CN115809582A - A method for judging tire durability performance through tire contact pressure distribution - Google Patents

Abstract

A method for judging the durability of a tire through the distribution of the tire grounding pressure belongs to the technical field of tire structure computer simulation design. The scheme is as follows: establishing a 3D model after the matching of the tire and the rim; outputting a stress cloud picture of a grounding area; dividing the grounding area into n sections according to the stress of the grounding area, wherein the tire pressure is P, delta _ij For the stress value of each node of the crown, the area S of each section _K And total area of ground S _t Evaluation index of tire durability

The value of M is indicative of the endurance of the tire at the contact pressure of each zone, and the two are negatively correlated. The method provides a method capable of accurately judging the durability of the tire andand the endurance performance improving direction is given, and direction guidance is provided for a tire design engineer.

Description

A method for judging tire durability by tire contact pressure distribution

technical field

The invention relates to the technical field of tire structure computer simulation design, in particular to a method, an application and a computer program product for judging tire durability through tire contact pressure distribution.

Background technique

The durability of tires is not only closely related to low-carbon environmental protection, but also related to driving safety. my country has put forward clear requirements on the durability of tires, and at the same time, various companies have formulated more stringent corporate standards on the basis of national standards to meet customer needs. But at present, all methods to obtain tire durability have only one way of bench test. The bench testing machine occupies a large area, the purchase cost is high, and the test cycle is also long.

In order to solve the shortcomings of the above-mentioned bench test, domestic and foreign scholars and experts have carried out a lot of research, expecting to reflect the tire durability through numerical simulation methods or by establishing the relationship between other characteristics of the tire and the durability performance. At present, the virtual crack propagation method is mainly used at home and abroad. By assuming that the durability damage of the tire is caused by the structural failure after the rubber intrinsic micro-cracks expand to a certain size, this method needs to measure the relationship between the initial rubber crack and the periodic load. relationship and the size of intrinsic microcracks, the workload and difficulty of material testing in the early stage are large, the test cycle is long, and it is not easy to promote. Some domestic scholars have proposed a method to characterize the durability of tires by using the strain energy density gradient, and obtain the relationship between the two through numerical fitting. This method needs to carry out a large number of bench tests on the tires in the early stage, and perform function fitting through the test results. To draw the relationship between the two, there are still disadvantages of bench testing.

At present, the tire durability evaluation method has high cost, long period, heavy workload and difficulty. Therefore, in the aspect of tire durability prediction, it is necessary to further explore the appropriate physical quantity and evaluation method, and provide the direction of improvement of durability performance.

Contents of the invention

In order to solve the above-mentioned technical problems, the object of the present invention is to provide a method for judging the tire durability through the tire contact pressure distribution, which establishes the relationship between the tire durability and other physical properties of the tire, and provides a method that can accurately The method of judging the durability of tires is given and the direction of improving the durability is given, which provides direction guidance for tire design engineers.

In order to achieve the above object, the present invention adopts the following technical solutions:

A method for judging tire durability through tire contact pressure distribution, the method includes the following steps:

Step 1, establishing a two-dimensional tire finite element analysis model according to the tire material distribution map;

Step 2. On the basis of step 1, let the two-dimensional tire finite element analysis model rotate 360 degrees along the tire rotation axis to generate a 3D model after the tire and rim are matched; establish a rigid flat road model to make the rigid flat road The straight road faces the tire displacement until the contact load of the two reaches the standard load of the tire; the tire load analysis is performed, and the stress value δ _ij of each node of the tire crown in contact with the ground is output, and the stress nephogram of the ground contact area is output simultaneously;

Step 3: Carry out segmental analysis on the stress nephogram of the tire tread contact area extracted in step 2: the tire pressure is P, _δij is the stress value of each node of the tire crown, and the contact area is divided into n sections according to the stress of the contact area , draw the plane contours for the extreme values of the nodal stresses in the n sections (i.e. the values of the two ends of the nodal stress section), and the area between two adjacent plane contours forms a closed area; the Kth stress The area of the closed area surrounded by two adjacent plane contours in the section is recorded as S _K K = 1,2,3,...,n;

Step 4. Obtain S _t = L/P according to the relationship between the tire pressure P, the tire load L and the total contact area S _t ;

Step 5. According to the area S _K of each section, the stress value δ _ij of each node of the tire crown and the total ground contact area S _t , the average value of the actual ground contact pressure can be obtained:

通过M值可表征各区段接地压力下轮胎耐久性能，二者负向相关。Step 6. Define tire durability evaluation index

The tire durability under the ground pressure of each section can be characterized by the M value, and the two are negatively correlated.

