JP5316155B2 - Method for creating twisted structure model and computer program for creating twisted structure model - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce a labor and trouble for making an analytic model of reinforcing cord. <P>SOLUTION: This method for making the analytic model a twist structure includes for making a straight line analysis model in which wires constituting reinforcing layers (step S101), respectively, have straight line shapes and which can be analyzed with a computer; for setting a boundary condition for analyzing twisting (step S102); for executing a twisting analysis for the straight line analysis model in the set boundary condition to make twist models which are made for the reinforcing layers, respectively (step S103); for combining the twist models made with respect to the reinforcing layers (step S106); and for setting restraint conditions between the twist models or the like (step S108). <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to modeling a twisted structure such as a reinforcing cord, which is a reinforcing material for a tire, that can be analyzed by a computer.

  Conventional tires have been developed through repeated trials and tests, which has the problem of poor development efficiency. In order to solve this problem, a method that can predict the physical properties of a tire, that is, the performance of the tire without producing a prototype by numerical analysis using a computer has been proposed and put into practical use in recent years. ing. When the performance of a tire is predicted by numerical analysis using a computer, it is necessary to make an analysis model that can be analyzed by the computer. The tire is a structure in which rubber is reinforced by a reinforcing cord such as a carcass or a belt.

  Since the reinforcing cord is configured by twisting and bundling complex core wires, if the reinforcing cord is faithfully modeled as an analysis model, the amount of information in the analysis model increases. As a result, it becomes difficult to create an analysis model, and the computational load of the computer increases. However, when examining the structure of the reinforcement cord, there is a demand for modeling the reinforcement cord as faithfully as possible. Regarding the analytical modeling of the reinforcement cord, for example, in Patent Document 1, a two-dimensional model of a tire cord is created, and the created two-dimensional model is developed in the longitudinal direction of the tire cord to create a three-dimensional shape. An analysis model creation method is disclosed.

JP, 2008-230375, A [0028], [0045], FIG. 5, FIG.

  In the technique disclosed in Patent Document 1, when the two-dimensional model is developed in the longitudinal direction of the tire cord, the two-dimensional model is rotated around the longitudinal direction of the tire cord while rotating the two-dimensional model in the longitudinal direction of the tire cord. Create a 3D model by extruding. For this reason, it takes time to create an analysis model of a reinforcing cord. This invention is made | formed in view of the above, Comprising: It aims at reducing the effort which creates the analytical model of a twist structure like a reinforcement cord.

  In order to solve the above-described problems and achieve the object, a method for creating a twisted structure model according to the present invention includes a combination of a plurality of reinforcing layers that combine a base material and a strand, and is embedded in a structure. When creating a model of the twisted structure that can be analyzed by a computer with respect to a twisted structure that reinforces the structure, the strands constituting each of the reinforcing layers are linearly shaped and can be analyzed by a computer. A procedure for creating a linear analysis model, a procedure for setting boundary conditions for twisting the linear analysis model around the central axis of each linear analysis model at both ends of each linear analysis model, and Based on the boundary conditions, each of the straight line analysis models is twisted about the central axis to perform a twist analysis. A procedure for creating a twist model corresponding to a wire analysis model, a procedure for combining the twist models, a constraint condition between the twist models, and a constraint condition between the strands and the base material of each twist model And creating a twisted structure model.

  As a preferred aspect of the present invention, in the method for creating a twisted structure model, it is desirable that at least one of the twisted models includes a part of the analysis model of the base material.

  As a preferred aspect of the present invention, in the method for creating a twisted structure model, it is desirable that at least one of both end portions of the twisted structure model be an analysis model of the base material.

  As a preferred aspect of the present invention, in the creation method of the twisted structure model, between the analysis model of the base material adjacent to the end surface of the analysis model of the strands constituting the twisted structure model, It is desirable to set peel or contact.

  As a preferred aspect of the present invention, in the method for creating a twisted structure model, it is desirable to change the shape of the twisted structure model in accordance with the state embedded in the analysis model of the structure.

  As a preferable aspect of the present invention, in the method for creating the twisted structure model, it is desirable that the base material is rubber.

  In order to solve the above-described problems and achieve the object, a computer program for creating a twisted structure model according to the present invention causes a computer to execute the method for creating a twisted structure model.

  INDUSTRIAL APPLICABILITY The present invention can reduce the trouble of creating an analytical model of a twisted structure such as a reinforcing cord.

