8, if the analysis model 1801 and the shape element 1802 deleted by the modeling are displayed side by side, the system user can easily confirm the changed portion. 3.5 Analysis Condition Input Means 105 The analysis condition input means 105 prompts the system user to input analysis conditions such as materials and boundary conditions, and registers the input analysis conditions in the model database 107. The analysis condition is designated by designating the shape element of the shape model changed by the modeling execution means 104 and inputting the material and the boundary condition. Therefore, the analysis condition is registered in the model database 107 in association with each shape element of the shape model. 3.6 Analysis Mesh Generation Unit 106 The analysis mesh generation unit 106 prompts the system user to generate an analysis mesh. When creating a mesh for a solid, use a hexahedral mesh or a tetrahedral mesh. When creating a mesh for a face, use a quadrilateral mesh or a triangle mesh. A beam mesh is used when creating a mesh for a line.

The analysis mesh generating means 106 converts the fastening information such as the attribute of the shape element and the tie information set by the modeling executing means 104 and the analysis condition inputting means 105 into the analysis mesh to the created analysis mesh. , Is registered in the model database 107.

[0110]

According to the present invention, a shape feature recognition means for recognizing a shape feature that is a candidate for modeling execution from a shape model and a modeling method applicable to each recognized shape feature are presented. Since the present invention is provided with the modeling presentation means for performing the modeling and the modeling execution means for modeling the shape feature by the modeling method selected by the system user, the system user associates the recognized shape feature with the shape feature. A desired analysis model can be generated simply by selecting the displayed modeling method. Therefore, the labor and time for creating the analysis model can be significantly reduced.

[Brief description of drawings]

FIG. 1 is a block diagram showing an overall configuration of an embodiment of an analysis model creating apparatus according to the present invention.

FIG. 2 is a conceptual diagram showing a model database 107 according to the present invention.

FIG. 3 is a conceptual diagram showing a phase data representation method by boundary representation in the present invention.

FIG. 4 is a diagram showing an example of a data structure of shape feature data according to the present invention.

FIG. 5 is a diagram showing an example of a data structure of analysis mesh data.

FIG. 6 is a diagram showing an example of a data structure of a modeling database 108 according to the present invention.

FIG. 7 is a diagram showing an example of modeling a hole shape according to the present invention.

FIG. 8 is a diagram showing an example of modeling a fillet according to the present invention.

FIG. 9 is a diagram showing an example of modeling a thin plate according to the present invention.

FIG. 10 is a diagram showing an example of modeling of adhesion, welding, and contact according to the present invention.

FIG. 11 is a diagram showing an example of a screen display of the analysis model creating apparatus according to the present invention.

FIG. 12 is a flowchart showing a processing procedure of shape feature recognition in the present invention.

FIG. 13 is a diagram showing an example of shape features retrieved by the present invention.

FIG. 14 is a diagram showing an example of a shape feature display screen according to the present invention.

FIG. 15 is a diagram showing an example of a screen display when the display control button is selected in the present invention.

FIG. 16 is a diagram showing an example of modeling processing set according to the present invention.

FIG. 17 is a diagram showing an example of an analysis model created by the present invention.

FIG. 18 is a diagram showing an example of a screen display when the modeled partial display button is selected in the present invention.

[Explanation of symbols]

100 I / O device 100a display device 100b keyboard 100c mouse 101 Shape model input means 102 shape feature recognition means 103 modeling presentation means 104 modeling execution means 105 Analysis condition input means 106 analysis mesh generation means 107 model database 108 modeling database

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Makoto Onodera             502 Kintatemachi, Tsuchiura City, Ibaraki Japan             Tate Seisakusho Mechanical Research Center (72) Inventor Yoshimitsu Hiro             890 Kashimada, Sachi-ku, Kawasaki City, Kanagawa Stock             Hitachi, Ltd. Cross Market Solution             Option Division F-term (reference) 5B046 JA07                 5B050 BA07 BA09 CA07 EA04 EA28                       FA02 FA13

Claims (4)

[Claims] 1. A shape feature is recognized from a shape model to be analyzed, and the recognized shape feature and at least one modeling method registered in association with the shape feature are presented to a system user, and presented. A method for creating a model for analysis, characterized by performing a modeling process selected by a system user from the modeling method described above and creating a model for analysis. 2. A shape feature is recognized from a shape model to be analyzed, and either or both of the recognized shape feature and the type of the shape feature are displayed on the shape model, and the recognized shape feature or the shape is displayed. At least one modeling method registered in association with the type of feature and shape feature is presented to the system user, and the system user uses the presented modeling method for each shape feature or the shape feature. A method for creating an analytical model characterized by performing the modeling process selected for each type and creating an analytical model. 3. A shape model input means for inputting a shape model of an analysis target, a shape feature recognition means for recognizing a shape feature from the shape model of the analysis target and specifying a type, and a recognition for each recognized shape feature. Modeling presenting means for presenting at least one analytical modeling method registered in association with the type of the shape feature to allow the system user to select the modeling method, and the shape feature for the shape feature selected by the selected modeling method. And a modeling execution means for carrying out modeling processing to create an analysis model. 4. A shape model input unit for inputting a shape model of an analysis target, a shape feature recognition unit for recognizing a shape feature from the shape model of the analysis target and specifying a type, the recognized shape feature or the shape feature. One or both of the above types are displayed on the shape model, and at least one analytical modeling method registered in association with each recognized type of the shape feature is presented and used by the system. Modeling presenting means for allowing a person to select a modeling method for each shape feature or for each type of the shape feature, and modeling processing is performed on the shape feature by the selected modeling method to create an analysis model. And a model execution device for analysis.