JP4691863B2 - Structure shape morphing method, computer program thereof, and computer-readable storage medium - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to the field of digital engineering using CAD / CAE software.
[0002]
[Prior art]
Conventionally, in the field of image processing using a computer, a so-called morphing technique has been proposed in which the shape of an object represented in an original image is transformed into another shape using a computer.
[0003]
In a conventional morphing process, in general, when a corresponding region is set by an operator in a plurality of different images (images based mainly on digital image information obtained by actual shooting), the computer Based on the information, intermediate interpolation processing is performed. In the middle-interpolation process, an intermediate value is generated so that various information such as the position, shape, and color of the object existing in the set area smoothly changes between the plurality of pieces of image information. When the computer reproduces and displays an image based on the plurality of pieces of image information, the intermediate value is referred to, thereby realizing movement of pixels constituting the display screen, change in display color of the pixels, and the like. Thus, the shape of the object to be deformed can be continuously changed during the reproduction and display of an image using a plurality of digital image information obtained by actual shooting, which does not originally have parameters that can be used for shape deformation.
[0004]
In recent years, as an example of such a morphing technique, Japanese Patent Application Laid-Open No. 9-106453 discloses an original image to be deformed divided into a plurality of blocks in a lattice form in an interactive manner by the operator. When the deformation range is specified, the lattice points within the deformation range move according to a predetermined movement rule, so that at least a part of the plurality of blocks is deformed, and thereby, the object represented in the original image is deformed. A technique for deforming the shape has been proposed.
[0005]
[Problems to be solved by the invention]
According to the above prior art, the operator can easily instruct the deformation of the object represented in the original image. However, since the conventional morphing technique described above is premised on an image represented by digital image data obtained by actual shooting, the planar shape deformation process represented by the two-dimensional coordinate system (XY) is also used in the conventional technique. The application and application to a three-dimensional shape are not described.
[0006]
In addition, deformation of an animation image or the like created using so-called computer graphics (CG) can be performed by continuously changing the parameters originally included in the data structure constituting the image information at the time of display. It is known that it is easier to implement than morphing by digital image data.
[0007]
On the other hand, 3D shape information such as solid models and surface models generated in design work by vehicle manufacturers using general-purpose software for CAD (Computer Aided Design) / CAE (Computer Aided Engineering) Since this is a complex data structure that includes a large amount of coordinate values and various attribute information, and the data structure varies greatly depending on the supplier (software vendor), it is a deformed shape from the original shape of the object as described above. No attempt has been made to generate or display.
[0008]
However, in the design work in a vehicle manufacturer or the like, CAE software that pseudo-analyzes the three-dimensional shape information of a structure generated using CAD software by a computer has become widespread. Analysis methods based on the element method (FEM) are widely used.
[0009]
In an analysis method based on FEM, a user first divides a structure to be analyzed represented by three-dimensional shape information into a mesh shape using a preprocessor, and then, for the mesh of the structure, It is necessary to make preparations such as setting attribute information such as constraint conditions and boundary conditions of predetermined items such as stress. This preparation has a great influence on the accuracy and processing time of the analysis processing actually performed using the FEM solver. For this reason, performing optimal settings prior to analysis processing is a considerable work burden for design department users who must develop a new vehicle in a short period of time by effectively using a limited development period. ing.
[0010]
However, in the development situation as described above, the new type vehicle to be developed by the design department is often a derived vehicle based on an existing vehicle. In this case, at the time of development of the existing vehicle, a data group (data set: equivalent to an FEM model in an embodiment described later) prepared as a preparation for analysis processing using a solver already exists in the database in the company. Therefore, such a data group should be effectively used as an asset when developing a new type vehicle such as a derivative vehicle.
[0011]
The present invention has been made in view of the above-described problems, and when an FEM model of a structure to be analyzed is acquired using an FEM model of a prototype structure, an unrealistic deformed shape is calculated. An object of the present invention is to provide a structure-morphing method, a computer program thereof, and a computer-readable storage medium that can be easily and easily prevented.
[0012]
[Means for Solving the Problems]
In order to achieve the above object, a structure shape morphing method according to the present invention is characterized by the following configuration.
[0013]
That is, At least an operation unit and a storage unit A structure morphing method using a computer, In the storage unit, The analysis target structure (for example, the body structure of a derived vehicle derived from an existing vehicle) is generated in advance using at least the external shape information and a preprocessor for an analysis solver based on the finite element method (FEM). A three-dimensional mesh model representing the outer shape of a prototype structure (for example, a body structure of an existing vehicle) and attached information associated with the mesh model (for example, attribute information representing boundary conditions, constraint conditions, materials, etc.) Including FEM model (Fig. 12) Is stored in advance, and the computer, in response to the operation of the operation unit, the external shape information of the structure to be analyzed from the storage unit, the FEM model of the prototype structure, As well as Obtained from the storage unit in response to the operation unit being operated With respect to the outer shape information of the structure to be analyzed and the mesh model of the prototype structure, the first constraint condition when changing the shape from the prototype structure to the structure to be analyzed is as follows: Setting And in a second viewpoint different from the first viewpoint, In response to the operation unit being operated, The second constraint condition when changing the shape Set A preparation process;
Said The computer set in the preparation process Based on the first and second constraints, Obtained from the storage unit Move multiple nodes that make up the mesh model of the prototype structure Let By changing the mesh model to the outer shape of the analysis target structure, according to the movement, I got it from the memory And a morphing step of calculating an FEM model (FIG. 23) for the analysis target structure by redefining the attached information and its associated state with respect to the mesh model after deformation.
[0014]
For example, in the morphing process, The computer is Set in the second viewpoint Shi The second constraint condition The , Set in the first viewpoint Shi Reflected to a range narrower than the application range of the plurality of reference points and the first constraint condition Shi And in the first viewpoint Obtained from the storage unit In the mesh model of the prototype structure, for example, a setting screen shown in FIG. 10 is used to set the cross-sectional shape of the portion extending in the longitudinal direction. Shi , Second constraint condition The Reflected in preference to the first constraint To do Is preferred.
[0015]
In a preferred embodiment, in the preparation step The computer Setting You The first constraint condition Obtained from the storage unit Move multiple nodes that make up the mesh model of the prototype structure Do At this time, a parameter for determining weighting for restricting the movement amount is included, and the parameter may be associated with the FEM model of the prototype structure.
[0016]
Here, the parameters for determining the weighting are set by the user using the setting screens shown in FIGS. 7 to 9 in the embodiment described later.
[0017]
Also, for example, in the preparation step The computer Setting You The first constraint condition further includes: Obtained from the storage unit External shape information of the analysis target structure, Obtained from the storage unit At the position corresponding to the mesh model of the prototype structure, automatically or In response to the operation unit being operated Setting Shi A plurality of reference points are included, and in the morphing process, The computer is Based on the correspondence of the plurality of reference points, Obtained from the storage unit Movement of a plurality of nodes constituting the mesh model of the prototype structure The line No , The amount of movement The , Regulated according to the weight determined by the parameter and the second constraint You Good.
[0018]
In this case, for example, the morphing step is: The computer obtained from the storage unit Set to mesh model of prototype structure Shi A plurality of first hexahedrons including at least one reference point as a vertex according to the plurality of reference points, Obtained from the storage unit Set to the external shape information of the structure to be analyzed Shi A hexahedron setting step of setting a plurality of second hexahedrons corresponding to the first hexahedron according to a plurality of reference points and including at least one reference point as the vertex; The computer is Of the plurality of first and second hexahedrons, according to the difference in shape between the first hexahedron and the second hexahedron corresponding to each other, the weight and the second constraint condition are reflected. Obtained from the storage unit Move multiple nodes that make up the mesh model of the prototype structure Let By changing the mesh model to the outer shape of the analysis target structure, according to the movement, I got it from the memory It is preferable to include an FEM model calculation step of calculating an FEM model for the analysis target structure by redefining the attached information and the association state thereof with respect to the deformed mesh model.
[0019]
Here, the plurality of reference points are the first FEM reference point shown in FIG. 14, the first CAD reference point shown in FIG. 15, and the first and second FEM shown in FIG. 16, in an embodiment (a morphing process based on a box) described later. The reference points correspond to the first and second CAD reference points shown in FIG.
