JP2008230375A - Method, device and program for creating analytic model of tire cord - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To analyze a tire cord with high accuracy in an analysis and the like of a tire. <P>SOLUTION: When a tire cord for modeling which is created as an analytic model is specified in S200 (S200), a two-dimensional model, in which filament (cross section) of each layer in each twisted direction is divided by elements and a circumscribed shape surrounding the circumference and contact elements are determined, is created (S202). The two-dimensional model is developed while being twisted and rotated in the longitudinal direction in sequence from an inner layer toward outer layer, and a three-dimensional shape is created (S204) to obtain the analytical model, by associating the contact elements between an inscribed shape and a circumscribed shape so as to make adjacent layers contact each other in accordance with contact conditions which specify the limit of relative movement between the elements. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a tire code analysis model creation method, apparatus, and program for a tire code used when numerically analyzing a tire used in an automobile or the like.

  The analysis of tire behavior is based on the results of measuring the tires actually designed and manufactured and using the results of performance tests obtained by mounting them on automobiles. Can now be realized. As a main method for analyzing the tire behavior by simulation, a numerical analysis method such as a finite element method (FEM) is mainly used. FEM is a technique of modeling a structure with a finite number of elements and analyzing the behavior of the structure using a computer, and divides the structure into a finite number of elements from its features (hereinafter referred to as mesh division or Element division). In order to simulate tire behavior with high prediction accuracy, how to produce a tire model for simulation (consisting of numerical data) composed of a finite number of elements in the same way as the actual tire shape is important.

By the way, the tire is configured to include many tire cords as well as a rubber material. This tire cord is used by forming a plurality of cores (filaments) in a complex twisted manner. Therefore, it is preferable to model the tire cord portion when the tire is simulated by FEM. As a technique that enables modeling of a tire cord, a technique that simplifies and models a tire cord so as to have equivalent rigidity is known (for example, see Patent Document 1).
JP 2004-102424 A

  However, it is difficult to perform highly accurate analysis by replacing the tire cord with a model simplified so as to have equivalent rigidity. That is, when modeling a tire, the tire cross-section elements are often modeled by three-dimensional development. However, tire cords are usually constructed by bundling a plurality of filaments, such as several wires or fibers, and the twist direction of each filament is various. Careful finite element modeling from the cross-section of the tire cord while considering it is complicated and increases the number of elements, which is virtually impossible.

  In consideration of the above-described facts, the present invention provides a tire cord that enables a tire code to be analyzed with high accuracy in calculation in a tire analysis by a numerical analysis method such as a finite element method (FEM). It is an object to obtain an analysis model creation method, apparatus, and program.

  In order to achieve the above object, the invention of claim 1 is a method for creating an analysis model of a tire code that constitutes a part of a tire model used to calculate a tire corresponding to a numerical calculation model, When the tire cord is formed by bundling a plurality of filament elements while twisting them in a predetermined direction and is composed of a plurality of classification layers from the center to the outside corresponding to the twisting direction of the filament elements, the inside of the classification layers A step of defining a first two-dimensional region including at least a filament element cross-sectional shape in a direction intersecting the longitudinal direction with respect to the first layer, and a longitudinal direction while twisting the first two-dimensional region in a corresponding twisting direction. Forming a first layer divided into predetermined division elements that can be numerically calculated while three-dimensionally developing, and a longitudinal direction of an outer second layer adjacent to the first layer, The step of defining a second two-dimensional region including at least the filament element cross-sectional shape in the direction of the difference, and the second two-dimensional region can be numerically calculated while three-dimensionally developing in the longitudinal direction while twisting in the corresponding twisting direction Forming a second layer divided by a predetermined division element, setting a contact element on at least one of an outer circumference of the first two-dimensional area and an inner circumference of the second two-dimensional area, and the setting Corresponding to the contact element on the outer periphery of the first layer, the inner peripheral element of the second layer in contact with the contact element, and the contact element on the inner periphery of the second layer and the contact element. And setting and associating at least one of the elements on the outer periphery of the first layer with a contact condition defining a restriction on relative movement between the elements.

  The invention of claim 2 is the tire cord analysis model creation method according to claim 1, wherein the contact element is set on at least a part of a peripheral surface, and the association is on the at least part of the surface. It is a surface of at least a part of the corresponding peripheral surface.

  The invention of claim 3 is the tire cord analysis model creation method according to claim 1 or claim 2, wherein the outer third layer adjacent to the second layer has a filament in a direction intersecting the longitudinal direction. A step of setting a third two-dimensional region including at least an element cross-sectional shape, and a predetermined divided element capable of numerical calculation while developing the third two-dimensional region in the longitudinal direction while twisting in the corresponding twist direction. Corresponding to the step of forming the divided third layer, the step of setting a contact element on at least one of the outer periphery of the second two-dimensional region and the inner periphery of the third two-dimensional region, and the set contact element The outer peripheral contact element of the second layer, the inner peripheral element of the third layer in contact with the contact element, and the inner peripheral contact element of the third layer and the second layer in contact with the contact element At least one of the peripheral elements of For it, characterized in that it further comprises a step of associating sets the contact conditions specified limits relative movement between the elements, the.

  The present invention can be applied to a tire cord composed of a plurality of classification layers exceeding three layers from the center toward the outside. That is, the third aspect may be repeatedly applied from the fourth layer to the outermost classification layer, or may be applied to the outermost layer or a middle layer of the plurality of classification layers. For example, a tire cord composed of n (n is a natural number of 4 or more) classification layers is sequentially adjacent from the first layer to the n-th layer. Therefore, for each layer after the fourth layer (kth layer: 3 <k <n), by replacing the (k-1) layer with the third layer and the (k-2) layer with the second layer, The present invention can be applied to each layer. In this case, the present invention is not limited to the application to all the layers from the first layer to the n-th layer. That is, the present invention can be applied only to the kth (3 <k <n) classification layer in the middle from the first layer to the nth layer.

  Further, the present invention can be applied to a tire cord group constituted by bundling a plurality of tire cords constituted by a plurality of classification layers or a tire cord group constituted by twisting a plurality. That is, by defining a tire cord composed of a plurality of classification layers as a single layer, the present invention can be applied to a tire cord group configured by twisting a plurality of tire cords composed of a plurality of classification layers. it can.

  A fourth aspect of the present invention is the tire cord analysis model creation method according to any one of the first to third aspects, wherein the two-dimensional region includes each region of a filament element and a filler. It is characterized by being.

