JP2009129339A - Tire performance simulation method, tire performance simulation apparatus and tire performance simulation program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To simulate tire performance accurately even for tires having complicated tread patterns. <P>SOLUTION: A tire performance simulation apparatus creates a tire body model, executes a pseudo rolling analysis of the tire body model, then creates a tread pattern model and executes a local analysis of the tread pattern model (Step S1 to S4). The local analysis of the tread pattern model includes interpolating connection information between nodal points of each mesh of the tire body model on a contact surface between the tire body model and the tread pattern model (Step S4-A), setting each nodal point of each mesh of the tread pattern model on the contact surface as an evaluation point and calculating a locus of the set evaluation point (Step S4-B), and calculating deformations of the tread pattern model according to the calculated locus (Step S4-C). <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a tire performance simulation method, a tire performance simulation device, and a tire performance simulation program. More specifically, the present invention relates to a tire performance simulation method, a tire performance simulation device, and a tire performance that simulate tire performance by a finite element method or the like. It relates to a simulation program.

  In the development of tires, instead of actually creating a tire, it has been conventionally practiced to create a finite element model of the tire and to improve the development efficiency by simulating various performance evaluations on a computer. .

  For example, the following three methods are widely known as methods for simulating the performance of a tread pattern of a rolling tire.

  As a first method, there is a method of rolling analysis of a tire model in which a tread pattern is modeled. Hereinafter, this method is referred to as pattern rolling analysis.

  As a second method, there is a method in which a part or all of the surface of the tire model is peeled off, a tread pattern model separately modeled on that portion is attached to the tire model, and rolling analysis is performed (see, for example, Patent Document 1). ). Hereinafter, this method is referred to as “patterned rolling analysis”.

  As a third method, a rolling analysis is performed with a tire body model 100 as shown in FIG. 9 in which a smooth tire, a rib pattern tire, or a tread pattern is simply modeled, and from the deformed shape of the obtained tire model. There is a method in which a detailed analysis is performed by creating a locus in a rolling state of the tread pattern model 102 as shown in FIG. 10 and rolling the tread pattern model 102 along the locus.

  Here, the analysis in the tire body model 100 is called global analysis, and the detailed analysis in the tread pattern model 102 is called local analysis. A tire tread pattern performance simulation method based on a combination of these is called rolling global / local analysis. For example, the simulation methods disclosed in Patent Documents 2 and 3 correspond to this.

Further, as a method of performing the rolling analysis of the tire model in a pseudo manner, there is a method of analyzing the steady rolling state of the tire in a pseudo manner without actually rolling the tire model in a simulation. For example, Steady State Transport analysis (steady transport analysis) described in Non-Patent Document 1. This is called pseudo rolling analysis.
JP 2002-22621 A JP 2006-111168 A JP 2006-199217 A ABAQUS Version 6.6 Analysis User's Manual 6.4.1

  However, the tire rolling analysis in the first to third methods requires a long time for the analysis. For this reason, the pattern rolling analysis and the rolling analysis with a pattern have a problem that it is necessary to re-execute a long time analysis every time a tire design element including a tread pattern is changed, resulting in poor design efficiency.

  Further, the rolling global / local analysis has an advantage that only the local analysis needs to be re-executed when only the tread pattern model is changed. However, when there is a change in a tire design element other than the tread pattern, for example, an internal reinforcing material, there is a problem that it is necessary to start again from the global analysis and the efficiency is low.

  On the other hand, pseudo-rolling analysis can simulate the condition of a tire that is rolling in a pseudo manner at a high speed, but it does not obtain a trajectory by rolling a tire model in the simulation, but in a pseudo-steady state. Since the rolling state is analyzed, that is, only the deformation in the steady state of the tire is obtained, it is difficult to obtain the trajectory at the time of tire rolling of each part of the tread pattern having a complicated shape. For this reason, only a simple pattern tire such as a smooth tire or a rib pattern tire can be handled, and there is a problem that it is difficult to accurately simulate a tire having a complicated shape tread pattern.

