JP4872583B2 - Shape model creation device - Google Patents

Description

The present invention is a CAE that numerically simulates a physical phenomenon by numerical analysis using a computer.
The present invention relates to a (Computer Aided Engineering) system, and more particularly, to creation of a shape model composed of shape data in CAE.

  By using CAE in the product development process, development costs and design development periods are shortened. In CAE, an analysis model is created from shape data created by a CAD (Computer Aided Design) system, and strength analysis, thermal analysis, vibration analysis, etc. are performed using analysis methods such as the finite element method and boundary element method. I do. The creation of an analysis model requires the work of creating mesh data from shape data and setting parameters, boundary conditions, etc. for each mesh in the mesh data, and a large amount of work is required for creating an analysis model.

  Thus, a technique for reducing the burden of creating an analysis model has been proposed. For example, in the technology disclosed in Patent Document 1, the CAD function and the CAE function are integrated into a single system, thereby reducing the burden of creating an analysis model.

  In the technique disclosed in Patent Document 2, a desired analysis model is created using an existing analysis model. Set the corresponding reference points for the existing analysis model, and move the reference points based on the correspondence between these reference points and the mesh model included in the existing analysis model. The target analysis model can be created by deforming the mesh model. This technology can eliminate the need to create mesh data and set boundary conditions if the existing analysis model can be used for the desired analysis model, greatly increasing the burden of creating the analysis model. Can be reduced.

Japanese Patent Laid-Open No. 03-70083 JP 2003-108609 A

  In the above prior art, in Patent Document 1, the CAD function and the CAE function are integrated into one system, so that the burden of creating an analysis model can be reduced. However, it is necessary to recreate the analysis model every time the shape is changed by CAD, and it is not practical for large-scale data.

  In Patent Document 2, the shape is changed as an analysis model, and is not CAD data (shape data) that is generally created as a design output. Since this shape data is also used as information for manufacturing, it is essential in the design process to create shape data. For this reason, in Patent Document 2, it is necessary to recreate the final product shape by CAD again.

  An object of the present invention is to solve the above-described problems of the prior art and easily create CAD data after changing the shape as an analysis model.

In order to achieve the above object, the present invention is an apparatus for changing a shape model corresponding to an analysis model before change by changing an analysis model that is mesh data having node and element data, A mesh shape change designation means for designating a shape change location, a shape change history registration unit for sequentially registering a change method and change parameters for the analysis model as shape change history data, and at least the specified shape change location Means for deforming the analysis model by performing any of node movement, element addition and element deletion, and registering data of the analysis model after shape deformation, and the change registered in the shape change history data A change operation based on a method and a change parameter is executed on the shape model using an API or a macro function. The

According to the present invention, CAD data after a shape change can be easily created from an analysis model, and the work of creating a shape model can be saved.

Configuration of shape model creation device
FIG. 1 is a system configuration diagram showing an embodiment of a shape model creation apparatus. A target model having an input / output device 101 including a keyboard, a pointing device, a display, and the like for a system user to input and display data, and means for designating target shape model data 102 and analysis model data 103 A mesh shape change designation 105 having a designation unit 104, a means for designating a shape change location for the analysis model data 103, and a change method and change parameters designated in the mesh shape change designation 105 are used as the shape change history data 106. A shape change history registration unit 107 that registers in order, and means for deforming the analysis model data 103 by moving nodes, adding elements, and deleting elements according to the designated shape change location, and registering them as analysis model data 108 after shape change Analytical model deformation unit 109 and shape By executing the same change operation as the change method and change parameter registered in the update history data 106 on the target shape model data 102, a post-shape-change shape model 110 equivalent to the post-shape-change analysis model 108 is created. A shape model deformation unit 111 having means is provided.

  In addition, regarding the shape model creation device, when the analysis model data 103 is deformed by moving a node, adding an element, or deleting an element according to a designated shape change location, the surface data of only the deformed portion is registered as the changed portion outer shape data 113. And a changed portion display section 112 having means for simultaneously displaying the target shape model data 102 and the changed portion outer shape 113 on the operation screen.

The processing procedure will be described below.
≪Target model input part≫
An example of the procedure of the mesh data input unit will be described with reference to FIG. First, the device user uses the input / output device 101 to input the shape model data 102 in the shape model data input field 202 and the file name of the analysis model data 103 in the analysis model data input field 203 on the operation screen of FIG. To do. When the execution button 202 is pressed, the file with the file name input in the shape model data input field 202 is registered as the shape model data 102, and the file with the file name input in the analysis model data input field 203 is registered as the analysis model data 103. Is done. If the cancel button 204 is pressed, the designation is canceled.

