JP7259515B2 - How to create structure data - Google Patents

Description

The present invention relates to a method for creating structure data having cross-sectional shapes of structures.

In recent years, simulation methods for evaluating the performance of various structures using computers have been proposed. Generally, in the simulation method, first, it is necessary to create an analysis model from the structure. Patent Document 1 below describes a simulation method for a tire as a structure. In this method, a tire analysis model is created by discretizing members such as carcass plies and belt plies with a plurality of elements. Each element has defined material properties such as density and Young's modulus.

JP 2017-193315 A

By the way, when the cross-sectional shape of a structure is divided into a first region and a second region by a reference line, the cross-sectional shape includes symmetrical members arranged in the first region and the second region symmetrically with respect to the reference line, An asymmetrical member disposed in the first region and the second region asymmetrically with respect to the reference line may be included.

For symmetrical members, for example, after defining material properties for the symmetrical member in the first region, by copying those elements so as to be symmetrical about the reference line, the material properties of the symmetrical member in the second region can be easily obtained. can decide.

On the other hand, since the asymmetric member is asymmetrically arranged in the first region and the second region, even if the asymmetric member in the first region is simply copied in a symmetrical shape, the material properties of the asymmetric region in the second region are determined. Can not. Therefore, it is necessary to define material properties for both the asymmetric member in the first region and the asymmetric member in the second region. Therefore, there is a problem that it takes a lot of time to create an analysis model.

SUMMARY OF THE INVENTION The present invention has been devised in view of the actual situation as described above, and a main object of the present invention is to provide a method capable of creating structure data including an analysis model in a short period of time.

The present invention is a method for creating structure data having a cross-sectional shape of a structure using a computer, wherein the cross-sectional shape can be divided into a first region and a second region by a reference line. wherein the cross-sectional shape is composed of symmetrical members arranged in the first region and the second region symmetrically with respect to the reference line, and the first region and the second region made of the same material but asymmetrically with respect to the reference line. wherein the method includes defining material properties in the first region; and wherein the computer determines the material properties of the asymmetric member in the second region to the first region. and determining with reference to information including the material properties of the asymmetric member.

In the structure data creation method according to the present invention, the determining step refers to the area of the asymmetric member in the second region and the information on the asymmetric member in the first region that is most similar. There may be.

In the structure data creation method according to the present invention, the step of determining includes determining the position of the center of gravity of the asymmetric member in the second region that is closest to the symmetrical position of the center of gravity of the asymmetric member with respect to the reference line. The information of the asymmetric member may be referred to.

The method for creating structure data according to the present invention may further include the step of discretizing the first area and the second area with a plurality of elements.

In the structure data creation method according to the present invention, the discretization step includes discretizing the first region with a plurality of elements and discretizing the asymmetric member in the second region by determining by reference to information including the shape of the elements of the asymmetric member of a region.

In the structure data creation method according to the present invention, the structure may be a tire.

The present invention is a method for creating structure data having a cross-sectional shape of a structure using a computer. The cross-sectional shape can be divided into a first region and a second region by a reference line. The cross-sectional shape is made of the same material as a symmetrical member arranged symmetrically in the first region and the second region with respect to the reference line, but arranged in the first region and the second region asymmetrically with respect to the reference line. and an asymmetric member.

The method of the present invention includes the steps of defining material properties in the first region, and wherein the computer defines the material properties of the asymmetric member in the second region and the material properties of the asymmetric member in the first region. It includes a step of referring to the information and making a decision.

As a result of extensive research, the inventors have found that the asymmetric member in the first region and the asymmetric member in the second region have common material properties, and the reference line We have found that they are often related in their shape, although they are not symmetrical with respect to . Based on such knowledge, in the method of the present invention, the material properties of the asymmetric member in the second region are determined by referring to information including the material properties of the asymmetric member in the first region. . Therefore, in the creation method of the present invention, the step of defining material properties for the asymmetric member in the second region can be omitted, so that structure data whose material properties are determined can be created in a short time.

It is a perspective view which shows an example of the computer for performing the preparation method of structure data. It is a figure which shows an example of the cross-sectional shape of the structure from which structure data are produced. 4 is a flow chart showing an example of a processing procedure of a structure data creation method; It is a figure which shows the outline of the cross-sectional shape of a structure partially. FIG. 5 is an enlarged view of FIG. 4; It is a flowchart which shows an example of the processing procedure of a 1st determination process. It is a flowchart which shows an example of the processing procedure of a 2nd determination process. It is a flowchart which shows an example of the processing procedure of the 2nd determination process of other embodiment of this invention. It is a flow chart which shows an example of the processing procedure of the 2nd decision process of further another embodiment of the present invention. It is a flowchart which shows an example of the processing procedure of the preparation method of the structure data of other embodiment of this invention. It is a figure which shows an example of a FEM analysis model (structure data). 9 is a flow chart showing an example of a processing procedure of a discretization step according to another embodiment of the present invention; It is a figure which shows an example of the 1st area|region discretized by the finite number of elements. It is a flowchart which shows an example of the processing procedure of a 3rd determination process. (a) is a diagram for explaining a state before information including the shape of the element of the symmetrical member in the first region is copied; It is a figure explaining the state which was made. It is a flowchart which shows an example of the process procedure of 4th determination process S95. (a) is a diagram for explaining a state before information including the shape of the element of the asymmetric member in the first region is copied; FIG. 13(c) is a diagram illustrating a state in which the non-overlapping regions of the second region are discretized; FIG.

An embodiment of the present invention will be described below with reference to the drawings.
In the structure data creation method (hereinafter, sometimes simply referred to as "method") of the present embodiment, a computer is used to create structure data having a cross-sectional shape of a structure. The structure data includes, for example, design data (CAD data) and analysis models used for FEM and the like, but is not limited to such aspects.