  The present invention has been made to solve the above problems, and a tire performance simulation method, a tire performance simulation apparatus, and a tire performance simulation capable of accurately simulating tire performance even with a tire having a tread pattern having a complicated shape. The purpose is to provide a program.

  In order to achieve the above object, a tire performance simulation method according to a first aspect of the present invention includes a step of performing a pseudo rolling analysis on a tire body model in which a tire body is mesh-divided into a plurality of tire body elements; A tread pattern model obtained by dividing a tire tread pattern into a plurality of tread pattern elements based on tire body element node information on nodes of each tire body element of the tire body model obtained by dynamic analysis, and the tire body model, Obtaining a nodal locus of the tread pattern element on the contact surface, and obtaining a tread pattern element deformation information related to the deformation of the tread pattern element based on the nodal locus of the tread pattern element. It is characterized by.

  According to the present invention, a pseudo rolling analysis is performed on the tire body model, and the tire tread is based on the tire body element node information regarding the nodes of each tire body element of the tire body model obtained by the pseudo rolling analysis. The tread pattern element node trajectory is obtained on the contact surface between the tire body model and the tread pattern model obtained by dividing the pattern into a plurality of tread pattern elements, and the tread pattern element is determined based on the obtained tread pattern element node trajectory. Tread pattern element deformation information related to the deformation of the.

  Thereby, the tire performance can be accurately simulated even with a tire having a tread pattern having a complicated shape.

  In addition, as described in claim 2, the connection related to the connection between the nodes of the tire body element on the contact surface based on the information on the node of the tire body element on the contact surface of the tire body element node information. A step of interpolating information may be included. Thereby, the tire performance can be simulated with higher accuracy.

  Further, as described in claim 3, the connection information may be interpolated using a cylindrical element in a cylindrical coordinate system in the circumferential direction of the tire. Thereby, the tire performance can be simulated with higher accuracy.

  Furthermore, in this case, as described in claim 4, the connection information may be interpolated by a linear expression for the radial direction of the tire and may be interpolated by a cubic expression for the circumferential direction of the tire. Thereby, the tire performance can be simulated with higher accuracy and in a relatively short time.

  The tire performance simulation device according to claim 5 is obtained by a pseudo rolling analysis unit that performs a pseudo rolling analysis on a tire body model in which a tire body is mesh-divided into a plurality of tire body elements, and the pseudo rolling analysis. Based on the tire body element node information relating to the nodes of each tire body element of the tire body model, the tread pattern model obtained by dividing the tire tread pattern into a plurality of tread pattern elements and the contact surface of the tire body model, Trajectory calculating means for obtaining a trajectory of a node of the tread pattern element; and deformation information calculating means for obtaining tread pattern element deformation information related to the deformation of the tread pattern element based on the trajectory of the node of the tread pattern element. It is characterized by.

  According to the present invention, tire performance can be accurately simulated even with a tread pattern tire having a complicated shape.

  The tire performance simulation program according to claim 6 includes a step of executing a pseudo rolling analysis on a tire body model obtained by dividing a tire body into a plurality of tire body elements, and the tire obtained by the pseudo rolling analysis. The tread pattern on the contact surface between the tire body model and the tread pattern model obtained by dividing the tire tread pattern into a plurality of tread pattern elements based on the tire body element node information relating to the nodes of the tire body elements of the body model A step of obtaining a nodal locus of the element and a step of obtaining tread pattern element deformation information relating to the deformation of the tread pattern element based on the nodal locus of the tread pattern element. And

  According to the present invention, tire performance can be accurately simulated even with a tread pattern tire having a complicated shape.

  As described above, according to the present invention, there is an effect that the tire performance can be accurately simulated even with a tire having a complicated tread pattern.

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

  FIG. 1 shows an outline of a personal computer as a tire performance simulation apparatus for creating a tire model of a pneumatic tire and performing performance prediction as an example. This personal computer includes a keyboard 10 for inputting data and the like, a computer main body 12 for creating a three-dimensional tire model and predicting performance according to a pre-stored processing program, calculation results and various screens by the computer main body 12 From the mouse 16 for performing operations such as moving the cursor displayed on the CRT 14 to a desired position, selecting, deselecting, or dragging the menu item or object at the cursor position. It is configured.