  The invention according to claim 5 is a tire cord analysis model creation device that constitutes a part of a tire model used to calculate a tire corresponding to a numerical computation model, wherein the tire cord includes a plurality of filament elements. When formed of a plurality of classification layers from the center toward the outside corresponding to the twisting direction of the filament element, the inner first layer of the classification layers is arranged in the longitudinal direction. First definition means for defining a first two-dimensional region including at least a filament element cross-sectional shape in a direction intersecting with the first two-dimensional region, and three-dimensionally developing the first two-dimensional region in the longitudinal direction while twisting in the corresponding twisting direction. The first forming means for forming the first layer divided into predetermined division elements that can be numerically calculated, and the outer second layer adjacent to the first layer intersect with the longitudinal direction. Second definition means for defining a second two-dimensional region including at least a filament element cross-sectional shape in the direction, and numerical calculation while three-dimensionally developing the second two-dimensional region in the longitudinal direction while twisting in the corresponding twisting direction A second forming means for forming a second layer divided by possible predetermined dividing elements, and a setting for setting contact elements on at least one of an outer circumference of the first two-dimensional area and an inner circumference of the second two-dimensional area Means, an outer peripheral contact element of the second layer corresponding to the set contact element, an inner peripheral element of the third layer in contact with the contact element, and an inner peripheral contact element of the third layer An association means for setting and associating at least one of the outer peripheral elements of the second layer contacting the contact element with a contact condition defining a restriction of relative movement between the elements; To do.

  According to a sixth aspect of the present invention, there is provided a computer for creating an analysis model of a tire code constituting a part of a tire model used for calculating a tire corresponding to a numerical calculation model, wherein the tire code includes a plurality of filaments. When the elements are formed by being bundled while being twisted in a predetermined direction and composed of a plurality of classification layers from the center to the outside corresponding to the twisting direction of the filament element, the inner first layer of the classification layers, First definition means for defining a first two-dimensional region including at least a filament element cross-sectional shape in a direction intersecting the longitudinal direction, and three-dimensional in the longitudinal direction while twisting the first two-dimensional region in a corresponding twisting direction. A first forming means for forming a first layer divided into predetermined dividing elements that can be numerically calculated while being expanded, and an outer second layer adjacent to the first layer, A second definition means for defining a second two-dimensional region including at least a filament element cross-sectional shape in a direction intersecting with the second element, and three-dimensionally developing the second two-dimensional region in the longitudinal direction while twisting in the corresponding twisting direction. A second forming means for forming a second layer divided by predetermined dividing elements capable of numerical calculation, and a contact element on at least one of an outer periphery of the first two-dimensional region and an inner periphery of the second two-dimensional region Setting means for setting, contact elements on the outer periphery of the second layer corresponding to the set contact elements, elements on the inner periphery of the third layer in contact with the contact elements, and elements on the inner periphery of the third layer A tire core that functions as an association means for setting and associating a contact condition that defines a restriction on relative movement between each of the contact elements and at least one of the outer peripheral elements of the second layer contacting the contact elements Is a model creation program of analysis.

  As described above, according to the present invention, the contact element is set around the classification layer constituting the tire cord, and the contact condition for the adjacent layer to regulate the relative movement is determined based on the contact element.・ Each tire cord can be moved relatively, and a tire cord analysis model that can be easily analyzed even if the tire cord is complicatedly formed by bundling a plurality of filaments while being twisted can provide an efficient tire There is an effect that development can be realized.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the present embodiment, the present invention is applied to creation of an analysis model for tire behavior analysis.

(Device configuration)
FIG. 1 shows an outline of a personal computer for creating a tire code analysis model and executing a tire behavior simulation using the created analysis model. The personal computer includes a keyboard 10 for inputting data and the like, a computer main body 12 that predicts tire performance according to a pre-stored processing program, and a CRT 14 that displays calculation results of the computer main body 12 and the like.

  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 processing routines and the like described later can be read from and written to the flexible disk FD using the FDU. Therefore, a program and 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, a mass storage device (not shown) such as a hard disk device is connected to the computer main body 12, and the processing program recorded on the FD is stored (installed) in the mass storage device (not shown) and executed. Also good. As the recording medium, there are optical disks such as CD-ROM and DVD, and magneto-optical disks such as MD and MO. When these are used, a corresponding device may be used instead of or in addition to the FDU. In addition to a personal computer, a workstation or a super computer may be used for tire analysis.

(Tire code)
First, a tire cord included in a tire, particularly a steel cord, is a single tire cord formed by twisting a plurality of thin cords (hereinafter referred to as filaments). In this case, a tire cord formed by twisting a plurality of filaments is used as a first layer (single layer twist) tire cord, and a second layer filament is twisted around the tire cord to form a two-layer twisted tire cord. it can. At this time, the first layer and the second layer are reversely rotated in the rotating direction. Further, the twist pitch and the filament diameter are not necessarily the same in the first layer and the second layer. By repeating this, a plurality of layers of tire cords can be created.

  In addition, by inserting a filler (matrix) such as rubber between the filaments of the tire cord, it is possible to suppress rust when used in the tire and moisture adheres around the cord due to trauma and improve durability. it can. A thicker tire cord can be created by further twisting these single or multiple layers of twisted tire cords.

  On the other hand, when the filler between the filaments is not modeled, it is sufficient to model only the filament regardless of the presence or absence of contact between the filaments, and a shape model can be easily created. In this case, if the contact between the filaments is defined, the behavior of the filament can be analyzed.

  As shown in FIG. 8, for example, in the case of a single twist cord, it is easy to model a filler around a filament and create a model with solid elements. In the case of multi-layer twisting, if the twisting direction and the pitch are the same between the layers, the positional relationship between the filaments is the same everywhere as long as it is rotated about the longitudinal direction of the tire cord. Therefore, even when there is a filler around the filament, if the element can be divided in the cross section, an entire tire cord model can be created by extruding this in the tire cord longitudinal direction.

  However, ordinary cords have different twisting directions and pitches between layers, and cannot be easily extruded as described above to create a tire cord model. It is also possible to create a three-dimensional solid model using CAD or the like. However, since the shape of the filler between the filaments is very complicated, it is very difficult to create a divided element (mesh) divided into elements. Specifically, there is a case where a tetrahedron cannot be created with automatic element division. Further, rubber usually used as a filler for tire cords is almost incompressible and has a Poisson's ratio close to 0.5. It is known in the finite element method that a hexahedron or a pentahedron (for example, a triangular prism) is necessary when such a material is analyzed with a finite element method with high accuracy. Since it is virtually impossible to automatically generate such a pentahedron in the filler portion obtained from CAD data, the analysis accuracy cannot be improved in consideration of the tire code. It was.

(Tire cord modeling)
In consideration of the above facts, in the present embodiment, the tire cord is classified and modeled by layer, and the entire tire cord is modeled by providing a relationship between the layers.

  FIG. 5 shows the processing routine of the tire code analysis model creation program according to the present embodiment, which is executed by the personal computer (FIG. 1). By executing the processing of FIG. 5, an analysis model of a tire code for creating a tire code alone or a tire code included in a tire design plan into a numerical analysis model is created, and the data is stored in a personal computer. be able to. The creation of the tire cord analysis model differs slightly depending on the numerical analysis method used. In this embodiment, a finite element method (FEM) is used as a numerical analysis method, and an analysis model of a tire cord to be created is divided into a plurality of elements by element division corresponding to the finite element method (FEM), for example, mesh division. This is the result of dividing the tire into a numerical value into an input data format for a computer program created based on numerical and analytical methods. This element division means to divide the tire cord into small (finite) small parts. After calculating every small part and calculating all the small parts, the whole response can be obtained by adding all the small parts.

