JP2006215949A - Analysis model creation support system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To widely apply know-how accumulated for an existing analysis model to creation of a new analysis model. <P>SOLUTION: This analysis model creation support system is provided with a database 114 accumulating existing analysis models, a similar analysis model search part 111 searching for a similar analysis model in the analysis models accumulated in the database according to a shape of a structure, for which an analysis model is created, and extracting the similar analysis model, and an existing analysis model application part 112 applying the similar analysis model searched and extracted by the similar analysis model search part to the structure for which an analysis model is created. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a technique for supporting the creation of an analysis model, and more particularly to an analysis model creation support suitable for an analysis model creation support when a structure to be analyzed is a structure described by CAD data. Regarding technology.

  The creation of an analysis model requires a lot of know-how regarding, for example, the shape and size of the mesh or the density of the mesh, and how much such know-how can be used greatly affects the quality of the analysis model. For this reason, it is not easy for an unskilled person who is not sufficiently familiar with the know-how of creating an analysis model to efficiently create a high-quality analysis model. For this reason, for example, a technique as disclosed in Patent Document 1 has been proposed. The technology of Patent Document 1 supports the creation of an analysis model for a new vehicle by making it possible to use an FEM model (analysis model) of an existing vehicle for creating an analysis model for a new vehicle. .

JP 2003-108609 A

  It can be said that the use of an existing analysis model as a newly created analysis model as in the prior art disclosed in Patent Document 1 is highly effective as an analysis model creation support. However, this prior art makes it possible to use an existing analysis model on the assumption of a specific relationship, such as an existing vehicle and a new model derived therefrom. For this reason, there remains a problem in versatility that the know-how accumulated in the existing analysis model can be widely used when creating a new analysis model.

  The present invention has been made in the background as described above. The know-how accumulated in the existing analysis model is widely used in the creation of a new analysis model, particularly in the creation of an analysis model from CAD data. The purpose of this is to provide an analytical model creation support system that enables an unskilled person to efficiently create a high-quality analytical model by making it available.

  For the above purpose, in the present invention, in the analysis model creation support system that supports the creation of the analysis model, the database for accumulating the existing analysis model, based on the shape of the structure for which the analysis model is created, Similarity analysis model search unit for searching for and extracting similar analysis model from analysis model stored in database, and similar analysis model searched and extracted by similar analysis model search unit It is characterized in that it is equipped with an existing analysis model application section that is applied to.

  Further, in the present invention, in the analysis model creation support system as described above, the similarity analysis model search unit retrieves and extracts the similarity analysis model by calculating the shape of the structure for which the analysis model is created on the shape. , A line connecting the points, and a surface surrounded by the line as recognition elements, and the shape of the recognized analysis model creation target structure is stored in the database in the analysis model This is done by comparing the points, lines, and surfaces as comparison elements.

  In the present invention, in the analysis model creation support system as described above, the similarity analysis model search unit stores the analysis model creation target structure and the database in the database in the process of searching and extracting the similarity analysis model. A shape correspondence table that records the correspondence relationship of the comparison element with the analysis model is created, and the existing analysis model application unit applies the analysis model creation target structure to the analysis model creation target structure based on the shape correspondence table. The similar analysis model is applied.

  In the present invention, a similar analysis model search unit searches for and extracts a similar analysis model from an existing analysis model stored in the database, and the existing analysis model application unit applies it to a structure for which an analysis model is to be created. By doing so, the creation of a model for analysis is supported. According to the present invention, the know-how accumulated in the existing analysis model can be widely used when creating a new analysis model, and even an unskilled person can efficiently use a high-quality analysis model. It becomes possible to create.

  Hereinafter, preferred embodiments for carrying out the present invention will be described. FIG. 1 shows the configuration of an analysis model creation support system according to an embodiment. The analysis model creation support system includes a first support unit 101 and a second support unit 102, and further includes a display unit 103. The first support unit 101 supports the creation of an analysis model using an existing analysis model. The second support unit 102 performs support similar to that generally performed conventionally as analysis model creation support. The display unit 103 is used for an interface with a system user (user) necessary for support.

