JP2022100070A - Tyre model modeling method, tyre model modeling device, and tyre model modeling program - Google Patents

Abstract

To provide a tyre model modeling method that can easily achieve tyre models having different positions of a main groove.SOLUTION: A tyre model modeling method includes: setting a reference tyre model with a main groove in a tread (S1); setting at least one main groove caused to move, and setting a nodal point group constituting each of the main grooves caused to move (S2); setting an amount of main groove movement to the main groove caused to move (S3); every main groove caused to move, designating three nodal points of the nodal points of a tread surface to obtain a center of a reference circle passing through the three nodal point, and a radius thereof (S7); calculating a movement angle from the amount of main groove movement on the basis of the center and radius of the reference circle, and calculating a radius of a circle corresponding to each nodal point of the nodal point group caused to move (S10); and rolling to move each nodal point of the nodal point groove at the movement angle, letting the center of the reference circle serve as a rotation center (S11).SELECTED DRAWING: Figure 1

Description

The present invention relates to a tire model creation method using a computer, a tire model creation device, and a tire model creation program.

A tire model modeled with computer-analyzable elements is used to design a tire with an optimum shape by simulating tire performance with a computer.

Morphing is a technique for creating tire models with different shapes. Morphing is a technique for directly changing the nodes and elements of a finite element model, and can reduce the man-hours required to prepare a tire model.

For example, in Patent Document 1, morphing is applied to the shape and thickness of a tire model and used to search for an optimum tire shape.

Japanese Unexamined Patent Publication No. 2017-091007

In the early stages of tire design, the position of the main groove on the tread is an important factor in determining the mold profile. In order to optimize the position of the main groove, it is necessary to prepare a plurality of tire models having different positions of the main groove, but it takes man-hours to prepare a plurality of tire models having different positions of the main groove.

In view of the above points, it is an object of the present invention to provide a tire model creation method, a creation device, and a creation program capable of easily obtaining tire models having different main groove positions.

The first aspect according to the present invention is a method in which a computer creates a tire model modeled by elements that can be analyzed by a computer, and a step of setting a reference tire model having at least one main groove in the tread. , A step of setting at least one main groove to be moved in the reference tire model, a step of setting a node group constituting each of the main grooves to be moved, and a step of setting the main groove movement amount for the main groove to be moved. Based on the step of designating three nodes of the tread surface for each main groove to be moved and obtaining the center and radius of the reference circle passing through the three nodes, and the center and radius of the reference circle. The step of calculating the movement angle from the amount of movement of the main groove and calculating the radius of the circle corresponding to each node of the node group to be moved, and the step of calculating each node of the node group with the center of the reference circle as the center of rotation. It is a tire model creation method including a step of rotating and moving at a moving angle.

A second aspect of the present invention comprises a reference model setting unit that sets a reference tire model that is modeled on a computer-analyzable element and has at least one main groove in the tread, and at least one that is moved in the reference tire model. A node group setting unit that sets one main groove and a node group that constitutes each of the main grooves to be moved, a movement amount setting unit that sets the main groove movement amount for the main groove to be moved, and the movement. A reference circle setting unit for designating three nodes on the surface of the tread for each main groove to obtain the center and radius of the reference circle passing through the three nodes, and the reference circle based on the center and radius of the reference circle. A movement angle calculation unit that calculates the movement angle from the movement amount of the main groove, a radius calculation unit that calculates the radius of the circle corresponding to each node of the node group based on the center of the reference circle, and each node of the node group. Is a tire model creating device having a rotationally moving portion that rotationally moves at the moving angle with the center of the reference circle as the center of rotation.

A third aspect of the present invention is a program for creating a tire model modeled with elements that can be analyzed by a computer, and a reference tire model having at least one main groove in the tread is set in the computer. Steps to be performed, at least one main groove to be moved in the reference tire model, a step to set a node group constituting each of the main grooves to be moved, and a main groove movement amount with respect to the main groove to be moved. A step to set, a step to specify three of the nodes on the tread surface for each main groove to be moved, a step to obtain the center and radius of a reference circle passing through the three nodes, and a step to obtain the center and radius of the reference circle. The step of calculating the movement angle from the amount of movement of the main groove based on the above, calculating the radius of the circle corresponding to each node of the node group to be moved, and rotating each node of the node group around the center of the reference circle. It is a tire model creation program for executing a step of rotating and moving at the movement angle as a center.

