JP2002189759A - System and method for mish processing for computer numerical analysis using overlap lattice and recording medium recording the system and the method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve analytic precision in computer numerical analysis using an overlap lattice. SOLUTION: A mesh processing system for computer numerical analysis using the overlap lattice has a storage device 4 storing member meshes which have member shapes and spaces around the members represented in meshes and are concerned in the respective members and a computer 1 which reads a plurality of member meshes out of the storage device 4 to generate an overlap lattice and processes meshes in the overlap lattice corresponding to the space sandwiched between the member joint surface of one member side and the member joints surface of the other member side joined with the member joint surface as meshes inadaptable to numerical analytic computation.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mesh processing system for computer numerical analysis using a superimposed grid, a mesh processing method, and a recording medium on which the mesh processing method is recorded, and more particularly to a method of processing a joint portion of a superposed grid. .

[0002]

2. Description of the Related Art Electrodeposition coating is a coating method utilizing a phenomenon of electrophoresis or electrodialysis of a polymer electrolyte. This coating is widely used as an undercoat for automobile bodies and parts because a coating film is uniformly formed on the surface of the object to be coated and has excellent corrosion resistance. However, for example,
There is a problem that it is difficult to deposit a coating film on a structural portion where the reinforcing members overlap one another like a front pillar or a center pillar of an automobile. In order to improve this, a shape correction such as adding a hole for introducing paint ions to the reinforcing member or widening a gap between the members is appropriately performed. However, such shape modification has a large effect on the strength or rigidity of the body and the members. In addition, since electrodeposition coating evaluation is often performed using actual vehicles in the latter half of vehicle development, if there is a problem with the evaluation results, the development period will be delayed and development costs will increase. Is done. For these reasons, it is important to examine the state of coating film deposition by electrodeposition coating analysis.

[0003]

By the way, when a superimposed grid used as an electrodeposition coating analysis mesh is formed from a plurality of member meshes, simply superimposing the respective member meshes results in a joint between the members. There is a possibility that minute gaps in numerical calculation may occur. If such minute gaps exist in the superimposed grid, it is considered that paint ions can enter the inside of the structure from there, and the analysis result is different from the actual amount of coating film deposited. In order to avoid such inconveniences, it is conceivable to generate a mesh for computer numerical analysis without using a superimposed grid,
Since mesh generation is complicated, it is not preferable in terms of work efficiency.

The present invention has been made in view of such circumstances, and an object of the present invention is to improve the analysis accuracy of computer numerical analysis using a superimposed grid.

[0005]

According to a first aspect of the present invention, in a mesh processing system for computer numerical analysis using a superimposed grid, a member shape and a space around the member are represented by a mesh. In addition, a storage device that stores a member mesh for each member, a plurality of member meshes are read out from the storage device to generate a superimposed lattice, and a mesh in the superimposed lattice, and a member joining one member side Provided is a mesh processing system that has a computer that processes a mesh corresponding to a space sandwiched between a surface and a member joining surface on the other member side joined to the member joining surface as a mesh that is not applicable to numerical analysis calculation. .

In the first invention, the member mesh includes:
A region corresponding to the member joining surface may be set in advance. In this case, the computer does not need to perform an operation for determining the member joining surface.

[0007] Further, the computer may determine the member joining surface by the following method. For example, in a superimposed grid, if the distance between opposed surface regions of a pair of members is equal to or less than an allowable value, the surface regions can be determined to be member joining surfaces. In this case, it is preferable to calculate a permissible value based on the plate thickness of each member for a superimposed grid generated from a member mesh in which the plate thickness is not considered. Further, as another method, the member mesh has at least one layer of a space mesh expressing a space around the member, and the first member mesh closest to the member surface.
When the height of the spatial mesh of the layer is set to be equal to or larger than the predetermined member gap, the surface of the member on the other member side is positioned in the spatial mesh of the first layer on the one member side in the overlapping grid. If a space exists, a surface region that spatially corresponds to this space can be determined as a member joining surface.