  First, in step 200 of FIG. 5, a tire code to be modeled to be created as an analysis model is designated. In this step 200, a tire code for which an analysis model is to be created or a design plan (tire shape, structure, material, etc.) of a tire including the tire code is determined. The above is not limited to the tire design plan, but includes the case of analyzing an existing tire. That is, the tire cord itself included in the existing tire may be set as the target model.

  For example, in step 200, the designation is made by selecting one of the tire codes included in the tire model. This designation may be performed by reading a user's keyboard input value and setting a corresponding part in the tire as a tire code, or automatically setting a part predetermined as a tire code from tire design plan data. it can. In this step 200, data relating to material properties such as Young's modulus, shear elastic modulus, Poisson's ratio, etc., and diameter, twist direction and layer configuration of the designated tire cord are obtained. To do.

  FIG. 4 shows an example of a tire cross-section model, and shows a pneumatic tire 20 having a carcass 22 divided for each of a plurality of rubber members. The carcass 22 is folded back by a bead 26. The inner side of the carcass 22 is an inner liner 24, and a bead rubber 36 is disposed on the inner liner 24 so as to extend. A substantially triangular area formed by the folded carcass 22 is a bead filler 28. A belt 30 is disposed above the carcass 22, a tread rubber 32 having a groove is disposed on the outer side in the radial direction of the belt 30, and a side rubber 34 is disposed on the outer side in the axial direction of the carcass 22. Yes. In addition, although the example which divided | segmented the tire cross-section model into multiple for every rubber member was given, you may divide | segment into arbitrary shapes, such as a triangle, according to the design objective. Any one tire cord may be selected from the tire cords included in the members constituting these tires.

  Next, although details will be described later, in step 202 of FIG. 5, a two-dimensional shape of the designated tire cord (which may be referred to as a cross-sectional shape or a two-dimensional model) is created, and the created tire cord is created in the next step 204. A two-dimensional shape is developed in the longitudinal direction of the tire cord to create a three-dimensional shape. When the modeling of the designated tire code is completed, it is determined whether or not the above processing has been completed for all tire models included in the tire model (step 206). If the determination is affirmative, this processing routine is terminated. On the other hand, if the result in Step 206 is negative, the process returns to Step 200, and the above processing is repeated for other tire cords.

  Hereinafter, in order to simplify the description, an example in which a belt is designated as a tire cord and one tire cord included in the belt is modeled as an analytical model capable of numerical calculation will be described in detail. The present invention is not limited to the belt of the tire cord, but can be applied to any one as long as a plurality of filaments such as metal wires are bundled. In many cases, the belt includes a cord formed by a bundle of a plurality of filaments such as several wires. This belt is modeled for each wire and an analysis model is obtained. That is, in the present embodiment, an analysis model of a tire cord is obtained by modeling in detail including a twist direction of each filament, using a belt in which metal wires as filaments are bundled as an example of a tire cord.

(Tire code 2D model creation)
In the process of creating the cross-sectional shape (two-dimensional model) in step 202, the creation process routine of FIG. 6 is executed. In step 210, the cross-sectional structure and material characteristics of the tire cord specified in step 200 are read, and in step 212, the filaments are classified by layer. In this classification, a plurality of filaments included in a designated tire cord are classified by layer for each filament in the same twist direction. FIG. 9 shows, as an example, a three-layer tire cord 40 having the same twist direction filament 48 in each of the innermost layer 42, the intermediate layer 44, and the outermost layer 46.

  In the next step 214, the first layer filament (cross section) is divided into elements so as to have a predetermined shape, and in the next step 216, a circumscribed shape surrounding the periphery of the first layer filament group is determined. In FIG. 10A, each of the filaments 48 included in the innermost layer 42 of the tire cord 40 as the first layer is divided into elements, and a circumscribed circle 50 of the filament 48 is defined as a circumscribed shape surrounding the periphery of the filament group. The case is shown. In the above description, the first layer is defined as the innermost layer 42, but the first layer may be the outermost layer 46.

  In the example of FIG. 10, the circumscribed circle 50 is employed as the circumscribed shape. However, the circumscribed shape is not limited to a circle, and may be an ellipse, a square, a triangle, a polygon, or the like. Moreover, it may be concave or convex between the filaments.

  Next, in step 218, the filler existing around the filament 48 is divided into elements so as to have a predetermined shape (see FIG. 10B). The element division of the filler is executed only when considering the case where the filler is present around the filament 48. That is, when the tire cord 40 is modeled, it may be sufficient to model at least the filament 48, and therefore, the element division of the filler is not always necessary. In other words, when there is no contact with the outside, for example, when analyzing a single filament, for example, there is no need to define when a force does not act on an external member. In addition, when the filler between the filaments is not modeled, only the filament needs to be modeled regardless of the presence or absence of contact between the filaments. Thereby, a feeling unit shape model can be created. If the contact between filaments is defined, the movement of the filament can be analyzed.

  In the next step 220, contact elements for the first layer are defined. As shown in FIG. 10C, the contact element 52 is positioned on the circumscribed shape (here, circumscribed circle 50) determined in step 216. The contact element 52 generates a force acting on the outside caused by contact due to deformation or movement of the filament group included in the first layer (here, the innermost layer 42) or a force acting on the first layer from the outside. , For associating between the first layer and the adjacent layer. That is, here, the contact element 52 that associates the circumscribed circle 50 with the second layer is determined. In the following description, a case where the contact element 52 is indicated by a point will be described. However, a line segment or a surface after three-dimensional development described later may be used. In addition, when the element division of the filler is performed in step 218, a contact element is defined on the outer periphery of the filler.

  When the setting of the cross-sectional shape of the first layer is completed as described above, the cross-sectional shape is sequentially set in the same manner as described above for the adjacent layers of the first layer. Specifically, the process proceeds to step 222, and the element is divided into the adjacent layer in the outward direction, here the second layer, in the same manner as in step 214 above. In the next step 224, the circumscribed shape surrounding the periphery of the filament group of the outer adjacent layer (here, the second layer) is determined in the same manner as in step 216. In addition, an inscribed shape inscribed in the filament group of the outer adjacent layer (here, the second layer) is defined around the filament group of the inner adjacent layer (here, the first layer). In FIG. 11A, each of the filaments 48 included in the intermediate layer 44 of the tire cord 40 as the second layer is divided into elements, and a circumscribed circle 56 of the filament 48 is defined as a circumscribed shape surrounding the periphery of the filament group. The inscribed circle 54 is defined as the inscribed shape.

  In the example of FIG. 11, a case where a circular shape is adopted as the circumscribed shape is shown, but the shape is not limited to a circular shape, and may be an ellipse, a square, a triangle, a polygon, or the like. Moreover, it may be concave or convex between the filaments.

  In addition, since the inscribed circle 54 of the inscribed shape of the second layer is in contact with the circumscribed shape of the first layer, if they are the same shape, they can be easily linked and associated (for example, joined). However, it is not limited to setting both to the same shape. Even if the shapes of the two are different, they contact each other in the initial shape, or after moving without causing stress or distortion so that both shapes match immediately after the start of calculations such as simulation described later. Can be set to.

  In the next step 226, as in step 218 described above, the filler existing around the filament 48 is divided into elements so as to have a predetermined shape (see FIG. 11B). The element division of the filler is defined when there is no contact with the outside, for example, when analyzing the filament alone in the same manner as described above, for example, when no force acts on an external member. There is no need.