FIG. 1 is a cross-sectional view showing a meridional section passing through a rotation axis of a tire. FIG. 2 is an explanatory diagram showing a configuration of a twisted structure model creation device according to the present embodiment. FIG. 3-1 is a cross-sectional view showing a tire reinforcing cord and rubber as a base material. FIG. 3-2 is a cross-sectional view illustrating an example in which a tire reinforcement cord and a base rubber material are modeled by a computer. FIG. 4 is a flowchart showing a procedure of a method for creating a twisted structure model according to the present embodiment. FIG. 5 is a cross-sectional view of the reinforcing cord. FIG. 6A is a perspective view of the linear analysis model. FIG. 6B is a perspective view of the linear analysis model. FIG. 7-1 is a cross-sectional view showing a linear analysis model. FIG. 7-2 is a cross-sectional view showing a linear analysis model. FIG. 8 is a perspective view of the analysis model of the strands constituting the linear analysis model. FIG. 9 is an explanatory diagram illustrating an example of a method for setting boundary conditions for twist analysis. FIG. 10 is an explanatory diagram illustrating another example of a method for setting boundary conditions for twist analysis. FIG. 11A is a perspective view of a twist model. FIG. 11-2 is a perspective view of a twist model. FIG. 12A is a perspective view illustrating an analysis model of a strand constituting the twist model. FIG. 12-2 is a perspective view illustrating an analysis model of the strands constituting the twist model. FIG. 13A is a cross-sectional view illustrating a first twist model. FIG. 13-2 is a cross-sectional view illustrating a second twist model. FIG. 13C is a cross-sectional view of the twisted structure model. FIG. 14A is a cross-sectional view of an example in which a reinforcing layer partially including a base material is modeled as an analysis. FIG. 14-2 is a cross-sectional view of an example in which a reinforcing cord having a reinforcing layer partially including a base material is converted into an analysis model. FIG. 15A is an explanatory diagram of a twisted structure model in which a wire model exists at both ends. FIG. 15-2 is an explanatory diagram of a twisted structure model in which one end portion is constituted only by a base material model. FIG. 16A is a schematic diagram illustrating a state in which a twist structure model is embedded in a tire model. FIG. 16-2 is a schematic diagram illustrating a twisted structure model before being embedded in a tire model.

  Hereinafter, the present invention will be described in detail with reference to the drawings. The present invention is not limited by the following contents. The following constituent elements include those that can be easily assumed by those skilled in the art and those that are substantially the same. The application target of the present invention is applicable to any tire having a reinforcing cord, and is not limited to a pneumatic tire. In the following, for convenience of explanation, a pneumatic tire is referred to as a tire unless otherwise specified.

  FIG. 1 is a cross-sectional view showing a meridional section passing through a rotation axis of a tire. As shown in FIG. 1, a carcass 2, a belt 3, a belt cover 4, and a bead core 5 appear on the meridional section of the tire 1. The tire 1 is a composite material structure in which rubber as a base material is reinforced by a reinforcing cord such as a carcass 2, a belt 3, or a belt cover 4 as a reinforcing material. Here, a layer of a reinforcing cord made of a cord material such as a metal fiber or an organic fiber, such as the carcass 2, the belt 3, and the belt cover 4, is referred to as a cord layer.

  The carcass 2 is a strength member that serves as a pressure vessel when the tire 1 is filled with air. The carcass 2 supports a load by its internal pressure and withstands a dynamic load during traveling. The belt 3 is a layer of reinforcing cords in which rubberized cords arranged between the cap tread and the carcass 2 are bundled. In the case of a bias tire, it is called a breaker. In the radial tire, the belt 3 plays an important role as a shape retention and strength member.

  A belt cover 4 is disposed on the ground surface G side of the belt 3. The belt cover 4 is formed by arranging, for example, organic fiber materials in layers, and has a role as a protective layer for the belt 3 and a role as a reinforcing layer for the belt 3. The bead core 5 is a bundle of steel wires that supports the cord tension generated in the carcass 2 by internal pressure. The bead core 5 becomes a strength member of the tire 1 together with the carcass 2, the belt 3, the belt cover 4, and the tread. A groove 7 is formed on the ground surface G side of the cap tread 6. This improves drainage during rainy weather. The side portion of the tire 1 is called a sidewall 8 and connects between the bead core 5 and the cap tread 6. Further, a shoulder portion Sh is provided between the cap tread 6 and the sidewall 8. Next, the apparatus which performs the preparation method of the twist structure model which concerns on this embodiment is demonstrated.

  FIG. 2 is an explanatory diagram showing a configuration of a twisted structure model creation device according to the present embodiment. The twisted structure model creating apparatus 50 shown in FIG. 2 executes the twisted structure model creating method according to the present embodiment. The twisted structure model creation apparatus 50 includes a processing unit 50p and a storage unit 50m. The processing unit 50p and the storage unit 50m are connected via an input / output unit (I / O) 59.

  The processing unit 50p includes a model creation unit 51, an analysis unit 52, and a condition determination unit 53. These execute the creation method of the twisted structure model according to the present embodiment. The model creation unit 51, the analysis unit 52, and the condition determination unit 53 are connected to an input / output unit 59, and are configured to exchange data with each other.

In addition, the terminal device 60 is connected to the input / output unit 59, and data necessary for executing the method for creating the twisted structure model according to the present embodiment, for example, physical property values of the material constituting the tire 1 Further, the physical property value of the fiber material, the boundary condition in the analysis, the running condition, and the like are given to the twisted structure model creation device 50 by the input / output device 61 connected to the terminal device 60. In addition, data for creating a twisted structure model is received from the twisted structure model creating apparatus 50, and the analysis result is displayed on the display device 62 connected to the terminal device 60. Furthermore, various data servers 64 ₁ , 64 _2, etc. are connected to the input / output unit 59 via the network 63. Then, in performing the creation of the structure model twisted according to the present embodiment, the processing unit 50p can be configured to take advantage of the various databases stored in the various data servers 64 _1, 64 ₂ Hitoshinai.