According to a second aspect of the present invention, in a mesh processing system for computer numerical analysis using a superimposed grid, a member shape and a space around the member are represented by a mesh and a gap between member joints is filled. A storage device that stores a member mesh for each individual member, in which at least the plate thickness at the member joining portion is set to be greater than the actual plate thickness, and a computer that reads a plurality of member meshes from the storage device and generates a superimposed grid A mesh processing system having:

According to a third aspect of the present invention, there is provided a mesh processing method for computer numerical analysis using a superimposed grid, wherein a member shape and a space around the member are represented by a mesh, and a region corresponding to a member joining surface is set in advance. Done,
A step of reading out member meshes relating to individual members; a step of generating a superimposed grid from the read out member meshes; and a mesh in the superimposed lattice, wherein the member joining surface on one member side and the other joining with the member joining surface And processing a mesh corresponding to a space sandwiched by the member-joining surfaces on the member side as a mesh that is not applicable to the numerical analysis calculation.

According to a fourth aspect of the present invention, there is provided a mesh processing method for computer numerical analysis using a superimposed grid, wherein a step of reading member meshes relating to individual members, in which a member shape and a space around the members are represented by a mesh, Generating a superimposed grid from the member mesh, and the mesh in the superimposed grid, if the distance between the opposed surface regions of the pair of members is less than or equal to an allowable value,
A step of determining the surface area as a member joining surface; and a mesh corresponding to a space sandwiched between the member joining surface on one member side and the member joining surface on the other member side joined to this member joining surface, And processing the mesh as a mesh that is not applied to the analysis calculation.

[0011] In the fourth invention, for a superimposed grid generated from a member mesh in which the plate thickness is not considered,
It is preferable that the method further includes a step of calculating an allowable value based on the plate thickness of each member.

According to a fifth aspect of the present invention, there is provided a mesh processing method for computer numerical analysis using a superimposed grid, wherein the member shape and the space around the member are represented by a mesh and at least one layer representing the space around the member. Having the spatial mesh of and the first closest to the member surface
The step of reading out the member mesh for each member, the height of the spatial mesh of the layer being set to be equal to or greater than the predetermined member gap, the step of generating a superimposed grid from the read out member mesh, If there is a space in which the surface of the member on the other member side is located in the space mesh of the first layer on the one member side, a step of determining a surface region that spatially corresponds to this space as the member joining surface; In the superimposed grid, the mesh corresponding to the space sandwiched between the member joining surface on one member side and the member joining surface on the other member joining to this member joining surface is treated as a mesh not applicable to numerical analysis calculation. And a mesh processing method.

According to a sixth aspect of the present invention, there is provided a mesh processing method for computer numerical analysis using a superimposed grid, wherein a member shape and a space around the member are represented by a mesh and a gap between member joints is filled. Provided is a mesh processing method that includes a step of reading out a member mesh for each member and a step of generating a superimposed grid from the read out member mesh, in which at least a plate thickness at a member joining portion is set to be larger than an actual plate thickness. .

Further, a seventh invention is a computer readable recording medium, wherein a superimposed grid is generated from member meshes relating to individual members, in which member shapes and spaces around the members are represented by meshes,
Applying a numerical analysis calculation to a mesh in the superimposed grid, the mesh corresponding to a space sandwiched between the member joining surface on one member side and the member joining surface on the other member side joined to this member joining surface And a computer-readable recording medium storing a program for executing a mesh generation method for generating a computer numerical analysis mesh, the method comprising:

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS [System Configuration] FIG. 1 is a configuration diagram of a mesh processing system. The mesh processing system includes a computer 1, an input device 2 such as a keyboard and a mouse, a display device 3 such as a CRT and a liquid crystal display, and a storage device 4 such as a magnetic disk. The computer 1 includes a CPU, a RAM, a ROM, an input / output interface, and the like, and performs a mesh process described later. Based on the information displayed on the display device 3,
The operator operates the input device 2 to specify a mesh element (cell) or a region, input a numerical value, or the like. further,
The storage device 4 stores member mesh data, overlapping grid data, and the like for each member.