  In the next step 228, the contact elements of the outer adjacent layer (here the second layer) are defined. That is, the contact element for at least the inner adjacent layer (here, the first layer) is defined. This step 228 is a process for determining a cooperating element for making contact with the inner adjacent layer (here, the first layer) at least in the inscribed shape. As shown in FIG. 11C, the inner contact element 59 is positioned on the inscribed shape (here, the inscribed circle 54) determined in step 224. If there is a further adjacent layer (here, the third layer) outside the layer (here, the second layer), the contact element for the adjacent layer (here, the third layer) is the same as in step 220 above. Determine. As shown in FIG. 11C, the contact element 58 is positioned on the circumscribed shape (here, circumscribed circle 56) determined in step 224. When there is no adjacent layer outside the layer, it is not necessary to determine a contact element for the adjacent layer. However, for the outermost layer where there is no adjacent layer on the outside, it is preferable to pre-define the contact elements outside the outermost layer when the tire cord is treated as a group of cords as a model for other simulations. .

  When the setting of the cross-sectional shape of the outer adjacent layer (here, the second layer) is completed as described above, the process proceeds to step 230 to determine whether the setting of the cross-sectional shape for all the layers of the tire cord 40 is completed. In the case of negative, the cross-sectional shape is set for the adjacent layers in the same manner as described above. That is, since the example in FIG. 9 has a three-layer structure, the processing from step 222 to step 228 is executed for the outermost layer 46. On the other hand, if the determination in step 230 is affirmative, the present processing routine is terminated.

  When creating a two-dimensional model of the cross-sectional shape, it is possible to create the entire cross-sectional shape at the same time, but after creating a two-dimensional model for a part of the cross-section, by copying the created two-dimensional model, A two-dimensional model having a cross-sectional shape can be created in a short time and with high accuracy. For example, as shown in FIG. 10, the innermost layer 42 has symmetry in the rotational direction, and the innermost layer 42 has three filaments arranged at equal intervals, so that it has the same shape every 120 degrees. Become. Considering this, after creating a cross-sectional shape obtained by dividing a part of the basic shape into elements, it is possible to periodically create element divisions of the same shape by developing them in the rotation direction. If created in this way, the accuracy can be improved by aligning the element sizes. Moreover, element generation can be performed in a short time.

  In the above processing (FIG. 6), the case where the contact elements are defined for all the layers from the innermost layer to the outermost layer of the tire cord 40 has been described, but the present invention is not limited to this, A contact element can be defined by specifying a layer. Moreover, the layer which defines a contact element should just be at least one of an outer periphery and an inner periphery. In this case, only the process of creating the two-dimensional model is executed for the processes of steps 220 to 230, and the layer designation is performed for the definition of the contact element. That is, it is assumed that a numerical value representing the layer has been input in advance for the layer of the contact element definition, and a process for determining whether or not to define the contact element is added between steps 226 and 228. This determination process determines whether or not the numerical value representing the layer input in advance is the current layer. When the determination is affirmative, the process proceeds to step 228, and when the determination is negative, the process proceeds to step 230. In this case, when the layer defining the contact element is defined for at least one of the outer periphery and the inner periphery, the contact element may be specified for at least one of the outer periphery and the inner periphery of the corresponding layer in addition to the layer specification.

  FIG. 12 shows the two-dimensional model created as described above. FIG. 12A shows a two-dimensional model of the three-layer tire cord 40 shown in FIG. 9, and FIG. 12B shows a two-dimensional model of the two-layer tire cord 40 that can be created in the process. . FIG. 13 shows an example of a two-dimensional model of a tire cord 41 formed by bundling three three-layer tire cords 40. In the tire cord 41 bundled in three shown in FIG. 13, the contact element is defined in the circumscribed shape (cord surface) of the third layer (outermost layer 46) of each tire cord 40. Tire cords 40 can be brought into contact with each other. Modeling rubber or the like outside the tire cord 40 and the tire cord 41 described above is very easy because it only creates an element outside the circle.

  When the deformation between the layers is small or when it is desired to suppress the deformation between the layers, the relationship between the contact element and the cooperation element associated with the contact element can be modeled so as to constrain each other. As will be described in detail later, this can be achieved by making the contact condition a characteristic that the degree of restraint changes according to the force acting on the contact element. For example, when the input is small (when it is equal to or less than a predetermined value), the contact condition is set to be mutually restrained, and when the input is exceeded, the contact condition is set so as to be relatively movable while being in contact.

(Create a three-dimensional tire cord model)
In the process of creating the three-dimensional shape in step 204, the creation process routine of FIG. 7 is executed. In step 240, the cross-sectional shape (two-dimensional model) which is the two-dimensional shape of the tire code obtained in step 202 (the execution result of the processing routine of FIG. 6) is read, and the first layer of the two-dimensional shape is read. In the next step 242, the innermost layer 42 is developed while being rotated along the longitudinal direction of the tire cord 40 and in the twisting direction. Note that the processing of step 242 includes element division processing.

  That is, since the first layer is a single-stranded tire cord, the three-dimensional model is pushed by a predetermined distance in the tire cord longitudinal direction while rotating the cross-sectional shape (two-dimensional model) around the longitudinal direction of the tire cord. Can be created (see FIG. 8).

  For example, the twisting direction of the corresponding layer (that is, the first layer) is known, and if a predetermined distance in the longitudinal direction of the tire cord is determined, the cross-sectional shape (two-dimensional model) divided into the elements in the longitudinal direction of the tire cord By extruding, a three-dimensional model can be created for the first layer of the tire cord. The predetermined distance in the longitudinal direction is preferably made to correspond to the length of the element when dividing in accordance with a predetermined pitch. A cross-sectional shape (two-dimensional model) rotated according to the twisting direction is formed at a position separated by a predetermined distance in the longitudinal direction, and a cross-sectional shape (two-dimensional model) between both cross-sectional shapes (two-dimensional model) is formed. It is only necessary to create a model with solid elements to connect the locus positions.

  At the time of creating the three-dimensional model, the contact element 52 determined at the time of creating the two-dimensional model may be determined for each processing distance or may be determined at a predetermined interval. Further, a curve serving as a locus of the contact element 52 may be determined. That is, as long as the contact element 52 is configured to be positioned on the cross-sectional shape of the created three-dimensional model, either a point or a curve may be used.

  In the case where a filler is provided around the filament of the first layer, it is easy to model the filler around the filament and create a model with solid elements. That is, even when there is a filler around the filament, if the element is divided in the cross-sectional shape, a three-dimensional model of the corresponding layer can be created by extruding this in the tire cord longitudinal direction.

  FIG. 14 shows a three-dimensional model of the innermost layer 42 having three filaments 48 as an example and twisting them in the same twist direction. FIG. 14A shows a case where the innermost layer 42 is constituted by only the filament 48, and FIG. 14B shows a case where the innermost layer 42 is constituted by providing a filler around the filament.