The storage unit 50m stores a computer program including a processing procedure of a method for creating a twisted structure model according to the present embodiment, which will be described later, and data such as material properties acquired from various data servers 64 ₁ , 64 _{2 and the} like. ing. In addition, data, such as material physical property, is used when performing the preparation method of the twist structure body model which concerns on this embodiment. Here, the storage unit 50m can be configured by a volatile memory such as a RAM (Random Access Memory), a nonvolatile memory, a hard disk device, or a combination thereof. The processing unit 50p can be configured by a memory and a CPU (Central Processing Unit). The storage unit 50m may be built in the processing unit 50p or may be in another device (for example, a database server). Thus, the twisted structure model creation device 50 may access the processing unit 50p and the storage unit 50m from the terminal device 60 by communication.

  The computer program can realize the processing procedure of the method for creating a twisted structure model according to the present embodiment, in combination with the computer program already recorded in the model creation unit 51, the analysis unit 52, and the like included in the processing unit 50p. It may be a thing. Further, the twisted structure model creation device 50 realizes the functions of the model creation unit 51, the analysis unit 52, and the condition determination unit 53 included in the processing unit 50p by using dedicated hardware instead of the computer program. It may be a thing.

  FIG. 3-1 is a cross-sectional view showing a tire reinforcing cord and rubber as a base material. FIG. 3-2 is a cross-sectional view illustrating an example in which a tire reinforcement cord and a base rubber material are modeled by a computer. As shown in FIG. 3A, the tire has a reinforcing cord 10 such as a belt or a carcass embedded in a rubber 20 that is a base material. In tire rolling analysis, vibration analysis, and the like, a computer-analyzed model (analysis model) is used to perform analysis by a computer. For this reason, in the rolling analysis and vibration analysis of the tire, it is necessary to convert the analysis target into an analysis model prior to the analysis.

  For example, when analyzing the structure of the tire or the reinforcing cord 10 by paying attention to the reinforcing cord 10 such as the structure of the reinforcing cord 10, it is preferable to model the shape of the reinforcing cord 10 as faithfully as possible. However, when analyzing the structure and behavior of a tire by FEM (Finite Element Method) analysis, as shown in FIG. 3-2, a simple plate element 10P that normally exhibits similar behavior to the reinforcing cord 10 is used. The reinforcing cord 10 is often modeled. In the example illustrated in FIG. 3B, the rubber 20 is modeled by a solid element 20S. Such a plate element 10 </ b> P may not be sufficient for studying the structure of the reinforcing cord 10.

  Further, the reinforcing cord 10 has a complicated twisted structure of wires and fibers, and the twisting direction and the pitch length differ depending on the structure. In the analysis using the finite element method, it is necessary to faithfully reproduce such a shape and perform element division based on the finite element method to create an analysis model. However, in order to divide the complex twisted structure such as the reinforcing cord 10 more faithfully into elements, the number of nodes (that is, the number of elements) increases and the calculation time increases.

  Moreover, since the reinforcement cord 10 generally uses a wire or fiber covered with rubber, the behavior of rubber existing around the wire or fiber is also an object of analysis. Here, when a rubber material having a Poisson's ratio close to 0.5 is targeted, the deformation of the tetrahedral solid element is underestimated and the accuracy becomes insufficient. In such a case, a tetrahedral ten-node element is created and analyzed based on a tetrahedral solid element. In such a tetrahedral ten-node element, the calculation time increases significantly due to a rapid increase in the number of nodes. . Therefore, in the analysis of the reinforcing cord 10 covered with rubber, it is preferable to use a pentahedral solid element or a hexahedral solid element. For example, in automatic element division using software, a pentahedral solid element or a hexahedral solid element is used. Is difficult to generate.

  The method for creating a twisted structure model according to the present embodiment creates a twisted structure model using pentahedral solid elements and hexahedral solid elements as much as possible when creating an analysis model of a twisted structure such as the reinforcement cord 10. In addition, element division can be realized automatically as much as possible. Next, a procedure for realizing a method for creating a twisted structure model according to the present embodiment will be described. The method for creating a twisted structure model according to the present embodiment can be realized by the twisted structure model creating apparatus 50 described above.

  FIG. 4 is a flowchart showing a procedure of a method for creating a twisted structure model according to the present embodiment. FIG. 5 is a cross-sectional view of the reinforcing cord. FIGS. 6A and 6B are perspective views illustrating the linear analysis model, and FIGS. 7A and 7B are cross-sectional views illustrating the linear analysis model. FIG. 8 is a perspective view of the analysis model of the strands constituting the linear analysis model.

  In the creation method of the twisted structure model according to the present embodiment, an analysis model of the reinforcing cord 10 in which the second reinforcing layer 12 is disposed outside the first reinforcing layer 11 as shown in FIG. The 1st reinforcement layer 11 which comprises the reinforcement cord 10 is comprised combining the 1st preform | base_material 14 and the 1st strand 13 which is a strand. The 1st reinforcement layer 11 which comprises the reinforcement cord 10 is comprised combining the 1st preform | base_material 14 and the 1st strand 13 which is a strand. The 1st strand 13 which comprises the 1st reinforcement layer 11 is a strand wire, such as a metal wire and an organic fiber, for example, In the example shown in FIG. The first reinforcing layer 11 is constituted by this. The first base material 14 is, for example, rubber.