Here, the member mesh expresses the shape of a member and the space around the member by a mesh. FIG. 2A is a diagram illustrating an example of a member mesh. The member mesh 5 includes a member surface 6 (mesh area indicated by hatching) representing a surface shape of the member and a space mesh 7 representing a space around the member. Member surface 6
Can be defined, for example, by setting a specific boundary name indicating a boundary between a certain member and a space as a boundary condition between adjacent meshes. The member surface 6 may be defined by setting a value that can specify the member as a material property value set for each mesh element. The number of layers of the space mesh 7 is appropriately set based on the required analysis accuracy of the space, and the space mesh 7 closest to the member surface 6 is set.
Is referred to as a “first layer spatial mesh” (hereinafter, the second layer and the third layer are continued). The superimposed grid is generated by superposing a plurality of member meshes 5 and is used as an electrodeposition coating analysis mesh.

[First Embodiment] FIG. 3 is a flowchart showing a procedure for generating a superimposed grid according to the first embodiment. First, in step 1, the computer 1 reads out the member mesh 5 on which member joining surfaces are set from the storage device 4. Here, the “member joining surface” refers to a member surface corresponding to a portion (for example, a flange portion) joined to another member. In the present embodiment, this member joining surface is specified in advance by the operator. The operator operates the input device 2 while watching the member mesh 5 (FIG. 2A) displayed on the display device 3, and on the member surface 6,
An area to be a joining surface with another member is designated.

In response to this, the computer 1 starts to operate as shown in FIG.
The region designated by the operator as shown in FIG. Specifically, a process of changing the boundary name or the material property value of the member joining surface 8 is performed so that the member joining surface 8 can be distinguished from the other member surfaces 6 in the same member. For example, when the mesh boundary between the member body and the space is specified as the boundary name “A”,
The boundary name for the member joining surface 8 is changed from “A” to “A ′”. On the other hand, when changing the material property value, the material property value related to the member joining surface 8 is changed from the material property value “B” related to the member surface 6 to “B ′” different therefrom. Here, the “material characteristic value” is a parameter capable of specifying the attribute (name) and physical properties (plate thickness, elastic modulus, etc.) of the member,
Basically, the same material characteristic value is set for each element constituting the same member. In this way, by making the boundary name or the material property value relating to the member joining surface 8 different from that of the member surface 6, it becomes possible to recognize the member joining surface 8 on the system side.

Next, in step 2, the computer 1 superimposes the read-out member meshes to generate a superimposed grid. As an example, a calculation target of the electrodeposition coating analysis having the shape of FIG. 4 will be described. An electrodeposition coating liquid (diluted water-soluble coating liquid) is stored in the electrodeposition coating liquid tank 10, and an anode plate and a cathode plate (not shown) are arranged at a predetermined interval. Further, in the liquid tank 10, an object 11 to be coated composed of three members is disposed in a state where the whole is immersed in the electrodeposition coating liquid. When a potential difference is applied between the anode plate and the object to be coated to make the object to be coated 11 negatively charged, a water-insoluble coating film is formed on the surface of the object to be coated 11 by electrophoresis of the coated particles. You.

FIG. 5 is a view showing each member mesh and the liquid tank mesh. The electrodeposition coating analysis mesh is formed by superimposing three member meshes 5a to 5c constituting the object 11 and a liquid tank mesh 13 in which square elements are arranged in a matrix in plan view. . The member joining surfaces 8 described above are set in advance in the individual member meshes 5a to 5c.