  The first support unit 101 includes a similar analysis model search unit 111, an existing analysis model application unit 112, a display unit control 113, and a database 114 in order to perform support using the existing analysis model. The similar analysis model retrieval unit 111 stores the shape of the structure for which an analysis model is to be created, specifically, the structure (CAD model) described in the CAD data in the existing analysis model stored in the database 114. Compared with the shape, an existing analysis model that is similar to the shape for a certain level is searched from the database 115 and extracted. The existing analysis model application unit 112 applies the mesh data of the similarity analysis model extracted by the similarity analysis model search unit 111 to the CAD model. The display control unit 113 displays images, data, and the like necessary for the support by the first support unit 101 on the display unit 103.

  FIG. 2 shows a data flow in processing performed by the first support unit 101. The database 114 stores a large number of analysis models 202 created in the past. When a CAD model (new shape CAD data) 203 for which an analysis model is created is input to the similarity analysis model search unit 111, the similarity analysis model search unit 111 converts the shape of the CAD model 203 into an analysis model in the database 114. Compared with the shape in 202, an analysis model 205 similar to the shape for a certain degree is searched from the database 114 and extracted. The similarity analysis model search unit 111 creates the shape correspondence table 206 in the search / extraction process. Shape comparison in search / extraction is performed using the points constituting the shape (vertices), the lines connecting the points (ridge lines or outlines), and the faces surrounded by the lines as comparison elements. The correspondence relationship of the comparison element is recorded. The similar analysis model 205 extracted by the similar analysis model search unit 111 and the shape correspondence table 206 created by the similar analysis model search unit 111 are passed to the existing analysis model application unit 112. The existing analysis model application unit 112 applies the mesh data of the similarity analysis model 205 to the CAD model 203 based on the shape correspondence table 206. In this application processing, the existing analysis model application unit 112 embeds the mesh data in the CAD model 203 based on the shape correspondence table 206, and the mesh data embedded in the CAD data in this processing is adapted to the CAD model. There is a process to process. The latter process is performed as an interactive process with the user. The processing result by the existing analysis model application unit 112 is output as a new analysis model (input CAD mesh model) 208 and is finally stored in the database 114.

  FIG. 3 shows the flow of processing performed by the first support unit 101. First, as target data input, CAD data for which an analysis model is created is provided to the similarity analysis model search unit 111 (step 301). Upon receiving the input of the target CAD data, the similarity analysis model search unit 111 first recognizes the shape of the CAD model for the CAD data (step 302). Next, a model for similarity analysis is searched and extracted from the database 114 based on the recognized shape (step 303). The similar analysis model is an existing analysis model having a shape that is more than a certain value similar to the shape of the CAD model. Next, the extraction result of the similar analysis model is determined (step 304). When the similar analysis model is extracted, several similar analysis models having a high degree of similarity are presented to the user, and the user Selection is made possible (step 305). If the similar analysis model cannot be extracted, the support by the first support unit 101 is terminated and the process proceeds to support by the second support unit 102 (step 306). Following step 305, the user selects one of the similar existing models for analysis presented in step 305 (step 307) and applies it to the CAD model (step 308). In applying the existing analysis model, first, mesh data (mesh model) of the existing analysis model is embedded in the CAD model, and then the embedded mesh model is processed and changed so as to be adapted to the CAD model (step 309).

  Below, these processes are demonstrated concretely. FIG. 4 shows an example of a screen displayed on the display unit 103 when the first support unit 101 supports the use of the existing analysis model. The example in the figure is a case where the CAD model is a connecting rod. In the existing analysis model use support screen 401, search buttons 402, an apply button 403, and a change button 404 are provided at the top of the screen, and a CAD model 405 is displayed at the bottom of the screen.