FIG. 1 is a perspective view showing an example of a computer 1 for executing the structure data creation method. A computer 1 includes a main body 1a, a keyboard 1b, a mouse 1c, and a display device 1d. The main body 1a is provided with an arithmetic processing unit (CPU), a ROM, a working memory, a storage device (not shown) such as a magnetic disk, disk drive devices 1a1 and 1a2, and the like. A processing procedure (program) for executing the method of the present embodiment is stored in advance in the storage device.

FIG. 2 is a diagram showing an example of a cross-sectional shape of a structure for which structure data is created. A tire 3 is exemplified as the structure 2 of the present embodiment.

The cross-sectional shape 4 of the structure 2 (tire 3 in this embodiment) can be divided into a first region 4A and a second region 4B by a reference line 5 (tire equator C in this embodiment). 4 A of 1st area|regions of this embodiment are cross-sectional shapes of the tire 3 of the one side of a tire axial direction with respect to the tire equator C. As shown in FIG. The second region 4B of the present embodiment is the cross-sectional shape of the tire 3 on the other side in the tire axial direction with respect to the tire equator C. As shown in FIG.

The cross-sectional shape 4 of the present embodiment includes a symmetrical member 6 and an asymmetrical member 7 (hereinafter, the symmetrical member 6 and the asymmetrical member 7 may be collectively referred to simply as "members"). . The symmetrical member 6 is arranged symmetrically with respect to the reference line 5 in the first region 4A and the second region 4B. On the other hand, the asymmetric member 7 is arranged asymmetrically with respect to the reference line 5 in the first region 4A and the second region 4B. Whether or not the structure is symmetrical with respect to the reference line 5 is determined based on the cross-sectional shape (the area surrounded by the outline) of the design data (CAD data) of the structure 2 and the like.

The symmetrical member 6 of this embodiment includes a sidewall rubber 12A, a clinch rubber 12B, an inner liner rubber 12C, a bead apex rubber 12D, a bead core 15, a carcass 16, and a belt layer 17.

The carcass 16 is arranged from the tread portion 3a to the bead core 15 of the bead portion 3c through the sidewall portion 3b. The carcass 16 is composed of at least one carcass ply 16A, two carcass plies 16B in this embodiment. The carcass plies 16A, 16B have carcass cords arranged at an angle of 75 to 90 degrees with respect to the tire equator C, for example. As described above, whether or not the structure is symmetrical with respect to the reference line 5 is determined based on the cross-sectional shape (the area surrounded by the outline) of the design data (CAD data) of the structure 2 and the like. Therefore, even if the carcass cords of the carcass plies 16A, 16B are not symmetrically arranged in the first region 4A and the second region 4B, the carcass plies 16A, 16B are classified as symmetrical members 6.

The belt layer 17 is arranged outside the carcass 16 in the tire radial direction and inside the tread portion 3a. The belt layer 17 includes inner and outer two belt plies 17A and 17B in which belt cords are arranged at an angle of, for example, 10 to 35 degrees with respect to the tire circumferential direction. These belt plies 17A and 17B are superimposed so that the belt cords intersect each other. Even if the belt cords of the belt plies 17A and 17B are not symmetrically arranged in the first region 4A and the second region 4B, the belt plies 17A and 17B are symmetrical from the same viewpoint as the carcass plies 16A and 16B. Sectioned as member 6 .

In the present embodiment, the sidewall rubber 12A (symmetrical member 6) arranged in the first region 4A and the sidewall rubber 12A (symmetrical member 6) arranged in the second region 4B are made of the same material (for example, the same material). compounded rubber). Similarly, the clinch rubber 12B, the inner liner rubber 12C, the bead apex rubber 12D, the bead core 15, the carcass ply 16A, and the belt plies 17A, 17B are also made of the same material in the first region 4A and the second region 4B. .

The asymmetric member 7 of this embodiment includes a tread rubber 12E. A main groove 19 continuously extending in the tire circumferential direction is provided on the outer surface of the tread rubber 12E. Thereby, the tread rubber 12</b>E is provided with a plurality of land portions 20 separated by the main grooves 19 . The main groove 19 of this embodiment includes a pair of center main grooves 21 and a pair of shoulder main grooves 22 .

The center main grooves 21 are arranged on both outer sides of the tire equator C. As shown in FIG. The center main groove 21 includes a first center main groove 21A arranged on the first region 4A side and a second center main groove 21B arranged on the second region 4B side. The first center main groove 21A and the second center main groove 21B of this embodiment are set to have the same groove width, and are formed symmetrically with respect to the tire equator C (reference line 5).

The shoulder main groove 22 is arranged axially outside the center main groove 21 . The shoulder main grooves 22 include first shoulder main grooves 22A arranged on the first region 4A side and second shoulder main grooves 22B arranged on the second region 4B side. The first shoulder main groove 22A and the second shoulder main groove 22B of this embodiment are set to have different groove widths, and are formed asymmetrically with respect to the tire equator C (reference line 5). Due to these first shoulder main grooves 22A and second shoulder main grooves 22B, the tread rubber 12E on the first region 4A side and the tread rubber 12E on the second region 4B side are asymmetric with respect to the tire equator C (reference line 5). is distributed to

In the present embodiment, the tread rubber 12E (asymmetric member 7) arranged in the first region 4A and the tread rubber 12E arranged in the second region 4B are made of the same material (in the present embodiment, the same compounded rubber). consists of

FIG. 3 is a flow chart showing an example of a processing procedure of a structure data creation method. In the method of this embodiment, first, the cross-sectional shape 4 (shown in FIG. 2) of the structure 2 is input to the computer 1 (step S1). FIG. 4 is a diagram showing the outline of the cross-sectional shape 4 of the structure 2. As shown in FIG. FIG. 5 is an enlarged view of FIG.