In generating the electrodeposition coating analysis mesh (polymerized grid), first, the member meshes 5a to 5c and the liquid tank mesh 13 are polymerized while maintaining the positional relationship for forming the object 11 to be coated. . FIG. 6 is a diagram showing the superposed lattice 14 thus obtained, and FIG. 7 is an enlarged view of a part A thereof. Next, the overlapping meshes in the overlapping grid 14 are removed. Specifically, for example, in a region where the meshes overlap each other in FIG. 7, for example, only the member mesh whose distance from the member surface 6 is short is deleted, and the others are deleted. As a result, as shown in FIG. 8, a region where no mesh exists exists between each member mesh. Then, as shown in FIG. 9, a new mesh is formed in this area, and the completed overlapped grid 14 is used as an electrodeposition coating analysis mesh. It should be noted that the above-described correction processing of the region where the meshes overlap with each other can be performed after processing of a joint portion described later (the same applies to the second to fourth embodiments).

In step 3, the computer 1
A space mesh 7 sandwiched between a pair of member joining surfaces 8 joined to each other is set as a dead mesh. here,
"Dead mesh" refers to a mesh that is not applicable to numerical analysis calculations. For example, in the potential distribution analysis calculation,
The potential state for the Dead mesh is not calculated (it is treated like an insulator). For example, in the mesh state shown in FIG. 10, the member joining surface 8 set on the surface of the member A
A mesh group (hatched area) corresponding to a space sandwiched by the member B and the member joining surface 8 ′ set on the surface of the member B is set as the Dead mesh 15.

In accordance with the determination in the subsequent step 4, the above-described Dead mesh processing (step 3) is performed on all the member joining surfaces 8 existing in the overlapping grid 14.
Then, when the processing for all the member joining surfaces 8 is completed, the overlap grid 14 subjected to the Dead mesh processing is output as output data (step 5) and stored in the storage device 4.

According to the present embodiment, a space mesh 7 sandwiched between a pair of adjacent member joining surfaces 8, such as a flange portion, is converted into a Dead mesh, and the area is treated as not being applied to the numerical analysis calculation. Thereby, the overlapping grid 14
Even if there is a small gap in the numerical calculation, the small gap is filled by the Dead mesh 15,
The numerical analysis accuracy can be improved.

Further, by setting the member joining surface 8 in the member mesh 5 serving as input data in advance, the dead mesh 1 which is not applicable to the numerical calculation in the overlapped grid 14 can be obtained.
5 can be specified automatically. Therefore, it is not necessary to set the dead mesh 15 every time the overlapping grid 14 is generated, so that the working efficiency can be improved and the time for generating the overlapping grid 14 can be shortened. As a result, the electrodeposition coating analysis is simplified, and the development of a vehicle body structure excellent in rust prevention can be efficiently performed.

It should be noted that the mesh processing according to the present embodiment
The present invention can also be applied to a member mesh that does not consider the thickness of the member (for example, a mesh in which a space mesh is formed around an FEM mesh located on a member center plane or a member reference plane (CAD Surface)). In this case, the above-mentioned member joining surface 8 is set in advance on a mesh in which the thickness of the base plate is not considered. And the overlapping grid 14
In the above, a mesh corresponding to a space sandwiched between the member joining surface 8 on one member side and the member joining surface 8 on the other member side joined thereto is treated as a Dead mesh.

[Second Embodiment] In the first embodiment described above, prior to the Dead meshing process of the overlapping grid 14,
It is necessary to specify the member joining surface 8 in the member mesh 5 in advance. On the other hand, in the present embodiment, such designation of the member joining surface 8 is not required, and the member joining surface 8 is automatically specified based on the mesh state of the heavy lattice 14.

FIG. 11 is a flowchart showing a procedure for generating a superimposed grid according to the second embodiment. First, in step 11, the computer 1 reads out the member meshes 5 of the individual members constituting the structure to be analyzed. However, in the present embodiment, unlike the above-described first embodiment, the member mesh 5 (the member joining surface 8 is not set) shown in FIG. 2A is used. In the following step 12, the computer 1 superimposes the readout member meshes 5 to generate a superimposed grid 14.