[0020]
Also, for example, the morphing step is The computer obtained from the storage unit Set to mesh model of prototype structure Shi In accordance with a plurality of reference points, a first feature line including the reference points on the line is set, and Obtained from the storage unit A feature line setting step of setting a second feature line corresponding to the first feature line and including the reference point on the line according to a plurality of reference points set in the outer shape information of the structure to be analyzed; , The computer is In accordance with the difference in shape between the first feature line and the second feature line, in a state reflecting the weighting and the second constraint condition, Obtained from the storage unit Move multiple nodes that make up the mesh model of the prototype structure Let By changing the mesh model to the outer shape of the analysis target structure, according to the movement, I got it from the memory It is preferable to include an FEM model calculation step of calculating an FEM model for the analysis target structure by redefining the attached information and the association state thereof with respect to the deformed mesh model.
[0021]
Here, the plurality of reference points set in the preparation step are the first FEM reference point shown in FIG. 14, the first CAD reference point shown in FIG. 24 corresponds to the first and third FEM reference points shown in FIG. 24 and the first and third CAD reference points shown in FIG.
[0022]
This object can also be achieved by an information processing apparatus corresponding to the structure morphing method of each structure described above.
[0023]
The object is also achieved by a program code for realizing the structure shape morphing method and information processing apparatus of each configuration described above by a computer, and a computer-readable storage medium storing the program code. The That is, the same object is a computer program for realizing morphing of a structure by a computer, and the computer has at least an operation unit and a storage unit, and the storage unit has an analysis target structure. A three-dimensional mesh model representing the outer shape of the prototype structure, which is generated in advance using at least the outer shape information of the analysis, and a preprocessor for an analysis solver based on the finite element method (FEM), and the mesh model The FEM model including the attached information is stored in advance, and in response to the operation of the operation unit being performed on the computer, the external shape information of the structure to be analyzed from the storage unit, and the prototype structure And obtaining an FEM model of the body, and in response to the operation unit being operated, The first constraint condition when changing the shape from the prototype structure to the analysis target structure is set to the outer shape information of the analysis target structure obtained from the memory and the mesh model of the prototype structure. A preparatory step of setting a second constraint condition when changing the shape in response to an operation of the operation unit at a second viewpoint that is set at one viewpoint and is different from the first viewpoint; The mesh model is analyzed by moving a plurality of nodes constituting the mesh model of the prototype structure obtained from the storage unit based on the first and second constraints set in the preparation step. In addition to changing to the outer shape of the target structure, the attached information obtained from the storage unit and its associated state are changed to the mesh A computer program for executing a morphing step of calculating an FEM model for the structure to be analyzed by redefining the model, and a program code of the computer program are stored Achieved by a computer readable storage medium .
[0024]
【The invention's effect】
According to the present invention described above, when an FEM model of a structure to be analyzed is acquired using an FEM model of a prototype structure, an unrealistic deformed shape is prevented from being calculated in advance and easily. A morphing method of a structure that can be used, a computer program thereof, and a computer-readable storage medium are provided.
[0025]
That is, according to the first aspect of the present invention, the first constraint condition (the parameter for determining the weight (Claim 6) and the correspondence) when morphing from the FEM model of the prototype structure to the FEM model of the structure to be analyzed The plurality of reference points (Claim 7) and the second constraint condition (Claim 2) reflected in a range narrower than the application range of the first constraint condition are reflected. Thereby, even if it is a part of the structure to be analyzed, it is possible to easily and easily prevent an unrealistic deformed shape from being calculated.
[0026]
Further, according to the invention of claim 3, with respect to the portion extending in the longitudinal direction that is difficult for the user to determine in the mesh model of the prototype structure in the first viewpoint (particularly, the sectional shape of the portion: claim 4), Since the second constraint condition can be easily set, it is possible to more efficiently prevent an unrealistic deformed shape from being calculated.
[0027]
According to the invention of claim 5, since the second constraint condition is reflected in preference to the first constraint condition during morphing, a more realistic deformed shape can be calculated.
[0028]
According to the eighth aspect of the present invention, a plurality of first hexahedrons set for the prototype structure and a plurality of second hexahedrons set for the analysis target structure are used for morphing. Morphing in which the difference in shape is accurately reflected is performed for each hexahedron, so that an FEM model of the analysis target structure in which the difference in shape from the prototype structure is faithfully reflected can be acquired.
[0029]
According to the ninth aspect of the present invention, the design of the entire vehicle is performed by the first feature line set for the prototype structure and the second feature line set for the analysis target structure during morphing. Morphing that accurately reflects the difference in shape between the two types of structures represented by these feature lines is performed without breaking the shape that characterizes the shape, so the difference in shape from the prototype structure is faithfully reflected An FEM model of the structure to be analyzed can be acquired.
[0030]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail with reference to the drawings as an embodiment in which the present invention is applied to a body structure of an automobile, which is a typical vehicle.
[0031]
[System Configuration] FIG. 1 is a diagram illustrating a configuration of a computer system applicable to the present embodiment.
[0032]
In the figure, a plurality of user terminals 1 and a host computer 2 are connected so as to be capable of bidirectional communication via a communication network 6 to constitute a general server / client environment. In this embodiment, each user terminal 1 (Operation section) Since the host computer 2 and the communication network 6 can employ general computers and network systems, detailed description of the device configuration is omitted.
[0033]
FEM model database 3 (Memory part) In this embodiment, FEM models for at least a plurality of types of existing vehicles are stored prior to the start of operation of the processing system described below in the present embodiment, and a new vehicle newly generated by the function of the processing system is stored. An FEM model (including derivative vehicles derived from existing vehicles: hereinafter simply referred to as “new vehicle”) can be stored.
[0034]
The FEM model of each existing vehicle is, for example, a data set generated by a person in charge of the design department of a vehicle manufacturer using a general preprocessor for FEM (finite element method) in the previous development and design work ( (Data file), but with the function of the FEM model generation process of the new vehicle, which will be described later in this embodiment, parameters for determining weights are newly stored in an associated state (note that the FEM model Details will be described later).
[0035]
CAD model database 4 (Memory part) For example, a person in charge of the design department of a vehicle manufacturer generates 3 models such as a solid model and a surface model for a new vehicle, which were generated using general CAD software in this development and design work. Dimensional shape information is stored in advance.
[0036]
Program database 5 (Memory part) Stores a communication function with the user terminal 1, a management program for each of the databases, and a software program for realizing the function of the FEM model generation processing for the new vehicle according to the present embodiment.
[0037]
The host computer 2 is connected to the FEM model database 3, the CAD model database 4, and the program database 5 so as to be accessible, and functions as an application server computer when the user terminal 1 logs in.
[0038]
The above-described system configuration is for convenience of explanation, and each database may be a single large-scale database or may be individually connected to the communication network 6. May be. Further, instead of a server / client environment constituted by the user terminal 1 and the host computer 2, an environment constituted by one computer having a man-machine interface and a database may be used.
[0039]
Hereinafter, the FEM model (FIG. 12) of the body structure (prototype structure) of the existing vehicle and the CAD model (FIG. 13) of the new vehicle are used by the function of the FEM model generation process of the new vehicle according to the present embodiment. A procedure for obtaining the FEM model (FIG. 23) of the body structure (analysis target structure) of the new vehicle that can be set as a solver for various analysis processes based on FEM will be described.
[0040]
<FEM Model of Existing Vehicle> First, the FEM model will be described with reference to FIG. FIG. 12 is a diagram illustrating an FEM model of an existing vehicle in the present embodiment.
[0041]
In the present embodiment, the FEM model is a general data group (data set) in a state where preparations for performing analysis by a FEM analysis processing solver such as strength analysis, thermal analysis, mechanism analysis, and vibration analysis are completed. Are stored in the FEM model database 3 in advance.
[0042]
The FEM model data set (hereinafter simply referred to as “FEM model”) includes a mesh shape as three-dimensional vehicle shape information. This information includes attribute information such as boundary conditions, constraint conditions, and materials. The predetermined attached information such as is defined (associated).