As shown in FIG. 4, the cross-sectional shape 4 input in step S1 includes a first region 4A and a second region 4B. The first area 4A and the second area 4B input to the computer 1 include an area 36 surrounded by the outline of the symmetrical member 6 and an area 37 surrounded by the outline of the asymmetrical member 7 . These areas 36 and 37 are defined by, for example, line data (CAD data or the like).

In the region 36 of the symmetrical member 6 of the first region 4A, there are a region 36A of the sidewall rubber 12A (shown in FIG. 2) of the first region 4A and a region 36B of the clinch rubber 12B (shown in FIG. 2) of the first region 4A. , a region 36C of the inner liner rubber 12C (shown in FIG. 2) of the first region 4A, and a region 36D of the bead apex rubber 12D (shown in FIG. 2) of the first region 4A.

Further, the region 36 of the symmetrical member 6 of the first region 4A includes a region 36E of the bead core 15 (shown in FIG. 2) of the first region 4A and the carcass plies 16A, 16B (shown in FIG. 2) of the first region 4A. and regions 36H, 36J of the belt plies 17A, 17B (shown in FIG. 2) of the first region 4A.

Region 37 of asymmetric member 7 of first region 4A includes region 37E of tread rubber 12E (shown in FIG. 2) of first region 4A. The cross-sectional shape of the structure 2 is stored in the computer 1. FIG.

Next, in the method of this embodiment, the computer 1 defines material properties in the first area 4A (step S2). In step S2, the material properties of the symmetrical member 6 of the structure 2 shown in FIG. 2 are respectively defined in the region 36 of the symmetrical member 6 of the first region 4A. Furthermore, in step S2, the material properties of the asymmetric member 7 of the structure 2 shown in FIG. 2 are defined respectively in the region 37 of the asymmetric member 7 of the first region 4A.

The material properties of the sidewall rubber 12A (shown in FIG. 2) are defined in the region 36A of the sidewall rubber 12A (shown in FIG. 2) in the first region 4A. The material properties of the clinch rubber 12B (shown in FIG. 2) are defined in the region 36B of the clinch rubber 12B (shown in FIG. 2) in the first region 4A. A region 36C of the inner liner rubber 12C (shown in FIG. 2) in the first region 4A defines material properties of the inner liner rubber 12C (shown in FIG. 2). A region 36D of the bead apex rubber 12D (shown in FIG. 2) of the first region 4A defines the material properties of the bead apex rubber 12D (shown in FIG. 2). These material properties include, for example, density, elastic modulus, loss tangent, damping coefficient or isotropic coefficient of thermal expansion.

The material properties of the bead core 15 (shown in FIG. 2) are respectively defined in the regions 36E of the bead core 15 (shown in FIG. 2) in the first region 4A. The material properties of the carcass plies 16A, 16B (shown in FIG. 2) are defined in the regions 36F, 36G of the carcass plies 16A, 16B (shown in FIG. 2) of the first region 4A, respectively. The material properties of the belt plies 17A, 17B (shown in FIG. 2) are defined in the regions 36H, 36J of the belt plies 17A, 17B (shown in FIG. 2) of the first region 4A, respectively. These material properties include, for example, modulus of elasticity, coefficient of thermal expansion along the length of the cord, and the like.

A region 37E of the tread rubber 12E (shown in FIG. 2) of the first region 4A contains the material properties of the tread rubber 12E (shown in FIG. 2), such as density, elastic modulus, loss tangent, damping coefficient, or isotropic properties. coefficient of thermal expansion, etc.) are defined respectively. These material properties are stored in computer 1 .

Next, in the method of this embodiment, the computer 1 selects one member (the symmetrical member 6 or the asymmetrical member 7) in the second area 4B shown in FIGS. 2 and 4 (step S3). In step S3 of this embodiment, the members of the second region 4B (in this embodiment, the region 36A of the sidewall rubber 12A (shown in FIG. 2), the region 36B of the clinch rubber 12B (shown in FIG. 2), the inner liner rubber 12C region 36C (shown in FIG. 2), region 36D of bead apex rubber 12D (shown in FIG. 2), region 36E of bead core 15 (shown in FIG. 2), region 36F of carcass plies 16A, 16B (shown in FIG. 2). , 36G, regions 36H, 36J of belt plies 17A, 17B (shown in FIG. 2), and region 37E of tread rubber 12E (shown in FIG. 2)). Such selection may be made randomly or may be made based on a predetermined procedure. Whether the selected member is the symmetrical member 6 or the asymmetrical member 7 is determined in the next step S4.

Next, in the method of this embodiment, the computer 1 determines whether or not the selected member (the symmetrical member 6 or the asymmetrical member 7) of the second area 4B is the symmetrical member 6 (step S4). In step S4 of the present embodiment, the area of the selected member in the second region 4B is compared with the area of each member (the symmetrical member 6 and the asymmetrical member 7) in the first region 4A, and the selected second It is determined whether the member in area 4B is the symmetrical member 6 or not. The area of each member in this embodiment is calculated as the area of regions 36 and 37 surrounded by the contours of those members in the cross-sectional shape 4 shown in FIG. Then, in step S4, it is determined whether or not a member having the same area as the member (the symmetrical member 6 or the asymmetrical member 7) of the second region 4B exists in the first region 4A.

When the selected member of the second region 4B is the symmetrical member 6 (for example, the region 36A of the sidewall rubber 12A (shown in FIG. 2), etc.), the selected second region in the first region 4A There is a member (ie symmetrical member 6) that has the same area as the member of 4B. Therefore, in step S4, if there is a member having the same area as the member (the symmetrical member 6 or the asymmetrical member 7) of the selected second region 4B in the first region 4A, the selected member of the second region 4B The member is determined to be the symmetrical member 6 ("Y" in step S4). In this case, the following first determination step S5 is performed.