In step 13, the computer 1
Calculates the distance L between the facing members in the surface region to be processed (one region (for example, one mesh element) on the member surface 6). This distance L can be calculated as the distance between the centers of gravity from the center of gravity of the surface area on one member side to the surface area of the other member side facing the center. For example, as shown in FIG. 12, when the surface area 6a of the member A is targeted, the center of gravity is first determined from the coordinates of each node constituting the surface area 6a. Next, on the member surface 6 'of the member B facing the member A, a plurality of surface regions 6a' to 6c 'existing near the position facing the surface region 6a.
Identify and determine these centers of gravity. And the surface area 6
The respective distances L1 to L3 from the center of gravity of “a” to the center of gravity of the surface regions 6a ′ to 6c ′ are calculated. Then, the minimum value (the distance L2 in the case shown) of the distances L1 to L3 between the centers of gravity is set to the distance L between the facing members in the surface region 6a.
And

In step 14, a value obtained by adding a predetermined margin α to the member gap δ assumed in the actual numerical analysis is set as the allowable value R of the member gap. As shown in FIG. 2, when the member mesh 5 in which the thickness of the member is considered is used, the allowable value R is set to a value corresponding to the margin α.

In step 15, it is determined whether or not the distance L is equal to or less than the allowable value R. If an affirmative determination is made in step 15, it is determined that the surface region 6a on the member A side and the surface region 6b 'on the member B side are joined to each other, and these surface regions 6a and 6b' are joined to the member joining surface 8 , 8 '(see FIG. 12). Then, a mesh corresponding to the space sandwiched between the set member joining surface pairs 8, 8 'is formed.
Set as Dead Mesh 15. On the other hand, if a negative determination is made in step 15, it is determined that the surface region 6 a on the member A side is not the member joining surface 8. In this case, the process skips steps 16 and 17 and proceeds to step 18.

In accordance with the determination in step 18, the distance L is calculated for all the surface regions existing in the overlapped grid 14 by the same method, and the calculated value is compared with the allowable value R. To identify. Then, a mesh corresponding to a space sandwiched between the pair of member joining surfaces 8 is formed into a Dead mesh. When all the Dead meshing processes are completed, the processed overlapping grid 14 is output as output data (step 19) and stored in the storage device 4.

According to the present embodiment, as in the first embodiment, since the dead mesh 15 is set in a small gap in the numerical calculation existing in the overlapping grid 14, the accuracy of the numerical analysis can be improved. it can. In addition, the member joining surface 8 necessary for setting the dead mesh 15 is automatically obtained from the mesh state of the overlapping grid 14, so that the working efficiency can be further improved.

It should be noted that the mesh processing according to the present embodiment
The present invention can also be applied to a superimposed grid 14 generated from a member mesh in which the thickness is not considered. The overlapping grid 14 shown in FIG. 13 is formed by overlapping the member mesh of the member A and the member mesh of the member B. Member A
Is formed by forming a plurality of layers of spatial mesh around the FEM mesh 16 whose thickness is not considered. This FEM mesh 16
Is formed on the center plane of the thickness of the member A, and the thickness D1 of the member A is not considered. Further, the member mesh of the member B is formed by forming a plurality of layers of space mesh around the FEM mesh 16 'whose thickness is not considered. This FEM mesh 16 'is a member B
The thickness D2 of the member B is not considered. In the superimposed grid 14 generated from such a member mesh, the computer 1 calculates the distance L between the opposing members with respect to a certain surface region 16a on the FEM mesh 16 from the distance between the centers of gravity described above.