  The computer main body 12 includes a flexible disk unit (FDU) into which a flexible disk (FD) as a recording medium can be inserted and removed. Note that a processing routine described later can be read from and written to the flexible disk FD using, for example, an FDU. Therefore, a processing routine to be described later may be recorded in the FD in advance and the processing program recorded in the FD may be executed via the FDU. Further, the processing program may be stored (installed) in a mass storage device (not shown) such as a hard disk device provided in the computer main body 12 and executed. As recording media, there are optical discs such as CD-ROM and DVD-ROM, and magneto-optical discs such as MD and MO. When these are used, instead of the above FDU or in addition, a CD-ROM device, DVD-ROM, etc. A ROM device, MD device, MO device, or the like may be used.

  The hard disk of the computer main body 12 stores a tire performance simulation program, which will be described later, and various parameters and data necessary for the execution thereof.

  Next, as a function of the present embodiment, a processing routine of a tire performance simulation program executed by the computer main body 12 will be described with reference to a flowchart shown in FIG.

  In step S1, a three-dimensional model of the tire body model is created. The tire body refers to a portion other than the tread portion such as a carcass, a belt, a sidewall, and a bead portion constituting the tire. Various known methods can be used for creating the tire body model. For example, first, the operator inputs various parameters necessary for creating a tire body model such as the shape (size), structure, and material of the cross section of the tire body in the tire radial direction. A tire body model can be created by creating a model of a cross section of the tire body in the radial direction of the tire based on the input parameters, dividing the model into meshes, and developing the tire in the circumferential direction of the tire. .

  The creation of the tire body model and the tread pattern model described later differs slightly depending on the numerical analysis method used. In this embodiment, a finite element method (FEM) is used as a numerical analysis method. Therefore, the tire body model and the tread pattern model created in the present embodiment are based on the numerical analysis method based on the element division corresponding to the finite element method (FEM), that is, the model divided into a plurality of elements by mesh division. This is a digitized input data format for a created computer program.

  This element division means dividing the tire into a large number of (finite) elements (small parts). Each element can be, for example, a tetrahedral element, a pentahedral element, a hexahedral element, or the like. After performing numerical calculation for each element and calculating all the elements, the entire response can be obtained by combining all the elements. The numerical analysis method is not limited to the finite element method, and other known numerical analysis methods such as a difference method, a finite volume method, and a discrete element method (DEM) may be used.

  In step S2, pseudo rolling analysis is performed on the tire body model. This pseudo rolling analysis can use a method as described in Non-Patent Document 1 described above.

  In the rolling analysis such as the conventional rolling global / local analysis described above, as shown in FIG. 3, the tire body model 22 mesh-divided into a plurality of elements 20 is rolled, and the tire body model 22 is in a steady state. The balance of force is calculated using a method such as the finite element method every moment until it becomes.

  On the other hand, in the pseudo rolling analysis, as shown in FIG. 4, the balance of force in the steady state of the tire body model 22 is directly obtained without rotating the tire body model 22. For this reason, while it takes a relatively long time to reach a steady state in the rolling analysis, in the pseudo rolling analysis, for example, it is possible to set the analysis time to about 1/50 or less of the rolling analysis. Become.

  As described above, in the pseudo rolling analysis, since the balance of force in the steady state of the tire body model 22 is directly obtained without rotating the tire body model 22, the node information regarding the nodes of each mesh in the steady state of the tire body model 22 is obtained. Etc. are obtained. This node information (tire body element node information) includes coordinate information of each node, connection information regarding connection between nodes, and the like. Thereby, the shape of the tire in a steady state can be grasped.