In the first to third aspects, when setting the main groove movement amount, a plurality of main groove movement amounts may be set for each of the main grooves to be moved. Then, the maximum movement amount is obtained from the plurality of main groove movement amounts for each of the main grooves to be moved, and the node group is moved by the maximum movement amount for each of the main grooves to be moved, so that the element is formed on the tread surface. It is determined whether or not crushing occurs, and when the element crushing occurs, a node further separated from the position moved by the maximum movement amount by a movement amount corresponding to the maximum movement amount or more is set as a fixed node. The nodes included from the node where the element collapsed to the front of the fixed node are set as the variable node, and when the variable node is set, each node of the node group is rotated and moved. Occasionally, it may further include evenly arranging the variable nodes between the nodes after rotational movement on the tread surface and the fixed nodes.

Further, in the case of determining whether or not the element collapse occurs, when the node group is moved by the maximum movement amount, the node on the tread surface of the node group moves beyond the other nodes. It may be determined that element collapse occurs.

According to the embodiment of the present invention, it is possible to easily obtain a tire model in which the positions of the main grooves are different.

Flow chart of tire model creation method according to one embodiment Block diagram of the tire model creating device according to the same embodiment Diagram showing an example of a tire model It is an enlarged view of the tread of a tire model, and is a diagram showing (A) the shoulder main groove on the cereal side, (B) the center main groove, and (C) the shoulder main groove on the anti-cerial side. Figure to explain the case where element collapse occurs Figure to explain how to set variable node Figure to explain how to modify variable node A flowchart showing an example of an optimization method for optimizing the main groove position. A flowchart showing another example of an optimization method for optimizing the main groove position.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a flowchart of a tire model creating method according to an embodiment, and FIG. 2 is a block diagram of a tire model creating device 10 according to an embodiment for realizing the creating method. The tire model creation method is a method of creating a tire model having a different main groove position by morphing, and the three nodes on the tread surface are designated for each main groove to be moved with respect to the reference tire model. The center and radius of a circle passing through a node are obtained, and the node group constituting the main groove is moved based on this circle, whereby a tire model having a different main groove position can be easily obtained.

As shown in FIG. 2, the tire model creating device 10 has a processing unit 12, an input unit 14, and an output unit 16. The processing unit 12 includes a reference model setting unit 18, a node group setting unit 20, a movement amount setting unit 22, a maximum movement amount acquisition unit 24, an element collapse determination unit 26, a variable node setting unit 28, and a reference circle. It has a setting unit 30, a movement angle calculation unit 32, a radius calculation unit 34, a rotation movement unit 36, a variable node correction unit 38, a determination unit 40, a memory 42, and a control unit 44. The tire model creating device 10 can be realized by using a computer as basic hardware, and can realize each of the above parts by causing a processor mounted on the computer to execute a program. At this time, the creating device 10 may be realized by installing the above program in a computer in advance, storing it in a storage medium such as a CD-ROM, or distributing the above program via a network. , This program may be realized by installing it on the computer as appropriate.

The input unit 14 is an input device for inputting various information according to an operator's instruction, and may include a mouse, a keyboard, and the like. The output unit 16 is a device that outputs a tire model that is the result obtained by the tire model creation method, and examples thereof include a display and a printer.

The processing unit 12 is controlled by the control unit 44, and has a reference model setting unit 18, a node group setting unit 20, a movement amount setting unit 22, a maximum movement amount acquisition unit 24, an element collapse determination unit 26, and a variable node setting unit 28. Processing is realized in each unit of the reference circle setting unit 30, the movement angle calculation unit 32, the radius calculation unit 34, the rotation movement unit 36, the variable node correction unit 38, and the determination unit 40. Each of these parts is connected to the memory 42, and is configured so that the information stored in the memory 42 can be read and the processing result can be output to the memory 42.