For the superimposed grid 14 generated from the member mesh in which the plate thickness is not taken into account, the individual members A and B
The allowable value R is calculated based on the plate thicknesses D1 and D2 (step 14). In this case, the member gap δ is equivalent to half the plate thickness of the member A (1/2 · D1) and half the plate thickness of the member B (1/2 · D1).
D2), and a value obtained by adding a margin α to this value is set as the allowable value R of the member gap. If such an allowable value R is appropriately set, the Dead mesh 15 is automatically set even for the overlapping grid 14 generated from the member mesh in which the plate thickness is not considered according to the flowchart shown in FIG. can do.

[Third Embodiment] FIG. 14 is a flowchart showing a procedure for generating a superimposed grid according to the third embodiment. First, in step 21, the computer 1
Reads out the member mesh 5 of each member constituting the structure to be analyzed. In the present embodiment, the member mesh (the member joining surface 8 is not set) shown in FIG. That is, as shown in FIG.
The height H of the first layer spatial mesh 7a closest to the member surface 6 is adjusted in advance so as to be equal to or greater than the above-described member gap δ. In the following step 22, the computer 1
Superimposes each of the modified member meshes 5 to generate a superimposed grid 14.

In step 23, it is determined whether or not the member surface 6 exists in the spatial mesh 7a of the first layer. As described above, the height H of the first layer spatial mesh 7a is intentionally adjusted so as to be equal to or larger than the member gap δ. Therefore, when the member surface 6 exists in the space mesh 7a of the first layer, it can be determined that the space is originally a portion where the member joining surfaces 8 should be joined. If an affirmative determination is made in step 23, a surface region that spatially corresponds to such a space is set as the member joining surface 8 (step 24). Then, this space in the first layer spatial mesh 7a is set as the Dead mesh 15. On the other hand, if a negative determination is made in step 23, steps 24 and 25 are skipped and the process proceeds to step 26.

According to the determination in step 26, the above-described determination is performed for all the first layer spatial meshes 7a existing in the overlapped grid 14, and the first layer spatial mesh 7a
In the space where the member surface 6 exists,
Make a mesh. And when all the processing is completed,
The processed overlapping grid 14 is output as output data (step 27) and stored in the storage device 4.

In the present embodiment, the spatial mesh 7 of the first layer
By setting the height H of a in consideration of the member gap δ, the member joining surface 8 is automatically determined, and the dead mesh 15
Is set. Thereby, the numerical analysis accuracy can be improved as in the above-described embodiments. Also,
Although it is necessary to tune the value of the height H of the space mesh 7a of the first layer to generate the member mesh 5, there is also an effect that the modification of the mesh generation software can be reduced. It should be noted that the mesh processing according to the present embodiment uses the overlapping grids 14 generated from the member meshes without considering the plate thickness.
Can also be applied to

[Fourth Embodiment] FIG. 16 is a flowchart showing a procedure for generating a superimposed grid according to a fourth embodiment. First, in step 31, the computer 1
Reads out the member mesh 5 relating to the individual members constituting the structure to be analyzed. In the present embodiment, FIG.
Member mesh shown in (a) (member joining surface 8 is not set)
A slightly modified version is used.

More specifically, as shown in FIG. 17, the plate thickness of each member is set to be somewhat thick so as not to impair the analysis accuracy. By setting the member plate thickness to be larger than the actual one, the member joining surfaces 8 are forcibly overlapped with each other, so that the gap at the joining portion can be surely eliminated. From such a viewpoint, it is preferable to set only the plate thickness at the member joining surface 8 to be thicker than to set the plate thickness of the member as a whole. In the following step 32, the computer 1 superimposes each of the member meshes 5 whose member thickness has been corrected to generate the superimposed grid 14.

In step 33, it is determined whether or not there is a surface area that cuts into the inside of the member. If an affirmative determination is made in step 33, the surface region that has digged into the inside of the member is set as the member joining surface 8 (step 34). On the other hand, if a negative determination is made in step 33, step 34 is skipped and the process proceeds to step 35.

According to the judgment in step 35, after setting the surface area of the entire portion of the superimposed grid 14 that has been cut into the inside of the member as the member joining surface 8, the processed superimposed grid 14 is output as output data (step 36). Are stored in the storage device 4.