  In step S3, a three-dimensional model of a tread pattern is created. In the creation of the tread pattern model, the operator inputs (specifies) various parameters necessary for creating the tread pattern model, such as the shape (size), height, arrangement, and material of the tread block constituting the tread pattern. Based on the input parameters, a three-dimensional model of the tread pattern is created. For example, it is possible to create a three-dimensional tread pattern model by creating a three-dimensional model of a tread pattern for one pitch and developing it in the circumferential direction of the tire.

  In step S4, a local analysis of the tread pattern model is performed. In the conventional rolling global / local analysis described above, the time history of the node coordinates of each mesh of the tire body model at the joint surface between the tire body and the tread pattern is obtained by the global analysis of the tire body model, and the tread is based on this. Get the trace of the pattern. That is, in the conventional global analysis, as shown in FIG. 5, the tire body model 22 is analyzed by rolling in the direction of the arrow A in the figure, for example, and therefore the joint surface 26 between the tire body model 22 and the tread pattern model 24 is analyzed. The locus 27, that is, the time history of the node coordinates of each mesh of the tire body model 22 on the joint surface 26 can be acquired.

  On the other hand, when the pseudo rolling analysis is used as the global analysis of the tire main body model as in the present embodiment, the tire main body model 22 is used in the pseudo rolling analysis as shown in FIG. Since it does not roll, only the shape of the tire in a steady state can be known. For this reason, the node coordinates of each mesh of the tire body model 22 on the joint surface 26 between the tire body model 22 and the tread pattern model 24 cannot be acquired as a time history.

  For this reason, in step S4, as shown in FIG. 6B, the nodes of each mesh of the tread pattern model 24 on the joint surface 26 between the tire body model 22 and the tread pattern model 24 are set as evaluation points, and this evaluation is performed. The trajectory of the tread pattern is obtained by acquiring the position of the evaluation point while moving the point along the tire circumferential direction.

  Here, since each mesh of the tire main body model 22 and each mesh of the tread pattern model at the joint surface 26 between the tire main body model 22 and the tread pattern model 24 are not normally aligned, adjacent meshes of the tire main body model 22 are adjacent to each other. After interpolating between the nodes, the trajectory of the tread pattern model 24 is obtained. Thereby, the trajectory of the tread pattern can be obtained with high accuracy.

  For example, the interpolation of a partial region 28 of the tire body model 22 shown in FIG. 4 will be described. FIG. 7A shows an enlarged view of the region 28 in FIG. As shown in FIG. 3A, the meshes 30 of the tread pattern model 24 and the meshes 32 of the tire body model 22 in the vicinity of the joint surface 26 between the tire body model 22 and the tread pattern model 24 do not match. That is, for example, the line connecting the nodes 34 of each mesh 30 of the tread pattern model 24 on the joint surface 26 does not match the line connecting the nodes 36 of the mesh 32 of the tire body model 22 on the joint surface 26.

  In such a case, as shown in FIG. 7B, each mesh 30 of the tread pattern model 24 and each mesh 32 of the tire body model 22 are matched, that is, the tread pattern model 24 of the tire body model 22 is matched. The connection information between the nodes of the node information of the tire body model 22 is interpolated so that the joint surface 26 on the side coincides with the joint surface of the tread pattern model 24 on the tire body model 22 side. Specifically, the tire circumferential direction indicated by the arrow C in the figure is interpolated in a curved manner by interpolation using cylindrical elements in a cylindrical coordinate system.

  As a result, as shown in FIG. 7B, the meshes on the joint surface 26 between the tread pattern model 24 and the tire body model 22 are aligned, and the trajectory of the tread pattern can be obtained with high accuracy. In FIG. 7, the mesh 32 of the tire body model 22 is also present on the outer side (upper side in FIG. 7) of the joint surface 26, and this includes the tire body model 22 up to the outermost surface of the tread pattern model 24. This is because it is modeled as follows.

  As shown in FIG. 8A, before the tire body model 22 is deformed, that is, before rolling, the ground contact portion 38 has a substantially arc shape, whereas after the tire body model 22 is deformed. That is, the shape of the ground contact portion 38 in a steady state after rolling is substantially linear as shown in FIG.