≪Mesh shape change designation part≫
There are various methods for changing the mesh shape. In this embodiment, the designation method will be described by taking the shape change by the following two methods as an example.
Mesh parametric deformation
This is a method of recognizing the geometric feature of the outer surface of the analytical model, changing the geometric parameter of the geometric feature, and moving the nodes associated with the geometric feature to match the changed geometric parameter.

In FIG. 3, the apparatus user uses the input / output device 101 to select the geometric recognition button 302 in FIG. 3 to recognize the geometric feature of the analysis model. Next, a geometric feature whose geometric parameter is to be changed is selected from the operation screen 301. Next, the geometric parameter 303 after the change is input.
Adding / deleting feature shapes
A shape to be added as a feature shape is created, a mesh is created for the added feature shape, and a feature shape is added by performing a set operation of the mesh of the added feature shape and the mesh before the shape change. Alternatively, select the area you want to delete as a feature shape, remove the elements included in this deleted area, create an extrapolated surface to close the deleted boundary, and add a mesh in this boundary, Delete.

  An example of a feature shape addition / deletion designation method will be described with reference to FIG. The device user uses the input / output device 101 to create a feature shape 402 using the operation screen 401 shown in FIG. Next, it is designated whether the created feature shape is added 403 or deleted 404.

≪Shape change history registration part≫
The change method and change parameter specified by the mesh shape change specification 105 are registered in order as the shape change history data 106. For example, the shape change history data 106 is registered as follows.
Geometric parameter change: The distance between the geometric feature plane 3 and the geometric feature plane 9 is changed from 3 mm to 5 mm. Geometric parameter change: The radius of the geometric feature cylindrical surface 7 is changed from 8 mm to 6 mm. Feature shape addition: Center point P (10, 0,5), a hole with a depth of 20 mm and a diameter of 3 mm is added. Feature shape deletion: The portion surrounded by geometric features 10, 11, 12 is deleted.

≪Analysis model deformation part≫
The analysis model is deformed based on the deformation method specified by the mesh shape change specifying unit. The processing procedure for deformation is as described in << Mesh shape change designation unit >>. Here, an example of each modification will be described.
Mesh parametric deformation
When an instruction to change the distance between planes of the geometric parameter 304 from the previous 5 mm to 7 mm is given to the analysis model displayed on the operation screen 301 in FIG. 3, the result of the deformation is as shown by 305 in FIG. become.
Adding / deleting feature shapes
When the addition of the shape 405 is instructed to the analysis model displayed on the operation screen 401 in FIG. 4, the result of the deformation is as indicated by 406 in FIG.

≪Shape model deformation part≫
By executing the same change operation as the change method and change parameter registered in the shape change history data 106 on the target shape model data 102, a post-shape-change shape model 110 equivalent to the post-shape-change analysis model 108 is created. To do. For example, it is assumed that the shape change history data 106 is registered as follows.
Geometric parameter change: Distance between faces of geometric feature surface 3 (plane) and geometric feature surface 9 (plane) changed from 3mm to 5mm
Geometric parameter change: Radius of geometric feature surface 7 (cylindrical surface) changed from 8 mm to 6 mm Feature shape added: Center point P (10, 0, 5), 20 mm deep, 3 mm diameter hole added Feature shape deleted: Geometric Delete the part surrounded by feature planes 10, 11, 12

  This apparatus searches for a surface of the shape model data 102 that matches the geometric feature surface 3 and the geometric feature surface 9 of the shape change history data (1), sets a distance dimension to the surfaces of these shape model data 102, and sets the distance. A process of changing the dimension parameter from 3 mm to 5 mm is executed. Next, the shape change history data (2) is processed in the same manner as the shape change history data (1) to change the radius of the cylindrical surface. Next, a process of adding a hole having a center point P (10, 0, 5), a depth of 20 mm, and a diameter of 3 mm to the shape model data 102 is executed as the shape change history data (3). Finally, as the shape change history data (4), the surface of the shape model data 102 matching the geometric feature surfaces 10, 11, and 12 is searched, and the features (shape model features) configured from these surfaces of the shape model data 102 are searched. ) And search for this feature. As a result, a post-shape change shape model 110 equivalent to the post-shape change analysis model 108 can be created.

