JP4466118B2 - Operation method of simulation apparatus - Google Patents

Description

The present invention relates to an operation method of a simulation apparatus for creating a tire model having a member model obtained by modeling a tire constituent member using a finite element and simulating tire characteristics .

  Various methods for predicting tire characteristics using a finite element model divided into a plurality of finite elements and designing a tire based on the tire characteristics have been proposed. Each of these methods creates a finite element model of the tire using a computer, reproduces the stationary state or rolling state of the tire using the created tire model, and the characteristic physical quantity acting on the model generated at this time Is used to evaluate the tire characteristics. By using this tire characteristic, a tire having excellent tire characteristics can be designed without actually manufacturing the tire.

As a method of creating a tire model used for such a tire simulation, a method of creating a finite element model of a tire with a tread pattern that can analyze the influence of the tread pattern has been proposed (see, for example, Patent Document 1).
In Patent Document 1, a tire body part model and a tread pattern part model in a tire finite element model are separately created, and then the tire finite element model is created by combining the models. At that time, by making various changes to the tread pattern part model with respect to the tire body part model, the tread pattern is taken into account and the tire characteristics with high accuracy applicable to actual development can be obtained. Simulation can be performed efficiently.

By the way, an actual tire is manufactured by vulcanizing a green tire obtained by wrapping a tire constituent member cut into a predetermined length into a cylindrical shape and forming it into a predetermined shape. When forming a green tire, the tire constituent members are always joined at both ends. For this reason, the cross-sectional shape is corrected at the joint portion of the tire constituent member so that the cross-sectional shape of the tire constituent member at the joint portion is constant with respect to the non-joint portion. However, even a tire constituent member with such a modification does not necessarily have a uniform cross-sectional shape. For this reason, in an actual tire, a subtle vibration component (uniformity component) is generated as the tire rolls due to the influence of the joining portion, and this vibration component affects the tire characteristics.
Japanese Patent No. 3314082

  However, in Patent Document 1, since the tire body portion in the tire finite element model is developed with the same cross-sectional shape in the circumferential direction of the tire to create a loop-shaped model, the joining of tire constituent members is considered. It has never been. For this reason, the tire characteristics including the vibration component due to the joining of the tire constituent members could not be simulated.

Accordingly, the present invention provides a method of operating a simulation apparatus capable of simulating the tire characteristic to create a tire model which reproduces the junction of the chromatic and tire components the modeled member model using the finite element tire component member The purpose is to provide.

In order to achieve the above object, the present invention is an operation method of a simulation apparatus for simulating tire characteristics, comprising an input device, an output device, and a CPU, wherein the CPU constitutes a tire. step tire component member and modeling, and creating a member models for non-loop shape with two ends, the member model created by the mesh divided in the tire circumferential direction, and generates a large number of finite elements and nodes that When the time of the member model loop shape by combining the both end portions of the member models, based on the constraints to regulate the behavior of the nodes which is input from the input device by the operator, one of said end portions It is determined that the relative position of the node of the finite element located at the joint of the finite element does not change relative to the node of the finite element located at the other joined part to be joined. Creating and setting a coupling portion that is, the steps of the member model loop shape by coupling the coupling portion which is set in the coupled parts, using the member model, the tire model of a three-dimensional shape A step of calculating a tire characteristic by executing a simulation calculation based on a simulation condition input from the input device by an operator to the tire model, and outputting the calculated tire characteristic by the output device There is provided a method for operating a simulation apparatus, characterized in that:
The constraint condition uses the behavior of the node located at the coupling portion as the behavior of the node of the finite element on the boundary surface when the node abuts on the boundary surface of the finite element located at the coupled portion. It is preferable that the coupling portion is set by applying this constraint condition to the coupling portion.
Moreover, it is preferable to give an incidental condition to the coupling part so that the constraint condition is released from the coupling part when a physical quantity acting on the coupling part is out of a predetermined range.