[0043]
Here, the vehicle shape information is a mesh model composed of a plurality of three-dimensional (for example, tetrahedron, hexahedron) three-dimensional elements (solid mesh) like a prototype (existing vehicle) FEM model illustrated in FIG. In addition, the roughness (mesh size) of the mesh varies appropriately depending on the vehicle-shaped part.
[0044]
In the FEM model, the geometric accuracy of the vehicle shape is determined by the coordinate values of a plurality of nodes constituting the vehicle shape in a three-dimensional coordinate space. Here, the nodes are lattice points (nodes) that form vertices of individual solid meshes that form the mesh shape (vehicle shape) of the FEM model.
[0045]
<CAD Model of New Model Vehicle> FIG. 13 is a diagram illustrating a CAD model of the new model vehicle in this embodiment.
[0046]
In the present embodiment, the CAD model of the new model is stored in advance in the CAD model database 4, and various three-dimensional CAD such as a surface model and a surface model are included if at least three-dimensional outline information of the new model is included. A model can be adopted.
[0047]
[FEM Model Generation Processing] Next, the FEM model generation processing for a new vehicle will be described in detail.
[0048]
FIG. 2 is a flowchart showing an overall outline of the FEM model generation process for the new vehicle according to the present embodiment. This shows the processing procedure of the hardware program.
[0049]
In the figure, Step S1: The user corresponds to the FEM model of an existing vehicle used as a prototype and the FEM model of the new vehicle desired to be obtained by the FEM model generation processing according to the present embodiment. Select a CAD model. In addition, setting of predetermined constraint conditions and the like is performed automatically or manually (manual operation). The details of the preparation process according to this step will be described later with reference to the flowchart shown in FIG.
[0050]
Steps S2 to S4: Depending on the selection operation by the user (Step S2), the morphing process based on the box (Step S3), the morphing process based on the feature line (Step S4), or both of these two types of morphing processes are executed. The In each morphing process, the FEM model is calculated for the new vehicle for which the CAD model is selected in step S1.
[0051]
The details of the morphing process based on the box according to step S3 will be described later with reference to the flowchart shown in FIG. Details of the morphing process based on the feature line in step S4 will be described later with reference to the flowchart shown in FIG.
[0052]
Step S5: The result of the morphing process in step S3 or step S4 is displayed on the display of the user terminal 1. In this step, when the two types of morphing processes are selected in the process selection of step S2, the FEM model of the new vehicle calculated individually by the two types of morphing processes is displayed on the same screen. . In this case, since the two displayed FEM models are not easily identified by the user, parts having different shapes in both FEM models and associated information having different values are displayed in different display colors, for example. It should be highlighted.
[0053]
In addition, the parts of the FEM model of the existing vehicle and the FEM model of the new model that are different in shape also have the shape of the new model of the existing vehicle such as when the new model is a derivative vehicle of the existing model. If it is similar to the shape of the vehicle, it is not easy for the user to identify. Therefore, in step S5, in response to the user's selection operation, the mesh shape (mesh model) of both FEM models is moved along with the morphing process in step S3 or step S4 (details will be described later). According to the moving amount and moving direction of the node to be displayed, it is preferable to display with an arrow or the like representing a vector arranged in the three-dimensional coordinate space as illustrated in FIG.
[0054]
Step S6: When the two types of morphing processes are selected in the process selection at step S2, the FEM model of the new model vehicle calculated by both or one of the morphing processes is selected according to the user's selection operation. Selected.
[0055]
Step S7: When the two types of FEM models are selected in Step S6, the mesh shapes of the two types of FEM models and their attached information are synthesized into one FEM model. In this step, the mesh shape of one synthesized FEM model or the validity of the mesh quality of any FEM model selected in step S6, and the entire data set of these FEM models Appropriateness is determined, notification of the determination result to the user, and automatic or manual adjustment are performed. The details of the result notification / adjustment process according to step S7 will be described later with reference to the flowchart shown in FIG.
[0056]
<Preparation Processing> FIG. 3 is a flowchart showing details of the preparation processing (step S1 in FIG. 2) in the FEM model generation processing for the new model vehicle in this embodiment.
[0057]
In the figure, step S11: for determining a weighting coefficient used for a morphing process (FIG. 4 or FIG. 5) to be described later with respect to the FEM model of the prototype existing vehicle stored in advance in the FEM model D / B3. The parameter is set by the user using the setting screen illustrated in FIGS. When a parameter is set, the parameter is stored in a state associated with the FEM model of the existing vehicle.
[0058]
In the present embodiment, the weighting coefficient is data determined according to the parameters set by the user, and the ridgeline, grid, etc. of the part that the user is interested in are changed by the morphing process (for example, shape deformation, large displacement amount) The degree (degree) indicating whether or not to change).
[0059]
FIG. 7 is a diagram illustrating a parameter setting screen that can be set by the user for each desired component in order to determine the weighting coefficient.
[0060]
That is, on the setting screen shown in FIG. 7A, the radio button of “deformation prohibited parts (common parts)” or “deformation restricted parts (general-purpose parts)” is selected by the user, and the “select” operation button is operated. In the case where the FEM model of the new model vehicle is generated from the FEM model of the existing vehicle in a morphing process to be described later from among a plurality of parts constituting the FEM model of the existing vehicle displayed in a list (not shown), It is possible to select a desired part that prohibits or restricts deformation. In this case, as the parameter is set by the user, the host computer 2 is considerably smaller than other cases to be described later in order to prohibit or restrict deformation of the target component when performing morphing. The weighting factor is set automatically.
[0061]
In the setting screen shown in FIG. 7A, when the user selects the “deformable component (dedicated component)” radio button and operates the “details” operation button, FIG. A new setting screen is displayed. The setting screen shown in FIG. 7B is set by the user so that the plate thickness and the spot welding position are held (constrained) before and after the morphing process as parameters for determining the weighting coefficient during morphing. Indicates the state. In this case, as the parameter is set by the user, the host computer 2 automatically sets a small weighting coefficient so that the thickness of the target component and the spot welding position do not change during execution of morphing. Set.
[0062]
In the setting screen shown in FIG. 7A, when the radio button “deformable component (dedicated component)” is selected by the user and the operation button “placement” is operated, FIG. A new setting screen is displayed. In the setting screen shown in FIG. 7C, the arrangement relationship between the dedicated member and other members is held (constrained) by a specific numerical value as a parameter for determining the weighting coefficient at the time of morphing by the user. The state set as follows is shown. In this case, as the parameter is set by the user, the host computer 2 reduces the distance and gap (gap length) between the target component and other components so that they do not change during morphing. The weighting factor is set automatically.
[0063]
FIG. 8 and FIG. 9 are diagrams illustrating parameter setting screens that can be set by the user for the entire FEM model of an existing vehicle, not for individual parts, in order to determine weighting coefficients.
[0064]
That is, in the setting screen shown in FIG. 8A, when the operation button of “collision test” is operated by the user, a setting screen illustrated in FIG. 8B is newly displayed. In the setting screen shown in FIG. 8B, the user selects an application part in the collision test as a parameter for determining the weighting coefficient at the time of morphing, and the shape and the door gap are maintained for the selected part. The state set to be (constrained) is shown. In this case, as the parameter is set by the user, the host computer 2 automatically sets a small weighting coefficient for the entire FEM model so that the target test result is not deteriorated by morphing. .
[0065]
Similarly, on the setting screen shown in FIG. 8A, when the user operates the “side impact test” and “endurance test” operation buttons, the user selects the weighting coefficient during morphing according to the operation. Can be set for a part desired by the user using a setting screen (not shown). Also in this case, as the parameter is set by the user, the host computer 2 automatically sets a small weighting coefficient for the entire FEM model so that the target test result is not deteriorated by morphing. To do.
[0066]
Further, in the setting screen shown in FIG. 8A, when the operation button of “component characteristics” is selected by the user, a setting screen illustrated in FIG. 8C is newly displayed. The setting screen shown in FIG. 8C is set by the user so that the plate thickness and the spot welding position are held (constrained) before and after the morphing process as parameters for determining the weighting coefficient during morphing. Indicates the state. In this case, as the parameter is set by the user, the host computer 2 sets a small weighting coefficient for the entire FEM model so that the plate thickness and the spot welding position do not change during the morphing. Set automatically.