Note that the shape change processing for the above-described shape model can be realized by an API (Application Program Interface) or a macro function that is generally installed in CAD.

≪Changed part display part≫
Means for registering the surface data of only the deformed portion as the changed portion outer shape data 113 when deformed by the analysis model deforming unit 109, and the target shape model data 102 and the changed portion outer shape 113 are simultaneously displayed on the operation screen. .

  For example, assume that a shape model 701 and an analysis model 702 in FIG. 7 are input, a rib shape 7031 is added to the analysis model 702, and the analysis model 703 is changed. Here, data indicating that a rib having a shape of 7031 has been added is registered in the shape change history data. Here, the changed portion display unit in this apparatus registers the changed portion outer shape data 704 of only 7031 registered in the shape change history data. The external shape data is output in a format that can be read by the apparatus and the CAD system (shape model creation tool). Next, the shape model 701 and the changed portion outer shape data 704 are simultaneously displayed on the operation screen. As a result, the diagram 705 is displayed on the operation screen. The operator confirms the result of the display and selects whether or not to deform the shape model. If so, the shape model deforming unit is executed, and finally the shape model 706 is completed.

Example (1) of using shape model creation device
A method of deforming the analysis model with respect to the shape model 501 and the analysis model 502 shown in FIG. 5 and also deforming the shape model in conjunction with the deformation will be described.
Assume that the length of the central protrusion of the analysis model 502 is extended from 20 mm to 30 mm, and the thickness is further changed from 3 mm to 5 mm. In this case, the operator instructs deformation of the analysis model 502 by, for example, mesh parametric deformation. As a result, an analysis model 503 is created. However, since the shape model 501 does not change, the CAD system (shape is also changed to the shape model 501 by extending the length of the central protrusion from 20 mm to 30 mm and changing the thickness from 3 mm to 5 mm. Must be done on the modeling tool).

  Therefore, this device registers the shape change operation performed on the analysis model in the shape change history registration unit, and the shape model deforming unit also processes this shape change operation on the shape model, so that the analysis model And the shape of the shape model. The processing procedure will be described below.

  It is assumed that the user of this apparatus operates the process of extending the length of the central protrusion from 20 mm to 30 mm by mesh parametric deformation using the mesh shape change designating unit. Specifically, an operation of setting the distance between the planes of the geometric feature surface 5021 and the geometric feature surface 5022 to 30 mm is performed. Here, this apparatus registers this operation as shape change history data. Next, it is assumed that the process of changing the thickness of the central protrusion from 5 mm to 3 mm is operated by mesh parametric deformation. Specifically, an operation of setting the distance between the planes of the geometric feature surface 5023 and the geometric feature surface 5024 to 3 mm is performed. Here, this apparatus additionally registers this operation as shape change history data.

  At this stage, the shape change history data is registered as 503-1. Note that the result of the shape change operation of the two analysis models is 503.

Next, this apparatus searches for a surface of the shape model 501 that matches the geometric feature surfaces 5021 and 5022 of the shape change history data (1). Here, the surface 5011 and the surface 5022 are searched. A distance dimension is set on the surface 5011 and the surface 5012, and processing for changing the distance dimension parameter from 20 mm to 30 mm is executed. Next, the surface of the shape model 501 that matches the geometric feature surfaces 5023 and 5024 of the shape change history data (2) is searched. Here, the surface 5013 and the surface 5014 are searched. A distance dimension is set on the surface 5013 and the surface 5014, and processing for changing the distance dimension parameter from 5 mm to 3 mm is executed. Thereby, the shape model 504 after shape change equivalent to the analysis model 503 can be created after shape deformation.

  The deformation process of the shape model is automatically performed by executing it using an API or macro of the CAD system. As a result, the result of deformation of the analysis model can be reflected in the shape model, and the analysis model and the shape model can be linked.

Example (2) of using shape model creation device
A method of deforming the analysis model with respect to the shape model 601 and the analysis model 602 in FIG. 6 and also deforming the shape model in conjunction with the deformation will be described.
Assume that the center projection of the analysis model 602 is deleted, and that a projection connecting the projections on both the upper and lower ends is added. In this case, the operator instructs the deformation of the analysis model 602 by adding / deleting a feature shape, for example. As a result, an analysis model 603 is created. However, since the shape model 601 does not change, the CAD system (shape model creation tool) is operated to delete the center protrusion and add a protrusion connecting the upper and lower protrusions to the shape model 601 after all. Must be done above.