  In the cylindrical coordinate system, three-dimensional coordinates are represented by (r, θ, z). Since θ represents a rotation angle, the tire radial and width coordinates are represented by r, z. The direction coordinate is represented by θ. Therefore, in order to interpolate the circular arc shape in the circumferential direction of the tire using the cylindrical element in the cylindrical coordinate system, it is possible to interpolate by linear interpolation by a linear expression, but in the cylindrical coordinate system, the linear shape in the circumferential direction of the tire is interpolated. In order to achieve this, it is necessary to interpolate with a second-order or higher order polynomial. Therefore, linear interpolation is performed between the nodes of the tire body model 22 in the tire radial direction indicated by the arrow B direction in FIG. 7B by a linear expression, and the tire circumferential direction indicated by the arrow C direction in FIG. Is interpolated by a second-order or higher order polynomial. Thereby, the shape in the steady state after tire rolling can be accurately interpolated.

  Therefore, the polynomial used for interpolation in the tire circumferential direction must be at least a quadratic polynomial, but in the case of the quadratic equation, coordinate information of three nodes is required, but the quadratic equation If you have the following problems.

  For example, as shown in FIG. 4, when attention is paid to the mesh 32A in the vicinity of the ground contact portion, coordinate information of three nodes is required when interpolating with a quadratic equation, but the two nodes 36A of the mesh 32A need to be coordinated. In addition, either the node 36B of the adjacent mesh 32B or the node 36C of the mesh 32C is required. In this case, the obtained quadratic expression differs depending on whether the node 36B or the node 36C is used. That is, depending on which node is used, the shape of the tire is different, and there are cases where interpolation cannot be performed with high accuracy.

  On the other hand, since the coordinate information of four nodes is necessary in the case of the cubic expression, the nodes used to determine the cubic expression are the two nodes 36A of the mesh 32A, the nodes 36B of the mesh 32B, and the mesh 32C. Therefore, the problem as in the case of the above quadratic expression does not occur. On the other hand, when the quartic equation or higher is used, the calculation load increases. Therefore, the polynomial used for the tire circumferential interpolation is preferably a cubic equation.

  The local analysis in step S4 includes a plurality of steps. First, in step S4-A, the meshes of the tire main body model 22 and the tread pattern model 24 in the vicinity of the joint surface 26 are matched by the interpolation process as described above.

  In step S4-B, the node 34 of each mesh 30 of the tread pattern model 24 on the joint surface 26 is set as an evaluation point, and each evaluation point is determined based on the node information of the tire body model 22 after interpolation. The trajectory of each evaluation point is obtained while moving in the circumferential direction.

  In step S4-C, deformation information (tread pattern element deformation information) regarding deformation of each mesh of the tread pattern model 24 is obtained based on the trajectory of each evaluation point using a known method such as a finite element method. As a result, it is possible to obtain information on the deformation of the tire in the steady state of the rolling tire, and to know the shape of the tire in the steady state.

  When the local analysis of the tread pattern model 24 is completed, in step S5, the simulation result based on the tire deformation calculation, for example, the tire shape or the like is displayed on the CRT 14 or the simulation result data is stored in the hard disk. Output simulation results.

  In step S6, it is determined whether or not a design change has been instructed by the user. If the design change has been instructed, the process returns to step S3 and the same processing is repeated, and if the design change has not been instructed. This routine ends. That is, when design change is instructed, only the local analysis of the tread pattern model 24 is performed without analyzing the tire body model 22.

  As described above, in the present embodiment, the pseudo rolling analysis is performed as a global analysis for the tire main body model 22, and the tread pattern trajectory is obtained based on the result, and the tread pattern model 24 is locally analyzed. The tire performance can be accurately simulated even with a tire having a tread pattern. Further, when it is desired to change the design of the tread pattern model 24, only the local analysis of the tread pattern model 24 needs to be performed, so that the analysis time can be significantly reduced compared to the conventional rolling global / local analysis. Design efficiency can be greatly improved.