[0067]
Further, in the setting screen shown in FIG. 8A, when the operation button of “part type” is selected by the user, a setting screen illustrated in FIG. 9A is newly displayed. The setting screen shown in FIG. 9A holds (restrains) the shapes of parts classified into the types of ribs and flanges before and after the morphing process as parameters for determining the weighting coefficient during morphing. The state set to be shown. In this case, as the parameter is set by the user, the host computer 2 automatically sets a small weighting coefficient so that the component belonging to the target component type is not deformed during morphing. .
[0068]
Further, in the setting screen shown in FIG. 8A, when the operation button “component shape” is selected by the user, a setting screen illustrated in FIG. 9B is newly displayed. The setting screen shown in FIG. 9B is a parameter for determining the weighting coefficient at the time of morphing by the user, and the branching shape where the ridgeline, corner radius (R), and stress are concentrated before and after the morphing process. The state set so that the shape of a branch part may be hold | maintained (restraint) is shown. In this case, as the parameter is set by the user, the host computer 2 automatically sets a small weighting coefficient so that the part having the target part shape is not deformed during the morphing. .
[0069]
Note that the setting screens shown in FIG. 8 and FIG. 9 described above are merely examples. In addition to this, for example, the weight, outline, etc. are constant before and after the morphing process for individual parts or the entire FEM model. Various settings are conceivable, such as setting to hold (constraint) or permitting a change in plate thickness in accordance with the size of a part generated by the morphing process.
[0070]
Step S12: In response to a user operation, the FEM model of the morphing target (prototype existing vehicle) associated with the parameter stored in the FEM model D / B3 is read and stored in the CAD model D / B4. Reads out the CAD model of the new vehicle.
[0071]
Step S13: The FEM model (FIG. 12) of the existing vehicle read in step S12 and the CAD model (FIG. 13) of the new vehicle are displayed on the display of the user terminal 1 from the same viewpoint (first viewpoint). Display according to.
[0072]
Step S14: Based on the data constituting the CAD model of the new model vehicle read in step S12, the contour line constituting the contour shape of the new model vehicle is calculated by a general method, and the calculated profile line is calculated. And displayed on the display of the user terminal 1.
[0073]
Step S15, Step S16: A plurality of first CAD reference points are automatically or manually set on the calculated outline of the CAD model (Step S15), and the FEM model of the existing vehicle read in Step S12 is First FEM reference points individually corresponding to the first CAD reference points are set automatically or manually (step S16).
[0074]
Here, a variation of the procedure for setting the first CAD reference point and the first FEM reference point at corresponding positions as shown in FIGS. 14 and 15 will be described.
[0075]
That is, when the first CAD reference point and the first FEM reference point are automatically set to the corresponding positions in step S15 and step S16, first, the outer shape of the new vehicle calculated in step S14 is configured. A plurality of first CAD reference points are automatically set on the intersections of the outlines, and the first FEM reference points are set on the mesh model of the FEM model of the existing vehicle corresponding to each set first CAD reference point. It may be set automatically. The intersection of the outlines may be automatically set by, for example, general image processing.
[0076]
In the above case, the first FEM reference point on the FEM model side corresponding to the first CAD reference point on the CAD model side is set in advance in the CAD model of the new vehicle and the FEM model of the existing vehicle. What is necessary is just to set using a component name, shape information, etc. More specifically, when the first CAD reference point is set on the intersection of the B pillar between the front door and rear door of the new vehicle and the line connecting the lower sides of the windows of the door, the existing vehicle The B pillar between the front door and the rear door of the existing vehicle corresponding to the first CAD reference point using the part name, shape information, etc. set in advance in the FEM model, and the doors It is only necessary to detect the intersection with the line connecting the lower sides of the window and automatically set the first FEM reference point on the detected intersection. In this case, since a plurality of first CAD reference points and first FEM reference points serving as morphing references are automatically set, user convenience is improved.
[0077]
Alternatively, when the user manually sets the first CAD reference point on the outline of the CAD model, in step S15 and step S16, the part names set in advance in the CAD model of the new vehicle and the FEM model of the existing vehicle For example, the first FEM reference point may be automatically set by detecting a corresponding position in the mesh shape of the FEM model of the existing vehicle.
[0078]
Or, conversely, when the user manually sets the first FEM reference point for the mesh shape of the FEM model of the existing vehicle, the CAD model of the new vehicle and the FEM model of the existing vehicle are set in Step S15 and Step S16. In addition, the first CAD reference point may be automatically set by detecting a corresponding position using a part name set in advance.
[0079]
FIG. 14 is a diagram illustrating a mesh shape of an FEM model of an existing vehicle in a state where a plurality of first FEM reference points are set. FIG. 15 is a diagram illustrating the outline of the new vehicle in which a plurality of first CAD reference points are set.
[0080]
Each “reference point” set as shown in FIG. 14 and FIG. 15 is a point where correspondence is always guaranteed before and after execution of a morphing process, which will be described later, and guarantees deformation accuracy by morphing according to the present embodiment. This is the reference position. In other words, there is a premise that the first FEM reference point set before deformation (existing vehicle) always moves to the first CAD reference point set after deformation (new model vehicle) corresponding to the reference point. .
[0081]
Next, the morphing process based on the box (FIG. 4) and the morphing process based on the feature line (FIG. 5) will be described in detail.
[0082]
<Box-Based Morphing Process> FIG. 4 is a flowchart showing details of the box-based morphing process (step S3 in FIG. 2) in the FEM model generation process for the new model vehicle in this embodiment.
[0083]
In the figure, step S31: a plurality of second FEM reference points are extracted from the FEM model of the existing vehicle read in step S12, and the extracted second FEM reference points and the preparation process (FIG. 3) are performed. Based on the plurality of first FEM reference points set in the above, B-BOX1 constituted by a plurality of hexahedrons (boxes) representing the outer shape of the existing vehicle is generated.
[0084]
FIG. 16 is a diagram showing a B-BOX 1 generated based on a plurality of first and second FEM reference points. In FIG. 16, circles (open circles) indicate the first FEM reference points. Each mark (black square) indicates a second FEM reference point.
[0085]
Here, the individual second FEM reference points are those on the outer plate of the existing vehicle (that is, the outer shape of the existing vehicle) or within the region outside the existing vehicle from the outer plate. A box constituted by a point and a plurality of first FEM reference points is automatically set so as to include the existing vehicle.
[0086]
Step S32: Based on the second CAD reference point extracted from the outline forming the outer shape of the new model vehicle calculated in step S14, and the first CAD reference point set in the preparation process (FIG. 3), An A-BOX 1 composed of a plurality of hexahedrons (boxes) representing the outer shape of the new vehicle is generated.
[0087]
FIG. 17 is a diagram showing A-BOX1 generated based on a plurality of first and second CAD reference points. In FIG. 17, ○ marks (open circles) indicate the first CAD reference points. Each mark (black square) indicates a second CAD reference point.
[0088]
Here, the individual second CAD reference points are defined on the outer plate of the new vehicle (that is, the outer shape of the new vehicle) or within the region outside the new vehicle from the outer plate. A box constituted by a point and a plurality of first FEM reference points is automatically set so as to include the new vehicle.
[0089]
In step S32, the individual CAD boxes constituting the B-BOX1 including the first and second FEM reference points are divided into the first CAD reference point set in the preparation process and the second CAD extracted from the outline in this step. A-BOX1 may be set by moving according to the reference point.
[0090]
Step S33: A uniform mesh (B-BOX11) is automatically set by a general method as shown in FIGS. 18 and 19 for the entire existing vehicle represented in the FEM model.
[0091]
FIG. 18 is a diagram showing a state in which B-BOX 11 having the same mesh size is set for the FEM model of the existing vehicle shown in FIG. FIG. 19 is a diagram showing only the set B-BOX 11.
[0092]
Step S34: A-BOX11 is calculated by transforming B-BOX11 based on B-BOX1 generated in step S31 and A-BOX1 generated in step S32.
[0093]
FIG. 20 is a diagram illustrating a state in which A-BOX11 and B-BOX1 are overlapped. FIG. 21 is a diagram showing A-BOX11 generated by deforming B-BOX11 based on B-BOX1 and A-BOX1.