  When the user presses the search button 402, processing by the similarity analysis model search unit 111 is activated. FIG. 5 shows an image of a similar analysis model search processing algorithm performed by the similar analysis model search unit 111. The left side of the figure is a CAD model, and the right side is an analysis model. Shape recognition with respect to a CAD model is performed using points (vertices), lines (ridge lines), and surfaces constituting the shape in the CAD model as recognition elements. As described above, these recognition elements are also comparison elements in the shape comparison between the CAD model and the analysis model. Each recognition element, that is, a comparison element is appropriately given an element number. The analysis model is stored in the database 114 as data in which an element number is assigned to each comparison element in advance. For the CAD model, there is a method of providing an element number assignment function in the model search unit 111 for similarity analysis, and automatically assigning an element number with the element number assignment function, and a method in which a user manually assigns an element number It is. In this embodiment, a method of automatically assigning element numbers is used. In the figure, for element numbers, the element numbers are attached to the points like circled numbers, the elements are attached to the lines like triangle numbers, and the faces are square numbers. An example in which element numbers are assigned is shown. Each point to which an element number is assigned is recognized by the coordinate value at the coordinates set for the CAD model. Coordinates are set for the CAD model by placing the coordinate origin at an appropriate position in the CAD model. Such coordinates can be set automatically and manually as in the case of assigning element numbers. Each line with an element number is recognized as a starting point and an end point. Each surface to which the element number is attached is recognized by a line surrounding it.

  When the CAD model shape is recognized as described above, the analysis model is searched based on the recognition, and the similar analysis model is extracted. The analysis model is searched by searching the analysis model for points, lines, and surfaces corresponding to points, lines, and surfaces in the CAD model. This search is performed using the point closest to the origin of the coordinates set in the CAD model as the reference point 501. That is, a search for a point is performed by searching for a corresponding point from the analysis model so as to follow a point adjacent in a predetermined adjacent direction from the reference point 501, and adjacent to the reference point 501 with the reference point 501 as a starting point. A line is searched by searching for a corresponding line from the analysis model so as to follow a line adjacent in a predetermined adjacent direction in order from a line 504 having the point 503 as an end point, and further from a surface 505 including the line 504 in order. A search for a surface is performed by searching for a corresponding surface from the analysis model so as to follow a surface adjacent in a predetermined adjacent direction.

  For example, the similarity determination of the searched analysis model with respect to the CAD model is performed based on the coordinate values of the points, lines, and surfaces that are comparison elements. Specifically, a similar range of coordinate values is determined in advance for each point, line, and surface, and a similar range ratio is determined in advance for the ratio of each point, line, and surface within the coordinate value similar range. Based on the range and the similar range ratio, an analysis model that satisfies the criteria is extracted as a similar analysis model. For the similarity analysis model retrieved and extracted, the degree of similarity is determined according to the degree of approximation of the coordinate values of each point, line, and surface, and the ratio of each point, line, and surface within the coordinate value similarity range. .

  In the above search / extraction process, the shape correspondence table in FIG. 2 is created for the extracted model for similarity analysis. FIG. 6 shows an example of the shape correspondence table. In the example of FIG. 6, a shape correspondence table is created for each point, line, and surface that is a comparison element. In the point shape correspondence table, the coordinate value of each point associated with the element number is recorded, and the line In the shape correspondence table, the start point and end point of each line associated with the element number are recorded with the element number of each point. In the surface shape correspondence table, the line included in each face associated with the element number is the element number. It is recorded in.

  When the similar analysis model is extracted as described above, several similar analysis models having a high degree of similarity are presented to the user, and the user is requested to select an analysis model to be applied. FIG. 7 is an example of a screen that presents a model for similarity analysis. A CAD model 701 is displayed on the lower left side of the screen, and a similarity analysis model 702 is displayed on the lower right side of the screen. When the user selects the similar analysis model 702 as an analysis model to be applied, the application button 403 is pressed in this display state.