According to the present embodiment, by setting the plate thickness of each member to be slightly thicker than the actual plate thickness, it is possible to forcibly eliminate a gap that may occur in the member joining surface 8. In particular, when the overlapping grid 14 is generated from the member mesh in consideration of the plate thickness, the gap can be filled most reliably. There is also an effect that almost no modification of the mesh generation software is required.

The mesh processing according to each embodiment described above can be used for various computer numerical analysis meshes including heat flow analysis and electric field analysis in addition to the electrodeposition coating analysis mesh described above. is there.

Further, a recording medium on which a computer program for realizing the functions of the above-described embodiment is recorded is shown in FIG.
May be supplied to a system having such a configuration. In this case, the object of the present invention can be achieved by causing the computer 1 in this system to read and execute a computer program stored in a recording medium. Therefore, since the computer program itself read from the recording medium realizes the novel functions of the present invention, the recording medium on which the program is recorded constitutes the present invention. Examples of the recording medium on which the computer program is recorded include a CD-ROM, a floppy (registered trademark) disk, a hard disk, a memory card, an optical disk, a DVD-ROM, a DVD-RAM, and the like.

[0047]

According to the present invention, by lowering the analysis accuracy due to minute gaps that can occur in numerical calculations, by processing the joints between members in the superimposed grid formed from the member mesh. be able to.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a mesh processing system.

FIG. 2 is a view showing an example of a member mesh;

FIG. 3 is a flowchart showing a procedure for generating a superimposed grid in the first embodiment.

FIG. 4 is a diagram showing a shape to be calculated in an electrodeposition coating analysis.

FIG. 5 shows a member mesh and a liquid tank mesh.

FIG. 6 is a diagram showing a superimposed grid.

FIG. 7 is an enlarged view of a portion A.

FIG. 8 is a diagram showing a state where an overlapped mesh is removed.

FIG. 9 is a diagram showing a state in which a mesh has been generated in a spatial domain;

FIG. 10 is an explanatory diagram of Dead mesh processing in the first embodiment.

FIG. 11 is a flowchart showing a procedure for generating a superimposed grid in the second embodiment.

FIG. 12 is an explanatory diagram of Dead mesh processing in the second embodiment.

FIG. 13 is a diagram showing a superimposed grid generated from a member mesh in which the thickness is not considered.

FIG. 14 is a flowchart showing a procedure for generating a superimposed grid in the third embodiment.

FIG. 15 is a diagram showing a member mesh according to the third embodiment.

FIG. 16 is a flowchart showing a procedure for generating a superimposed grid in the fourth embodiment.

FIG. 17 is a diagram showing a state of being cut into a member;

[Explanation of symbols]

 Reference Signs List 1 computer, 2 input device, 3 display device, 4 storage device, 5 member mesh, 6 member surface, 7 space mesh, 8 member joining surface, 10 electrodeposition coating liquid tank, 11 object to be coated, 13 liquid tank mesh, 14 Overlaid grid, 15 Dead mesh, 16 FEM mesh

Claims (12)