  As shown in FIG. 14, the first layer (innermost layer 42) is twisted by being rotated clockwise as viewed from the longitudinal direction. A three-dimensional model can be created by developing several parts per pitch and developing in the longitudinal direction while twisting. In this modeling, since the filament and the surrounding filler share a node, the element division in the cord longitudinal direction of the filament and the filler is the same. At this time, if the number of element divisions per pitch is reduced, irregularities on the surface of the filler increase and contact becomes difficult. However, a three-dimensional model that can reduce analysis time can be provided by reducing the number of elements. On the other hand, when the number of element divisions is increased, the surface becomes smooth and contact between the layers becomes easy, and a three-dimensional model that can reduce the analysis time can be provided by increasing the number of elements. In the example of FIG. 14, it is divided into 10 per pitch.

  When there is no filler around the filament, the three-dimensional model to be created can be made smooth by modeling the filler portion as a space. That is, in this case, the filler portion between the filament of the innermost layer 42 and the outer surface (the circumscribed circle 50) may be left blank. In other words, the three-dimensional model shown in FIG. 14B can be treated as a tire cord composed of a filament group that constitutes a layer from a plurality of filaments and a virtual filler. It can be understood that the outer surface of the tire cord composed of the filament group and the virtual filler is much smoother than the outer surface of the three-dimensional model of the filament group of filaments (see FIG. 14A). By forming such a smooth surface, it is possible to facilitate contact with the outer filament on this surface.

  When the creation of the three-dimensional model of the first layer is completed as described above, the process proceeds to step 244, and the two-dimensional shape of the outer adjacent layer is set at the position adjacent to the current layer in the outer direction. Here, the two-dimensional model of the intermediate layer 44 that is the second layer of the cross-sectional shape (two-dimensional model) that is the two-dimensional shape of the tire code read in step 240 is set around the innermost layer 42. In the next step 246, as in step 242 described above, the outer adjacent layer (here, the second layer) is developed along the longitudinal direction of the tire cord 40 and in the twisting direction. At the time of creating the three-dimensional model, a position on the three-dimensional model (a point or a curve serving as a trajectory of the contact element 52) is also determined for the contact element (at least the inner contact element) determined at the time of creating the two-dimensional model. When there is no adjacent layer outside the layer, it is not necessary to determine the contact element for the adjacent layer. However, for the outermost layer where there is no adjacent layer on the outside, it is preferable to pre-define the contact elements outside the outermost layer when the tire cord is treated as a group of cords as a model for other simulations. .

  The twist direction of the second layer with respect to the first layer may be the same or opposite. This twist direction is not limited to the relationship between the first layer and the second layer, but the twist direction of each layer is not limited, and the definition of the twist direction defined in the following description is limited thereto. It is not a thing. That is, the twisting direction may be clockwise or counterclockwise, and the cord can be configured by any combination of twisting directions.

  FIG. 15 shows a three-dimensional model of only the intermediate layer 44 having nine filaments 48 as an example and twisted in the same twist direction around the innermost layer 42. FIG. 15A shows a case where the intermediate layer 44 is configured only by the filament 48, and FIG. 15B shows a case where the intermediate layer 44 is configured by providing a filler around the filament.

  As shown in FIG. 15, the second layer (intermediate layer 44) is twisted by rotating counterclockwise when viewed from the longitudinal direction. In the example of FIG. 15, the twist pitch is set to twice that of the first layer. A three-dimensional model can be created by developing several parts per pitch and developing in the longitudinal direction while twisting. In this modeling, since the filament and the surrounding filler share a node, the element division in the cord longitudinal direction of the filament and the filler is the same. At this time, if the number of element divisions per pitch is reduced, irregularities on the surface of the filler increase and contact becomes difficult. However, a three-dimensional model that can reduce analysis time can be provided by reducing the number of elements. On the other hand, when the number of element divisions is increased, the surface becomes smooth and contact between the layers becomes easy, and a three-dimensional model that can reduce the analysis time can be provided by increasing the number of elements. In the example of FIG. 15, 20 divisions per pitch.

  When there is no filler around the filament, the three-dimensional model to be created can be made smooth by modeling the filler portion as a space as described above. That is, in this case, the filler portion between the filament of the intermediate layer 44 and the inner and outer surfaces (the inscribed circle 54 and the circumscribed circle 56) may be left blank. In other words, the three-dimensional model shown in FIG. 15B can be treated as a tire cord composed of a filament group that constitutes a layer from a plurality of filaments and a virtual filler. It can be understood that the inner and outer surfaces of the tire cord composed of the filament group and the virtual filler are much smoother than the inner and outer surfaces of the three-dimensional model of the filament group of the single filament (see FIG. 15A). By forming such a smooth surface, contact with the inner and outer layer filaments can be facilitated on this surface.

  Next, in step 248, a contact element is associated between the inscribed shape of the outwardly adjacent layer (here, the second layer) and the circumscribed shape of the previous layer (here, the first layer). This process is for creating a three-dimensional model of a tire cord that can move relatively while contacting a plurality of adjacent layers. In this process, a contact condition is set and associated that enables relative movement while contacting the previous layer (first layer) and the outer adjacent layer (second layer). This contact condition prescribes | regulates the restriction | limiting of a relative movement about several adjacent layers. In the specific processing here, the relationship between the contact element 52 of the first layer and the inner peripheral element of the second layer at the position corresponding to the contact element 52 is relatively different between the contact element and the element at the corresponding position. Set and associate contact conditions for movably contacting. Similarly, with respect to each relationship between the contact element 59 on the inner side of the second layer and the element on the outer periphery of the first layer at the position corresponding to the contact element 59, the contact element and the element at the corresponding position are relatively moved. Set and associate contact conditions where possible.

  FIG. 16 shows a cross-sectional shape near the boundary between the innermost layer 42 and the intermediate layer 44 of the tire cord 40. FIG. 16A shows the relationship between the innermost layer 42 and the intermediate layer 44, and FIG. 16B shows the relationship when the innermost layer 42 and the intermediate layer 44 are in contact (for example, bonded). A contact element 52 (drawing points Pa and Pb as an example in FIG. 16) is defined in the circumscribed circle 50 of the first layer which is the innermost layer 42. At the time of creating the three-dimensional model of the intermediate layer 44, an association element (drawing points Da and Db as an example in FIG. 16) corresponding to the contact element 52 of the innermost layer 42 is determined.

  When the innermost layer 42 and the intermediate layer 44 are in contact with each other, the innermost layer 42 and the intermediate layer 44 are relatively movable. At this time, if it is assumed that the innermost layer 42 and the intermediate layer 44 are rigid bodies, when a force (deformation) accompanying movement occurs in one of the layers, it acts on the other layer and self-shape-preserving force (for example, rigidity) ) Etc., the other layer moves (deforms). More specifically, the contact element 52 and the associating element change from a restrained state in which the contact element 52 moves while maintaining the same position to a sliding state in which each of the contact elements 52 and the associated element are separated by a predetermined amount. It is defined that the relationship between the innermost layer 42 and the intermediate layer 44 changes from a restraint state to a sliding state in accordance with an input (acting force or generated force) (relative movement Stipulate restrictions) as a contact condition.