  The second reinforcing layer 12 constituting the reinforcing cord 10 is a reinforcing layer disposed outside the first reinforcing layer 11. The 2nd reinforcement layer 12 is comprised combining the 2nd base material 16 and the 2nd strand 15 which is a strand. The 2nd strand 15 which comprises the 2nd reinforcement layer 12 is a strand wire, such as a metal wire and an organic fiber, for example, and in the example shown in FIG. The second reinforcing layer 12 is constituted by this. The second base material 16 is, for example, rubber. The second reinforcing layer 12 is a reinforcing layer having an annular cross section configured to surround the first reinforcing layer 11 with a plurality of second strands 15.

  In executing the method for creating a twisted structure model according to the present embodiment, in step S101, the model creating unit 51 of the twisted structure model creating apparatus 50 shown in FIG. 2 is a straight line in which straight strands are incorporated into the base material. Create an analysis model. The straight line analysis model is a three-dimensional analysis model, and is created for each of the first reinforcement layer 11 and the second reinforcement layer 12. The linear analysis model of the first reinforcement layer 11 is the first linear analysis model 11M1 shown in FIGS. 6-1 and 7-1, and the linear analysis model of the second reinforcement layer 12 is FIGS. 6-2 and 7-. 2 is a second linear analysis model 12M1 shown in FIG.

  In the present embodiment, the first linear analysis model 11M1 and the second linear analysis model 12M1 are models used for performing rolling analysis, deformation analysis, and the like using a numerical analysis method such as a finite element method or a finite difference method. A computer-analysable model (analysis model). In the present embodiment, a tire model is created using a twisted structure model, and rolling analysis, vibration analysis, and the like are performed using a finite element method (FEM). Since the finite element method is an analysis method suitable for structural analysis, it can be suitably applied particularly to a twisted structure such as the reinforcing cord 10 or a structure such as a tire.

  The model creation unit 51 divides the first reinforcing layer 11 and the second reinforcing layer 12 into a plurality of finite elements E composed of a plurality of nodes based on a method used for analysis (finite element method in the present embodiment). Then, the first linear analysis model 11M1 and the second linear analysis model 12M1 shown in FIGS. 6-1 and 6-2 are created. Each element E is composed of a plurality of nodes. In the present embodiment, the model creation unit 51 acquires information (for example, coordinate information) related to the shapes of the first reinforcement layer 11 and the second reinforcement layer 12 and can automatically divide the element. Is read from the storage unit 50m and executed. Thereby, the model creation unit 51 divides the first reinforcement layer 11 and the second reinforcement layer 12 into elements, and creates the first linear analysis model 11M1 and the second linear analysis model 12M1.

  In general, in the finite element method, for example, in a three-dimensional body, a solid element such as a tetrahedral solid element, a pentahedral solid element, a hexahedral solid element, a triangular shell element, a shell element such as a quadrangle shell element, a surface element, etc. An analysis model is created based on factors that can be used in a computer. In the present embodiment, the first linear analysis model 11M1 and the second linear analysis are mainly composed of at least one of a pentahedral solid element and a hexahedral solid element in order to convert the twisted structure more faithfully into an analytical model and improve analysis accuracy. A model 12M1 is created. In the process of analysis, the elements divided in this way are identified one by one using three-dimensional coordinates in the three-dimensional model.

  The model creation unit 51 creates an analysis model of the reinforcement cord 10 without distinguishing between the first reinforcement layer 11 and the second reinforcement layer 12 of the reinforcement cord 10, and then the first linear analysis model 11M1 and the second linear analysis model. The interface with 12M1 may be set, and the analysis model of the reinforcing cord 10 may be divided at the interface to create the first linear analysis model 11M1 and the second linear analysis model 12M1. In addition, the model creation unit 51 may create the first linear analysis model 11M1 and the second linear analysis model 12M1 by separately modeling the first reinforcement layer 11 and the second reinforcement layer 12 respectively.

  As shown in FIGS. 6-1 and 7-1, the first linear analysis model 11M1 is obtained by analyzing the first base material 14 and the first strand 13 shown in FIG. And the first strand model 13M. Similarly, as shown in FIGS. 6-2 and 7-2, the second linear analysis model 12M1 is obtained by analyzing the first base material 16 and the second strand 15 shown in FIG. This is an analysis model in which the material model 16M and the second strand model 15M are combined.

  As shown in FIG. 8, the first strand model 13M (analysis model of the first strand 13) of the first straight line analysis model 11M1 and the second strand model 15M (second strand 15 of the second straight line analysis model 12M1). Are analytical models having a linear shape. That is, the first strand model 13M is parallel to the central axis Z1 of the first linear analysis model 11M1, and the second strand model 15M is parallel to the central axis Z2 of the second linear analysis model 12M1. Here, the central axis Z1 of the first linear analysis model 11M1 and the central axis Z2 of the second linear analysis model 11M1 are the same as the central axis Z (see FIG. 5) of the reinforcing cord 10 before these are converted into an analysis model. Become.