On the other hand, if the selected member of the second region 4B is the asymmetric member 7 (for example, the region 37E of the tread rubber 12E (shown in FIG. 2) colored in FIG. 5), then the first region 4A , there is no member having the same area as the member of the selected second region 4B. Therefore, in step S4, if there is no member having the same area as the selected member of the second region 4B (the symmetrical member 6 or the asymmetrical member 7) in the first region 4A, the selected member of the second region 4B is not the symmetrical member 6 (that is, it is the asymmetrical member 7) ("N" in step S4). In this case, the following second determination step S6 is performed.

Thus, in step S4, by comparing the area of the selected member in the second region 4B and the area of each member in the first region 4A (the symmetrical member 6 and the asymmetrical member 7), the selected Whether or not the member of the second region 4B is the symmetrical member 6 can be reliably determined.

In step S4 of the present embodiment, the area of each member in the first region 4A and the area of each member in the second region 4B are compared to determine whether the selected member in the second region 4B is the symmetrical member 6. Although it was determined whether or not, it is not limited to such an aspect. For example, the coordinate value of the contour of each member in the first region 4A may be compared with the coordinate value of the contour of each member in the second region 4B. (not shown) may be compared with the position of the center of gravity of each member in the second region 4B.

Next, in a first determination step S5, the computer 1 determines the material properties of the symmetrical member 6 of the second region 4B. In the first determination step S5 of the present embodiment, the information including the material properties of the symmetrical member 6 in the first area 4A is copied to determine the material properties of the symmetrical member 6 in the second area 4B. FIG. 6 is a flow chart showing an example of the processing procedure of the first determination step.

In the first determination step S5 of the present embodiment, first, the selected symmetrical member 6 in the second region 4B (regions 36A to 36J) and the symmetrical member 6 in the first region 4A that is symmetrical with respect to the reference line 5 (region 36A 36J) is identified (step S51). In the present embodiment, the member of the first region 4A determined to have the same area as the selected member of the second region 4B in step S4 is specified as the symmetrical member 6 of the first region 4A. The identified symmetry member 6 of the first area 4A is stored in the computer 1. FIG.

Next, in the first determination step S5 of the present embodiment, the information including the material properties of the identified region 36 of the symmetrical member 6 of the first region 4A is transferred to the selected region 36 of the symmetrical member 6 of the second region 4B. (step S52).

In step S52, the material properties of the symmetrical member 6 of the selected second region 4B are determined with reference to the material properties defined in the regions 36 (36A-36J) of the symmetrical member 6 of the identified first region 4A. (definition) The symmetry members 6 of the second area 4B are stored in the computer 1. FIG.

Accordingly, in the method of the present embodiment, for example, the operator does not need to define material properties for the region 36 (36A to 36J) of the symmetrical member 6 of the second region 4B. Six regions 36 (36A-36J) can be defined in a short time.

Next, in the second determination step S6 of the present embodiment, the computer 1 determines material properties of the asymmetric member 7 in the second region 4B. As a result of extensive research, the inventors have found that the asymmetric member 7 of the first region 4A shown in FIG. 5 and the asymmetric member 7 of the second region 4B have commonalities in material properties. and are not symmetrical about the reference line 5, but are often related in their shape (e.g. shape, area and/or centroid position are close to each other). Based on such knowledge, in the second determination step S6 of the present embodiment, the material properties of the asymmetric member 7 in the second region 4B are determined with reference to information including the material properties of the asymmetric member 7 in the first region 4A. have decided.

In the second determination step S6 of the present embodiment, information including the area of the asymmetric member 7 in the second region 4B and the closest material properties of the asymmetric member 7 in the first region 4A is referred to. FIG. 7 is a flow chart showing an example of the processing procedure of the second determination step S6.

In the second determination step S6 of the present embodiment, first, the area of the asymmetric member 7 in the second region 4B and the asymmetric member 7 in the first region 4A that is most similar are identified (step S61). In step S61, as shown in FIG. 5, the area of the region 37 of the asymmetric member 7 in the selected second region 4B, the region 36 of each member (the symmetric member 6 and the asymmetric member 7) of the first region 4A, 37, and the region of the member of the first region 4A that is most similar to the area of the region 37 of the asymmetric member 7 of the selected second region 4B is the region of the asymmetric member 7 of the first region 4A. 37. By such a procedure, in step S61, from the plurality of members (the symmetrical member 6 and the asymmetrical member 7) of the first region 4A, the asymmetrical member 7 of the second region 4B and the asymmetrical member 7 of the second region 4B having a shape relationship The member 7 can be specified with high accuracy. The identified asymmetric member 7 in the first region 4A is stored in the computer 1. FIG.

In step S61, the difference ( absolute value) is within a predetermined allowable range, the asymmetric member 7 (region 37) of the first region 4A is preferably identified. As a result, in step S61, it is possible to prevent the asymmetric member 7 in the first region 4A from being specified, which is greatly different from the area of the asymmetric member 7 in the second region 4B. , the asymmetric member 7 in the first region 4A having relevance to can be specified with higher accuracy.

Next, in the second determination step S6 of the present embodiment, the material properties of the asymmetric member 7 in the second region 4B are determined with reference to information including the material properties of the asymmetric member 7 in the first region 4A (step S62).

In step S62, the material properties of the asymmetric member 7 (region 37) of the selected second region 4B are determined with reference to the material properties defined for the region 37 of the asymmetric member 7 of the identified first region 4A ( definition). The asymmetric member 7 of the second area 4B is stored in the computer 1. FIG.

Thus, the method of the present embodiment does not require the operator to define material properties for the region 37 (37E) of the asymmetric member 7 of the second region 4B, for example. A region 37 can be defined in a short time.

Next, in the method of this embodiment, the computer 1 determines whether or not all the members (the symmetrical members 6 or the asymmetrical members 7) in the second region 4B shown in FIGS. 4 and 5 have been selected (step S7). If it is determined in step S7 that all the members of the second region 4B have been selected ("Y" in step S7), the material properties of all the members of the second region 4B have been determined. As a result, the method of this embodiment has the cross-sectional shape of the structure (the tire 3 in this embodiment), and the material properties are defined for all the members of the first region 4A and the second region 4B Structure data 10 (shown in FIGS. 4 and 5) can be created.