  There are three types of contact conditions: a contact condition based on sliding resistance, a contact condition based on a friction coefficient, and a contact condition based on shape preservation. As shown in FIG. 16C, the contact condition by the sliding resistance is to add a sliding resistance having a predetermined characteristic (function) with respect to the relative movement between the innermost layer 42 and the intermediate layer 44. . Specifically, the contact element 52 and the association element are associated with each other as a contact condition that the point Pa and the point Da and the point Pb and the point Db are defined in terms of the sliding resistance as a contact condition. . This sliding resistance is a linear function, a gradually increasing function of asymptotic characteristics, a gradually decreasing hyperbolic function, a function by a polynomial in which the value of sliding resistance changes stepwise according to input, a nonlinear function, etc. Can be determined by a combination of functions. For example, up to a predetermined input value, a predetermined value of a large sliding resistance is in a restrained state in which the same position is maintained and moved, and when the input value exceeds this value, each slides apart by a predetermined amount of deviation. A function can be defined to be in a state.

  As shown in FIG. 16D, the contact condition based on the friction coefficient adds a predetermined coefficient of friction to the relative movement (sliding) between the innermost layer 42 and the intermediate layer 44. . Specifically, the contact element 52 and the association element are associated with each other under the condition that the frictional coefficient defines the coordinate relationship for the point Pa and the point Da and the point Pb and the point Db to be three-dimensionally separated. This friction coefficient may be a constant value or may be determined by various functions similar to the above.

  As shown in FIG. 16E, the contact condition by shape preservation adds a shape preservation coefficient such as an elastic coefficient having a predetermined value for the relative movement between the innermost layer 42 and the intermediate layer 44. Specifically, the contact element 52 and the association element are associated with each other by using, as a contact condition, the coordinate relationship for the three-dimensional separation between the point Pa and the point Da and the point Pb and the point Db is defined by the shape preservation coefficient. . This shape preservation coefficient may be a constant value or may be determined by various functions similar to the above. Note that the shape preservation coefficient is preferably defined for each of the three-dimensional directions as shown in FIG. Thereby, contact conditions can be defined for each of the three-dimensional directions.

  Therefore, in the process of step 248, specifically, the contact element 52 and the associated element (point Pa and The points Da and Pb and the point Db) are associated with each other by applying a contact condition that defines a relative movement restriction that enables a three-dimensionally spaced coordinate relationship.

  Thereby, between the contact element 52 and the association element, a force acting on the outside caused by deformation or movement of the filament group included in the first layer (here, the innermost layer 42), or the first layer An externally applied force can be associated between the contacted first layer and the adjacent layer.

  Although not shown, a contact element 59 is defined on the inscribed circle 54 of the second layer, which is the intermediate layer 44, as described above, and corresponds to the contact element 59 when creating the three-dimensional model of the intermediate layer 44. The association element is determined on the circumscribed circle 50 of the first layer which is the innermost layer 42. Therefore, the contact element 59 and the association element on the circumscribed circle 50 are associated with each other by giving a contact condition that regulates a relative movement restriction. Thereby, between the contact element 59 and the associating element, a force acting on the outside caused by deformation or movement of the filament group included in the second layer (here, the intermediate layer 44), or the second layer An externally applied force can be associated between the first layer and the adjacent layer so that the contacted state can be reproduced.

  In the above description, a case has been described in which the association elements are individually determined corresponding to each of the contact elements 52 and 59. However, the association may be performed between the contact elements. For example, the closest contact elements may be associated with each other by applying a contact condition that defines a relative movement restriction. In this case, the association element is not necessary, and can be executed by processing using only the contact element.

  When the creation of the three-dimensional model of the outer adjacent layer (here, the second layer) is completed as described above, the process proceeds to step 250 to determine whether the creation of the three-dimensional model for all layers of the tire cord 40 is completed. In the case of negative, a three-dimensional model is sequentially created for the adjacent layers in the same manner as described above. That is, in the example of FIG. 9, because of the three-layer structure, the processing from step 244 to step 248 is executed for the outermost layer 46. On the other hand, if the determination at step 250 is affirmative, the present processing routine is terminated.

  By the above processing, a layer composed of filament groups can be formed sequentially from the inner layer to the outer layer, and a three-dimensional model composed of a plurality of layers in which adjacent layers are in contact with each other can be created.

  In the above processing (FIG. 7), the case where the contact elements are defined for all the layers from the innermost layer to the outermost layer of the tire cord 40 has been described, but the present invention is not limited to this, A contact element can be defined by specifying a layer. In this case, only the process of creating the three-dimensional model is executed for the processes of steps 244 to 250, and the layer designation is performed for the definition of the contact element. That is, it is assumed that a numerical value representing a layer has been input in advance for the layer of definition of the contact element, and a process for determining whether or not to associate the contact element is added between steps 246 and 248. This determination process determines whether or not the numerical value representing the layer inputted in advance is the current layer. When the determination is affirmed, the process proceeds to step 248, and when the determination is negative, the process proceeds to step 250.

  As described above, the present embodiment can be easily applied to a tire cord including two or more classification layers from the center toward the outside. That is, as described in the processing of steps 222 to 230 and the processing of steps 244 to 250, since it is repeatedly applied from the second layer to the outermost classification layer, two layers, three layers, four layers, and so on. Applicable to multiple layers. Also, any layer can be specified and applied.

  Further, the present invention can be applied to a tire cord group constituted by bundling a plurality of tire cords constituted by a plurality of classification layers or a tire cord group constituted by twisting a plurality. In other words, by defining a tire cord composed of a plurality of classification layers as a single layer, the present embodiment is configured by tying a tire cord group composed of a plurality of tire cords composed of a plurality of classification layers or a plurality of twists. It can be applied to the configured tire cord group.

  In FIG. 17, as an example of the three-dimensional model created according to the above processing, each of the innermost layer 42, the intermediate layer 44, and the outermost layer 46 has filaments 48 having the same twist direction and filaments 48 having different twist directions between the layers. A layered tire cord 40 is shown. FIG. 18 shows an example of a three-dimensional model of a tire cord 41 formed by bundling three tire cords 40 of the three layers shown in FIG.

  The three-dimensional model shown in FIG. 17 is a three-dimensional model that is contacted between the layers. In the three-dimensional model shown in FIG. 18, the contact elements are formed on the circumscribed shape (cord surface) of the third layer (outermost layer 46) of each tire cord 40. As a result, a three-dimensional model in which three tire cords 40 of three-layer twist are brought into contact with each other is obtained. Modeling rubber or the like outside the tire cord 40 and the tire cord 41 described above is very easy because it only creates an element outside the circle.

  Although not shown, a three-dimensional model can be created for a spiral tire cord by the same processing as described above.

(Behavior simulation)
Next, an example in which a tire model is formed using the tire code of the above three-dimensional model and the behavior of the tire is analyzed will be described.