  By using the first strand model 13M and the second strand model 15M as a linear shape analysis model, the first base material model 14M and the second base material model 16M also become a linear shape analysis model. The analysis model 11M1 and the second linear analysis model 12M1 are also linear analysis models. As described above, in the present embodiment, the first straight line analysis model 11M1 and the second straight line analysis model 12M1 are straight line analysis models, so that an analysis model can be easily created, and a pentahedral solid element or a hexahedral solid element. The first straight line analysis model 11M1 and the second straight line analysis model 12M1 can be configured by using as a main component. This effect is particularly great when using automatic element splitting. When the linear analysis model is created in step S101, the process proceeds to step S102.

  FIG. 9 is an explanatory diagram illustrating an example of a method for setting boundary conditions for twist analysis. FIG. 10 is an explanatory diagram illustrating another example of a method for setting boundary conditions for twist analysis. 11-1 and 11-2 are perspective views of a twist model. FIGS. 12A and 12B are perspective views illustrating an analysis model of the strands constituting the twist model. In step S102, boundary conditions for torsion analysis are set. In the torsion analysis, the stress and strain states of the first linear analysis model 11M1 and the like when a predetermined twist angle (rotation angle) is given to both ends of each of the first linear analysis model 11M1 and the second linear analysis model 12M1. To analyze. In the present embodiment, by performing torsion analysis, the nodes constituting the first linear analysis model 11M1 and the nodes constituting the second linear analysis model 12M1 are rotated around the respective central axes by a predetermined angle. Then, an analysis model of each reinforcing layer constituting the reinforcing cord 10 is created.

  The boundary condition set in step S102 is a condition of how much the nodes constituting the first linear analysis model 11M1 and the nodes constituting the second linear analysis model 12M1 are displaced when the torsional analysis is executed. As a method of giving this boundary condition, for example, as shown in FIG. 9, nodes N1 and N2 of an arbitrary cross section Tc perpendicular to the central axes Z1 and Z2 of the first linear analysis model 11M1 and the second linear analysis model 12M1 are used. ... Nn is related to the reference node N that controls the deformation. Then, a boundary condition of rotating the reference node N in a predetermined direction by a predetermined angle (arrow R in FIG. 10) is given, and the nodes N1, N2,... Nn of the cross section Tc are set around the central axes Z1, Z2. Rotate.

  The boundary condition using the reference node N is always given to both ends T1 and T2 of the first linear analysis model 11M1 and the second linear analysis model 12M1. For example, the end T1 does not rotate the reference node N, and the end T2 rotates the reference node N by a predetermined angle. Accordingly, one end T1 of the first linear analysis model 11M1 and the second linear analysis model 12M1 can be fixed, and the other end T2 can be twisted by a predetermined angle. In the twist analysis in step S103, the analysis unit 52 of the twisted structure model creation device 50 applies a twist to the first linear analysis model 11M1 and the second linear analysis model 12M1, and calculates the stress state and strain. The result is stored in the storage unit 50m.

  The boundary conditions using the reference node N are the center axes of the first linear analysis model 11M1 and the second linear analysis model 12M1, as well as the ends T1 and T2 of both the first linear analysis model 11M1 and the second linear analysis model 12M1. You may give to arbitrary cross sections Tc perpendicular | vertical to Z1 and Z2. By doing in this way, even if twist is large, it can control that modification of the 1st straight line analysis model 11M1 and the 2nd straight line analysis model 12M1 deviates from an actual deformation. In addition, the arbitrary cross section which provides the boundary condition using the reference node N other than both ends T1 and T2 of both the first linear analysis model 11M1 and the second linear analysis model 12M1 is not limited to one.

  In addition to the method using the reference node N described above, a method of giving a displacement corresponding to rotation around the central axis as a boundary condition to the nodes constituting the first linear analysis model 11M1 and the nodes constituting the second linear analysis model 12M1 There is. Next, a method for obtaining a displacement corresponding to rotation around the central axis will be described with reference to FIG. In this method, the rotation angle of the other end T2 with respect to one end T1 of the first linear analysis model 11M1 or the second linear analysis model 12M1, and the central axis of the first linear analysis model 11M1 or the second linear analysis model 12M1. Based on the first straight line analysis model 11M1 in the Z1 and Z2 directions and the distance l from the end T1 of the second straight line analysis model 12M1, the nodes constituting the first straight line analysis model 11M1 and the second straight line analysis model 12M1 are formed. The node to be rotated is rotated around the respective central axes Z1 and Z2. Then, the displacement of each node is obtained from the coordinates of the node before and after the rotation.

  When the nodes constituting the first linear analysis model 11M1 and the nodes constituting the second linear analysis model 12M1 are rotated around the central axes Z1 and Z2, the nodes are rotated around the central axes Z1 and Z2 by a predetermined rotation. Rotate by an angle. This is realized by rotationally converting the coordinates of the node to be rotated using the rotation angle. For this reason, the other end T2 of the first linear analysis model 11M1 and the second linear analysis model 12M1 is rotated by the rotation angle (end rotation angle) Θ with respect to one end T1, and both ends T1, During T2, the rotation angle is changed according to the distance from one end T1 so that the other end T2 has the end rotation angle Θ.