On the other hand, if it is determined in step S7 that all the members (symmetrical members 6 or asymmetrical members 7) in the second region 4B shown in FIGS. 4 and 5 have not been selected (“N” in step S7). , one member of the second region 4B that has not yet been selected is selected (step S8), and steps S4 to S7 are performed again. This allows the method of the present embodiment to determine the material properties of all members of the second region 4B. Therefore, according to the method of the present embodiment, a structure having the cross-sectional shape of the structure (the tire 3 in the present embodiment) and having material properties defined for all members of the first region 4A and the second region 4B Object data (design data including CAD data) 10 can be created reliably.

In the structure 2 of the present embodiment, the first region 4A and the second region 4B of the symmetrical member 6 and the asymmetrical member 7 are made of the same material. A part made of a material different from that of the region 4B may be included. In such a case, in step S52 shown in FIG. 6, since the original material properties cannot be defined for the symmetrical member 6 in the second region 4B, the original material specification is defined by the operator after step S7. good too.

If there are a plurality of asymmetric members 7 in the first region 4A that are most similar in area to the asymmetric member 7 in the second region 4B, the asymmetric member 7 in the first region 4A is identified in step S61 shown in FIG. I can't. In such a case, the original material specification may be defined by the operator in step S62 since the material properties cannot be determined for the asymmetric member 7 in the second region 4B.

The structure data (for example, design data including CAD data) 10 created by the method of the present embodiment can be used, for example, for mass analysis of the structure 2 and simulation for evaluating the performance of the structure 2. can. The simulation procedure can be appropriately set according to the performance of the structure 2, for example.

In the step of evaluating the performance, if the performance of the structure 2 (the tire 3 of this embodiment) is determined to be good, the structure 2 is manufactured. On the other hand, if it is determined that the performance of the structure 2 is not good, the design of the structure 2 is changed, and the structure data 10 is created again based on the processing procedure shown in FIGS. be. Then, a simulation using the structure data 10 is performed again, and the performance of the structure 2 is evaluated. This ensures that a structure 2 (shown in FIG. 2) with good performance can be designed.

In the second determination step S6 of the present embodiment, the area of the asymmetric member 7 (region 37) in the second region 4B shown in FIGS. 4 and 5 and the closest asymmetric member 7 (region 37) in the first region 4A Reference was made to information including material properties of, but is not limited to such aspects. For example, as shown in FIG. 5, the asymmetry of the first region 4A having the center of gravity position 47 is closest to the symmetry position 46 with respect to the reference line 5 of the center of gravity position 45 of the asymmetric member 7 (region 37) of the second region 4B. Information including material properties of member 7 (region 37) may be referenced. FIG. 8 is a flow chart showing an example of the processing procedure of the second determination step S6 of another embodiment of the invention. In addition, in this embodiment, the same code|symbol is attached|subjected about the structure same as the previous embodiment, and description may be abbreviate|omitted.

In the second determination step S6 of this embodiment, first, as shown in FIG. The asymmetric member 7 (area 37) of the first area 4A having the center-of-gravity position 47 is identified (step S63). In step S63, first, the symmetrical position 46 of the asymmetrical member 7 in the selected second region 4B is obtained. Next, in step S63, the center-of-gravity position 47 of each member of the first region 4A (the region 36 of the symmetrical member 6 and the region 37 of the asymmetrical member 7) is specified. Next, in step S63, the distance between the selected symmetrical position 46 of the asymmetric member 7 in the second region 4B and the center-of-gravity position 47 of each member (the symmetrical member 6 and the asymmetrical member 7) in the first region 4A is calculated respectively.

Then, in step S63, based on the calculated distance, the member of the first region 4A having the center-of-gravity position 47 closest to the symmetrical position 46 of the asymmetric member 7 of the second region 4B is the asymmetric member of the first region 4A. 7 (area 37). Based on such a procedure, in step S63, from the plurality of members (the symmetrical member 6 and the asymmetrical member 7) of the first region 4A, the asymmetrical member 7 (region 37) of the second region 4B and the relationship in shape The asymmetric member 7 (area 37) in the first area 4A can be specified with high accuracy.

In step S63, the center-of-gravity position 47 of the member of the first region 4A located closest to the symmetrical position 46 of the asymmetrical member 7 of the second region 4B and the selected symmetrical position 46 of the asymmetrical member 7 of the second region 4B. is within a predetermined tolerance, the asymmetric member 7 in the first region 4A is preferably identified. As a result, in step S63, it is possible to prevent the asymmetric member 7 in the first region 4A from being specified which is greatly separated from the symmetrical position 46 of the asymmetric member 7 in the second region 4B. The asymmetric member 7 in the first region 4A having a relationship with the shape can be specified with higher accuracy.

In the embodiments so far, information including the area of the asymmetric member 7 in the second region 4B and the most approximate material properties of the asymmetric member 7 in the first region 4A, and the center-of-gravity position 45 of the asymmetric member 7 in the second region 4B Reference has been made to information including the material properties of the asymmetric member 7 of the first region 4A having the center of gravity position 47 closest to the symmetry position 46 with respect to the reference line 5 of , but is not limited to such an aspect. For example, for the symmetrical region 50 (shown in FIG. 5) with respect to the reference line 5 of the asymmetric member 7 in the second region 4B, the maximum and closest coordinate values on each coordinate axis (X-axis and Y-axis in this embodiment) Information including material properties of the asymmetric member 7 in the first region 4A may be referred to. FIG. 9 is a flow chart showing an example of the processing procedure of the second determination step S6 of still another embodiment of the present invention. In addition, in this embodiment, the same code|symbol may be attached|subjected about the structure same as an old embodiment, and description may be abbreviate|omitted.