[0094]
Since B-BOX1 and A-BOX1 each have one corresponding box as shown in FIG. 20, in step S34, a uniform mesh (B- BOX11) Among all the nodes that make up BOX11), all the processes to move each node contained in one box with B-BOX1 according to the shape of one box with A-BOX1 corresponding to that box To the box. Thereby, A-BOX11 shown in FIG. 21 is calculated.
[0095]
That is, in B-BOX1 and A-BOX1, the difference between the shapes of the two corresponding boxes is that the coordinate values of the first and / or second FEM reference points forming one box constituting B-BOX1 It is represented by the difference from the coordinate value of the first and / or second CAD reference point forming any one box constituting A-BOX1 corresponding to the first and / or second FEM reference point. Then, the movement vectors (direction and size) from the first and second FEM reference points to the first and second CAD reference points, which are in a corresponding relationship, are uniquely determined.
[0096]
Therefore, in step S34, a plurality of nodes included in one box of B-BOX1 are defined by the first and second FEM reference points constituting the box and the corresponding first and second CAD reference points. Move according to the movement vector. By performing this process for all boxes, A-BOX11 is calculated. The calculated A-BOX 11 is a master mesh representing an aspect of the shape change from the outer shape of the existing vehicle to the outer shape of the new vehicle, and corresponds to a template representing the difference in the outer shape of the existing vehicle and the new vehicle.
[0097]
Step S35: First, when there is a reference point that is deviated (displaced) from the nodes constituting the B-BOX 11 among the plurality of first and second FEM reference points, the nodes near the reference point are present. Is adjusted to be positioned on the reference point. Similarly, when there is a reference point that is deviated (displaced) from the nodes constituting the A-BOX 11 among the plurality of first and second CAD reference points, the node near the reference point The position of the node is adjusted so as to be positioned on the reference point (in the case where the amount of deviation is large, a plurality of surrounding nodes may be moved as appropriate). Such adjustment of the node position is a preparation for realizing high-precision morphing, and is particularly preferable when the user manually sets the first FEM reference point and / or the first CAD reference point.
[0098]
In step S35, the mesh of the FEM model based on the weighting coefficient determined according to the parameters associated with the FEM model of the existing vehicle (prototype) and the A-BOX11 and B-BOX11 whose node positions are adjusted. By deforming the shape, the mesh shape of the FEM model for the new vehicle is calculated, and each node to the calculated mesh shape (i.e., the second mesh shape to be included in the FEM model of the new vehicle) (i.e., Attached information such as various attribute information, boundary conditions, and constraint conditions associated with the FEM model related to the existing vehicle according to the movement of the plurality of nodes constituting the first mesh shape included in the FEM model of the existing vehicle) Is redefined (merged) with respect to a plurality of nodes constituting the second mesh shape, To calculate the data set type vehicle FEM model (Fig. 23). The calculated FEM model of the new vehicle is displayed on the display of the user terminal 1 in step S5 as described above.
[0099]
FIG. 22 is a diagram illustrating a state in which the A-BOX11 and the B-BOX11 whose node positions are adjusted are overlapped. Basically, the mesh of the FEM model relating to the existing vehicle according to the correspondence between these two mesh shapes. From the shape, the mesh shape of the FEM model relating to the new model vehicle is generated. When the coordinate position of each node is moved, the amount of movement is regulated according to the above weighting coefficient.
[0100]
Here, in step S35, prior to the deformation of the mesh shape of the FEM model, a setting screen as illustrated in FIG. 10 is displayed on the display of the user terminal 1.
[0101]
FIG. 10 is a setting screen for the user to set the morphing of the A pillar. This setting screen is automatically displayed when it is detected that the state (step) immediately before the morphing according to the present embodiment is executed. Further, in a preferred embodiment, this setting screen is displayed by a predetermined operation such as an operation in which the user selects the A pillar portion of the FEM model of the existing vehicle with a mouse or the like when the user desires to set. Is also displayed.
[0102]
In step S13 of the above-described preparation process (FIG. 3), the plurality of first CAD reference points and the corresponding first FEM reference points are set automatically or manually so that the user can easily recognize them visually. The FEM model (FIG. 12) of the existing vehicle and the CAD model (FIG. 13) of the new vehicle were displayed on the display of the user terminal 1 in accordance with the same viewpoint as the first viewpoint. On the other hand, the setting screen shown in FIG. 10 allows the user to set a new constraint condition that is referred to when changing the deformation of the mesh shape of the FEM model at a second viewpoint different from the first viewpoint. This is the screen. This second viewpoint is a viewpoint in which the user can easily recognize the cross-sectional shape of a member extending in the longitudinal direction in the first viewpoint (in this embodiment, an A-pillar as an example).
[0103]
More specifically, when the user moves the software button 101 to the left or right by using a pointing device such as a mouse, the A pillar (the connection portion with the roof on the upper side of the A pillar, The cross-sectional shape before deformation (except for the connection portion with the bonnet) is displayed in the region 102, and the cross-sectional shape after deformation is displayed in the region 103. When the user moves the software button 101 to a desired position and the user selects an operation button for “hold cross-sectional shape” in that state, the cross-sectional shape of the A pillar after the morphing process is the inclination of the A pillar. Is changed according to the CAD model of the new vehicle, the shape displayed in the area 103 when the selection operation is performed is maintained.
[0104]
In addition, when the user selects an operation button of “impossible cross-sectional deformation”, deformation of the cross-sectional shape of the A-pillar is prohibited before and after the morphing process, so that the inclination of the A-pillar is a CAD model of the new model vehicle. The cross-sectional shape of the A pillar included in the FEM model of the existing vehicle (mesh model of the FEM model) is included in the FEM model of the new vehicle (mesh model of the FEM model). It is held (restrained) as the cross-sectional shape of the A pillar.
[0105]
When the user selects the “manual setting” operation button, more detailed settings can be made regarding the cross-sectional shape of the A pillar using a setting screen (not shown).
[0106]
As described above, using the setting screen illustrated in FIG. 10, the parameters set in the second viewpoint include the plurality of first CAD reference points set in the first viewpoint and the corresponding first FEM reference points. Although the constraint condition is reflected in a range narrower than the applicable range, the parameter set in the second viewpoint is preferably reflected in the morphing process with priority over the plurality of reference points. As a result, even if it is a part of the new model vehicle, it is possible to easily and easily prevent an unrealistic deformed shape from being calculated for an important part in the body structure. In the above-described morphing process based on a box, it consists of a B-BOX1 consisting of a plurality of boxes (first hexahedron) set for an existing vehicle and a plurality of boxes (second hexahedron) set for a new vehicle. Because A-BOX1 performs morphing that accurately reflects the difference in shape for each corresponding box, obtain an FEM model of a new model that accurately reflects the difference in shape from existing vehicles Can do.
[0107]
<Morphing Process Based on Feature Line> FIG. 5 is a flowchart showing details of the morphing process based on the feature line (step S4 in FIG. 2) in the FEM model generation process of the new model vehicle in this embodiment.
[0108]
In the figure, a plurality of third CAD reference points are set on the outline of the CAD model calculated in step S41: preparation process (FIG. 3), and these third CAD reference points and the first CAD set in the preparation process are set. Based on the reference point, the feature line (A-BAR1) of the new model is set.
[0109]
Here, the individual third CAD reference points may be set by manual designation by the user or by appropriately automatically dividing the outline of the new vehicle obtained by connecting a plurality of first CAD reference points. At this time, in order to perform a calculation with higher accuracy, the number of extracted third CAD reference points may be increased.
[0110]
Step S42: Based on the first FEM reference point set in the preparation process (FIG. 3) and the third FEM reference point extracted from the FEM model of the existing vehicle, the feature line (B-BAR1) of the existing vehicle is determined. Set.
[0111]
Here, each of the third FEM reference points may be set by manually specifying the user or automatically automatically dividing the outline of the existing vehicle obtained by connecting a plurality of first FEM reference points. .
[0112]
FIG. 24 shows the feature line (A-BAR1) of the new model in which the first and third CAD reference points are set, and the feature line (B-BAR1) of the existing vehicle in which the first and third FEM reference points are set. It is a figure which shows the state overlaid in the common three-dimensional coordinate space.