The member model is preferably a model that reproduces at least one member selected from a tread rubber member, a side rubber member, a bead filler rubber member, a liner rubber member, a carcass member, a belt member, and a bead core member. .
Both end portions of the member model are coupled so as to overlap along the tire circumferential direction, and the cross-sectional shape of the member model is constant regardless of the position in the tire circumferential direction including the both end portions, and the member model It is preferable that the material constants at both ends are also constant.
The member model has a cross-sectional shape in which each cross-sectional shape of the both end portions becomes asymptotically smaller as it approaches the end so that a cross-sectional shape when the both end portions are joined becomes equal to a cross-sectional shape at a non-joining position. It is preferable.
It is preferable to set the mass density and the stiffness constant 1.2 to 1.8 times higher than the non-bonded portion among the material constants of the bonded portions at both ends in the member model.

The present invention provides a method of operating a simulation apparatus capable of simulating the tire characteristic to create a tire model which reproduces the junction of the chromatic and tire components the modeled member model using the finite element tire component member can do. As a result, it is possible to simulate tire characteristics including vibration components due to joining of tire constituent members.

FIG. 1 is a schematic diagram showing an outline of a simulation apparatus for executing a simulation of tire characteristics in the operation method of the simulation apparatus of the present invention.
The simulation apparatus 1 includes a central processing unit (CPU) 2 that controls functions of each part (processing unit) and controls processing of the entire apparatus, and a RAM that temporarily stores calculation results obtained in each part. And a memory 3 such as a ROM for storing various control information for executing processing of each part, and an input / output port 4. The simulation apparatus 1 includes an input device 5 such as a keyboard and a mouse for inputting various conditions such as a model creation condition, a processing condition, or a characteristic calculation condition via an input / output port 4, and an input result or tire by the input device 5. It is connected to an output device 6 such as a display or a printer for displaying a simulation result of characteristics and an external storage device 7 such as a hard disk or a magneto-optical disk.

Such a simulation apparatus 1 creates a tire finite element method analysis model (hereinafter referred to as a tire model) in accordance with an operator input, sets simulation conditions, executes a simulation, and calculates tire characteristics.
FIG. 2 shows the flow of the tire characteristic simulation process executed by the simulation apparatus 1.

As a process for executing the simulation, a tire model is created using a method described later (step S101).
The created tire model is composed of models (member models) of a plurality of tire constituent members (hereinafter referred to as members), and the elements constituting each member model are three-dimensional models.
FIG. 3 is a perspective view of an example of a tire model of a passenger car tire.
The tire model 10 is mainly divided into a tread pattern portion model 12 and a tire body portion model 14, and these models are separately created, and then the tread pattern portion model 12 and the tire body portion model 14 are combined. . At that time, the models are created by joining the nodes of the joined portions, or by giving a predetermined constraint condition to the nodes of the joined portions. Each model is constituted by a large number of finite elements, for example, a hexahedral solid element, a pentahedral solid element, a tetrahedral solid element, a shell element, or a membrane element. Thus, after the tread pattern part model 12 and the tire body part model 14 are created separately, the tire characteristics are simulated by changing the tread pattern part model 12 without changing the tire body part model 14. Because.

FIG. 4A is a perspective view of an example of the tire body part model 14.
The tire body portion model 14 is a model obtained by removing the tread pattern portion model 12 from the tire model 10 and has a substantially toroidal shape. In FIG. 4 (a), the tire circumferential direction is the A direction, the tire width direction is the B direction, the tire cross-sectional direction is the plane direction when cut along a plane that passes through the tire rotation axis and is orthogonal to the tire circumferential direction. To express. FIG. 4B is a cross-sectional view of the right half of the tire body part model 14 when cut in the tire cross-sectional direction of the tire body part model 14.
The tire body part model 14 mainly includes a belt member model 14a reproducing a belt member, a tread base member model 14b reproducing a tread base member, a carcass member model 14c reproducing a carcass member, and a side member reproducing a side member. A model 14d, a bead filler member model 14e reproducing the bead filler member, a bead member model 14f reproducing the bead member, and the like are configured.