In the second determination step S6 of this embodiment, first, as shown in FIG. The asymmetric member 7 of the first region 4A that is closest to the maximum value of the coordinate values of is specified (step S64). In step S64, first, the maximum coordinate value in the X-axis direction and the maximum coordinate value in the Y-axis direction of the symmetrical region 50 of the asymmetrical member 7 of the selected second region 4B are obtained. Next, in step S64, the maximum coordinate value in the X-axis direction and the coordinate value in the Y-axis direction of each member (the symmetrical member 6 (region 36) and the asymmetrical member 7 (region 37)) in the first region 4A are obtained respectively. Next, in step S64, the maximum coordinate value in the X-axis direction of the symmetrical region 50 of the asymmetric member 7 of the selected second region 4B and the X-axis of each member (regions 36, 37) of the first region 4A The difference (absolute value) from the maximum coordinate value of the direction, the maximum value of the Y-axis direction coordinate value of the symmetrical region 50 of the asymmetric member 7 of the selected second region 4B, and each of the first region 4A Differences (absolute values) from the maximum values of coordinate values in the Y-axis direction of the members (regions 36 and 37) are calculated.

Then, in step S64, based on the calculated difference in the X-axis direction and the calculated difference in the Y-axis direction, the maximum value of the coordinate values in the X-axis direction and the Y The asymmetric member 7 (region 37) of the first region 4A that is closest to the maximum coordinate value in the axial direction is identified. By such a procedure, in step S64, from the plurality of members (the symmetrical member 6 and the asymmetrical member 7) of the first region 4A, the asymmetrical member 7 of the second region 4B and the asymmetrical member 7 of the first region 4A having relationship in shape. The member 7 can be specified with high accuracy.

In step S64, the asymmetric member 7 in the first region 4A is desirably identified when the difference in the X-axis direction and the difference in the Y-axis direction are within a predetermined allowable range. As a result, in step S64, the asymmetry of the first region 4A greatly deviating from the maximum value of the coordinate values in the X-axis direction of the symmetry region 50 of the asymmetric member 7 in the second region 4B and the maximum value of the coordinate values in the Y-axis direction. Since it is possible to prevent the member 7 from being specified, the asymmetric member 7 in the first region 4A having a shape relationship with the asymmetric member 7 in the second region 4B can be specified with higher accuracy.

In the second determination step S6 of the previous embodiments, by performing any of step S61 (shown in FIG. 7), step S63 (shown in FIG. 8), and step S64 (shown in FIG. 9), The asymmetric member 7 of the first region 4A having a shape relationship with the asymmetric member 7 of the second region 4B was identified from the plurality of members (the symmetric member 6 and the asymmetric member 7) of the first region 4A. It is not limited to a specific aspect. For example, the asymmetric member 7 in the first region 4A may be specified by combining at least two steps of step S61, step S63, and step S64.

In this way, by combining step S61 (shown in FIG. 7), step S63 (shown in FIG. 8), and step S64 (shown in FIG. 9), for example, the asymmetric member of the first region 4A in step S61 7 cannot be identified (for example, when the area of the asymmetric member 7 (region 37) in the second region 4B and the members (regions 36, 37) in the first region 4A that approximate within the allowable range are identified) By performing at least one of Step S63 and Step S64, the asymmetric member 7 in the first region 4A having a shape relationship with the asymmetric member 7 in the second region 4B can be specified more reliably. It should be noted that the combination and execution order of the steps S61, S63, and S64 can be appropriately set according to the shape of the asymmetric member 7 in the second region 4B.

FIG. 10 is a flow chart showing an example of a processing procedure of a structure data creation method according to another embodiment of the present invention. In addition, in this embodiment, the same code|symbol may be attached|subjected about the structure same as an old embodiment, and description may be abbreviate|omitted. In the method of this embodiment, an FEM analysis model is created as structure data. FIG. 11 is a diagram showing an example of the FEM analysis model (structure data).

In the method of this embodiment, the computer 1 discretizes the first region 4A and the second region 4B shown in FIGS. 4 and 5 with a plurality of elements (discretization step S9). In the discretization step S9, for the first region 4A and the second region 4B, the region 36 surrounded by the outline of the symmetric member 6 and the region 37 surrounded by the outline of the asymmetric member 7 are obtained by the numerical analysis method shown in FIG. is discretized with a finite number of elements F(i) (i=1, 2, . . . ) that can be handled by . Thereby, the FEM analysis model 10A can be defined as the structure data 10. FIG.

As the numerical analysis method, for example, the finite element method, the finite volume method, the difference method, or the boundary element method can be appropriately adopted. In this embodiment, the finite element method is adopted. As the element F(i), for example, when the structure data 10 is set two-dimensionally, it is desirable to use a plane element such as a triangular element or a quadrilateral element. When the structure data 10 is set in three dimensions, it is desirable to use tetrahedral solid elements, pentahedral solid elements, hexahedral solid elements, or the like. Each element F(i) has multiple nodes 28 . Numerical data such as the element number, the number of the node 28, and the coordinate values of the node 28 are defined for each element F(i).

Such an FEM analysis model 10A can be used for simulation such as rolling calculation, for example, when the structure 2 is a tire 3 (shown in FIG. 2). As an example of such a simulation method, first, a two-dimensional FEM analysis model 10A is expanded in the tire circumferential direction to set a three-dimensional FEM analysis model (not shown), as in the conventional simulation. Then, a calculation is performed to roll the three-dimensional FEM analysis model on a road surface model (not shown) obtained by discretizing the road surface with a finite number of elements. As a result, the strain, stress, etc. associated with the deformation of the tire 3 are calculated, and for example, the deformed shape, vertical spring, rolling resistance, wear performance, etc. of the tire 3 (shown in FIG. 2) can be evaluated.

