JP3363443B2 - Simulation method of tire performance - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [0001] BACKGROUND OF THE INVENTION 1. Field of the Invention
Simulation of tire performance that can simulate performance
About the method. [0002] 2. Description of the Related Art
Tire development involves creating prototypes, testing them,
It is a repetitive process of making further prototypes from the fruits
Had been This method is often used for prototype production and experimentation.
Costs and time, limiting the efficiency of development
is there. To overcome such problems, in recent years, approximate solutions
Computer simulation using analysis methods
Predicts and solves some performance without prototype tires
An analysis method has been proposed. [0003] In computer simulation, various
Is used. For example, the one using the finite element method is
Well known. Finite Element Metho
d) The structure is a finite element called a finite element.
Into a number of domains, giving each finite element relatively simple properties.
This is a technique for analyzing the entire system. Analysis of Conventional Tire Performance by Finite Element Method
Is a load analysis in the non-rolling state of the tire,
For the tread pattern, there is no groove, so-called
Lots of plain treads, all tread patterns on tires
There is no known finite element model. Ma
Also, inside the tire, there are cords such as carcass and belt
Reinforcement layers and the like that are laminated at different angles are provided,
These are also simplified models using a single plane shell element.
Most of the analyzes were converted to standardized ones. [0005] The present invention provides a method of accuracy that can be applied to actual development.
Tire performance stains that can simulate good tire performance
It is intended to provide a simulation method. [0006] Means for Solving the Problems Claim 1 of the present invention
The invention described above uses a finite number of tires to be evaluated.
Approximate by the tire finite element model divided into
Tire performance from the tire finite element model using elementary method
Simulation of tire performance
In the wayAnd saidTire finite element model on virtual road surface
Ground and contact the virtual road surface
The rotation axis is freely supported, and friction due to the movement of the virtual road surface
Force the tire finite element model to roll over half a turn
It is characterized by that. [0007]Claim 1The described inventionThen, the tire
The finite element model isReinforcement of cord including belt and belt
Material and rubber part including sidewall rubber and bead rubber
And the bead core are continuous with the same cross-sectional shape in the tire circumferential direction.
Of the tire body part to be
Expand the dimensional shape in the circumferential direction and divide the elements into tire body parts
Processing to set the element model;Vertical extending in the tire circumferential direction
A trough with a groove and a horizontal groove extending in the direction intersecting this vertical groove
Finite pattern over the entire circumference in the tire circumferential direction.
The tread pattern part element model divided into elements
Processing to set,The tire body part element model
Combining the tread pattern part element model
Is formed. [0008] BRIEF DESCRIPTION OF THE DRAWINGS FIG.
It will be described based on. In the present embodiment, as shown in FIG.
Radial tires for passenger cars (hereinafter simply referred to as tires)
There is. ) Simulate the performance of T
ing. The tire T is moved from the tread 12 to the sidewalk.
Around the bead core 15 of the bead portion 14 through the
Folded and the cord approximately 90 degrees to the tire circumferential direction
And a carcass 16 composed of a ply 16a tilted at
Of the tire 16 in the tire radial direction and the tread portion 12
A cord reinforcing material F including a belt layer 17 disposed inward is provided.
Equipped. In the present embodiment, the belt layer 17 is formed around the tire.
Inside and outside two bells paralleled at an angle of 20 degrees to the direction
Topply 17A, 17B in the direction where the cords cross
It is configured by being laminated. In this example, the belt layer 1
Nylon cord around tire radially outside of tire
A band layer 19 arranged substantially parallel to the
Lifting of the belt layer 17 during high-speed running is prevented.
You. The band layer 19 is formed, for example, at both ends of the belt layer 17.
And an edge band covering substantially the entire width of the belt layer 17.
With a band. The carcass 16 is made of, for example,
Use organic fiber cords such as
A and 17B are steel cords, respectively.
It is configured to be covered with a ping rubber. Note that
The carcass 16 and the belt layer 1
7. Reinforce the rigidity of the bead portion 14 in addition to the band layer 19
Bead reinforcing filler etc. can be included as needed
it can. The tire T is made of the cord reinforcing material F
Outside, tread rubber 20, sidewall rubber 21,
A bead rubber 22 is provided. The tread rubber 20
Are arranged radially outside of the belt layer 17 in this example.