Hereinafter, the tire model creating method according to the embodiment will be described with reference to the flowchart of FIG. 1 together with the configuration of each of the above parts.

In step S1, the reference model setting unit 18 sets a reference tire model having at least one main groove in the tread. The reference tire model is a tire model that serves as a reference (initial shape) when creating a plurality of tire models having different main groove positions by morphing. The tire model is a model of a pneumatic tire with a finite number of elements that can be numerically analyzed by a computer. Here, a two-dimensional tire finite element model (two-dimensional FE model) in a cross section in the tire meridional direction is used.

As the reference tire model, a tire model created in advance may be input via the input unit 14, or may be created by a known method based on the model creation conditions input via the input unit 14.

As an example, as shown in FIG. 3, the reference tire model 50 is composed of quadrilateral elements as the finite number of elements. The reference tire model 50 connects the pair of left and right bead 52, 52, the pair of sidewalls 54, 54 extending outward in the radial direction of the tire from the beads 52, 52, and the outer ends of the left and right sidewalls 54, 54. Is provided with a tread 56 provided between both sidewalls 54 and 54. In the reference tire model 50, a carcass ply 58 extending in a toroid shape straddling between a pair of beads 52 and 52 and a plurality of belts 60 arranged on the outer peripheral side of the carcass ply 58 in the tread 56 are also modeled. There is.

The tread 56 of the reference tire model 50 is provided with at least one, usually a plurality of main grooves 62, extending in the tire circumferential direction. In this example, four main grooves 62 are provided, one is a pair of center main grooves 62A and 62A provided in the central portion of the tread 56, and the other is a pair of left and right shoulder main grooves 62B and 62B provided on the outside thereof. ..

Next, in step S2, the node group setting unit 20 sets at least one main groove to be moved in the reference tire model, and also sets a node group constituting the main groove to be moved.

The main groove to be moved may be all or a part of at least one main groove provided in the tread. In this example, a case where a plurality of main grooves are moved will be described. The main groove to be moved means a main groove whose position in the tire meridian direction is changed by morphing. The node group setting unit 20 may set, for example, the main groove designated via the input unit 14 as the main groove to be moved, or, for example, all the main grooves may be set based on the information stored in the memory 42. It may be set as a main groove to be moved.

The node group constituting the main groove to be moved is a set of nodes to be moved when the position of a certain main groove is moved, and includes at least all the nodes on the contour line in the cross-sectional shape of the main groove. In this example, the node existing from the groove bottom of the main groove to the inner surface of the tire is also included, that is, for example, in the case of the shoulder main groove 62B on the right side shown in FIG. 3, all the nodes included in the range surrounded by the chain line X. Let the nodes be a node group. The node group is set for all the main grooves to be moved.

In step S3, the movement amount setting unit 22 sets the movement amount of the main groove with respect to the main groove to be moved. One main groove movement amount may be set for one main groove, but usually, a plurality of main groove movement amounts are set for each main groove to be moved. The main groove movement amount is an amount for moving the main groove to one side and the other side in the tire meridian direction along the tread surface, and is defined as a movement amount on the tread surface as an embodiment. In this example, the main groove is moved in the tire meridian direction while maintaining its cross-sectional shape.

In one embodiment, the movement amount setting unit 22 sets a list of main groove movement amounts for a plurality of designs to be generated by morphing. For example, the amount of movement of the main groove in the tire meridian direction is specified by a plurality of sizes on one side and the other side in the tire meridian direction (for example, ± 2 mm, ± 4 mm, etc.), and is determined for each main groove to be moved. Set the list.

The movement amount setting unit 22 may set, for example, the movement amount for each main groove input via the input unit 14 as the main groove movement amount, or may move based on the information stored in the memory 42. The main groove movement amount may be set for the groove.

Next, in step S4, the maximum movement amount acquisition unit 24 obtains the maximum movement amount from the plurality of main groove movement amounts for each main groove to be moved. Specifically, in each main groove to be moved, the maximum of the plurality of main groove movement amounts set above is specified as the maximum movement amount for each of one side and the other side in the tire meridian direction.