  FIG. 2 shows a processing routine of the tire behavior analysis program. In step 100, a design plan (tire shape, structure, material, etc.) of a tire to be subjected to behavior analysis is determined. Note that the setting in step 100 is not limited to the tire design plan, but includes the case of analyzing an existing tire. That is, the existing tire itself may be set as the target model. In the next step 102, a tire tire model for creating a tire design plan into a numerical analysis model is created. The creation of the tire model 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 model created in step 102 is divided into a plurality of elements by element division corresponding to the finite element method (FEM), for example, mesh division, and the tire is created based on a numerical / analytical method. This is a digitized input data format for computer programs. This element division means dividing an object such as a tire and a road surface (described later) into several small (finite) small parts. After calculating every small part and calculating all the small parts, the whole response can be obtained by adding all the small parts.

  In the creation of the tire model in step 102, a tire model creation routine shown in FIG. 3 is executed. First, in step 112, a tire radial section model (tire section model, that is, tire section data) is created. In addition, rubber in the tire cross section, supplementary teaching materials (belts, plies, etc., reinforcing cords made of iron / organic fibers, etc., bundled in a sheet shape, etc.) are modeled according to the modeling method of the finite element method, respectively. . In the next step 114, two-dimensional tire cross-section data (tire radial cross-section model) is developed for one turn (360 degrees) in the circumferential direction to create a three-dimensional (3D) model of the tire.

  For tire cords including supplementary teaching materials (belts, plies, etc., reinforcing cords made of iron / organic fibers, etc., bundled in a sheet), a detailed analysis model will be created as described later. Then, what is necessary is just to create a model as a uniform tire code.

  Next, in step 116 of FIG. 3, the constituent material of the rubber of each part of the tire is set. In this step, a constituent material having material characteristics such as rigidity corresponding to each part of the tire is selected. In the next step 118, a tire code analysis model creation process for modeling the tire code in detail is executed, and this routine is terminated. In the tire code analysis model creation process in step 118, the above-described processing routine for creating the tire code analysis model (see FIG. 5) is executed.

  After the tire model including the finite element model (analysis model) of the tire cord 40 created as described above is created, the process proceeds to step 104 in FIG. 2, and the road surface setting, that is, the creation of the road surface model and the input of the road surface state are performed. Made. In this step 104, the road surface is modeled and input for setting the modeled road surface to an actual road surface state. The road surface is modeled by dividing the road surface shape into elements and selecting the road surface friction coefficient μ and inputting the road surface state. For example, depending on the road surface condition, there is a road friction coefficient μ corresponding to dry (DRY), wet (WET), on ice, snow, unpaved, etc., so by selecting an appropriate value for the friction coefficient μ, The road surface condition can be reproduced.

  A fluid model may be created and provided between the road surface and the tire model. The fluid model divides and models a part (or all) of a tire, a ground contact surface, and a fluid region including a region where the tire moves and deforms.

  In this way, when the road surface condition is input, the boundary condition is set in the next step 106. The boundary conditions are necessary for analysis of the tire model, that is, for simulating the behavior of the tire, and are various conditions given to the tire model. In the setting of the boundary condition in step 106, first, an internal pressure is applied to the tire model, and at least one of rotational displacement and straight displacement (displacement may be force or speed) is applied to the tire model, a predetermined load load, Give at least one of In addition, when considering friction with the road surface, only one of rotational displacement (or force or speed) or straight displacement (or force or speed) may be used.

  Next, a deformation calculation of the tire model as an analysis is performed based on the numerical model created or set up to step 106. That is, when the setting of the boundary condition is completed in step 106, the process proceeds to step 108, and the tire model is calculated for deformation. In this step 108, deformation calculation of the tire model is performed based on the finite element method from the tire model and the given boundary conditions. This deformation calculation repeats the tire model deformation calculation (for example, repeat the calculation within 1 msec) in order to obtain the tire rolling state (to obtain a transient state), and each time the boundary condition May be updated. The deformation calculation can employ a predetermined calculation time assuming that the tire deformation is in a steady state. In the next step 110, the calculation result is output. This calculation result uses a physical quantity at the time of tire deformation. Specifically, side deflection amount, contact shape, contact pressure distribution, lateral force acting on the tire center, and the like.

  The calculation result may be output by visualizing the value or distribution of the shape of the contact portion of the tire, the distribution of contact pressure, the force acting on the center of the tire, or the like. These can be derived from the calculation result value, change amount or change rate, force direction (vector) and distribution, and if they are shown together with the tire model and pattern periphery in a diagram etc., they are presented for easy understanding. Possible visualizations can be made.

  As described above, in the present embodiment, the tire cord included in the tire is modeled in detail by the finite element model, and the tire behavior including the model (analysis model) is analyzed in accordance with the actual shape. It becomes possible to do. Therefore, it is possible to analyze the tire cord with higher accuracy than in the case where the tire cord is analyzed by a simplified element.

  Next, embodiments of the present invention will be described in detail.

The tire cord modeled and prototyped as a working example in accordance with the contact condition was all 0.25 mm in filament diameter (2r), and the filament in the first layer was {2r / 3 · (3) ^1/2 · Three are arranged in a uniform arrangement on a circumference of 0.125} mm, the second layer is arranged so as to be in contact with the first layer, and the third layer is arranged so as to be in contact with the second layer. . The twist pitch was 5, 10, and 15 mm from the first layer, and the element division in the tire cord longitudinal direction was 10, 20, and 30 / pitch from the first layer. This tire cord was modeled by a length of 30 mm. Also, rubber was used as a filler around the filament. The analysis was carried out by fixing in both end planes and pulling in the longitudinal direction.

  FIG. 19 shows a three-dimensional model before and after deformation. FIG. 19A is a three-dimensional model before deformation in which a filler exists around the filament, and FIG. 19B is a three-dimensional model after deformation. FIG. 19C is a three-dimensional model before deformation of only the filament, and FIG. 19D is a three-dimensional model after deformation. As can be understood from the figure, a result conforming to the actual shape was obtained in which the angle formed by the filament with the longitudinal direction of the cord is reduced by tensile deformation, and the distance between the nodes in the longitudinal direction is increased.

  The result of analyzing the tire provided with the tire cord 40 is as follows. The tire modeled and prototyped as this example has a tire size of 205 / 55R16, an internal pressure of 220 kPa, a load of 4.4 kN, and the result of carrying out an analysis of 30 mm in the lateral direction after pressing the tire against the road surface. . In Table 1 below, with respect to the displacement in the width direction of the steel belt in the outermost layer at a point vertically downward from the center of rotation in the tire width direction center, an actual measurement value is set to 100, and a simplified model of the conventional method and an analysis of the present embodiment The results are shown by index for the model.

  As understood from Table 1, by using the analysis model of this embodiment, a result closer to actual measurement could be obtained.