Through the groove bottom line of the longitudinal groove G1 in the tire meridional section.
Tread portion extending substantially along the surface of the tread portion 12
Rubber 20a and the outer rubber 20a
From the tread cap rubber 20b that transmits various forces
An example of a configured two-layer structure is shown. The sidewall rubber 21 is used for the tire.
The part that bends significantly when rolling and comes into contact with the curb on the road surface
It protects the side of the tire T even when
Flexible with a smaller complex modulus than the tread rubber 20
It is preferred to use rubber. The bead rubber 22
Is located near the mating part that contacts the rim flange.
From rubber with relatively high elastic modulus and excellent wear resistance
Can be configured. The outer surface of the tread portion 12 has, for example,
For example, a vertical groove G1 extending in the tire circumferential direction intersects the vertical groove G1.
A predetermined tread pad is formed by a lateral groove G2 extending
A turn is formed. This tread pattern
This has a significant effect on the ear performance, and
In this method, this tread pattern
The effect of tires on tire performance.
You. In the simulation method or apparatus of this embodiment,
Shows such a tire T to be evaluated in FIG.
Divided into a finite number of elements 2a, 2b, 2c, etc.
Approximated with the tire finite element model 2 using the finite element method
The tire performance from the tire finite element model 2
Is to simulate. The present simulation apparatus is, for example, shown in FIG.
As shown, a CPU as an arithmetic processing unit and this CPU
ROM that stores the processing procedure of
RAM which is a working memory capable of temporarily storing numerical values
, Input / output ports, and a data bus connecting them.
Has been established. In the present embodiment, the input / output port is
Enter numerical values for setting the ear finite element model
Input means I such as a keyboard, a mouse, etc.
Display, pudding that can display the simulation results
Output means O such as a hard disk and a magneto-optical disk.
And an external storage device D such as a disk. In the ROM, a system as shown in FIG.
The processing procedure of the simulation is stored.
I will tell. Tire finite element model for which simulation is performed
Dell 2 has a tire body part element model 3 and a tread
And a turn part element model 4. The tire body part element model 3 is shown in FIG.
1. As shown in FIG. 2, the tire body 1B is a finite element
It is obtained by dividing based on the law. Also tire wheel
Depart 1B is the circumferential direction of the tire to be evaluated.
Parts that are substantially the same material and have the same cross-sectional shape
In this example, the tread rubber 2
0, except for the tread cap rubber 20b
I have. Specifically, the tire body 1B is
Tire carcass 16, belt layer 17, band layer 19
And a tread of tread rubber 20
Base rubber 20a, sidewall rubber 21, bead
A rubber portion including the rubber 22 and the bead core 15 are included. In the simulation method of this embodiment, the
The ear body 1B has a finite number of elements based on the finite element method.
Is divided into An element based on the finite element method is, for example, 2
A quadrilateral element in a three-dimensional plane and a tetrahedron as a three-dimensional element
Solid element, pentahedral solid element, hexahedral solid required
Elements that can be used on computers, such as
And these elements are one by one using the three-dimensional coordinates XYZ.
Can be specified. As the cord reinforcing material F, for example, a belt layer
As shown in FIG.
This is set to the strong material element model 5. In this example, cord reinforcement
The cord material c of F is modeled by the quadrangular membrane elements 5a and 5b.
And the topping rubber t is hexahedral
Example modeled with solid elements 5c, 5d, 5e
Is shown. The quadrilateral modeling the code material c
The material definition of the membrane element 5a is, for example, the thickness of the cord material c.
And orthogonal to the arrangement direction of the cord material c.
Orthotropic materials with different stiffness in different directions
Treated as if the rigidity in each direction was homogenized
Are illustrated. In addition, topping of cord reinforcement F
The hexahedral solid elements 5c to 5e representing the gum rubber t are
Defined and treated as a super viscoelastic material like a rubber member
be able to. The tread portion of the tire body portion 1B
Rubber portion 10a, sidewall rubber 21, beadgo
For example, the hexagonal solid
To model with pad elements or pentahedral solid elements
I do. Such modeling is performed using the input means I.
Can be done. In addition, tire body part element model 3
Identifies the two-dimensional shape of the meridional section, including the axis of rotation of the tire
By dividing it into elements that expand in the circumferential direction.