  In applying the analysis model to the CAD model, a process of arranging and embedding nodes on the mesh model in the analysis model on the CAD model is first performed. In the node embedding process in the CAD model, first, nodes on corresponding points in the mesh model are arranged on each point of the CAD model. In order to perform the node placement processing on the points, the nodes of the mesh model are moved according to the difference in the shape of the CAD model with respect to the analysis model, that is, the difference in the coordinate values of the corresponding points of the CAD model and the analysis model. Therefore, information on the moving direction and moving amount of the node is required. Information on the movement direction and movement amount of the node can be obtained based on information (point coordinate values) recorded in the shape correspondence table.

  Next, nodes on corresponding lines in the mesh model are arranged on each line of the CAD model. The arrangement of nodes on a line is related to the shape of the line (straight line, curve). Line shape information cannot be obtained from the shape correspondence table as described above. Therefore, in a preferred embodiment, a temporary triangular mesh is created in the CAD model, the shape of the line is interpolated based on the coordinates of the triangular mesh, and the nodes of the mesh model are arranged on the interpolated line. In addition, in the arrangement of the nodes on the line, it is necessary to determine the position of each node on the line in the mesh model. The position of each node is determined based on the ratio of the distance between the end points (start point and end point) and the end point (start point or end point) to the distance between the nodes on the line of the mesh model. Is a preferred example. Also, in the node arrangement process on the line, information on the movement direction and the movement amount of the node corresponding to the difference in the shape of the CAD model with respect to the analysis model is required, as in the case of the node arrangement on the point. This can also be obtained based on the information recorded in the shape correspondence table.

  Next, the nodes on the corresponding surface in the mesh model are arranged on each surface of the CAD model. In the arrangement of nodes on the surface, the nodes are arranged in the order in which the positions are close to the line surrounding the surface. For that purpose, the position information of the nodes on the surface of the mesh model is obtained by first finding the position of the node on the surface connected to the node on the line surrounding the surface, and then on the surface connected to the node where the position is obtained This can be obtained by performing the process of obtaining the positions of other nodes on all the nodes on the surface. The information about the movement of the node in the arrangement of the node on the surface is first obtained from the movement direction and movement amount of the node on the line surrounding the surface by the weighted average of the movement direction and movement amount of the node connected to the node, Then, the movement direction and the movement amount of other nodes connected to the node whose movement direction and movement amount are obtained can be obtained by performing the process of obtaining the weighted average for all the nodes on the surface.

  When the arrangement of the nodes on the surface is finished, the nodes are finally arranged in the space portion surrounded by the surface, that is, the volume portion. In the arrangement of the nodes in the volume part, the nodes are arranged in the order in which the positions are close to the surface surrounding the volume part. Therefore, the position information of the nodes in the volume part of the mesh model is obtained by first finding the position of the node in the volume part connected to the node on the surface surrounding the volume part by linear interpolation, and then the node from which the position is obtained Can be obtained by performing the process of obtaining the positions of other nodes in the volume part connected to, by linear interpolation for all the nodes in the volume part. The information on the movement of the nodes in the placement of the nodes in the volume part is the weighted average of the movement direction and movement amount of the nodes connected to the node from the movement direction and movement amount of the nodes on the surface surrounding the volume part. It can be obtained by first calculating and then calculating the moving direction and moving amount of other nodes connected to the node for which the moving direction and moving amount are obtained by performing a weighted average on all the nodes in the volume part. .

  When the arrangement of the nodes in the CAD model, that is, the embedding of the mesh data of the existing analysis model into the CAD model is finished as described above, the result is presented to the user. FIG. 8 is an example of a screen that presents an embedding result. An analysis model 801 created for a CAD model is presented by embedding mesh data of an existing analysis model in the central portion at the bottom of the screen.

  At this time, the analysis model 801 may not have sufficient quality due to the difference in shape between the CAD model and the application analysis model. In such a case, the user processes and changes the analysis model 801 appropriately. To change the analysis model 801, a change button 404 is pressed to activate a change function in the existing analysis model application unit 112.