Next, in step S5, the element collapse determination unit 26 determines whether or not element collapse occurs on the tread surface by moving the node group with the maximum movement amount for each main groove to be moved. Element crushing means that when the node group constituting the main groove is moved by the maximum amount of movement, the node of the node group overtakes the adjacent node, so that the element shape cannot be maintained, or the finite element method is used. It means that the element width becomes very small (for example, 0.5 mm or less) so that the stability of the numerical calculation is impaired.

In one embodiment, whether or not element collapse occurs may be determined by whether or not a node on the tread surface of the node group moves beyond other nodes when the node group is moved by the maximum amount of movement. Often, it may be determined that tread collapse occurs when moving over other nodes.

FIG. 5 is a diagram showing an example of a case where element collapse occurs. When the node 66 of the node group 64 constituting the main groove 62 is moved to one side (right side) by the maximum movement amount specified above, the node 66 defining the groove wall surface on one side (right side) of the main groove 62. Moves beyond the node 68 adjacent to one side (right side) and further to the other side (right side), and moves to the position indicated by the reference numeral 66A by the alternate long and short dash line. Therefore, the element 69 formed between the node 68 and the main groove 62 is crushed by the movement of the node group 64, and the element crush occurs.

When it is determined in step S5 that element collapse occurs, in step S6, the variable node setting unit 28 sets a node further away from the position moved by the maximum movement amount by a movement amount corresponding to the maximum movement amount or more as a fixed node. At the same time, the nodes included from the node where the element is crushed to the front of the fixed node are set as the variable node.

FIG. 6 is a diagram showing an example of a method of setting a variable node when element collapse occurs in FIG. 5. It shows a state in which the node group 64 is moved by the maximum movement amount, and the first node (that is, separated by the movement amount or more) further away from the position moved by the maximum movement amount by the movement amount corresponding to the maximum movement amount or more. The closest node) is set as the fixed node 70. In the example of FIG. 6, in the state before the movement shown in FIG. 5, the third node on the right side from the node 66 defining the groove wall surface on the right side of the main groove 62 is set as the fixed node 70.

Then, the nodes included from the node 68 where the element collapsed to the front of the fixed node 70 (in this example, the node 68 where the element collapsed and the node 72 adjacent to one side (right side) thereof) are set as variable nodes. do.

The above fixed and variable nodes are preferably set not only for the nodes on the surface of the tread but also for the nodes existing at least to the depth of the main groove in the thickness direction of the tread according to the node group to be moved. It may be set for the nodes of the entire thickness.

Here, the fixed node means a node that is not moved when the main groove position is changed by morphing, and the variable node means a node that can be moved together with the node group constituting the main groove by changing the main groove position. A node.

After setting the variable node in step S6 in this way, the process proceeds to step S7. If it is determined in step S5 that element collapse does not occur, the process proceeds to step S7 as it is.

In step S7, the reference circle setting unit 30 designates three nodes among the nodes on the tread surface located in the vicinity of the main groove for each main groove to be moved, and the center and radius of the reference circle passing through the three nodes. Ask for. If three points are specified, the number of circles passing through the three points is fixed to one, so that the reference circle for rotating the node group can be uniquely determined.

The three nodes for determining the reference circle may be specified from the following selection range. The selection range is all the nodes included in the tread surface including the main groove movement range and the first surface node separated from both sides by the maximum movement amount or more. Further, as the designation method, there is a method of designating three points that define an arc so that the mean square error between all the nodes included in the selection range and the arc is minimized. Here, the main groove movement range is the total movement range when the main groove is moved to both sides thereof with the maximum movement amount. A surface node is a node existing on the surface of a tread.

FIG. 4 shows the shoulder main groove 62B (FIG. 4 (A)) on the cerial side, the center main groove 62A (FIG. 4 (B)), and the shoulder main groove 62B (FIG. 4 (C)) on the anti-cerial side. It is a figure which showed the three nodes selected on the tread surface respectively. In each figure, the three selected nodes are indicated by black circles. Further, the maximum movement amount is shown by MA, the main groove movement range GR, and the selection range by SR. In the example of FIG. 4 (A), the selection range SR has 6 surface nodes, in the example of FIG. 4 (B), the selection range SR has 7 surface nodes, and in the example of FIG. 4 (C), the selection range. The SR has seven surface nodes.