Modeling can be performed relatively easily. As described above, in this example, the cord reinforcing material F is
If we model with one plane shoulder element as before
No, like cord material c, topping rubber t, etc.
By modeling according to the characteristics of each material,
Simulate tire performance closer to the actual product
It becomes possible. In addition, each rubber part 20-22, cord supplement
When modeling the strong material F and the bead core 14 into finite elements
Is the complex elastic modulus of each rubber and cord, and the elastic modulus of the bead core.
The material and rigidity can be defined based on the above. Next, the tread pattern part element model
4 indicates the tire tread pattern all around the tire circumferential direction
Tread pattern divided into a finite number of elements over
It is obtained by the process of setting the element part. This pattern is required
In this example, the elementary model 4 is a tread portion of the tread rubber.
A model of the cap rubber 20b, wherein the tire
After being set separately from the body part element model 3,
An example of what is connected to the ear body part element model 3
I have. In this embodiment, the pattern element model 4
Is the tread cap rubber 2 arranged in the tire circumferential direction.
0b is divided into a finite number of tetrahedral elements 4a, 4b,.
The tire is configured over the entire circumference of the tire.
In this way, the pattern element model 4 is
By modeling separately from the elementary model 3, for example,
More detailed than the tire body part element model 3 as in this example
Can be finely divided into elements (meshed), shadow of tread pattern
This is preferable because the sound can be analyzed in more detail. Also tire
With the same internal structure but different tread patterns
For each tire, tread pattern part element model
4 only, three for the tire body element model
Can be shared, and development efficiency can be further improved
There are advantages. In the present embodiment, the tire body
The tread pattern part element model is added to the part element model 3.
4 by combining the tire finite element models.
Complete Dell 2. In addition, as shown in FIG.
The inner surface or node of the pattern part element model 4 is
The phase for the face or node of the body element model 3
Define it to be forcibly displaced so that the pair position does not change
Joined. Next, this tire finite element model 2 is
Attached to the rim and grounded on the virtual road surface 7 under predetermined running conditions
A traveling stain that contacts or moves relative to the virtual road surface
Perform the calculation process. The above-mentioned “Tire Finite Element Model 2 is a virtual rim
"Attach to" means a tire finite element as shown in FIG.
The rim contact area of the model 2 is restricted and the model 2
Forcibly displace the tire axial distance W of the bead to the rim width
Means The rotation axis of the tire finite element model 2
CL is the tire finite element model 2 as shown in FIG.
The connection fixed so that the relative distance r from the rim constraint area is always constant.
Is defined. The virtual road surface 7 is a flat quadrilateral rigid table.
Modeled as a surface. Therefore, the real rim assembly
Reproduce state easily and accurately on simulation
You. In the above-mentioned running simulation process, a predetermined
The driving conditions include, for example, the tire finite element model 2
Pressure, axial load, slip angle α, camber angle, tire finite
Including friction information between the element model 2 and the virtual road surface 7
No. The inner pressure is the inner surface of the tire finite element model 2.
A uniform load equivalent to the tire internal pressure
More can be set. The "slip angle α" is shown in FIG.
As shown, the distance between the traveling direction of the road surface and the
It refers to the corner. Generally, such a rolling state (cornerin
Tires) are shown in the tread section as shown in FIG.
The ground contact surface keeps in contact with the road surface over time.
Move from side to side. In this way, the surface of the tread
Surface is pressed laterally, causing the tread to shear.
Waking up, thereby causing a force perpendicular to the direction of travel.
Knurling force occurs. The camber angle is
Road surface and tire circumference when the tire is viewed from the front in the traveling direction
The angle formed by the direction center line. Then, the tire finite element model 2 is
When simulating, for example, the tire finite element
After restraining the bead part of the model and applying internal pressure, FIG.
The virtual road surface 7 is converted into the tire finite element model 2 as shown in FIG.
Press or rotate the tire finite element model 2
By pressing the axis CL against the virtual road surface 7, the tire
The limited element model 2 is brought into contact with the virtual road surface 7 to
Set various conditions such as load according to the requirements. For example, when analyzing cornering characteristics, etc.
In this case, the tire finite element model 2 is
Contact as described above, and the slip angle α will be
By turning them around and moving them relative to each other.