  FIG. 5 is a perspective view of the tread pattern portion model 12. The tread pattern portion model 12 is a model that reproduces the tread pattern of the tire, and is composed of fine finite elements as compared with the tire body portion model 14. Such a tire model 10 is created by the tire model creation method of the present invention described later.

Next, simulation conditions are set for the created tire model 10 (step S102).
Boundary conditions and test conditions are set as simulation conditions. The boundary condition includes a dynamic boundary condition and a geometric boundary condition. The mechanical boundary condition is a condition related to a so-called external force, and the geometric boundary condition is a condition related to a constraint condition or a forced displacement.
The test conditions are the use conditions when the tire is used (various conditions such as load, internal pressure, travel speed, road surface condition, etc.). For example, when simulating the tire characteristics in the running state, the condition for performing the internal pressure filling process on the tire model and setting the grounded state is set as the test condition. In other words, the internal pressure filling is reproduced by attaching a rim model created separately to the tire model and applying a certain load to the inner peripheral surface of the tire model. After the internal pressure filling process, the tire model is set to a rigid road surface model and grounded with a load, and a grounded tire model is created.

Next, a simulation calculation is executed, and the calculation result is output to the output device (step S103).
For example, when simulating tire characteristics in a running state, a translation calculation and a rotational angular velocity are given to a tire model set in a ground contact state, and a simulation calculation is performed in a state where the tire runs on a road surface. The simulation calculation is performed using a known finite element solver or the like.

Simulation calculations include, for example, dry performance during cornering with camber angle and slip angle, braking / driving performance when braking torque or driving torque is applied to the tire rotation axis, and a fluid model that reproduces the wet road surface. A simulation calculation of wet performance such as hydroplaning performance on the road surface is given, and the calculation is performed using the above test conditions.
A predetermined characteristic physical quantity acting on the tire model 10 is calculated as a calculation result, and the calculated characteristic physical quantity is displayed on the display as an index of tire characteristics. Alternatively, it is output to a printer.
Such tire characteristics are affected by the uniformity component accompanying the rolling of the tire, but in the present invention, the tire characteristics can be simulated in consideration of the uniformity.

FIG. 6 is a flowchart for explaining the flow of the tire model creation method of the present invention.
First, a three-dimensional shape model of a tire constituent member is created (step S201). The three-dimensional shape model is a non-loop shape member model having both end portions in the tire circumferential direction.
FIG. 7A shows a three-dimensional shape model 110 of the side rubber member as an example. The three-dimensional shape model 110 has a non-loop shape and has both end portions 112. FIG. 7B is an enlarged view in which the vicinity of both end portions 102 is enlarged. The both end portions 112 are asymptotically smaller as they approach the end so that the cross-sectional shape does not increase at the coupling portion during coupling, and surfaces 114a and 114b are formed. The surfaces 114a and 114b are connected to each other.

Next, the three-dimensional shape model is divided into meshes (step S202), and a large number of finite elements and nodes are generated.
FIG. 8A is a view in the X direction of the three-dimensional shape model 110 shown in FIG. As shown in FIG. 8A, the member model 110 has a non-loop shape composed of hexahedral solid elements and pentahedral solid elements.
Next, for the created member model, a coupling surface is set so that a loop-shaped member model is created (step S203).

Specifically, a coupling surface and a coupled surface for creating a loop-shaped member model by coupling both ends of the created member model are defined, and the nodes of the finite elements located on this coupling surface are A binding surface is set by applying a constraint condition so that the relative position does not change with respect to the nodes of the finite element located on the other coupled surface to be coupled.
For members model 110 shown in FIG. 8 (a), defines a coupling surface 112 _a and the coupling face 112 _b, the node ₁₁₂ u, 112 _v located coupling surface 112 _a is located in the coupling surface 112 _b nodal A constraint condition is given so that the relative position does not change with respect to 112 _x and 112 _y . This constraint condition will be described later.

Thus, as shown in FIG. 8 (b), the coupling surface 112 _a is as if members model 110 to behave as if in contact with 'is created for the coupling face 112 _b (step S204). That is, in connection, the node 112 _x and the node 112 _u and the node 112 _y and the node 112 _v are not integrated and shared in one node, but exist as the nodes in the member model 110 ′. . Thus, coupling surfaces 112 _a and the coupling face 112 _b is also defined as a boundary surface of different finite element in members model 110 '.