1 is a schematic diagram of a personal computer for creating a tire code analysis model and performing a tire behavior simulation using the created analysis model according to an embodiment of the present invention. FIG. It is a flowchart which shows the flow of a process of the tire behavior analysis program concerning this Embodiment. It is a flowchart which shows the flow of a tire model creation process. It is a diagram which shows a tire cross-section model. It is a flowchart which shows the flow of the process which produces the analysis model of a tire cord concerning embodiment of this invention. It is a flowchart which shows the flow of a 2-dimensional model creation process of a tire code. It is a flowchart which shows the flow of a 3-dimensional model creation process of a tire code. It is explanatory drawing of modeling of the tire cord of a single twist. It is an image figure which shows the filament layer of a tire cord. FIG. 5 is an explanatory diagram of modeling of the innermost layer 42 of the tire cord, where (A) is an element-divided filament, (B) is an element-divided filler, and (C) is a contact element 52 defined on a circumscribed circle 50. Yes. FIG. 5 is an explanatory diagram of modeling of the intermediate layer 44 of the tire cord, where (A) is an element-divided filament, (B) is an element-divided filler, and (C) is a contact element 58 defined by a circumscribed circle 58. Yes. It is an image figure which shows a two-dimensional model, (A) has shown the tire cord of 3 layers, (B) has shown the tire cord of 2 layers. It is an image figure showing a tire cord constituted by bundling three tire cords of three layers. It is an image figure which shows the three-dimensional model about an innermost layer, (A) shows only a filament and (B) has shown what provided the filler around the filament. It is an image figure which shows the three-dimensional model about an intermediate | middle layer, (A) shows only a filament and (B) has shown what provided the filler around the filament. It is explanatory drawing of a contact element. It is an image figure which shows an example of the tire code of the three-dimensional model created according to the process of this embodiment. It is an image figure showing an example of a three-dimensional model of a tire cord formed by bundling three tire cords. It is an image figure which shows the three-dimensional model before and behind a deformation | transformation concerning an Example, (A) is a three-dimensional model before a deformation | transformation with a filler, (B) is after a deformation | transformation, (C) is the three-dimensional before a deformation | transformation of only a filament. The model (D) shows the state after deformation.

Explanation of symbols

10 Keyboard 12 Computer body 14 CRT
30 Tire model FD Flexible disk (recording medium)

Claims (6)

An analysis model creation method for a tire code that constitutes a part of a tire model used to calculate a tire corresponding to a numerical calculation model,
When the tire cord is formed by bundling a plurality of filament elements while twisting them in a predetermined direction and is composed of a plurality of classification layers from the center to the outside corresponding to the twist direction of the filament elements, Defining, for the inner first layer, a first two-dimensional region including at least a filament element cross-sectional shape in a direction intersecting the longitudinal direction;
Forming the first two-dimensional region by dividing the first two-dimensional region into predetermined dividing elements that can be numerically calculated while three-dimensionally developing in the longitudinal direction while twisting in the corresponding twisting direction;
Defining, for an outer second layer adjacent to the first layer, a second two-dimensional region including at least a filament element cross-sectional shape in a direction intersecting the longitudinal direction;
Forming the second layer by dividing the second two-dimensional region by a predetermined dividing element that can be numerically calculated while three-dimensionally developing in the longitudinal direction while twisting in the corresponding twisting direction;
Setting a contact element on at least one of an outer periphery of the first two-dimensional region and an inner periphery of the second two-dimensional region;
Corresponding to the set contact element, the outer peripheral contact element of the first layer, the inner peripheral element of the second layer in contact with the contact element, and the inner peripheral contact element of the second layer and the contact element Setting and associating at least one of the outer peripheral elements of the first layer in contact with each other with a contact condition that defines a restriction on relative movement between the elements;
A method for creating an analysis model of a tire code, comprising: The tire according to claim 1, wherein the contact element is set on at least a part of a peripheral surface, and the association is at least a part of a peripheral surface corresponding to the at least part of the surface. Code analysis model creation method. Setting a third two-dimensional region including at least a filament element cross-sectional shape in a direction intersecting the longitudinal direction for an outer third layer adjacent to the second layer;
Forming the third layer by dividing the third two-dimensional region by a predetermined dividing element capable of numerical calculation while three-dimensionally developing in the longitudinal direction while twisting in the corresponding twisting direction;
Setting contact elements on at least one of an outer periphery of the second two-dimensional region and an inner periphery of the third two-dimensional region;
The contact element on the outer periphery of the second layer corresponding to the set contact element, the inner periphery element of the third layer in contact with the contact element, and the contact element on the inner periphery of the third layer and the contact element Setting and associating at least one of the elements on the outer periphery of the second layer in contact with each other with a contact condition defining a restriction on relative movement between the elements; and
The tire code analysis model creation method according to claim 1, further comprising: The tire code analysis model creation method according to any one of claims 1 to 3, wherein the two-dimensional region includes each region of a filament element and a filler. An analysis model creation device for a tire code constituting a part of a tire model used for calculating a tire corresponding to a numerical calculation model,
When the tire cord is formed by bundling a plurality of filament elements while twisting them in a predetermined direction and is composed of a plurality of classification layers from the center to the outside corresponding to the twist direction of the filament elements, A first defining means for defining a first two-dimensional region including at least a filament element cross-sectional shape in a direction intersecting the longitudinal direction with respect to the inner first layer;
First forming means for forming a first layer divided into predetermined dividing elements capable of numerical calculation while twisting the first two-dimensional region in the longitudinal direction while twisting in the corresponding twisting direction;
A second defining means for defining a second two-dimensional region including at least a filament element cross-sectional shape in a direction intersecting a longitudinal direction with respect to an outer second layer adjacent to the first layer;
A second forming means for forming a second layer by dividing the second two-dimensional region by a predetermined dividing element capable of numerical calculation while three-dimensionally developing in the longitudinal direction while twisting in the corresponding twisting direction;
Setting means for setting contact elements on at least one of the outer periphery of the first two-dimensional region and the inner periphery of the second two-dimensional region;
The contact element on the outer periphery of the second layer corresponding to the set contact element, the inner periphery element of the third layer in contact with the contact element, and the contact element on the inner periphery of the third layer and the contact element Association means for setting and associating at least one of the outer peripheral elements of the second layer in contact with each other by setting a contact condition defining a restriction on relative movement between the elements;
An analysis model creation device for a tire code, comprising: A computer for creating an analysis model of a tire code constituting a part of a tire model used for calculating a tire corresponding to a numerical calculation model;
When the tire cord is formed by bundling a plurality of filament elements while twisting them in a predetermined direction and is composed of a plurality of classification layers from the center to the outside corresponding to the twist direction of the filament elements, A first defining means for defining a first two-dimensional region including at least a filament element cross-sectional shape in a direction intersecting the longitudinal direction with respect to the inner first layer;
First forming means for forming a first layer divided into predetermined dividing elements capable of numerical calculation while twisting the first two-dimensional region in the longitudinal direction while twisting in the corresponding twisting direction;
A second defining means for defining a second two-dimensional region including at least a filament element cross-sectional shape in a direction intersecting a longitudinal direction with respect to an outer second layer adjacent to the first layer;
A second forming means for forming a second layer by dividing the second two-dimensional region by a predetermined dividing element capable of numerical calculation while three-dimensionally developing in the longitudinal direction while twisting in the corresponding twisting direction;
Setting means for setting contact elements on at least one of the outer periphery of the first two-dimensional region and the inner periphery of the second two-dimensional region;
The contact element on the outer periphery of the second layer corresponding to the set contact element, the inner periphery element of the third layer in contact with the contact element, and the contact element on the inner periphery of the third layer and the contact element Association means for setting and associating at least one of the elements on the outer periphery of the second layer that contact with each other by setting a contact condition that defines a relative movement restriction between the elements;
An analysis model creation program for tire cords to function as

Images