Simulation. At this time, as in this example, the tire
The finite element model 2 is, for example, a case where the rotation axis is freely supported.
In this case, rolling occurs due to frictional force caused by the movement of the virtual road surface 7.
Can be done. The cornering force and the like are simulated.
When running, the tire finite element mode is
Analyze accurate information that Dell will roll more than half a turn
It is necessary at the point where it is possible. Because the cornering of the tires
The gforce changes over time and becomes steady state
This is because a certain amount of rolling of the tire is required. Next, in the simulation of this example,
From tire finite element model 2 during running simulation
An information acquisition process for acquiring predetermined information is performed. This process
Is calculated from the tire finite element model 2
Information including force, shape of the tread or internal stress distribution
Value information or image information such as animation
Can be obtained. This simulation is based on the finite element method.
Done. Generally, various boundary conditions are added to the finite element model.
Procedure to give information such as force and displacement of the entire system
About to follow the well-known example
Can be. The calculation algorithm in this example is an explicit method.
is there. For example, element shape, element material properties, e.g.
Based on the degree, Young's modulus, damping coefficient, etc.
Rix M, rigid matrix K, damping matrix C
Create The above matrices are combined to form a stain.
Create a matrix of the entire system
You. Also, by applying the boundary conditions as appropriate,
Create a formula. (Equation 1)This equation (1) is sequentially executed by the CPU at every minute time t.
A simulation can be performed by performing the following calculation.
The minute time t of the above-mentioned successive calculation is the stress for all the elements.
Calculate the propagation time of the wave and make it 0.9 times or less the minimum time
Preferably, it is time. The tire has a cornering force and a braking force.
Performance, noise performance, wear performance, rolling resistance performance, etc.
Performance is required, especially analyzing the performance of these tires
Requires a simulation to roll the tires
Becomes In this simulation, the tire body part element
Both model 2 and tread pattern element model 3
Rolling simulation is possible because it is continuous in the circumferential direction.
Cornering performance, wear performance, and damping effect
In consideration of vibration performance and hydrodynamic coupling,
Prediction and analysis of training performance can be performed. As described above, the present invention is not limited to the above-described embodiment.
The tire body portion 1B is not limited to this.
Up to the belt layer and tread base rubber 20a
Deformation into various aspects such as including in the red pattern part
sell. [0041] [Example] The tires simulated this time were 2
35 / 45ZR17LMG02 (Sumitomo Rubber Industries, Ltd.)
Made), cornering force, during cornering
Tread surface, internal stress distribution. The finite element of this tire
The elementary model is the same as that shown in FIG.
3896 and the number of elements is 76359. The virtual road surface is modeled as a flat rigid surface.
It has become. And restrain the bead part of the tire finite element model
After applying the tire internal pressure load, the virtual road surface is
Press against the model to apply a load, and the road surface against the tire
Simulate by moving so that the slip angle is obtained
went. Tire finite element model with free axis of rotation
It rolls due to the frictional force caused by the movement of the road surface. tire
And the coefficient of friction between the road surface and the static friction was set to 1.0.
The traveling speed of the road surface was 20 km / h. In this simulation, the slip angle α
To set 0, 1, 2, and 4 deg.
Rations. The result is shown in FIG. As is clear from FIG.
After about 0.15 seconds after moving on the road surface,
It can be seen that the force is almost stable. this is
When converted to the number of rotations of a tire, it is about a little less than half a rotation. But
Simulate cornering force
To do this, at least roll the tires
Is necessary, and for that, the tread pattern
It has been found that it is preferable to provide it all around. Also, the cornerry obtained by this simulation
And the steady state by actual measurement using a drum tester
Almost in line with the cornering force (Experiment)
The high accuracy of this simulation can be confirmed.
Was. In this simulation, the slip angle was 0deg.
There is a slight cornering force, which is mainly
As a structure in which the belt layer is bias-laminated.
The plysteer current caused by the coupling effect
It can be seen that an elephant appeared. Such a ply
Faithfully represented in this simulation up to the steer phenomenon
It is shown, and high accuracy can be seen. Next, the corner at a slip angle of 4 deg.
Fig. 12 shows the result of analysis of the stress distribution at the center of the grounding surface during rolling.