Next, a tire model is created by integrating with another member model created separately (step S205). Here, in order to integrate with other member models, constraint conditions are set so that the joint positions of the finite elements to be joined are shared, or the relative positions between the joints of the finite elements to be joined do not change as described later. Is done.
FIG. 9 is a perspective view showing a part of the tire model 120. A member model 110 in which a side rubber member is modeled as a solid element is incorporated in a region A (gray region) of the tire model 120. The created tire model 120 is used for calculation of tire characteristics.

In the tire model creation method of the present invention, a non-loop member model is created in advance, and then both ends are joined. At that time, the nodes connected at the end portions are not shared with the nodes to be connected, exist separately, and the connection surface is defined so that the relative position between these nodes does not change. Specifically, the behavior of the node located on the coupling surface is regulated using the behavior of the node of the finite element on this boundary surface when this node abuts on the boundary surface of the finite element located on the coupled surface. The constraint condition to be applied is given to the bonding surface.
Therefore, the position of the node of the coupling surface does not need to overlap the position of the node of the coupled surface, and the position of the node of the coupling surface may be on the boundary surface of the finite element on the coupled surface. Therefore, as shown in FIG. 10, it is also possible to couple the coupling surface and the coupled surface in a shifted form.

Hereinafter, setting of the constraint condition to be applied to such a coupling surface will be described. FIG. 11 is a diagram for explaining the transformation T used for setting the constraint conditions.
The node (x, y) (marked with ● in the figure) of the coupling surface shows a state where it is located on the boundary surface of the finite element of the coupled surface. The transformation T is a quadrature on the physical space formed by the nodes 1, 2, 5, 4 of the finite element of the coupled surface and the line segments connecting these nodes, and a reference shape (normal) defined in the parametric space. Is converted into a square having a side length of 2. Nodes 1, 2, 5, and 4 are mapped to the vertices of the square, each side of the square is mapped to each side of the square, and the inner area of the square is mapped to the inner area of the square. Further, the inverse transformation T- ^{1 is used} to convert a square into a quadrangle, and the square inner area is mapped to the square inner area, each vertex of the square is mapped to each node of the square, and each side of the square is mapped to each side of the square. The That is, the transformation T maps the boundary surface of the finite element of the coupled surface in the XY coordinate space to the square in the RS coordinate space on a one-to-one basis.
Therefore, the corresponding points on the square can be obtained by the transformation T with respect to the nodes of the coupling surface included in the finite element of the coupled surface or positioned on the side.
More specifically, the position in the XY coordinate space using the shape functions N ₁ (r, s), N ₂ (r, s), N ₃ (r, s), and N ₄ (r, s). The coordinates (x, y) can be associated with the position coordinates (r, s) by the following formula (1). Here, x ₁ , y ₁ , x ₂ , y ₂ , x ₅ , y ₅ , x ₄ , y ₄ are the position coordinates of the nodes ₁ , ₂ , ₅ and ₄ of the finite element of the coupled part, respectively. .
In the example of FIG. 11, the reference shape in the parametric space is a square shape, but is not limited to this shape. A triangular shape, a rectangular shape, etc. may be sufficient.

Here, the shape functions N ₁ (r, s), N ₂ (r, s), N ₃ (r, s), and N ₄ (r, s) are defined in FIGS. Function. Here, when the matrix in the expression (1) is M, the components of the matrix M are the weighting factors W at the nodes described above.
FIG. 13 is a view of the member model shown in FIG. 10 in the Y direction, and shows a state in which the coupling surface and the coupled surface are shifted and coupled. More specifically, with reference to FIG. 13, the weighting factor W (200) for the node 200 (position coordinates (x ₀ , y ₀ )) is the position coordinate of the corresponding point in the RS space coordinates of the node 200 ( When r ₀ , s ₀ ) is used, N ₁ (r ₀ , s ₀ ) is obtained, and the position coordinates (x ₀ , y ₀ ) of the node 200 can be expressed by the following formula (2).