Next, in step S8, the reference circle setting unit 30 designates a positive movement direction in each main groove to be moved. In this example, as shown in FIG. 4, in the shoulder main groove 62B on the cerial side, the center main groove 62A, and the shoulder main groove 62B on the anti-cerial side, the movement to the right side (that is, the anti-cerial side) along the tread surface. Is defined as a "positive" movement, and the movement to the left side (that is, the cerial side) on the opposite side is defined as a "negative" movement.

Next, in step S9, the reference circle setting unit 30 determines whether or not the reference circle and the moving direction have been set for all the main grooves to be moved, that is, all the node groups, and if not, returns to step S5. , Steps S5 to S9 are repeated until all the node groups are set. Then, if it is determined that the setting is made by all the node groups, the process proceeds to step S10.

In step S10, the movement angle calculation unit 32 calculates the movement angle from the main groove movement amount based on the center and radius of the reference circle. Further, the radius calculation unit 34 calculates the radius of the circle corresponding to each node of the node group to be moved based on the center of the reference circle.

In this example, since a plurality of main groove movement amounts are set for each main groove to be moved, the movement angle calculation unit 32 calculates the corresponding movement angles from the plurality of main groove movement amounts. Specifically, when the main groove movement amount is set as the movement amount on the tread surface, the nodes existing on the tread surface among the node groups constituting the main groove are based on the center and radius of the reference circle and the main groove movement amount. , The movement angle corresponding to the movement amount of the main groove can be obtained.

The radius calculation unit 34 calculates the radius of the circle corresponding to each node of the node group by obtaining the distance from the center of the reference circle for each node of the node group to be moved.

Next, in step S11, the rotational movement unit 36 rotates and moves each node of the node group around the center of the reference circle at the above movement angle. That is, each node of the node group is rotationally moved at the movement angle obtained in step S10, with the center of the reference circle as the center of rotation, using the radius obtained in step S10. As a result, the position of the main groove can be changed by the specified amount of movement of the main groove.

Next, in step S12, the variable node correction unit 38 determines whether or not the variable node is set in step S6 in relation to the moved main groove. Then, if the variable node is set, the process proceeds to step S13.

In step S13, the variable node correction unit 38 evenly arranges the variable nodes between the nodes after the rotational movement of the node group on the tread surface and the fixed nodes set in step S6. Specifically, the angle formed by the node after the rotational movement of the node group and the fixed node in the reference circle is obtained, this angle is divided by the number of variable nodes on the tread surface and averaged, and the variable node is averaged for each angle. Should be placed.

FIG. 7 is a diagram for explaining a method of correcting the variable node when the variable node is present, and as an example shown in FIGS. 5 and 6, two variable nodes are formed on the tread surface on one side (right side) of the main groove. This is the case when 68 and 72 are present. In this case, after rotating the node 66 of the node group 64, the two variable nodes 68 and 72 are arranged at an equal angle between the node 66 of the node group 64 and the fixed node 70 on the tread surface. The positions of the variable nodes 68 and 72 are corrected and arranged. The variable nodes on the inner side in the thickness direction of the tread are also evenly arranged between the nodes 66 and the fixed nodes 70 of the node group 64, similarly to the variable nodes on the surface of the tread.

After correcting the variable node in step S13 in this way, the process proceeds to step S14. If it is determined in step S12 that the variable node does not exist, the process proceeds to step S14 as it is.

In step S14, the rotational movement unit 36 determines whether or not all the main grooves to be moved, that is, all the node groups, have been rotationally moved, and if there is a node group that has not been moved, the process returns to step S10 and all the nodes are moved. Steps S10 to S14 are repeated until the rotational movement of the node group is completed. Then, if it is determined that the rotational movement is completed for all the node groups, the process proceeds to step S15, and a tire model in which the main groove positions of all the main grooves to be moved are updated is obtained.