In the discretization step S9 of this embodiment, the first region 4A and the second region 4B are each discretized with the element F(i), but the present invention is not limited to such a mode. In the discretization step S9, after discretizing the symmetrical member 6 and the asymmetrical member 7 in the first region 4A with a plurality of elements F(i), the computer 1 discretizes the symmetrical member 6 and the asymmetrical member 7 in the second region 4B. may be determined with reference to the shapes of the elements F(i) of the symmetric member 6 and the asymmetric member 7 of the first region 4A. FIG. 12 is a flow chart showing an example of the processing procedure of the discretization step S9 according to another embodiment of the present invention.

In the discretization step S9 of this embodiment, first, the first region 4A is discretized with a plurality of elements F(i) (step S91). In step S91, the regions 36 and 37 surrounded by the contours of the symmetrical member 6 and the asymmetrical member 7 in the first region 4A shown in FIGS. (i=1, 2, . . . ) are discretized respectively. Element F(i) is as described in the previous embodiment. FIG. 13 is a diagram showing an example of the first region 4A discretized with a finite number of elements.

Next, in the discretization step S9 of this embodiment, the computer 1 selects one member (the symmetrical member 6 or the asymmetrical member 7) in the second region 4B shown in FIGS. 4 and 5 (step S92), It is determined whether or not the selected member (symmetrical member 6 or asymmetrical member 7) of the second region 4B is the symmetrical member 6 (step S93). Steps S92 and S93 are performed in the same procedure as steps S3 and S4 shown in FIG.

In step S93, it is determined that the selected member in the second region 4B is the symmetrical member 6 ("Y" in step S93). In this case, the following third determination step S94 is performed. On the other hand, if it is determined that the selected member in the second region 4B is the asymmetric member 7 ("N" in step S93), the following fourth determination step S95 is performed.

Next, in the third determination step S94, the discretization of the symmetrical members 6 in the second region 4B is determined by referring to information including the shapes of the elements of the symmetrical members 6 in the first region 4A. FIG. 14 is a flow chart showing an example of the processing procedure of the third determination step.

In the third determination step S94 of this embodiment, first, the selected symmetrical member 6 of the second region 4B and the symmetrical member 6 of the first region 4A that is symmetrical with respect to the reference line 5 are identified (step S11). Step S11 is performed in the same procedure as step S51 (shown in FIG. 6) of the first determination step S5.

Next, in the third determination step S94 of this embodiment, the information including the shape of the element F(i) of the symmetrical member 6 of the selected first region 4A is converted to the shape of the symmetrical member 6 of the selected second region 4B. It is copied to area 36 (step S12). FIG. 15(a) is a diagram for explaining the state before information including the shape of the element of the symmetrical member in the first area is copied. FIG. 15(b) is a diagram for explaining a state in which information including the shape of the element of the symmetrical member in the first area is copied. FIG. 15 illustrates the copying of information including the shape of element F(i) of region 36H of inner belt ply 17A (shown in FIG. 2).

In step S12, the selected element F(i) of the symmetrical member 6 in the first region 4A is symmetrical with respect to the reference line 5 (tire equator C). Copied to the area. As shown in FIG. 4, the symmetrical member 6 of the first region 4A (eg, the inner belt ply 17A (shown in FIG. 2) region 36) and the symmetrical member 6 of the second region 4B (eg, the inner belt ply 17A). Region 36) (shown in FIG. 2) has a contour that is symmetrical with respect to reference line 5 . Therefore, in step S12, as shown in FIGS. 15A and 15B, the region 36 of the symmetrical member 6 of the selected second region 4B and the region 36 of the symmetrical member 6 of the first region 4A Easily determine the discretization of the symmetry members 6 of the second region 4B based on the shape of the elements F(i) of the symmetry members 6 of the first region 4A by referencing and copying the elements F(i) be able to. Thereby, in the third determination step S94, the symmetrical member 6 obtained by discretizing the symmetrical member 6 of the second region 4B with a plurality of elements F(i) can be defined.

Thus, in the method of this embodiment, for example, it is not necessary to discretize the symmetrical member 6 of the second region 4B with a plurality of elements F(i). can be created with

Next, as shown in FIG. 12, in a fourth determination step S95, the discretization of the asymmetric member 7 in the second region 4B is performed by referring to information including the shape of the elements of the asymmetric member 7 in the first region 4A. decide. FIG. 16 is a flow chart showing an example of the processing procedure of the fourth determination step S95.

In the fourth determination step S95 of this embodiment, first, the area of the asymmetric member 7 in the second region 4B and the asymmetric member 7 in the first region 4A that are most similar are identified (step S13). Step S13 is performed in the same procedure as step S61 (shown in FIG. 7) of the second determination step S6.

Next, in the fourth determination step S95 of this embodiment, the information including the shape of the element F(i) of the asymmetric member 7 in the first region 4A is referenced to discretize the asymmetric member 7 in the second region 4B. determined (step S14). FIG. 17(a) is a diagram illustrating a state before information including the shapes of the elements of the asymmetric member in the first area is copied. FIG. 17(b) is a diagram illustrating a state in which information including the shapes of the elements of the asymmetric member in the first area is copied. FIG. 17(c) is a diagram illustrating a state in which the non-overlapping regions of the second region are discretized.

In step S14, first, as shown in FIG. 17(a), a symmetrical region 41 with respect to the reference line 5 (tire equator C) is determined for the asymmetric member 7 (shown in FIG. 5) of the first region 4A. Next, as shown in FIG. 17(b), in step S14, in the asymmetric member 7 of the second region 4B, a region that overlaps the symmetrical region 41 of the asymmetric member 7 of the first region 4A (hereinafter simply referred to as "overlapping The element F(i) of the asymmetric member 7 in the first region 4A is duplicated in the region 42 (shown in color in FIG. 17(a)). Accordingly, in step S14, it is possible to easily determine the discretization of the overlapping region 42 of the asymmetric member 7 in the second region 4B based on the shape of the element F(i) of the asymmetric member 7 in the first region 4A. .