The calculated weighting factor W is defined and listed for each node of the coupling surface, but each finite element of the coupled surface is also defined by the weighting factor W.
In the above case, the nodes of the coupled surfaces overlap the nodes of the joint surface. However, for the nodes of the coupled surfaces located on the sides of the finite elements of the coupled surfaces, the weighting factor W is doubled with different finite elements. Set to For this reason, one of the overlapping nodes is deleted.

The constraint condition that regulates the behavior of the node located on the coupling surface described above uses the physical quantity acting on each node of the coupling plane, the physical quantity of the node of the finite element of the coupled surface that includes this node, and the weight coefficient W. And is given to the coupling surface by a constraint formula as shown in the above formulas (3) to (5).
If the predetermined physical quantities of the nodes 1, 2, 5, and 4, for example, the displacement in the X direction are u (1), u (2), u (5), and u (4), the displacement u ( 200) is determined by the following equation (3). Similarly, the displacement v (200) in the Y direction can also be expressed by the following equation (4) using the same weighting factor W.

  Thus, the behavior of the finite element on the coupling surface can be regulated by expressing the physical quantity acting on the node of the coupling surface by the physical quantity of the node of the finite element of the coupled surface that includes the node.

For example, the deformation behavior of the created tire model 10 is dynamically calculated. That is, when dynamic analysis is performed, an explicit method is performed in which the following calculation is performed at every predetermined time step. At a certain time step, the force acting on the joint surface (constrained point) and the mass of this joint are distributed to the joint surface (constrained node) according to the weighting factor w _i . Modify the mass of these nodes (the nodes that constrain the coupled surface) and the forces acting on them. In this case, after the above distribution is performed on all the nodes on the coupling surface, the accelerations of the nodes of the member model excluding the nodes on the coupling surface are calculated. Thereafter, the acceleration of the node restrained by the coupled surface is distributed to the boundary node of the coupled surface using the weighting factor wi. In this way, the acceleration of the node on the coupling surface can be obtained. The force applied to this node is obtained using the acceleration at the obtained node and the mass at this node. Thus, the force acting in the next time step is obtained. Of course, when a force is applied to the node at the next time step as an external force, this force is also added. Such an explicit method is suitable for a simulation calculation that dynamically reproduces the behavior of the tire.

Moreover, when performing a static analysis as follows, an implicit method can also be performed.
For example, a model matrix is created in which the degrees of freedom of the boundary nodes on the coupling surface are eliminated from the constraint equation. This method is suitable for a simulation calculation that statically reproduces the behavior of the tire, and the degree of calculation required for the analysis can be reduced because the degree of freedom in the entire matrix is reduced by eliminating the degrees of freedom of the nodes.
Alternatively, instead of the method of eliminating the degrees of freedom of the nodes from the constraint equation, the same value is obtained for the diagonal components of the nodes of the constrained coupling surface and the constrained surface in the matrix of the entire model. The corrected model matrix is created by adding the penalty number and subtracting the penalty value of the same value from the intersection component.

For example, in a model matrix such as the following equation (6), when a constraint equation of u ₃ = u ₂ is determined, the matrix component of u ₃ is deleted as shown in the following equation (7), and u ₁ , U ₂ , u ₄ .
Further, as shown in the following equation (8), a penalty coefficient K is added to the diagonal components k ₂₂ and k ₃₃ corresponding to u ₂ and u ₃ in the matrix, and the intersection component of u ₂ and u ₃ in the matrix A penalty coefficient K having the same value is subtracted from k ₂₃ and k ₃₂ . Here, the penalty coefficient K is, for example, a very large value obtained by multiplying 10 ¹⁰ times the larger of the diagonal components k ₂₂ and k ₃₃ of u ₂ and u _{3 in} the matrix.

