A method, application, and computer program product for predicting the rolling resistance of a tire with periodic patterns

Abstract

The present invention relates to the technical field of tire simulation design, and in particular to a method, application and computer program product for predicting the rolling resistance of a periodic tread tire. A method for predicting the rolling resistance of a periodic tread tire, the method comprising the following steps: First step, performing static load numerical simulation on a tire with periodic treads; Second step, dividing the calculation process into multiple segments and outputting the unit stress and strain data of each segment; Third step, extracting the stress-strain history data of the unit; Fourth step: calculating the energy loss e of the rubber material unit by using the fitted parameter data ii ; Fifth step: adding the energy losses generated by the stress and strain in 6 directions of each unit to obtain the energy loss E of the unit i , and calculating the rolling resistance through the formula. The method of the present invention only needs to perform a simple rolling calculation of one intercept angle, and the Fourier transform method can be used to quickly calculate the rolling resistance of a tire with complex treads, providing guidance for tread design and tire structure design.

Description

Technical Field

[0001] The present invention relates to the technical field of tire simulation design, and particularly to a method, application, and computer program product for predicting the rolling resistance of a periodic tread tire. Background Art

[0002] With the implementation of the European tire labeling law, the industry development trend of green tires, and the demand for the driving range of electric vehicles, low rolling resistance tires have long become a consensus pursuit in the tire industry. Rolling resistance is one of the key indicators for measuring tire performance. The measurement and evaluation of tire rolling resistance mainly include experimental and finite element simulation methods. Although the experimental method can accurately obtain the tire rolling resistance value, it requires manufacturing tires for testing, with high costs and long cycles, and it is impossible to obtain the internal deformation state of the tire. Multiple tests need to be carried out for different structural tires to find the reasons for high or low rolling resistance. In contrast, the finite element simulation method has low costs, short cycles, and can intuitively obtain the deformation and stress state of the tire, facilitating the analysis of the influence of structure and materials on tire deformation and rolling resistance.

[0003] Currently, the simulation analysis research on tire rolling resistance mainly focuses on smooth tires or longitudinal groove tires, and there are few reports on the simulation calculation of the rolling resistance of tires with complex treads. The main reason is that the complex tread breaks the original axisymmetric structure, resulting in discontinuous element data and ineffective data processing. If stress-strain data for a complete revolution of the tire is to be obtained, it is necessary to calculate one full revolution of the tire, which requires a large amount of computing resources and time. The calculation of rolling resistance using a viscoelastic rubber model is too complex, requiring a large number of material tests, which is time-consuming and laborious, and cannot reflect the rubber material parameters commonly used in engineering (modulus and loss tangent), making it impossible to obtain regular experience. Summary of the Invention

[0004] In order to solve the above problems existing in the prior art, the object of the present invention is to provide a method for predicting the rolling resistance of a periodic tread tire. This method only requires a simple rolling calculation at an intercept angle, and by applying the Fourier transform method, the rolling resistance of a complex tread tire can be quickly calculated, providing guidance for tread design and tire structure design.

[0005] To achieve the above object, the present invention adopts the following technical solutions:

[0006] A method for predicting the rolling resistance of a periodic tread tire, the method comprising the following steps:

[0007] First step, perform a static load numerical simulation on a tire with periodic treads;

[0008] Second step, divide it into two cases:

[0009] 2.1) Set the friction coefficient between the tire and the road surface to 0, apply an angular displacement θ around the wheel axis to the rim, where θ is the angular value of a single intercept of the tire tread pattern;

[0010] 2.2) Set the road surface friction coefficient to the actual test value, apply an angular displacement θ around the wheel axis to the rim, where θ is the angular value of a single intercept of the tire tread pattern, and at the same time apply a horizontal displacement d in the direction opposite to the rotation of the rim to the road surface. d is calculated as follows:

[0011] ,

[0012] where r is the tire load radius;

[0013] Divide the calculation process into multiple segments and output the unit stress and strain data of each segment;

[0014] Step 3: Extract the stress-strain history data of the elements

[0015] The element number of the original intercept of the tire is i, the offset value of the element numbers of other intercepts is p, the number of element intercepts is n, and the output result of the k-th element in the t-th segment in the second step is recorded as the force history of the element with the element number k%p. The abscissa x is recorded as (int(k / p)*θ + t*θ / 10), where % represents taking the remainder and int() represents taking the integer. The ordinate is the true stress and strain values in 6 directions of the element, which are recorded as σ value and ε value respectively. Use a 100-order trigonometric series to fit the σ and ε values of the element:

[0016] ,

[0017] ,

[0018] Step 4: Calculate the energy loss e of the rubber material element using the fitted parameter data ii ,where tanδ is the loss tangent of the rubber material and V is the element volume:

[0019] ,

[0020] Step 5: Add up the energy losses generated by the stress and strain in 6 directions of each element to obtain the energy loss E of the element i ,The rolling resistance is calculated according to the following formula:

[0021] 。

[0022] Preferably, in step 1, apply the rated air pressure to the tire model, establish the road surface model, fix the rim, apply the rated load to the road surface, and press it against the tire. The determination of the air pressure and the load is based on the "China Tire Rim Valve Yearbook".

[0023] Preferably, in step 2.2), the road surface friction coefficient is between 0.3 and 1.0.

[0024] Preferably, in step two, the calculation process is evenly divided into 8 - 20 segments, and the unit stress and strain data of each segment are output.

[0025] Furthermore, the present invention also discloses the application of the described method in tire tread pattern design or tire structure design.

[0026] Furthermore, the present invention also discloses a computer device, including a memory, a processor, and a computer program stored on the memory, and the processor executes the computer program to implement the method.

[0027] Furthermore, the present invention also discloses a computer - readable storage medium, on which a computer program or instruction is stored, and when the computer program or instruction is executed by a processor, the method is implemented.

[0028] Furthermore, the present invention also discloses a computer program product, including a computer program or instruction, and when the computer program or instruction is executed by a processor, the method is implemented.

[0029] Due to the adoption of the above - mentioned technical solution, the method only needs to perform a simple rolling calculation of an intercept angle, and by applying the Fourier transform method, the rolling resistance of a tire with a complex tread pattern can be quickly calculated, providing guidance for tread pattern design and tire structure design. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a tire model with a complex tread pattern of 215 / 50R15;

[0031] Figure 2 It is a load - deformation diagram of a tire with a complex tread pattern of 215 / 50R15;

[0032] Figure 3 It is a schematic diagram of the tire rotation axis, rim angular displacement, and tread - road surface friction of a 215 / 50R15 tire;

[0033] Figure 4 It is a single - tread intercept model of a 215 / 50R15 tire;

[0034] Figure 5 It is a schematic diagram of the intercept angle of a single tread of a 215 / 50R15 tire;

[0035] Figure 6 It is the stress output value of some units of a 215 / 50R15 tire;

[0036] Figure 7 It is the strain output value of some units of a 215 / 50R15 tire;

[0037] Figure 8 The stress S11 history curve of unit 11673 in the 215 / 50R15 tire;

[0038] Figure 9 The strain LE11 history curve of unit 11673 in the 215 / 50R15 tire;

[0039] Figure 10 The unit energy loss distribution diagram of the single intercept tread section of the 215 / 50R15 tire. Detailed implementation manners

[0040] The present invention will be further described in detail below with reference to the accompanying drawings: This embodiment is implemented on the premise of the technical solution of the present invention, and detailed implementation manners are given, but the protection scope of the present invention is not limited to the following embodiments.

[0041] Taking the 215 / 50R15 tire as an example:

[0042] First step, perform static load numerical simulation on the tire with periodic tread patterns. According to the "China Tire Rim Valve Yearbook", apply the rated air pressure of 0.18 MPa and the rated load to the tire model with periodic tread patterns, establish the road surface model, and fix the rim. As Figure 1 shown, apply the rated load of 6000 N to the road surface to press it against the tire, as Figure 2 shown;

[0043] Second step, in this embodiment, the first case is adopted, set the friction coefficient between the tire and the road surface to 0, and apply an angular displacement of rotation around the wheel axis to the rim θ = 10 degrees (as Figure 3 ), θ is the angular value of a single intercept of the tire tread, as Figure 4 and Figure 5 shown. Divide the calculation process into 10 segments, and output the unit stress and strain data of each segment. Some results are as Figure 6 - Figure 7 shown.