[Claims] 1. A mesh processing system for computer numerical analysis using a superimposed grid, comprising: a storage device for storing a member mesh for each member, in which a member shape and a space around the member are represented by a mesh; A plurality of member meshes are read out from the matrix to generate a superimposed lattice, and the meshes in the superimposed lattice, wherein the member bonding surface on one member side and the member bonding surface on the other member side bonded to the member bonding surface And a computer that processes a mesh corresponding to a space sandwiched by the above as a mesh to which the numerical analysis calculation is not applied. 2. The mesh processing system according to claim 1, wherein an area corresponding to a member joining surface is set in said member mesh in advance. 3. The computer according to claim 2, wherein, when the distance between the opposed surface regions of the pair of members is less than or equal to an allowable value, the computer determines the surface region as a member joining surface. 2. The mesh processing system according to 1. 4. The computer according to claim 1, further comprising: a superimposed grid generated from a member mesh in which the thickness is not considered.
The mesh processing system according to claim 3, wherein the permissible value is calculated based on a thickness of each member. 5. The member mesh has at least one layer of a space mesh representing the space around the member, and the height of the space mesh of the first layer closest to the member surface is higher than a predetermined member gap. The computer is configured such that, in the overlapping grid, when there is a space in which the surface of the member on the other member side is located in the space mesh of the first layer on the one member side, the space and the position are determined. The mesh processing system according to claim 1, wherein a surface region corresponding to the target is determined as a member joining surface. 6. A mesh processing system for computer numerical analysis using a superimposed grid, wherein a member shape and a space around the member are represented by a mesh, and a gap between member joints is filled.
A storage device that stores a member mesh for each member, in which at least a plate thickness at a member joining portion is set to be larger than an actual plate thickness, and a computer that reads a plurality of member meshes from the storage device and generates a superimposed grid And a mesh processing system comprising: 7. A mesh processing method for computer numerical analysis using a superimposed grid, wherein a member shape and a space around the member are represented by a mesh, and an area corresponding to a member joining surface is set in advance. Reading a member mesh related to the member of the above; generating a superimposed grid from the read member mesh; and a mesh in the superimposed grid, wherein the member joining surface on one member side and the other joining with the member joining surface And processing a mesh corresponding to a space sandwiched by the member joining surfaces on the member side as a mesh not applicable to the numerical analysis calculation. 8. A mesh processing method for computer numerical analysis using a superimposed grid, comprising: reading out member meshes relating to individual members, in which a member shape and a space around the member are represented by a mesh; Generating a superimposed grid, the mesh in the superimposed grid, if the distance between the opposed surface areas of the pair of members is less than or equal to an allowable value,
Judging the surface area as a member joining surface; and, in the overlapping grid, corresponding to a space sandwiched between the member joining surface on one member side and the member joining surface on the other member joining with the member joining surface. And processing the mesh to be processed as a mesh to which the numerical analysis calculation is not applied. 9. The method according to claim 1, further comprising the step of calculating the permissible value based on the plate thickness of each member for a superimposed grid generated from a member mesh in which the plate thickness is not considered. A mesh processing method according to claim 8. 10. A mesh processing method for computer numerical analysis using a superimposed grid, wherein a member shape and a space around a member are represented by a mesh, and at least one layer of a space mesh representing the space around the member is represented by a mesh. A step of reading out the member meshes relating to the individual members, wherein the height of the spatial mesh of the first layer closest to the member surface is set to be equal to or greater than a predetermined member gap; And generating a superimposed grid from the above. In the superimposed grid, when there is a space where the member surface of the other member is located in the space mesh of the first layer on the one member side, the space corresponds to the space. Determining a surface region to be a member joining surface; and, in the overlapping grid, contacting the member joining surface of one member with the member joining surface. Processing a mesh corresponding to a space sandwiched between member joining surfaces of the other member to be joined as a mesh not applicable to the numerical analysis calculation. 11. A mesh processing method for computer numerical analysis using a superimposed grid, wherein a shape of a member and a space around the member are represented by a mesh, and a gap between member joints is filled.
A mesh comprising: a step of reading out a member mesh relating to an individual member, in which a plate thickness at least at a member joint is set to be larger than an actual plate thickness; and a step of generating a superimposed grid from the read member mesh. Processing method. 12. A computer-readable recording medium, comprising: generating a superimposed grid from member meshes relating to individual members, in which a member shape and a space around the member are represented by a mesh; A mesh corresponding to a space sandwiched between the member joining surface on one member side and the member joining surface on the other member joined to the member joining surface is processed as a mesh not applicable to the numerical analysis calculation. And a computer-readable recording medium storing a program for executing a mesh generation method for generating a computer numerical analysis mesh.