As a preference, in said step 1, the specific steps of establishing the finite element analysis model of the tire are as follows: firstly establish a two-dimensional axisymmetric analysis model of the tire, divide the tire material distribution map into grids, and divide the grids into regions according to the types of each component And assign corresponding material properties to each component, establish a rigid rim 2D model, make the tire and rim in the same coordinate system, and set contact pairs, so that the tire bead and rim are combined to obtain the tire finite element analysis model. Then apply the rated inflation pressure on the boundary layer on the inner surface of the tire for inflation analysis.

As a preference, in step six, when M decreases by 0.1, the durability level increases by 13%-15%; when the pressure difference between the inner and outer sides of the tire tends to 0, the durability performance reaches the best.

As a preference, in the step 3, the grounding area is divided into 10 sections according to the stress size, n=10, and the method of segment analysis is as follows:

The first paragraph: δ _ij <0.1P; The second paragraph: 0.1P≤δ _ij <0.3P;

The third paragraph: 0.3P≤δ _ij <0.5P; The fourth paragraph: 0.5P≤δ _ij <0.7P;

Fifth paragraph: 0.7P≤δ _ij <0.9P; Sixth paragraph: 0.9P≤δ _ij <1.1P;

The seventh paragraph: 1.1P≤δ _ij <1.3P; The eighth paragraph: 1.3P≤δ _ij <1.5P;

The ninth paragraph: 1.3P≤δ _ij <1.7P; The tenth paragraph: 1.7P≤δ _ij ;

Plane isolines are drawn for the nodal stresses in the above ten sections respectively to form 10 closed areas.

As a further preference, set |M|≤0.1 as the target value, at this time δ _ij ∈[0.9P,1.1P]; the area of the closed area surrounded by the two plane contours of the node stress section is S ₆ , |M| As S ₆ increases and decreases, the durability performance is improved at this time; if |M|>0.1, it indicates that there is room for improvement in the tire durability performance, which can be optimized until |M| reaches the target value.

As a further preference, according to the above-mentioned conclusions, the durability of the tire can be judged from the ratio of the enclosed area _S6 enclosed by the two-plane contours whose nodal stress δ _ij is [0.9P, 1.1P] to the total ground contact area If you want to improve tire durability, you must increase S ₆ .

Further, the present invention also discloses the application of the method for judging tire durability through tire contact pressure distribution in tire simulation design.

Further, the present invention also discloses a computer device, which includes a memory, a processor, and computer programs or instructions stored on the memory, and the processor executes the computer programs or instructions to realize the judging tire contact pressure distribution through the tire approach to durability.

Further, the present invention also discloses a computer-readable storage medium, on which computer programs or instructions are stored, and when the computer programs or instructions are executed by a processor, the method for judging tire durability through tire contact pressure distribution is realized.

Further, the present invention also discloses a computer program product, including computer programs or instructions, and when the computer programs or instructions are executed by a processor, the method for judging tire durability performance through tire contact pressure distribution is realized.

Because the present invention adopts the above-mentioned technical scheme, by establishing the relationship between tire durability and other physical properties of tires, it provides a method for accurately judging tire durability and provides the direction of improvement of durability, which is helpful for tire design engineers. Provides directional guidance.

Description of drawings

Fig. 1 is a tire two-dimensional axisymmetric analysis model;

Figure 2 is the 3D model of the tire and rim after matching;

Figure 3 is the stress cloud map of the grounding area;

Figure 4 is an area map of the closed area surrounded by two adjacent plane contours in the Kth stress section;

Fig. 5 is the inflation analysis chart of embodiment 1 tire Abaqus software;

Fig. 6 is the specific angle distribution figure in embodiment 1 step 3;

Fig. 7 is the contour distribution shape diagram of each node in the tire ground contact area of embodiment 1;

Fig. 8 is the inflation analysis chart of embodiment 2 tire Abaqus software;

Fig. 9 is a distribution shape diagram of the contours of each node in the tire ground contact area of embodiment 2;

FIG. 10 is a diagram of the improved grounding footprint of Embodiment 2. FIG.