[0044] Third step, extract the stress and strain history data of the unit. Taking the unit with the unit number 465721 as an example, the unit number offset value of other intercepts is p=16216， The unit number of the original intercept of the tire is i=11673 , the number of unit intercepts is n= 36 , the output result of the unit numbered 465721 in the second step in the 1 th segment is recorded in the force history of the unit numbered 11673 , and its abscissa x is recorded as (28 *10+1*10 / 10 ) = 281. The unit numbered 465721 is in the5 The output result of this segment is recorded as the force history of the element with element number 11673 In the force history of the element, its abscissa x is recorded as (28 *10+5*10 / 10 ) = 285, and the ordinate is the true stress and strain values of the element (including the 11 direction, 22 direction, 33 direction, 12 direction, 13 direction, and 23 direction), which are recorded as the σ value and ε value respectively. Taking σ 11 as an example, this value is 0.213. Extract all the calculation results of element 11673 and draw a curve as Figure 8 and Figure 9 shown. The σ and ε values of all elements are fitted using a 100-order trigonometric series:

[0045]

[0046]

[0047] Part of the fitting results are shown in Table 1.

[0048] Table 1 shows the partial trigonometric series fitting coefficients of the circumferential 11-direction strain of element 11673 of the 21550R15 tire

[0049] Order <![CDATA[ε nc > <![CDATA[ε ns > n=1 0.048677128161277006 -0.01178 n=2 0.005762 0.034562 n=3 -0.02496 0.006944 n=4 -0.01306 -0.01652 n=5 0.010247 -0.0155 n=6 0.009846 0.008189 n=7 -0.00664 0.005613 n=8 -0.00468 -0.00443 n=9 0.00364 -0.00312 n=10 0.000865 0.003969

[0050] Fourth step: Calculate the energy loss eii of the rubber material element using the fitted parameter data. The tanδ value is the loss tangent of the rubber material, V is the volume of the element. Taking e11 as an example,

[0051]

[0052] Part of the calculation results are shown in Table 2.

[0053] Table 2 shows the e 11 value, the volume of the element, and the tanδ value of some elements of the 21550R15 tire

[0054] Element number <![CDATA e 11 > V tanδ 275 2.45E-06 14.51 0.213 276 3.39E-06 19.41 0.213 277 3.90E-06 26.61 0.213 278 5.53E-06 26.50 0.213 279 6.39E-06 24.00 0.213 280 2.48E-06 21.50 0.213 281 1.76E-06 36.50 0.213 282 2.45E-06 32.74 0.213 283 3.39E-06 16.35 0.213 284 5.84E-06 21.49 0.213 285 1.52E-06 29.55 0.213 286 6.41E-07 29.53 0.213 287 5.25E-06 26.83 0.213 288 2.29E-06 24.11 0.213 289 2.00E-06 39.20 0.213 290 1.16E-06 34.56 0.213 291 5.76E-07 18.01 0.213 292 9.17E-07 23.02 0.213 293 5.84E-06 31.64 0.213 294 1.38E-06 31.60 0.213 295 1.06E-06 14.51 0.213 296 1.38E-06 19.41 0.213 297 1.44E-06 26.61 0.213 298 8.12E-07 26.50 0.213 299 1.19E-07 24.00 0.213 300 5.32E-08 21.50 0.213 301 6.84E-08 36.50 0.213 302 8.78E-08 32.74 0.213 303 1.06E-07 16.35 0.213 304 6.10E-08 21.49 0.213 305 5.22E-08 29.55 0.213 306 4.34E-08 29.53 0.213

[0055] Fifth step: Add up the energy losses generated by the stress and strain in 6 directions of each element to obtain the energy loss of the element E i , and the rolling resistance is calculated according to the following formula:

[0056] .

[0057] According to the above method, the rolling resistance of a tire with periodic tread can be predicted. The distribution diagrams of the rolling resistance of each element are as Figure 10 shown. Among them rIt is 315 mm. The energy losses of some units are shown in Table 3. The overall rolling resistance of the tire is 37.588 N. The analysis result of the smooth tire is about 42.26 N. The calculated rolling resistance of the tire with only longitudinal groove patterns is about 40.58 N, while the measured result is about 36.8 N, which fully proves the accuracy of the method of this patent.