The constraint condition thus obtained is applied to the joint surface, and both ends of the member model are coupled.
In the example shown in FIG. 13, the node position of the coupling surface does not correspond to the position of the node of the non-coupling surface, but of course the nodes of the coupling surface as shown in FIGS. It may be a coupled form in which the position coincides with the position of the node of the non-bonded surface.
Further, in the present invention, as shown in FIG. 14, the coupling may be such that the coupling surfaces 140 _a and the coupled surfaces 140 _b at both ends of the member model are in contact with each other, as shown in FIG. 15. , the cross-sectional shape of the member model is constant regardless of the tire circumferential positions including both ends, even members model coupling surface 0.99 _a and the coupling face 0.99 _b a bound form overlapping along the tire circumferential direction Good.

In the case of the coupling form in FIG. 14, the material constants of the finite elements to be coupled, for example, the mass density and the stiffness constant (Young's modulus and shear stiffness) are 1.2 to 1. By setting it 8 times higher, it is possible to represent the non-uniformity in the tire circumferential direction caused by the joint portion in the tire model.
In the case of the coupling form shown in FIG. 15, the material constant values at both ends in the member model are also set to the same values as in the non-bonded portion, and the mass and rigidity change due to the shape change in which the thickness increases at the bonded portion. . As a result, the non-uniformity in the tire circumferential direction caused by the joint portion in the tire model can be expressed.

Further, in the present invention, examples of the tire constituent member that is a target of the non-loop member model include a tread rubber member, a side rubber member, a bead filler rubber member, a liner rubber member, a carcass member, a belt member, and a bead core member. It is done.
FIG. 16 is a plan view of a member model in which a belt member is modeled by a shell element. The coupling portion of the member model (bond line) 160 _a and the coupling portion (coupling lines) 160 _b are inclined with respect to the tire circumferential direction, is bonded the inclined coupling part 160 _a and the coupling portion 160 _b Is done.
FIG. 17 is a plan view of a member model obtained by modeling a carcass member with a shell element. The coupling portion of the member model (bond line) 170 _a and the coupling portion (coupling lines) 170 _b are perpendicular to the tire circumferential direction, the coupling portions 170 _a and the coupling portion 170 _b is coupled.

18 and 19 are diagrams for explaining the joint surface of the tread member model.
FIG. 18A is a cross-sectional view of the tread member model cut along a plane parallel to the tire circumferential direction, and reference numeral 181 represents a joint surface. FIG. 18B is a perspective view schematically showing the joint surface of the tread member model shown in FIG. The joint surface is inclined with respect to the tire circumferential direction, and the inclined coupling portion and the coupled portion are coupled.
FIG. 19A is a cross-sectional view of the tread member model cut along a plane parallel to the tire circumferential direction, and reference numeral 191 represents a joint surface. FIG. 19B is a perspective view schematically showing the joint surface of the tread member model shown in FIG. The joining surface is orthogonal to the tire circumferential direction, and the coupling portion and the coupled portion are coupled.

When the tire model has a plurality of member models including coupling surfaces, it is preferable that the coupling surfaces of the respective member models are arranged without being concentrated in one place with respect to the circumferential direction of the tire. That is, it is preferable to arrange so that the joint surfaces of the respective member models are equally spaced with respect to the tire circumferential direction. For example, if there are two member models having connecting surfaces, the connecting surfaces of each member model are arranged diagonally with respect to the tire circumferential direction, and if there are three member models having connecting surfaces, It is preferable to dispose the joining surfaces of the respective members by shifting by 60 ° with respect to the tire circumferential direction.
An example of the case where the carcass member, the sidewall member, and the tube strainer member have a coupling surface is shown in FIG. Reference numeral 201 represents the position of the bonding surface of the carcass member, reference numeral 202 represents the position of the bonding surface of the sidewall member, and reference numeral 203 represents the position of the tubeless liner. In this case, the connecting surfaces of the respective member models are arranged at equal intervals in the tire circumferential direction.

  The tire model creation method according to the present invention has been described in detail above. However, the present invention is not limited to the above embodiment, and various improvements and modifications are made without departing from the gist of the present invention. May be.