[0113]
Step S43: Similar to the uniform mesh (B-BOX11: FIGS. 18 and 19) in step S33 of FIG. 4 described above, the uniform mesh (B--) is applied to the entire existing vehicle represented in the FEM model. BAR11 (not shown) is automatically set by a general method.
[0114]
Step S44: A-BAR11 (not shown) is calculated by deforming the uniform mesh (B-BAR11) according to the difference in shape between the two types of feature lines A-BAR1 and B-BAR1.
[0115]
That is, in the feature lines A-BAR1 and B-BAR1, there are a first CAD reference point and a first FEM reference point having a correspondence relationship, and a third CAD reference point and a third FEM reference point having a correspondence relationship. As in the case of the morphing process based on, the movement vector (direction and size) from the first and third FEM reference points to the first and third CAD reference points, which are in a corresponding relationship, is uniquely determined.
[0116]
Therefore, in step S44, first, among the plurality of nodes constituting the uniform mesh (B-BAR11), the node corresponding to the first and third FEM reference points is moved to the first and third CAD reference points. Then, when moving other nodes in the vicinity of the first and third FEM reference points (hereinafter referred to as neighboring nodes), the movement amounts (movement distances) from the nodes for the first and third FEM reference points are used.
[0117]
That is, by calculating a weighted average of the movement amounts of the moved (calculated) first and third FEM reference points located in the vicinity of the neighboring node, the movement amount of the neighboring node is calculated. Move its neighboring nodes according to the amount. A-BAR11 can be calculated through these two procedures. Here, the A-BAR11 calculated in this step has a mesh shape similar to the A-BOX11 calculated in step S34 of FIG. 4 described above.
[0118]
Step S45: As in step S35 of FIG. 4, first, among the plurality of first and third FEM reference points, there is a reference point that is deviated (displaced) from the nodes constituting the B-BAR11. In this case, the nodes near the reference point are adjusted so as to be positioned on the reference point. Similarly, when there is a reference point that is deviated (displaced) from the nodes constituting the A-BAR 11 among the plurality of first and third CAD reference points, the node near the reference point The position of the node is adjusted so as to be positioned on the reference point (in the case where the amount of deviation is large, a plurality of surrounding nodes may be moved as appropriate). Such adjustment of the node position is a preparation for realizing high-precision morphing, and is particularly preferable when the user manually sets the first FEM reference point and / or the first CAD reference point.
[0119]
And in step S45, based on the weighting coefficient determined according to the parameter linked | related with the FEM model of the existing vehicle (prototype), and A-BAR11 and B-BAR11 by which the node position was adjusted, step S35 of FIG. In the same manner as in, the mesh shape of the FEM model for the new vehicle is calculated by deforming the mesh shape of the FEM model, and the calculated mesh shape (that is, the second shape to be included in the FEM model of the new vehicle). The various attributes associated with the FEM model related to the existing vehicle according to the movement of each node (that is, the plurality of nodes constituting the first mesh shape included in the FEM model of the existing vehicle) Attached information such as information, boundary conditions, constraint conditions, etc. to multiple nodes constituting the second mesh shape By redefining (merge) Te, it calculates the data sets of the new vehicle FEM model (Fig. 23). The calculated FEM model of the new vehicle is displayed on the display of the user terminal 1 in step S5 as described above.
[0120]
In step S45, prior to the deformation of the mesh shape of the FEM model, a setting screen as illustrated in FIG. 10 described in the box-based morphing process (FIG. 4) is displayed. The user can set the morphing setting for the A pillar in the second viewpoint.
[0121]
In the morphing process based on the feature line described above, the feature line set for the existing vehicle (B-BAR1: first feature line) and the feature line set for the new vehicle (A-BAR1: second feature) Line), morphing that accurately reflects the difference between the two types of vehicles represented by these feature lines is performed without breaking the shape that characterizes the overall design of the vehicle. It is possible to acquire an FEM model of the new vehicle in which the difference is faithfully reflected.
[0122]
<Result Notification / Adjustment Processing> Next, the result notification / adjustment processing will be described in detail.
[0123]
FIG. 6 is a flowchart showing details of the result notification / adjustment process (step S7 in FIG. 2) in the FEM model generation process of the new vehicle in the present embodiment.
[0124]
In the figure, the FEM model of the new vehicle calculated in the morphing process based on the box and / or feature line is selected and synthesized according to the selection result of the process result in step S71: step S6 (FIG. 2).
[0125]
In this step, when combining FEM models of new vehicles calculated by morphing processing based on boxes and feature lines into one, for example, boxes were used for parts with large areas such as roofs and bonnets. It is preferable to use the morphing result and use the morphing result using the feature line in the vicinity of the outline of the new vehicle. In this case, in a region where two types of morphing results are adjacent to each other in one synthesized FEM model, for example, in a band region having a predetermined width centered on the adjacent boundary, the region from one morphing result to the other Data selection processing in which the degree of correlation gradually decreases as the area approaches the morphing result is performed on each of the two types of morphing results in the band area. In this case, it is possible to obtain a more suitable FEM model of a new vehicle by using the analysis process performed in a later process.
[0126]
Step S72: The mesh quality (mesh distortion, etc.) of a plurality of three-dimensional (solid mesh) three-dimensional elements (solid meshes) constituting the mesh shape of the FEM model relating to the selected and synthesized new vehicle Whether it is worse than a predetermined level is determined by a general method. If the mesh quality is good, the process proceeds to step S73. If the mesh quality is poor, the process proceeds to step S77.
[0127]
Step S73, Step S74: It is determined whether the performance / characteristics / reproducibility of the past test of the data set of the FEM model relating to the new model is worse than a predetermined level (Step S73). Proceeding to S75, if the FEM model is satisfactory, the fact is displayed on the display of the user terminal 1, and a data set of the FEM model related to the new vehicle is stored in the FEM model D / B3 (step S74). The process is terminated.
[0128]
Step S75, Step S76: Since the FEM model is determined to be defective in Step S73, the fact is notified to the user (Step S75), and the parameters (weighting) associated with the FEM model relating to the new model vehicle selected and synthesized. The FEM model is adjusted by appropriately changing the attached information such as the coefficient), various attribute information, and constraint conditions automatically or manually (step S76), and the process returns to step S72. In a preferred embodiment, when the attached information or the like is automatically adjusted in step S76, it is preferable to inform the user of what value is changed so that the user can recognize it.
[0129]
Here, for example, the following procedure can be considered as the method for determining the quality of the FEM model in step S73 and the method for adjusting the FEM model performed in step S76 when the determination result is not good.
[0130]
That is, in the FEM model relating to the new vehicle generated by the morphing process described above, for example, when judging whether the rigidity of the parts constituting the new vehicle is good or bad, the rigidity is simulated in units of parts, and the simulation is performed. If the judgment is made based on whether the rigidity of the individual parts of the new vehicle represented by the result is deteriorated beyond a predetermined level as compared with the rigidity simulation result of the same part in the FEM model related to the existing vehicle. good.
[0131]
If the judgment result is not good, the weighting coefficient used when morphing the target part (or other parts around it as necessary) is changed to a small value. Or the plate thickness may be changed to a large value.
[0132]
Further, as a characteristic of a new model vehicle, for example, when judging whether the weight is good or bad, the weight of each component is simulated for each component, and the weight of each component of the new model vehicle indicated by the simulation result is related to the existing vehicle. What is necessary is just to judge based on whether it has exceeded the predetermined level compared with the simulation result of the weight about the same component in a FEM model.
[0133]
If the judgment result is not good, the weighting coefficient used when morphing the target part (or other parts around it as necessary) is changed to a small value. Or the plate thickness may be changed to a small value.
[0134]
In the correspondence methods in the two specific examples described above, the method of adjusting the weighting coefficient is that the quality of the FEM model of the existing vehicle is good and the quality of the FEM model of the new vehicle generated by the morphing process according to the present embodiment is If it is not good, if the weighting coefficient referred to in the recalculation is automatically changed to a small value automatically, the movement of the node during morphing will be restricted, so a new model calculated using the adjusted weighting coefficient The vehicle FEM model is based on the precondition that it approaches a FEM model of an existing vehicle with good quality.