Detailed ways

The present invention will be described in further detail below in conjunction with the accompanying drawings: the present embodiment is implemented on the premise of the technical solution of the present invention, and detailed implementation is provided, but the protection scope of the present invention is not limited to the following embodiments.

A method for judging tire durability through tire contact pressure distribution, the method includes the following steps:

1) Establish a two-dimensional tire finite element analysis model according to the tire material distribution map

First, a two-dimensional axisymmetric analysis model of the tire is established. As shown in Figure 1, the tire material distribution map is meshed, and the mesh is divided according to the type of each component and the corresponding material properties are given to each component to establish a rigid rim 2D model. , so that the tire and rim are located in the same coordinate system, and set contact pairs, so that the tire bead and rim are combined together, and the finite element analysis model of the tire is obtained. Then apply the rated inflation pressure on the boundary layer of the inner surface of the tire, and the direction of the inflation pressure is consistent with the normal direction of the inner surface of the tire for inflation analysis.

2) On the basis of the first step, the tire finite element analysis model is rotated 360 degrees along the tire rotation axis to generate a 3D model of the tire and rim after fitting, as shown in Figure 2. A rigid flat road model is established at a position 1mm away from the tire surface, and the rigid flat road surface is displaced until the contact load between the two reaches the standard load of the tire. Carry out tire load analysis, output the stress value δ _ij of each node of the tire crown in contact with the ground, and simultaneously output the stress nephogram of the ground contact area, as shown in Figure 3.

3) Perform segmental analysis on the stress nephogram of the tire tread ground contact area extracted in step 2). The tire pressure is P, and _δij is the stress value of each node of the tire crown. The method of subsection analysis is as follows:

Divide the grounding area into 10 sections according to the stress:

The first paragraph: δ _ij <0.1P; The second paragraph: 0.1P≤δ _ij <0.3P;

The third paragraph: 0.3P≤δ _ij <0.5P; The fourth paragraph: 0.5P≤δ _ij <0.7P;

Fifth paragraph: 0.7P≤δ _ij <0.9P; Sixth paragraph: 0.9P≤δ _ij <1.1P;

The seventh paragraph: 1.1P≤δ _ij <1.3P; The eighth paragraph: 1.3P≤δ _ij <1.5P;

The ninth paragraph: 1.3P≤δ _ij <1.7P; The tenth paragraph: 1.7P≤δ _ij ;

Plane isolines are drawn for the nodal stresses in the above ten sections respectively to form 10 closed areas. The area enclosed by the stress plane contours of two adjacent nodes is denoted as S _K , K=1,2,3,4,5,6,7,8,9,10, which means that it is in the Kth stress section The area of the closed area surrounded by two adjacent plane contours, as shown in Figure 4.

4) S _t = L/P is obtained according to the relationship between the tire pressure P, the tire load L and the total contact area S _t ;

5) According to the area S _K of each section, the stress value δ _ij of each node of the tire crown and the total ground contact area S _t , the average value of the actual ground contact pressure can be obtained as:

通过M值可表征各区段接地压力下轮胎耐久性能，二者负向相关。当M每减小0.1，耐久水平提升13％-15％。轮胎在接地各区段内外压差趋于0时，耐久性能达到最佳。但各区段内外压差不可能全部为0，即由节点应力为P的平面等值线围成的封闭区域面积不可能等于S_t。6) Define tire durability evaluation index

The tire durability under the ground pressure of each section can be characterized by the M value, and the two are negatively correlated. When M decreases by 0.1, the durability level increases by 13%-15%. When the pressure difference between the inside and outside of each section of the tire tends to 0, the durability performance reaches the best. However, the pressure difference between the inside and outside of each section cannot be all zero, that is, the area of the closed area surrounded by the plane contour with the node stress P cannot be equal to S _t .

7) Let |M|≤0.1 be the target value, at this time δ _ij ∈[0.9P,1.1P]. The area of the closed area surrounded by the two plane contours in the stress section of this node is S ₆ , and |M| decreases with the increase of S ₆ , and the durability performance is improved at this time. If |M|>0.1, it means that there is room for improvement in the tire durability and can be optimized until |M| reaches the target value.