[0058] Table 3 Unit energy loss values of some units of 215 / 50R15 tires

[0059] Element number <![CDATA[Unit energy loss E i > Element number <![CDATA[Unit energy loss E i > 1 1.76E-05 20 6.34E-06 2 8.84E-06 21 1.43E-05 3 3.06E-06 22 4.04E-06 4 2.29E-06 23 2.09E-05 5 2.42E-05 24 2.22E-05 6 2.66E-05 25 9.22E-06 7 1.56E-05 26 7.04E-05 8 3.64E-05 27 5.61E-05 9 1.37E-05 28 1.29E-05 10 6.62E-06 29 0.00017 11 2.59E-06 30 8.25E-05 12 3.16E-06 31 2.59E-05 13 2.43E-05 32 0.000282 14 3.10E-05 33 0.000112 15 7.96E-06 34 3.24E-05 16 3.38E-06 35 0.000164 17 1.89E-06 36 0.000171 18 1.27E-05 37 6.32E-06 19 4.22E-06 38 1.22E-05

[0060] If the rolling resistance is calculated by rolling the tire model for one week, the calculation time is about 36 times that of the method of this patent, and the data processing time will exceed 36 times that of the method of this patent. If the viscoelastic method is used, the viscoelastic parameters of the material need to be tested, and the test cost and time will be more than 10 times that of the patented method, which proves the advancement of the method of this patent.

[0061] The above is the description of the embodiments of the present invention. Through the above description of the disclosed embodiments, those skilled in the art can implement or use the present invention. Various modifications to these embodiments will be obvious to those skilled in the art. The general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to these embodiments shown herein, but will conform to the widest scope consistent with the principles and novel points disclosed herein.

Claims

1. A method for predicting the rolling resistance of a periodic pattern tire, characterized in that, The method includes the following steps: In the first step, perform static load numerical simulation on a tire with periodic tread patterns; In the second step, it is divided into two cases: 2.1) Set the friction coefficient between the tire and the road surface to 0, and apply an angular displacement to the rim that rotates around the wheel axis θ , θ is the angular value of a single intercept of the tire tread 2.2) Set the road surface friction coefficient to the actual test value, and apply an angular displacement to the rim that rotates around the wheel axis θ , θ is the angular value of a single intercept of the tire tread. At the same time, apply a horizontal displacement to the road surface in the direction opposite to the rotation of the rim d , d Calculate according to the following method: ， wherein r is the tire load radius; Divide the calculation process into multiple segments, and output the element stress and strain data of each segment; In the third step, extract the stress-strain history data of the elements The unit number of the original intercept of the tire is i , the offset value of the unit number of other intercepts is p, the number of unit intercepts is n, the output result of the t-th segment in the second step of the unit numbered k is recorded as the force history of the unit numbered k%p. In it, the abscissa x is recorded as (int(k / p)*θ + t*θ / 10), where % represents taking the remainder, int() represents taking the integer, and the ordinate is the true stress and strain values in 6 directions of the unit, which are recorded as σ value and ε value respectively. The σ and ε values of the unit are fitted using a 100-order trigonometric series: ， ， Step 4: Calculate the energy loss of the rubber material unit using the fitted parameter data e ii , where tanδ is the loss tangent of the rubber material and V is the unit volume: ， Step 5: Add up the energy losses generated by the stress and strain in six directions of each unit to obtain the energy loss of the unit E i , and the rolling resistance is calculated according to the following formula: 。 2. The prediction method of the rolling resistance of a periodic pattern tire according to claim 1, characterized in that In step one, apply the rated air pressure to the tire model, establish the road surface model, fix the rim, apply the rated load to the road surface, and make it press against the tire. The determination of the air pressure and load is based on the "China Tire Rim Valve Yearbook".

3. The prediction method for the rolling resistance of a periodic pattern tire according to claim 1, characterized in that, In step 2.2), the road surface friction coefficient is between 0.3 and 1.

0.

4. The prediction method for the rolling resistance of a periodic pattern tire according to claim 1, characterized in that, In the second step, divide the calculation process into 8 - 20 segments, and output the element stress and strain data of each segment.

5. Application of the method according to any one of claims 1 - 4 in tire tread design or tire structure design.

6. A computer device, comprising a memory, a processor, and a computer program stored on the memory, characterized in that, The processor executes the computer program to implement the method according to any one of claims 1 - 4.

7. A computer-readable storage medium having a computer program or instructions stored thereon, characterized in that, When the computer program or instruction is executed by the processor, it implements the method according to any one of claims 1 - 4.

8. A computer program product comprising a computer program or instructions, characterized in that, When the computer program or instruction is executed by the processor, it implements the method according to any one of claims 1 - 4.

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