[0135]
FIG. 11 is a diagram illustrating a display screen for notifying the user of the morphing result. Since the calculated morphing result is poor in quality, the user is notified that automatic or manual adjustment is necessary. Yes.
[0136]
In the display screen shown in FIG. 11A, when the “OK” operation button is selected by the user, execution of the process of step S76 is started, and when the “cancel” operation button is selected. For example, the result notification / adjustment process may be terminated, and the process may return to step S1 or step S2 described above.
[0137]
In addition, on the display screen shown in FIG. 11B, the user can manually or partially correct the mesh shape, attached information, and the like for the FEM model related to the new vehicle as a morphing result. . In this display screen, when the “display” operation button is selected by the user, the poor quality portion is highlighted and displayed on the display screen (not shown), and the user can select a desired shape or value. For example, when the “OK” operation button is selected by the user, the process returns to step S72, and when the “Cancel” operation button is selected, the result notification / adjustment process ends. And it is good to return to step S1 or step S2 mentioned above.
[0138]
Here, some of the results of various performance evaluation tests on existing vehicles are not simulations using computers, but are, for example, crash tests performed in a vehicle manufacturer's laboratory where various data measurement environments are prepared. In some cases, the actual test results already exist. In this case, when developing a new type vehicle (especially in the case of a derivative vehicle) based on the existing vehicle, There may be no need to perform the same type of test.
[0139]
On the other hand, even when developing a new model based on an existing vehicle, there are cases where it is clear that there are different test results among the various evaluation tests that should actually be performed. In some cases, it is necessary to newly perform an actual test for the target performance evaluation item.
[0140]
Therefore, in the present embodiment, in order to automatically determine which case corresponds to the above case and notify the user, the existing vehicle with respect to the target portion of the performance evaluation test that has been actually performed on the existing vehicle in the past. It is determined whether the mesh shape of the FEM model related to and the mesh shape of the FEM model related to the new vehicle newly generated by the processing according to the present embodiment are the same or similar with respect to the target part. Then, according to the determination result, whether or not a plurality of types of performance evaluation tests that should be actually performed, such as a collision test and a side collision, is automatically determined as the performance of the new vehicle (that is, the target parts are not similar). In this case, a new test is required). For example, when notifying the user of the morphing result as described above, it is preferable to notify the user together.
[0141]
Step S77, Step S78: Since the quality of the mesh shape of the FEM model relating to the new model vehicle is judged to be poor in Step S72, this is notified to the user (Step S77), and the mesh shape is automatically or manually determined. To change the parameter (weighting coefficient) as appropriate (step S78) and return to step S72.
[0142]
The notification to the user in step S77 is limited to the mesh shape of the FEM model related to the new vehicle, but the display screen illustrated in FIG. 11 described above may be displayed on the display of the user terminal 1.
[0143]
As described above, according to the present embodiment described above, the FEM model of the existing vehicle prepared earlier and the CAD model of the new model have different data formats, but the product as the product calculated as described above is used. The FEM model of the new model has the same data format as the FEM model of the existing vehicle, and it is a high quality that can be set and used as it is for various analysis processing solvers such as strength analysis, thermal analysis, mechanism analysis, and vibration analysis. It is a data set.
[0144]
That is, if the user of the user terminal 1 can prepare the FEM model of the existing vehicle (prototype structure) and at least the external shape information of the new vehicle (analysis target structure), the analysis process based on the finite element method for the new vehicle The FEM model of the new model can be quickly and quickly associated with associated information such as attribute information representing boundary conditions, constraint conditions, and materials without performing various setting operations that were necessary in the past. It can be easily obtained. As a result, it is possible to effectively utilize the FEM model of the existing vehicle that has already existed and to speed up the entire analysis work of the new vehicle.
[0145]
In the present embodiment, the weighting coefficient to be referred to when executing the morphing is determined according to the parameters set by the user using the setting screens illustrated in FIGS. Therefore, it is possible to obtain a realistic FEM model of a new vehicle, and to minimize the quality degradation of the FEM model of the new vehicle compared with the FEM model quality of the existing vehicle. Such an effect is particularly noticeable when the new model vehicle is a so-called derivative vehicle similar to an existing vehicle.
[0146]
In the present embodiment, if the quality of the calculated FEM model of the new vehicle and its mesh shape is not good, the user is notified of this, and the FEM model and mesh shape are It can be adjusted manually or automatically. Thereby, it is possible to prevent the analysis of the new vehicle using the low-quality FEM model from being performed by the user in a subsequent process.
[0147]
Further, in this embodiment, when the calculated quality of the FEM model of the new vehicle (for example, the degree of distortion of the mesh model, component performance, characteristics, etc.) is deteriorated from a predetermined level, the high quality that can be used for the analysis processing is high. Since it is possible to automatically perform recalculation until the FEM model of the new model vehicle can be obtained, the convenience of the user is improved, and the analysis of the new model vehicle using the low quality FEM model is performed in a later process. It is possible to prevent the user from performing it.
[0148]
In the above-described embodiment, for convenience of explanation, the FEM model generation processing of the new vehicle has been described with reference to a plurality of drawings. However, display screens corresponding to all the drawings are displayed on the display of the user terminal 1. There is no need to do.
[Brief description of the drawings]
FIG. 1 is a diagram illustrating a configuration of a computer system applicable to the present embodiment.
FIG. 2 is a flowchart showing an overall outline of FEM model generation processing for a new vehicle in the present embodiment.
FIG. 3 is a flowchart showing details of a preparation process (step S1 in FIG. 2) in the FEM model generation process for a new vehicle in the present embodiment.
FIG. 4 is a flowchart showing details of a box-based morphing process (step S3 in FIG. 2) in the FEM model generation process for a new vehicle according to the present embodiment.
FIG. 5 is a flowchart showing details of a morphing process based on a feature line (step S4 in FIG. 2) in the FEM model generation process of the new vehicle in the present embodiment.
6 is a flowchart showing details of a result notification / adjustment process (step S7 in FIG. 2) in the FEM model generation process for a new vehicle in the present embodiment.
FIG. 7 is a diagram illustrating a parameter setting screen that can be set by a user for each desired component in order to determine a weighting coefficient;
FIG. 8 is a diagram illustrating a parameter setting screen that can be set by the user for the entire FEM model of an existing vehicle in order to determine a weighting coefficient;
FIG. 9 is a diagram illustrating a parameter setting screen that can be set by the user for the entire FEM model of an existing vehicle in order to determine a weighting coefficient;
FIG. 10 is a setting screen for the user to perform morphing settings for the A pillar.
FIG. 11 is a diagram illustrating a display screen for notifying a user of a morphing result.
FIG. 12 is a diagram illustrating an FEM model of an existing vehicle in the present embodiment.
FIG. 13 is a diagram illustrating a CAD model of a new vehicle in the present embodiment.
FIG. 14 is a diagram illustrating a mesh shape of an FEM model of an existing vehicle in a state where a plurality of first FEM reference points are set.
FIG. 15 is a diagram illustrating an outline of a new vehicle in a state where a plurality of first CAD reference points are set.
FIG. 16 is a diagram showing B-BOX1 generated based on a plurality of first and second FEM reference points.
FIG. 17 is a diagram showing A-BOX1 generated based on a plurality of first and second CAD reference points.
18 is a diagram illustrating a state in which B-BOX 11 having the same individual mesh size is set for the FEM model of the existing vehicle illustrated in FIG. 12;
FIG. 19 is a diagram showing only the B-BOX 11 set in the present embodiment.
FIG. 20 is a diagram showing a state in which A-BOX11 and B-BOX1 are overlapped.
FIG. 21 is a diagram showing A-BOX11 generated by deforming B-BOX11 based on B-BOX1 and A-BOX1.
FIG. 22 is a diagram showing a state in which A-BOX11 and B-BOX11 whose node positions are adjusted are overlapped.
FIG. 23 is a diagram illustrating a new vehicle FEM model calculated in the FEM model generation process for a new vehicle according to the embodiment;
FIG. 24 shows a feature line (A-BAR1) of a new vehicle in which first and third CAD reference points are set, and a feature line (B-BAR1) of an existing vehicle in which first and third FEM reference points are set. It is a figure which shows the state overlaid in the common three-dimensional coordinate space.