In the asymmetric member 7 of the second region 4B, a region that does not overlap the symmetrical region 41 of the asymmetric member 7 of the first region 4A (hereinafter sometimes simply referred to as "non-overlapping region") 43 (shown in FIG. 17(b) ) cannot copy the element F(i) of the asymmetric member 7 in the first region 4A. Therefore, in step S14, as shown in FIG. 17(c), the non-overlapping region 43 shown in FIG. 17(b) is discretized with a plurality of elements F(i). Instead of the discretization of the non-overlapping region 43, morphing may be performed to define the elements of the non-overlapping region 43 by deforming the elements F(i) of the overlapping region 42. FIG. Accordingly, in the fourth determination step S95, the asymmetric member 7 obtained by discretizing the asymmetric member 7 of the second region 4B with a plurality of elements F(i) can be defined. The asymmetric member 7 of the second area 4B is stored in the computer 1. FIG.

Thus, the method of this embodiment duplicates the element F(i) of the asymmetric member 7 in the first region 4A, resulting in the asymmetric member 7 in the second region 4B, as shown in FIG. 17(b). The discretization can be determined for at least a portion of (ie, the overlap region 42). As a result, in the method of this embodiment, for example, the step of discretizing the asymmetric member 7 of the second region 4B with a plurality of elements F(i) is omitted (in this embodiment, the discretization of the non-overlapping region 43 is omitted). (limited only to definition), the asymmetric member 7 of the second region 4B can be produced in a short time.

Next, as shown in FIG. 12, in the discretization step S9 of this embodiment, the computer 1 processes all the members (the symmetrical members 6 or the asymmetrical members) in the second region 4B shown in FIGS. 7) is selected (step S96). If it is determined in step S96 that all members of the second region 4B have been selected ("Y" in step S96), discretization of all members of the second region 4B has been determined. Thereby, the method of this embodiment allows a structure (in this embodiment, the tire 3) including the symmetrical members 6 and the asymmetrical members 7 of the first region 4A and the symmetrical members 6 and the asymmetrical members 7 of the second region 4B. A cross-sectional FEM analysis model (structure data) 10A (shown in FIG. 11) can be created.

On the other hand, if it is determined in step S96 that all the members (symmetrical members 6 or asymmetrical members 7) in the second region 4B shown in FIGS. 4 and 5 have not been selected (“N” in step S96). , one member in the second region 4B that has not yet been selected is selected (step S97), and steps S93 to S96 are performed again. As a result, the discretization step S9 of this embodiment determines the discretization of all the members of the second region 4B, and the FEM analysis model (structure Data) 10A can be created reliably.

In the method of this embodiment, a first determination step S5 and a second determination step S6 (shown in FIG. 10) of determining the material properties of the second region 4B with reference to information including the material properties of the first region 4A; , a third determining step S94 and a fourth determining step S95 (shown in FIG. 12) of determining the discretization of the second region 4B with reference to information including the shape of the elements of the first region 4A, respectively. However, it is not limited to such an aspect. For example, both the discretization and material properties of the second region 4B may be determined (copied) by referring to information including both the shape and material properties of the elements of the first region 4A. Thus, the method of this embodiment can efficiently create the FEM analysis model (structure data) 10A.

Although the particularly preferred embodiments of the present invention have been described in detail above, the present invention is not limited to the illustrated embodiments and can be modified in various ways. Although the structure 2 of this embodiment was exemplified by the tire 3, it is not limited to such an aspect. As the structure 2, any structure can be appropriately adopted as long as its cross-sectional shape can be divided into a first region and a second region by a reference line and includes an asymmetric member 7. FIG.

Structure data of the cross-sectional shape of the tire shown in FIG. 2 was created (Example, Comparative Example). In an embodiment, after the steps of defining material properties for the first region are performed according to the procedures illustrated in FIGS. , was determined with reference to information containing the material properties of the symmetric and asymmetric members of the first region.

On the other hand, in the comparative example, material properties were defined for both the first region and the second region. Then, the time for creating the structure data by the method of the example and the time for creating the structure data by the method of the comparative example were measured. Common specifications are as follows.

Tire size: 195/60R15
Total number of symmetrical and asymmetrical members:
First region: 30 pieces
Second region: 30 pieces

As a result of the test, the preparation time of the method of Example could be shortened to 1/5 of the preparation time of the method of Comparative Example. Therefore, the method of the example was able to create structure data in a shorter time than the method of the comparative example.

S3 Defining material properties in the first region S7 Determining material properties of the asymmetric member in the second region

Claims (6)

A method for creating structure data having a cross-sectional shape of a structure using a computer,
The cross-sectional shape can be divided into a first region and a second region by a reference line,
The cross-sectional shape is made of the same material as a symmetrical member arranged symmetrically in the first region and the second region with respect to the reference line, but arranged in the first region and the second region asymmetrically with respect to the reference line. and an asymmetric member;
The method includes:
defining material properties in the first region;
determining the material properties of the asymmetric member in the second region by reference to information including the material properties of the asymmetric member in the first region;
How to create structure data. 2. The method of generating structure data according to claim 1, wherein said step of determining refers to said information on said asymmetric member in said first region that is closest to said area of said asymmetric member in said second region. . The determining step refers to the information of the asymmetric member in the first region having a center-of-gravity position closest to the symmetrical position with respect to the reference line of the center-of-gravity position of the asymmetric member in the second region. A method for creating structure data according to claim 1 . 4. The method of generating structure data according to claim 1, further comprising the step of discretizing said first area and said second area with a plurality of elements. The step of discretizing comprises discretizing the first region with a plurality of elements;
and determining the discretization of the asymmetric member in the second region with reference to information including the shape of the element of the asymmetric member in the first region. Method. 6. The structure data creating method according to claim 1, wherein said structure is a tire.

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