Shown in As a result, the tire side inside the cornering
Large tensile stress (dots)
Was. FIG. 11 shows the contact pressure distribution of the tread at this time.
Shown in As a result, the center of the tire behind the tread
The deformation in the block is large and the ground pressure is high (dot part
Minute). So far, the actual car was used
Contact pressure distribution during tire rolling cannot be measured experimentally
However, this can be known in this simulation.
By collecting such data, the tire
Details on what parts of the
Detailed analysis enables efficient tire pattern design.
Well done and very useful. This simulation
Is a 40-hour CP using a supercomputer
U calculation time was required. [0047] As described above,Claim 1In the described invention
Touches the tire finite element model to the virtual road surface and
Move or move relative to the road
Roll the tire finite element model more than half a turn on the road surface
Change over time to a steady state
Is a tire that requires a certain amount of rolling
Accurate simulation of cornering forces, etc.
Accurate tire performance that can be applied to actual development.
Help to simulate.Also tire finite element model
The cord reinforcements including carcass and belt, and the side
Rubber part including wall rubber and bead rubber, and bead core
Tire body with the same cross-sectional shape in the tire circumferential direction
Around the two-dimensional shape of the meridional section including the rotation axis.
And split the elements to set the tire body element model.
Process, the longitudinal groove extending in the tire circumferential direction, and this longitudinal groove
Tread pattern with lateral grooves extending in the direction of intersection
Divided into a finite number of elements over the entire circumference of the tire
Setting the tread pattern part element model
And the tread pattern on the tire body part element model.
And a process of combining the segment element models.
Therefore, modeling can be easily performed.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a tire finite element model of the present invention. FIG. 2 is a perspective view of a tire body part element model. FIG. 3 is a conceptual diagram showing element modeling of a cord reinforcing material. FIG. 4 is a perspective view of a tread pattern part element model. FIG. 5 is a diagram illustrating a modification of the tire finite element model. FIG. 6 is a block diagram showing an embodiment of a simulation device of the present example. FIG. 7 is a flowchart illustrating a processing procedure according to the embodiment; FIG. 8 is a conceptual diagram of a cross section in which a tire finite element model is grounded on a virtual road surface. FIG. 9 is a conceptual diagram of a plane in which a tire finite element model is grounded on a virtual road surface. FIG. 10 is a graph showing a simulation result of a cornering force. FIG. 11 is a diagram showing a tread surface of a tire finite element model during cornering. FIG. 12 is a diagram showing a cross section of a tire finite element model during cornering. FIG. 13 is a sectional view of a tire. FIG. 14 is a diagram illustrating a cornering force. [Description of Signs] T Tire 2 Tire Finite Element Model 3 Tire Body Part Element Model 4 Tread Pattern Part Element Model 5 Code Reinforcement Element Model 7 Virtual Road Surface

──────────────────────────────────────────────────続 き Continuing the front page (56) References Masataka Koishi et al., PAM_SHOCK for cornering simulation of tires, Proceedings of 1996 PAM Users Conference in Asia, Japan, November 14, 1996, p.175-179 (58) ) Surveyed field (Int.Cl. ⁷ , DB name) G06F 17/50

Claims (1)

(57) [Claims 1] A tire to be evaluated is approximated by a tire finite element model obtained by dividing the tire into a finite number of elements, and a tire is obtained from the tire finite element model using a finite element method. A tire performance simulation method for simulating performance, wherein the tire finite element model includes a carcass and a belt
Includes cord reinforcement, sidewall rubber and bead rubber
Rubber section and bead core have the same cross section in the tire circumferential direction
Shape of the tire body that is continuous
Tire by expanding the two-dimensional shape of the cross section in the circumferential direction and dividing it into elements
The process of setting the body part element model, the vertical groove extending in the tire circumferential direction, and the direction intersecting this vertical groove
The tread pattern with extending lateral grooves is
Said tread divided into a finite number of elements over the entire circumference
Processing for setting a pattern part element model; and the tread pattern for the tire body part element model.
And a process of combining the partial element models , and the tire finite element model is brought into contact with the virtual road surface and brought into contact with the virtual road surface, and the rotation axis thereof is freely supported, and the friction caused by the movement of the virtual road surface A tire performance simulation method characterized by rolling a tire finite element model by a half turn or more by force.