Next, in step S16, the determination unit 40 determines whether or not a tire model in which the main groove is changed for all of the plurality of designs set in step S3 is obtained, and if not, returns to step S10. , Steps S10 to S16 are repeated until the tire models of all the designs are acquired. Then, if the tire models of all the designs are acquired, the obtained tire models are output via the output unit 16. The output can be displayed by a display, printed by a printer, or written to a storage means such as a disk or a database.

As described above, according to the present embodiment, for the reference tire model, three nodes on the tread surface are designated for each main groove to be moved, and the center and radius of the circle passing through the three nodes are obtained, and the main groove is obtained. By moving the node group constituting the tire based on this circle, the position of the main groove in the two-dimensional tire FE model can be easily changed. Therefore, it becomes easy to acquire a plurality of tire models having different main groove positions, and the man-hours for creating the tire models can be significantly reduced.

In addition, even when element collapse occurs due to the movement of the node group constituting the main groove, it is possible to easily create a tire model with a large amount of movement of the main groove by setting a variable node and correcting its position. can.

The tire model creating method according to the above embodiment can be used, for example, in a tire shape optimization method, and the main groove position can be optimized.

As an example, FIG. 8 is a flowchart of an optimization method for optimizing the main groove position using cluster analysis. Cluster analysis is a method for automatically classifying given data without an external standard. For example, there are Ward's method, K-means method, and the like, and sample points having similar characteristic values are classified by clustering.

In the optimization method shown in FIG. 8, first, in step S21, the conditions necessary for optimizing are set. Specifically, obtain a reference tire model that serves as a reference when creating multiple tire models, a list of multiple main groove movement amounts that you want to generate by morphing, characteristic values (objective functions) related to tire performance, and characteristic values. Set the finite element analysis conditions for the purpose and the analysis conditions necessary for performing the cluster analysis.

Then, in step S22, the tire model creating method shown in FIG. 2 described above is performed to create a plurality of tire models having different positions of the main grooves. Then, in step S23, a finite element analysis is performed for each of the plurality of tire models, and as a result, an objective function as a characteristic value is acquired for each tire model in step S24. The two-dimensional tire model created in step S22 may be expanded in the tire circumferential direction to generate a three-dimensional tire model, and then the finite element analysis may be performed.

Next, in step S25, a cluster analysis is performed on the objective function to classify those having similar objective function values into the same cluster, and in step S26, the main groove position and the tendency of the objective function in each cluster are confirmed. , In step S27, the optimum main groove position is determined.

As another example, FIG. 9 is a flowchart of an optimization method for optimizing the main groove position using the response surface methodology. The response surface methodology is a method of performing optimization on the approximate curved surface using an approximate function (response curved surface) created based on the data of the sample points.

In the optimization method shown in FIG. 9, first, in step S31, the conditions necessary for optimizing are set. Specifically, acquire a reference tire model as a reference when creating multiple tire models, a list of multiple main groove movement amounts to be generated by morphing, characteristic values (objective functions) related to tire performance, and characteristic values. Set the finite element analysis conditions for this purpose, the analysis conditions necessary for performing the optimization calculation by the response surface methodology, and the constraint conditions.

Then, in step S32, the tire model creating method shown in FIG. 2 described above is performed to create a plurality of tire models having different positions of the main grooves. Then, in step S33, a finite element analysis is performed for each of the plurality of tire models, and as a result, an objective function as a characteristic value is acquired for each tire model in step S34. The two-dimensional tire model created in step S32 may be expanded in the tire circumferential direction to generate a three-dimensional tire model, and then the finite element analysis may be performed.

Next, in step S35, a response curved surface is generated using the obtained objective function, constraint conditions are set in step S36, and optimization calculation using these response curved surfaces and constraint conditions is performed in step S37. , Determine the optimum main groove position.

The tire shape optimization method, the optimization device, and the program for that using the tire model creation method according to the present embodiment are not limited to those using the cluster analysis and the response surface methodology, and various methods are used. It can be configured using optimization techniques.

Although some embodiments have been described above, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other embodiments, and various omissions, replacements, and changes can be made without departing from the gist of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are also included in the scope of the invention described in the claims and the equivalent scope thereof.