It is the schematic which shows the outline of a simulation apparatus. It is a figure which shows the flow of the simulation process of the tire characteristic performed with a simulation apparatus. It is a perspective view of an example of a tire model of a tire for passenger cars. (A) is a perspective view of an example of the tire body part model 14, (b) is sectional drawing of the right half of a tire body part model when it cut | disconnects in the tire cross section direction of a tire body part model. It is a perspective view of a tread pattern part model. It is a flowchart explaining the flow of the tire model creation method of this invention. It is a figure which shows the three-dimensional shape model of a side rubber member. It is an X direction arrow directional view of the three-dimensional shape model shown to Fig.7 (a). It is a perspective view which shows a part of tire model. It is a figure which shows an example of the engagement form of a three-dimensional shape model. It is a figure explaining the conversion T used in order to set a constraint condition. It is a figure which shows a shape function. It is a figure explaining conversion T of the member model shown in FIG. It is a figure which shows an example of the coupling | bonding form of a three-dimensional shape model. It is a figure which shows an example of the coupling | bonding form of a three-dimensional shape model. It is a top view of the member model which modeled the belt member with the shell element. It is a top view of the member model which modeled the carcass member with the shell element. It is a figure for demonstrating the joint surface of a tread member model. It is a figure for demonstrating the joint surface of a tread member model. It is a figure which shows an example in case a carcass member, a side wall member, and a tube strainer member have a coupling surface.

Explanation of symbols

1 Simulation device 2 Central processing unit (CPU)
3 Memory 4 Input / Output Port 5 Input Device 6 Output Device 7 External Storage Device

Claims (8)

An input device;
An output device;
CPU,
An operation method of a simulation apparatus for simulating tire characteristics, comprising:
The CPU is
The tire components constituting the tire was modeling, creating a member models for non-loop shape with both end portions in the tire circumferential direction,
Meshing the created member model to generate a large number of finite elements and nodes;
When the member model loop-shaped bonded to the both end portions of the member model, based on the constraints to regulate the behavior of the nodes which is input from the input device by the operator, one bond of the end portions Setting a coupling part defined such that the relative position of the node of the finite element located in the part does not change relative to the node of the finite element located in the other coupled part to be coupled;
Coupling the set coupling part to the coupled part to form a loop-shaped member model;
Using this member model to create a three-dimensional tire model;
Based on the simulation conditions input from the input device by the operator for the tire model, performing simulation calculation to calculate tire characteristics;
Outputting the calculated tire characteristics by the output device;
The operation method of the simulation apparatus characterized by performing this . The constraint condition uses the behavior of the node located at the coupling portion as the behavior of the node of the finite element on the boundary surface when the node abuts on the boundary surface of the finite element located at the coupled portion. It is intended to regulate Te, by applying the constraint to the coupling portion, the operation method of the simulation apparatus according to claim 1, wherein the coupling portion is set. The operation method of the simulation apparatus according to claim 2, wherein when a physical quantity acting on the coupling portion is out of a predetermined range, an incidental condition for releasing the constraint condition from the coupling portion is given to the coupling portion. 2. The member model is a model reproducing at least one member selected from a tread rubber member, a side rubber member, a bead filler rubber member, a liner rubber member, a carcass member, a belt member and a bead core member. The operation | movement method of the simulation apparatus of any one of -3. The operation method of the simulation apparatus according to claim 1, wherein both ends of the member model are coupled so as to overlap along a tire circumferential direction. The operation method of the simulation apparatus according to claim 5, wherein a cross-sectional shape of the member model is constant regardless of a position in a tire circumferential direction including the both end portions, and a material constant of the both end portions in the member model is also constant. . The member model has a cross-sectional shape in which each cross-sectional shape of the both end portions becomes asymptotically smaller as it approaches the end so that a cross-sectional shape when the both end portions are joined becomes equal to a cross-sectional shape at a non-joining position. The operation method of the simulation apparatus according to claim 1. The operation of the simulation apparatus according to claim 7, wherein a mass density and a stiffness constant are set to be 1.2 to 1.8 times higher than a non-bonded portion among material constants of a bonded portion at both ends in the member model. Method.

Images