  Next, examples of the present invention will be described. The inventor obtained the time required for the analysis of the conventional rolling analysis with a pattern, the rolling global / local analysis, and the analysis according to the present invention for a predetermined tire model. The results are shown below.

  The analysis time is shown as a relative value with the analysis time of the rolling analysis with a pattern as 100.

  As is clear from Table 1 above, the analysis time of the global analysis in the analysis of the present invention is 1/10 of the analysis time of the global analysis in the rolling global / local analysis, and the analysis time can be greatly shortened. Recognize. In the rolling global / local analysis, if there is a design change, both the global analysis and the local analysis must be performed again. However, in the analysis according to the present invention, only the local analysis needs to be executed. It was found that the analysis time can be greatly shortened and the design efficiency can be greatly improved.

It is the schematic of the personal computer for implementing preparation of a tire model and performance prediction of a tire. It is a flowchart of a tire performance simulation and a tire performance analysis program. It is a figure for demonstrating the rolling analysis of a tire. It is a figure which shows the steady state of a tire. It is a figure for demonstrating the rolling analysis of a tire. It is a figure for demonstrating the pseudo | simulation rolling analysis of a tire. (A) is a figure for demonstrating the mismatching of a mesh of a tire main body model and a tread pattern model, (B) is a figure for demonstrating the interpolation process for eliminating the said mismatching. (A) is a figure for demonstrating the shape of the grounding part before a deformation | transformation of a tire, (B) is a figure for demonstrating the shape of the grounding part after a deformation | transformation of a tire. It is a perspective view of the tire model which simplified the tread pattern. It is a perspective view which shows a part of tread pattern model.

Explanation of symbols

10 Keyboard 12 Computer body 14 CRT
16 mice

Claims (6)

Performing pseudo-rolling analysis on a tire body model obtained by meshing a tire body into a plurality of tire body elements;
A tread pattern model in which a tire tread pattern is mesh-divided into a plurality of tread pattern elements based on tire body element node information relating to the nodes of each tire body element of the tire body model obtained by the pseudo rolling analysis, and the tire Obtaining a locus of nodes of the tread pattern element on the contact surface with the main body model;
Obtaining tread pattern element deformation information related to deformation of the tread pattern element based on the trajectory of the nodes of the tread pattern element;
Tire performance simulation method including   Interpolating connection information related to connection between nodes of the tire body element on the contact surface based on information on nodes of the tire body element on the contact surface among the tire body element node information. The tire performance simulation method according to claim 1.   The tire performance simulation method according to claim 2, wherein the connection information is interpolated using a cylindrical element in a cylindrical coordinate system in the circumferential direction of the tire.   4. The tire performance simulation method according to claim 3, wherein the connection information is interpolated by a linear expression for the radial direction of the tire and is interpolated by a cubic expression for the circumferential direction of the tire. A pseudo-rolling analysis means for performing a pseudo-rolling analysis on a tire body model obtained by dividing a tire body into a plurality of tire body elements;
A tread pattern model in which a tire tread pattern is mesh-divided into a plurality of tread pattern elements based on tire body element node information relating to the nodes of each tire body element of the tire body model obtained by the pseudo rolling analysis, and the tire A trajectory calculating means for obtaining a trajectory of the node of the tread pattern element on the contact surface with the main body model;
Deformation information calculation means for obtaining tread pattern element deformation information related to deformation of the tread pattern element based on the trajectory of the nodes of the tread pattern element;
Tire performance simulation device equipped with. Performing pseudo-rolling analysis on a tire body model obtained by meshing a tire body into a plurality of tire body elements;
A tread pattern model in which a tire tread pattern is mesh-divided into a plurality of tread pattern elements based on tire body element node information relating to the nodes of each tire body element of the tire body model obtained by the pseudo rolling analysis, and the tire Obtaining a locus of nodes of the tread pattern element on the contact surface with the main body model;
Obtaining tread pattern element deformation information related to deformation of the tread pattern element based on the trajectory of the nodes of the tread pattern element;
Tire performance simulation program for causing a computer to execute processing including

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