  The end rotation angle Θ is an angle at which the end T2 is rotated with respect to the end T1. As shown in FIG. 10, when the end portion T2 is rotated by the end portion rotation angle Θ, the node (pre-movement node) P1 in an arbitrary cross section Tc orthogonal to the central axis Z1 of the first linear analysis model 11M1 rotates. To the position of the node (node after movement) P2. The same applies to the second linear analysis model 12M1, and therefore, in the following description, the first linear analysis model 11M1 will be described.

The rotation angle θ of the post-movement node P2 in the arbitrary cross section Tc of the first linear analysis model 11M1 is the end portion rotation angle Θ and the distance from the end T1 (end opposite to the end T2) to the arbitrary cross section. Using the distance between 1 and the end portions T1 and T2 (the distance along the central axis Z1), the equation (1) is obtained. From equation (1), θ at the end T1 is zero.
θ = Θ × 1 / L (1)

  The coordinates of the node P1 before movement are P1 (x1, y1, z1), and the coordinates of the node P2 after movement are P2 (x2, y2, z1). Then, (x2, y2) of the coordinates of the post-movement node P2 can be obtained by Expression (2) using (x1, y1) of the coordinates of the pre-movement node and θ of Expression (1). From the equation (2), at the end T1 (l = 0), x1 = x2 and y1 = y2, so that the pre-movement node P1 and the post-movement node P2 coincide. That is, the node at the end T1 does not move.

  If the end rotation angle Θ is given, since the distance from the end T1 of an arbitrary cross section Tc orthogonal to the central axis Z1 of the first linear analysis model 11M1 is given by l, the expressions (1) and (2) Is used to obtain the coordinates of the post-movement node existing in an arbitrary cross section Tc. Then, by using the coordinates of the nodal point after movement and the coordinates of the contact point before movement, the first straight line analysis model 11M1 when the other end T2 of the first straight line analysis model 11M1 is rotated by the end portion rotation angle Θ is obtained. Displacement of all the nodes that constitute, that is, the boundary condition given by the torsion analysis is obtained. Note that the end rotation angle Θ is determined according to the specifications of the twisted structure model to be created.

  In setting the boundary condition, the model creation unit 51 converts the coordinates of the nodes existing in all cross sections orthogonal to the central axis Z1 of the first linear analysis model 11M1 using the equations (1) and (2). Then, the coordinates of the node after movement are obtained. Then, the model creation unit 51 uses the coordinates of the post-movement nodes and the coordinates of the pre-movement contact points to obtain the displacements of all the nodes constituting the first linear analysis model 11M1, and as a boundary condition to be given in the torsion analysis And stored in the storage unit 50m.

  In step S102, for example, boundary conditions such as the reference node and the rotation angle of the reference node, and information (end rotation angle Θ) for causing the model creating unit 51 to calculate the displacement of the node such as the first linear analysis model 11M1 are included. The input / output device 61 inputs the twisted structure model creation device 50. When the displacement of the node is used as the boundary condition for torsion analysis, the model creation unit 51 obtains the displacement of the node constituting the first linear analysis model 11M1 or the like from the input end rotation angle Θ and stores it in the storage unit 50m. To do.

  In step S103, the analysis unit 52 performs torsion analysis on the first linear analysis model 11M1 under the boundary condition set in step S102. The analysis model expressed by each node after executing the twist analysis is the first twist model 11M2 shown in FIG. The first twist model 11M2 includes a first strand model 13M2 and a first base material model 14M2. The first twist model 11M2 is created by being twisted in the direction of the arrow R1 in FIG. Thereby, as shown in FIG. 12A, the first twist model 11M2 has a shape in which the first strand model 13M2 is twisted.

  When the twist analysis ends, the process proceeds to step S104. In step S104, the condition determination unit 53 of the twisted structure model creation device 50 performs all the reinforcement layers, that is, all the linear analysis models (in the present embodiment, the first linear analysis model 11M1 and the second linear analysis model 12M1). ) To determine whether or not the torsional analysis has been completed. When it determines with No by step S104, it returns to step S103 and the analysis part 52 performs a twist analysis with respect to the linear analysis model in which the twist analysis is not complete | finished.

  For example, when the twist analysis of the second straight line analysis model 12M1 is not completed, the analysis unit 52 performs the twist analysis on the second straight line analysis model 12M1 under the boundary condition set in step S102. The analysis model expressed by each node after the torsion analysis is executed becomes the second twist model 12M2 shown in FIG. The second twist model 12M2 includes a second strand model 15M2 and a second base material model 16M2. The second twist model 12M2 is created by being twisted in the direction of arrow R2 in FIG. As a result, as shown in FIG. 12B, the second twist model 12M2 has a shape in which the second strand model 15M2 is twisted. When it determines with Yes by step S104, it progresses to step S105.

  In step S105, the model creation unit 51 extracts the deformation state from the first linear analysis model 11M1 and the second linear analysis model 12M1 after the torsion analysis is executed. That is, the model creation unit 51 acquires the coordinates of each node from the first twist model 11M2 and the second twist model 12M2, and stores them in the storage unit 50m. When the deformation state is extracted from the first twist model 11M2 and the second twist model 12M2, the process proceeds to step S106.