  FIG. 9 is an example of a screen that displays the analysis model to be changed in the mesh data changing process. When the user moves the mouse cursor 902 to an arbitrary point or line in the displayed analysis model 901 to be changed and drags it to the position intended by the user, it can be moved to that position, for example, as a point 903. At the same time, the mesh can be moved as the point moves. FIG. 10 is an example of a display screen showing a state where the mesh has moved as the point is moved as in the example of FIG. The mesh moves according to the movement amount of the point 1001.

  FIG. 11 is another example of the display screen in a state where the analysis model is being processed. In this example, when a mesh node 1101 is moved to deform the mesh, the mouse cursor 1102 is placed on the node 1101 and moved to an intended position by dragging. FIG. 12 is an example of the analysis model display screen after the mesh is deformed as in the example of FIG. The coordinates of the moved node are calculated, and the moved node 1201 and the mesh are displayed based on the calculated coordinates.

  Regarding the movement of the nodes in the processing of the analysis model, it is possible to move not only a single node but also a plurality of nodes collectively. FIG. 13 is an example of a display screen when such an operation is performed. In the example shown in the figure, a region 1301 including a plurality of nodes is designated with a cursor 1302, and the region is moved to an intended position by dragging, thereby moving a plurality of nodes in the region 1301. FIG. 14 shows an example of an analysis model display screen after a plurality of nodes are moved together by area designation as in the example of FIG. 13, in which a plurality of nodes 1401 moved by area designation are displayed. Yes.

It is a figure which shows the structure of the model creation assistance system for analysis by one Embodiment. It is a figure which shows the flow of the data in the process performed by the 1st assistance part. It is a figure which shows the flow of the process performed by the 1st assistance part. It is a figure which shows the example of the screen displayed at the time of the assistance of the existing analysis model utilization by the 1st assistance part. FIG. 5 is a diagram illustrating an image of an algorithm for search processing for a model for similarity analysis performed by a model search unit for similarity analysis. It is a figure which shows the example of a shape corresponding table. It is a figure which shows the example of the screen which presents the model for similarity analysis. It is a figure which shows the example of the screen which presents the embedding result to the CAD model of the mesh data of the model for existing analysis. It is a figure which shows the example of the screen which displays the model for analysis of change object in the mesh data change process. It is a figure which shows the example of the display screen which shows the state which moved the mesh with having moved the point in the example of FIG. It is a figure which shows the other example of the display screen in the state which is processing the model for analysis. It is a figure which shows the example of the model display screen for analysis after deform | transforming a mesh in the example of FIG. It is a figure which shows the example of a display screen in the case of performing operation which moves several nodes collectively. It is a figure which shows the example of the analysis model display screen after moving several nodes collectively by area | region designation.

Explanation of symbols

111 Model Analysis Unit for Similar Analysis 112 Model Application Unit for Existing Analysis 114 Database 206 Shape Correspondence Table

Claims (3)

In an analysis model creation support system that supports creation of an analysis model,
A database for storing existing analysis models, a model search unit for similarity analysis that searches for and extracts models for analysis from the models for analysis stored in the database based on the shape of the structure for which an analysis model is to be created, and An analysis model creation support system comprising an existing analysis model application unit that applies a similar analysis model retrieved and extracted by the similarity analysis model retrieval unit to the analysis model creation target structure.   The similarity analysis model search unit by the similarity analysis model search unit searches / extracts the shape of the structure for which the analysis model is created, points on the shape, a line connecting the points, and a surface surrounded by the line Is recognized as a recognition element, and the shape of the recognized analysis model creation target structure is compared with the shape in the analysis model stored in the database as the comparison element using the points, lines, and surfaces as comparison elements. The analysis model creation support system according to claim 1, wherein The similarity analysis model search unit records a correspondence relationship of the comparison element between the analysis model creation target structure and the analysis model stored in the database in the similarity analysis model search / extraction process. A shape correspondence table is created, and the existing analysis model application unit applies the similar analysis model to the analysis model creation target structure based on the shape correspondence table. The analysis model creation support system according to claim 1 or 2.

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