10 ... Tire model creation device, 18 ... Reference model setting unit, 20 ... Node group setting unit, 22 ... Movement amount setting unit, 24 ... Maximum movement amount acquisition unit, 26 ... Element collapse determination unit, 28 ... Variable node setting unit, 30 ... Reference circle setting unit, 32 ... Movement angle calculation unit, 34 ... Radius calculation unit, 36 ... Rotational movement unit, 38 ... Variable node correction unit, 62 ... Main groove, 64 ... Node group, 66 ... Node group node, 68, 72 ... Variable node, 70 ... Fixed node

Claims (5)

A method by which a computer creates a tire model modeled on elements that can be analyzed by a computer.
Steps to set a reference tire model with at least one main groove in the tread,
A step of setting at least one main groove to be moved in the reference tire model and a step of setting a node group constituting each main groove to be moved.
The step of setting the main groove movement amount with respect to the main groove to be moved, and
A step of designating three of the nodes on the tread surface for each of the main grooves to be moved and finding the center and radius of the reference circle passing through the three nodes.
A step of calculating the movement angle from the main groove movement amount based on the center and radius of the reference circle, and calculating the radius of the circle corresponding to each node of the node group to be moved.
A step of rotating and moving each node of the node group at the movement angle with the center of the reference circle as the center of rotation.
How to create a tire model including. In the step of setting the main groove movement amount, a plurality of main groove movement amounts are set for each main groove to be moved.
The method for creating a tire model is as follows.
For each of the main grooves to be moved, a step of obtaining the maximum movement amount from the plurality of main groove movement amounts, and
A step of determining whether or not element crushing occurs on the tread surface by moving the node group at the maximum movement amount for each main groove to be moved.
When the element collapse occurs, a node further separated from the position moved by the maximum movement amount by a movement amount corresponding to the maximum movement amount or more is set as a fixed node, and the fixed node is set from the node where the element collapse occurs. Steps to set the nodes included before this to variable nodes,
When the variable node is set, when each node of the node group is rotationally moved, the variable node is evenly arranged between the node after the rotational movement on the tread surface and the fixed node.
The tire model making method according to claim 1, further comprising. In the step of determining whether or not the element collapse occurs, when the node group is moved by the maximum movement amount, the element collapse when the node on the tread surface of the node group moves beyond the other nodes. The tire model creating method according to claim 2, wherein it is determined that the tire model is generated. A reference model setting unit that sets a reference tire model that is modeled with computer-analyzable elements and has at least one main groove in the tread.
In the reference tire model, at least one main groove to be moved is set, and a node group setting unit for setting a node group constituting each main groove to be moved, and a node group setting unit.
A movement amount setting unit that sets the movement amount of the main groove with respect to the main groove to be moved,
For each of the main grooves to be moved, a reference circle setting unit for designating three nodes on the tread surface and obtaining the center and radius of the reference circle passing through the three nodes, and a reference circle setting unit.
A movement angle calculation unit that calculates a movement angle from the main groove movement amount based on the center and radius of the reference circle, and
A radius calculation unit that calculates the radius of the circle corresponding to each node of the node group based on the center of the reference circle, and
A rotational movement unit that rotates and moves each node of the node group at the movement angle with the center of the reference circle as the center of rotation.
Tire modeling device with. A program for creating a tire model modeled on computer-analyzable elements.
On the computer
Steps to set a reference tire model with at least one main groove in the tread,
A step of setting at least one main groove to be moved in the reference tire model and a step of setting a node group constituting each main groove to be moved.
The step of setting the main groove movement amount with respect to the main groove to be moved, and
A step of designating three of the nodes on the tread surface for each of the main grooves to be moved and finding the center and radius of the reference circle passing through the three nodes.
A step of calculating the movement angle from the main groove movement amount based on the center and radius of the reference circle, and calculating the radius of the circle corresponding to each node of the node group to be moved.
A step of rotating and moving each node of the node group at the movement angle with the center of the reference circle as the center of rotation.
Tire model creation program to execute.

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