  FIG. 13-1 is a cross-sectional view of the first twist model, and FIG. 13-2 is a cross-sectional view of the second twist model. FIG. 13C is a cross-sectional view of the twisted structure model. In step S106, the model creation unit 51 combines the created first twist model 11M2 and the second twist model 12M2. In combining the first twist model 11M2 and the second twist model 12M2, the node on the surface BP1 of the first twist model 11M2 shown in FIG. 13-1 is the inner surface BP2 of the second twist model 12M2 shown in FIG. 13-2. To be placed on top. That is, the nodes existing on the surface BP1 of the first twist model 11M2 and the nodes existing on the inner surface BP2 of the second twist model 12M2 are made to be on the same plane.

  Next, it progresses to step S107, and the model preparation part 51 acquires each distortion (initial strain), stress (initial stress), and other physical quantities from the 1st twist model 11M2 and the 2nd twist model 12M2, and the memory | storage part 50m To store. In the present embodiment, since the first straight line analysis model 11M1 and the second straight line analysis model 12M1 are created in a straight line shape, the first straight line analysis model 11M1 mainly composed of pentahedral solid elements and hexahedral solid elements can be easily created. . An initial stress or initial strain can be generated in the first linear analysis model 11M1 or the like by executing a twist analysis in which the first linear analysis model 11M1 or the like having a linear shape is twisted at both ends thereof. Thereby, an actual twist structure can be reproduced more faithfully. When the physical quantity is acquired from the first twist model 11M2 and the second twist model 12M2, the process proceeds to step S108.

  In step S108, a constraint condition is set. The constraint conditions are between the first twist model 11M2 and the second twist model 12M2 constituting the twist structure model 10M, and the strands of the first twist model 11M2 (first strand model 13M2) and the base material (first It is set between the base material model 14M2) and between the strand of the second twist model 12M2 (second strand model 15M2) and the base material (second base material model 16M2). Examples of the constraint conditions to be set include contact, peeling, and sticking.

  The fixing is a setting for fixing the node on the surface BP1 of the first twist model 11M2 on the inner surface BP2 of the second twist model 12M2. The contact is set such that a node on the surface BP1 of the first twist model 11M2 can move with a certain amount of frictional force on the inner surface BP2 of the second twist model 12M2. Further, the peeling fixes the nodes on the surface BP1 of the first twist model 11M2 on the inner surface BP2 of the second twist model 12M2, and a predetermined shearing force acts on the nodes on the surface BP1 of the first twist model 11M2. In this case, the setting is released.

  In this way, the twisted structure model 10M is completed by combining the first twist model 11M2 and the second twist model 12M2 and setting the constraint conditions. In the completed twisted structure model 10M, the coordinates of the nodes and the constraint conditions are stored in the storage unit 50m. When performing rolling analysis or vibration analysis, the model creation unit 51 reads the coordinates and constraint conditions of the nodes of the twisted structure model 10M from the storage unit 50m, and embeds them in the tire model created in advance. Based on the analysis conditions input from the input / output device 61, the analysis unit 52 of the production device 50 performs rolling analysis and the like on the tire model in which the twisted structure model 10M is embedded.

  FIG. 14A is a cross-sectional view of an example in which a reinforcing layer partially including a base material is modeled as an analysis. FIG. 14-2 is a cross-sectional view of an example in which a reinforcing cord having a reinforcing layer partially including a base material is converted into an analysis model. In the twisted structure model 10Ma shown in FIG. 14-2, the base material 14 is not provided in the vicinity of the central axis Z of the first reinforcing layer 11 (see FIG. 5). This is an analytical model of a reinforcing cord with materials. The twist model 11M2a shown in FIG. 14-1 is an analysis model that constitutes the twist structure model 10Ma shown in FIG. 14-2, and the first base material model 14M2a and the first base material model 14M2a in which the base material is not provided near the central axis Z1. It is configured by combining with one strand model 13M2.

  The twist model 11M2a creates a linear first linear analysis model in which the base material 14 is not provided in the vicinity of the central axis Z of the first reinforcing layer 11, and the movement of the nodes described above with respect to the first linear analysis model It is created by executing. In addition, the reinforcement layer in which the base material partially exists may be at least one of the plurality of reinforcement layers constituting the reinforcement cord. Further, in a portion where the base material model does not exist (portion indicated by C in the twist model 11M2a), contact may be defined between the wire models (between the plurality of first wire models 13M2).

  FIG. 15A is an explanatory diagram of a twisted structure model in which a wire model exists at both ends. FIG. 15-2 is an explanatory diagram of a twisted structure model in which one end portion is constituted only by a base material model. In the twisted structure model 10M shown in FIG. 15A, the first and second base material models 14M and 16M and the first and second strand models 13M and 15M exist at both ends T1 and T2. On the other hand, in the twisted structure model 10Mb shown in FIG. 15A, the first and second base material models 14M and 16M and the first and second strand models 13M and 15M exist at one end T2. However, only the first and second base material models 14M and 16M exist at the other end T1. In addition, you may comprise so that only the 1st, 2nd base material models 14M and 16M may exist in both edge part T1, T2.

  When at least one end of the twisted structure model is used only as the base material analysis model, separation or contact is set between the end of the strand analysis model and the end of the base material analysis model. In the example shown in FIG. 15B, separation or separation occurs between the end faces BPc of the first and second strand models 13M and 15M and the end faces BPg of the first and second base material models 14M and 16M adjacent thereto. Define contact. Thereby, the behavior of the base material and the wire can be accurately reproduced.