FIG. 25 shows the degree of change in shape from the FEM model of an existing vehicle that is a prototype with respect to the FEM model of the new vehicle generated by the FEM model generation processing of the new vehicle according to the present embodiment. It is a figure which illustrates the case where it displays by ().
[Explanation of symbols]
1: User terminal (Operation section) ,
2: Host computer
3: FEM model database (Memory part) ,
4: CAD model database (Memory part) ,
5: Program database (Memory part) ,
6: Communication network,

Claims (13)

A structure morphing method using a computer having at least an operation unit and a storage unit ,
The storage unit 3 represents at least the outer shape information of the structure to be analyzed and the outer shape of the prototype structure that is generated in advance using a preprocessor of an analysis solver based on the finite element method (FEM). A dimension mesh model and an FEM model including attached information associated with the mesh model are stored in advance;
In response to the operation of the operation unit, the computer obtains the external shape information of the analysis target structure and the FEM model of the prototype structure from the storage unit , and the operation unit is operated. In response to the external shape information of the analysis target structure obtained from the storage unit and the mesh model of the prototype structure, the first change in shape from the prototype structure to the analysis target structure is performed. The first constraint condition is set at the first viewpoint, and the second constraint at the time of changing the shape in response to the operation unit being operated at a second viewpoint different from the first viewpoint. A preparation process for setting conditions;
The computer is based on the first and second constraint condition set in the preparatory step, the Rukoto moving the plurality of nodes that form a mesh model of the prototype structure obtained from the storage unit, the mesh By changing the model to the outer shape of the structure to be analyzed, and by redefining the attached information obtained from the storage unit and its association state with respect to the mesh model after deformation, according to the movement, And a morphing step of calculating an FEM model for the structure to be analyzed. In the morphing process, the computer, the second constraint condition set in the second aspect, with respect to a narrower range than the applicable range of the first constraint condition set in the first aspect structure shape morphing method of claim 1, wherein that you reflect. Wherein said computer is a second constraint, which in the mesh model of the prototype structure obtained from the storage unit in the first viewpoint, characterized that you set for site extending in the longitudinal direction Item 3. A structure morphing method according to Item 2. The computer, the second constraint, morphing method of a structure shape of claim 3, wherein that you set against the cross-sectional shape of the portion extending in the longitudinal direction. In the morphing process, the computer is, the structure according to the second constraint, in any one of claims 1 to 4, characterized that you reflected in preference to the first constraint Shape morphing method. Wherein the said computer to that of the first constraint set in preparation step, upon moving the plurality of nodes that form a mesh model of the prototype structure obtained from the storage unit, to restrict the amount of movement 6. A structure according to any one of claims 1 to 5, characterized in that a parameter for determining weighting is included, the parameter being associated with an FEM model of the prototype structure. Body shape morphing method. Wherein said computer in the preparation process to set the first constraint, further the outer shape information of the structure to be analyzed, obtained from the storage unit, the mesh of the prototype structure obtained from the storage unit the corresponding positions of the model, automatically or the operation unit includes a plurality of reference points set in response to being operated,
In the morphing process, the computer, based on the correspondence between the plurality of reference points, have rows movement of a plurality of nodes that form the mesh model of the prototype structure obtained from the storage unit, the amount of movement , a weighting determined by the parameters, morphing method of a structure shape according to claim 6, wherein that you regulated according with the second constraint. The morphing process includes
The computer sets a plurality of first hexahedrons including at least one reference point as a vertex according to a plurality of reference points set in the mesh model of the prototype structure obtained from the storage unit , and the storage unit A plurality of second hexahedrons corresponding to the first hexahedron and including at least one reference point as a vertex are set according to the plurality of reference points set in the outer shape information of the structure to be analyzed obtained from A hexahedron setting process;
The computer is, among the plurality of first and second hexahedrons, according to the shape difference between the first hexahedron and a second hexahedron corresponding to each other, in a state that reflects the weighting and the second constraint, the memory the Rukoto moving the plurality of nodes that form a mesh model of the prototype structure obtained from parts, as well as change the mesh model to the outer shape of the structure to be analyzed, in accordance with the movement, the storage unit An FEM model calculation step of calculating an FEM model for the structure to be analyzed by redefining the attached information and the associated state obtained from the modified mesh model. The method for morphing a structure according to claim 7. The morphing process includes
According to a plurality of reference points set in the mesh model of the prototype structure obtained from the storage unit, the computer sets a first feature line including the reference points on the line, and the computer obtains the feature line from the storage unit. A feature line setting step of setting a second feature line that corresponds to the first feature line and includes the reference point on the line according to a plurality of reference points set in the outer shape information of the structure to be analyzed; ,
The mesh of the prototype structure obtained from the storage unit in a state in which the computer reflects the weighting and the second constraint condition according to a difference in shape between the first feature line and the second feature line. the Rukoto moving the plurality of nodes that form the model, as well as change the mesh model to the outer shape of the structure to be analyzed, in accordance with the movement, the accessory information and associated state thereof obtained from the storage unit 8. A morphing of a structure shape according to claim 7, further comprising: an FEM model calculation step of calculating an FEM model for the structure to be analyzed by redefining the mesh model after deformation. Method. 2. The structure shape morphing method according to claim 1, wherein the auxiliary information stored in the storage unit is at least boundary conditions, constraint conditions, and attribute information representing a material.   2. The structure shape according to claim 1, wherein the prototype structure is a body structure of an existing vehicle, and the structure to be analyzed is a body structure of a derived vehicle derived from the existing vehicle. Morphing method. A computer program for realizing morphing of a structure by a computer,
The computer has at least an operation unit and a storage unit,
The storage unit 3 represents at least the outer shape information of the structure to be analyzed and the outer shape of the prototype structure that is generated in advance using a preprocessor of an analysis solver based on the finite element method (FEM). A dimension mesh model and an FEM model including attached information associated with the mesh model are stored in advance;
In the computer,
In response to the operation unit being operated, the external shape information of the analysis target structure and the FEM model of the prototype structure are obtained from the storage unit, and the operation unit is operated. Then, with respect to the external shape information of the analysis target structure obtained from the storage unit and the mesh model of the prototype structure, a first constraint condition when changing the shape from the prototype structure to the analysis target structure Is set at the first viewpoint, and a second constraint condition for changing the shape is set in response to the operation of the operation unit at a second viewpoint different from the first viewpoint. A preparation process;
Based on the first and second constraint conditions set in the preparation step, by moving a plurality of nodes constituting the mesh model of the prototype structure obtained from the storage unit, the mesh model is analyzed. About the structure to be analyzed by changing the outer shape of the structure and redefining the attached information obtained from the storage unit and the associated state with respect to the deformed mesh model according to the movement And a morphing step for calculating the FEM model of the computer. A computer- readable storage medium storing a program code for realizing morphing of a structure by a computer ,
The computer has at least an operation unit and a storage unit,
The storage unit 3 represents at least the outer shape information of the structure to be analyzed and the outer shape of the prototype structure that is generated in advance using a preprocessor of an analysis solver based on the finite element method (FEM). A dimension mesh model and an FEM model including attached information associated with the mesh model are stored in advance;
In the computer,
In response to the operation unit being operated, the external shape information of the analysis target structure and the FEM model of the prototype structure are obtained from the storage unit, and in response to the operation unit being operated. The first constraint condition for changing the shape from the prototype structure to the analysis target structure is obtained with respect to the external shape information of the analysis target structure obtained from the storage unit and the mesh model of the prototype structure. Preparation for setting a second constraint condition for changing the shape in response to the operation of the operation unit at a second viewpoint that is set at the first viewpoint and is different from the first viewpoint Process,
Based on the first and second constraint conditions set in the preparation step, by moving a plurality of nodes constituting the mesh model of the prototype structure obtained from the storage unit, the mesh model is analyzed. About the structure to be analyzed by changing the outer shape of the structure and redefining the attached information obtained from the storage unit and the associated state with respect to the deformed mesh model according to the movement A computer-readable storage medium storing program code for executing a morphing step of calculating the FEM model of the computer .

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