Therefore, this device registers the shape change operation performed on the analysis model in the shape change history registration unit, and the shape model deforming unit also processes this shape change operation on the shape model, whereby the analysis model And the shape of the shape model. The processing procedure will be described below.
First, it is assumed that the user of this apparatus operates the process of deleting a central protrusion by adding / deleting a feature shape using the mesh shape change designation unit. Specifically, an operation of deleting a portion surrounded by the geometric feature surfaces 6021 and 6022 is performed. Here, this apparatus registers this operation as shape change history data. Next, it is assumed that the process of adding protrusions connecting the protrusions on both upper and lower ends is operated by mesh parametric deformation. Specifically, an operation of adding a projection having a width of 3 mm connecting the points 6023 and 6024 is performed. Here, this apparatus additionally registers this operation as shape change history data. At this stage, the shape change history data is registered as 603-1. The result of the shape change operation of these two analysis models is 603.

Next, this apparatus searches for a surface of the shape model 601 that matches the geometric feature surfaces 6021 and 6022 of the shape change history data (1). Here, the surface 6011 and the surface 6022 are searched. Next, a feature (feature model feature) composed of the surface 6011 and the surface 6022 is searched, and the deletion process of this feature is executed. In this case, the central protrusion is deleted. Next, this apparatus calculates the coordinate values of points 6023 and 6024 of the shape change history data (2), and adds a protrusion feature having a width of 3 mm to the shape model 601 at the same coordinate position as the points 6023 and 6024. Execute the process to add. Thereby, the post-shape change shape model 604 equivalent to the post-shape change analysis model 603 can be created. The deformation process of the shape model is automatically performed by executing it using an API or macro of the CAD system. As a result, the result of deformation of the analysis model can be reflected in the shape model, and the analysis model and the shape model can be linked.

1 is an overall block diagram of a shape model creation device according to an embodiment. FIG. The operation screen of object model specification by one Embodiment. Explanatory drawing which shows an example of the designation | designated method of mesh parametric deformation | transformation. Explanatory drawing which shows an example of the designation | designated method of addition / deletion of a feature shape. Explanatory drawing which shows one example (the 1) of this apparatus utilization method. Explanatory drawing which shows one example (the 2) of this apparatus utilization method. Explanatory drawing which shows one example of a change part display part.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 101 ... Input / output device, 102 ... Shape model data, 103 ... Analysis model data, 105 ... Mesh shape change designation means, 106 ... Shape change history data, 107 ... Shape change history registration part, 108 ... Analysis model data after shape change, 110 ... Shape model after shape change.

Claims (5)

A device for changing a shape model corresponding to an analysis model before change by changing an analysis model that is mesh data having node and element data,
Mesh shape change designating means for designating a shape change location for the analysis model;
A shape change history registration unit for sequentially registering change methods and change parameters for the analysis model as shape change history data;
Means for deforming the analytical model by performing at least one of node movement and element addition and element deletion at the designated shape change location, and registering data of the analytical model after shape deformation, and
A shape model creation apparatus , wherein a change operation based on the change method and change parameters registered in the shape change history data is executed on the shape model using an API or a macro function . In claim 1,
The change method is a dimension change,
The change parameter is registered in the shape change history data as a post-change dimension,
Transform the analysis model by moving the specified shape change point to the node,
A shape model creating apparatus, wherein the shape model is changed based on the dimension change registered in the shape change history data and the post-change dimension. In claim 1,
The change method is addition of a feature shape,
The change parameter is registered in the shape change history data as a feature shape type and its parameters,
A shape model creating apparatus characterized in that an element is added in accordance with the type of the feature shape registered in the designated shape change location and its parameters. In claim 1,
The change method is deletion of a feature shape;
The change parameter is registered in the shape change history data as a feature shape type and its parameters,
A shape model creation device, wherein elements are deleted according to the type of feature shape registered in the designated shape change location and its parameters. In claim 1,
Register the outer shape of only the analysis model changed part registered in the shape change history data as changed portion outer shape data,
A shape model creation apparatus that simultaneously displays the shape model and the changed portion outer shape on an operation screen.

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