  FIG. 16A is a schematic diagram illustrating a state in which a twist structure model is embedded in a tire model. FIG. 16-2 is a schematic diagram illustrating a twisted structure model before being embedded in a tire model. Yr in FIGS. 16-1 and 16-2 is a rotation axis of the tire model 30M. The twisted structure model 10M and the like created by the method for creating a twisted structure model according to the present embodiment is an analytical model of the tire reinforcing cord 10, and a tire model obtained by analytically modeling a tire that is a structure. Embedded in 30M for rolling analysis and vibration analysis.

  In this embodiment, before embedding the twisted structure model 10M in the tire model 30M, the shape of the twisted structure model 10M or the like is changed in accordance with the state embedded in the tire model 30M. Specifically, the model creation unit 51 deforms the structure model 10M and the like according to the radius rt in the portion where the twisted structure model 10M is embedded in the tire model 30M. For example, the model creation unit 51 performs bending analysis on the twisted structure model 10M so that the radius of curvature is rt, and deforms the twisted structure model 10M. Thus, the twisted structure model 10M and the like can be easily embedded in the tire model 30M by changing the twisted structure model 10M and the like according to the state embedded in the tire model 30M.

  As described above, in the present embodiment, first, the reinforcement layer of the twist structure is used as a linear analysis model (linear analysis model), and then the twist model is twisted by performing twist analysis that twists both ends of the linear analysis model. Create for each body reinforcement layer. Then, an analysis model of a twist structure is created by combining twist models corresponding to the respective reinforcing layers. In this way, by using a linear shape analysis model, the shape of the twisted structure can be faithfully reproduced, and a straight line analysis model mainly composed of pentahedral solid elements and hexahedral solid elements can be easily created. A twist model can be easily created by executing a twist analysis in which a straight line-shaped straight line analysis model is twisted at both ends thereof. As described above, in this embodiment, an analysis model of a twisted structure mainly composed of a pentahedral solid element and a hexahedral solid element can be easily created. Therefore, labor for creating an analysis model of a twisted structure can be reduced. . Moreover, in this embodiment, since the analysis model of the twist structure mainly composed of the pentahedral solid element and the hexahedral solid element can be created, the analysis accuracy is improved, and the performance of the twist structure can be appropriately evaluated. Furthermore, a twist analysis model with initial stress and initial strain can be created by performing a twist analysis that twists the linear analysis model at both ends, so the stress and strain state of the actual twist structure can be reproduced more faithfully. it can.

  As described above, the method for creating a twisted structure model and the computer program for creating a twisted structure model according to the present invention are useful for creating an analysis model of a twisted structure that can be analyzed by a computer.

DESCRIPTION OF SYMBOLS 1 Tire 2 Carcass 3 Belt 4 Belt cover 5 Bead core 6 Cap tread 10 Reinforcement cord 10M, 10Ma, 10Mb Twisted structure model 10P Board element 11 1st reinforcement layer 11M2, 11M2a 1st twist model 11M1 1st linear analysis model 12 2nd Reinforcement layer 12M2 Second strand model 12M1 Second linear analysis model 13, 15 Strand 13M, 13M2 First strand model 14, 16 Base material 14M, 14M2, 14M2a First base material model 15M, 15M2 Second strand model 16M , 16M2 second base material model 20 rubber 20S solid element 30M tire model 50 twisted structure model creation device 50m storage unit 50p processing unit 51 model creation unit 52 analysis unit 53 condition determination unit 59 input / output unit 60 terminal device 61 input / output Device 62 Display device

Claims (7)

When creating a model of a twisted structure that can be analyzed by a computer for a twisted structure that reinforces the structure by combining a plurality of reinforcing layers that are a combination of a base material and wire. ,
A procedure for creating a linear analysis model that can be analyzed by a computer, in which the strands constituting each of the reinforcing layers have a linear shape,
A procedure for setting boundary conditions for twisting the linear analysis model around the central axis of the linear analysis model at both ends of the linear analysis model;
A procedure for creating a twist model corresponding to each linear analysis model by performing a twist analysis that twists each linear analysis model around each central axis based on the set boundary conditions;
Combining each of the twisted models;
A procedure for creating a twisted structure model by setting a constraint condition between each of the twist models, and a constraint condition between the strand and the base material of each of the twist models,
A method for creating a twisted structure model, comprising:   The method for creating a twisted structure model according to claim 1, wherein at least one of the twisted models includes an analysis model of the base material in part.   The method for creating a twisted structure model according to claim 1 or 2, wherein at least one of both ends of the twisted structure model is an analysis model of the base material.   4. Creation of a twisted structure model according to claim 3, wherein separation or contact is set between an end face of an analysis model of a strand constituting the twisted structure model and an analysis model of the adjacent base material. Method.   The method for creating a twisted structure model according to any one of claims 1 to 4, wherein the shape of the twisted structure model is changed according to a state embedded in an analysis model of the structure.   The method for creating a twisted structure model according to any one of claims 1 to 5, wherein the base material is rubber.   A computer program for creating a twisted structure model, which causes a computer to execute the method for creating a twisted structure model according to any one of claims 1 to 6.

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