8) According to the conclusion drawn in 7), the durability performance of the tire can be judged from the ratio of the closed area S ₆ enclosed by the two plane contours with nodal pressure δ _ij of [0.9P, 1.1P] to the total ground contact area , in order to improve tire durability, S ₆ must be increased.

Further, in the step of establishing the tire finite element analysis model, the tire material distribution diagram is meshed, wherein the rubber material and the traveler material without the skeleton material are divided into quadrilateral or triangular elements; the elements containing the skeleton material are divided into Quadrilateral unit; ② Define the unit type of the divided cells: the skeleton material is defined as rebar unit type, and other units are defined as CGAX4; ③ According to the tire material distribution diagram, define the material properties of the divided tire mesh; ④ According to The analyzed tire specification type defines relevant parameters such as rim specification, standard air pressure, etc.

An application of the method for judging tire durability through tire contact pressure distribution in tire simulation design.

A computer device includes a memory, a processor, and computer programs or instructions stored on the memory, the processor executes the computer programs or instructions to implement the method for judging tire durability through tire contact pressure distribution.

A computer-readable storage medium, on which computer programs or instructions are stored, and when the computer programs or instructions are executed by a processor, the method for judging tire durability performance through tire contact pressure distribution is implemented.

A computer program product, including computer programs or instructions, characterized in that, when the computer programs or instructions are executed by a processor, the method for judging tire durability performance through tire contact pressure distribution is realized.

Example 1

Take the 12R22.5 tire as an example for illustration.

Step 1, grid division of tire material distribution map. The tire material distribution map is meshed, the rubber material is divided into triangular units or quadrilateral units, the rubber material where the skeleton material is located is divided into quadrilateral units, and the skeleton material is divided into 2-node one-dimensional units.

Step 2, material property definition. On the basis of step 1, assign material properties to the divided mesh area according to the actual situation. The linear elastic constitutive model is selected as the rubber material, and the MALLOW model is selected as the skeleton material. The model parameters of each component are obtained by fitting according to the material test data.

Step 3, boundary condition setting. On the basis of step 2, apply 0.9MPa air pressure to the inner surface of the tire inner liner; establish a rigid rim 2D model to constrain the position of the bead, and use a standard rim with a model of 9.00×22.5. Abaqus software was used to analyze the inflation, and the results are shown in Figure 5.

Step 4, 3D model establishment. On the basis of step 3, the tire section is rotated 360 degrees in the circumferential direction to obtain a 3D model of the tire and rim, and the section is divided in the circumferential direction. In order to improve calculation efficiency and ensure calculation accuracy, a week is divided into 74 sections, of which the angle between the sections in the grounding area is 2 degrees, and the angle between the sections away from the grounding area is 5-9 degrees. The specific angle distribution is shown in Figure 6 As shown, 5*12 in area 1 and area 3 means that both area 1 and area 3 are divided into 12 sections, and the angle between two adjacent sections is 5°; 2*30 degrees in area 2 means What is more important is that area 2 is divided into 30 sections, and the angle between two adjacent sections is 2°; 2*30 degrees in area 4 and area 5 means that both area 4 and area 5 are divided into 10 sections, The angle between two adjacent sections is 9°. The rim of the analytical rigid body is constrained, and the road surface is displaced so that the load applied to the tire is a standard load of 35500N.

Step 5, grounding characteristic data extraction. On the basis of step 4, extract the stress distribution data of some nodes in the tire ground contact area (as shown in Table 1) and the contour distribution shape map, as shown in Figure 7, and divide the plane contours according to the extracted data (Figure 7). Calculate the area S _K of each segment and the total area S _t of the grounding area (as shown in Table 2).

Table 1 Stress distribution data of some nodes in the tire contact area

Table 2 The area of closed area S _K and the total area of grounded area S _t enclosed by two adjacent plane contours in each stress section

Step 6, calculation of durability evaluation index. On the basis of step 5, calculate the ratio of the area S _K of the closed area surrounded by the two plane contours of each stress section to the total area S _t of the grounding area. Further calculate the durability evaluation index M (Table 2). According to the calculation results, it shows that |M|＝0.09≤0.1, reaching the target value. Through the actual measurement of the bench test, it is found that the durability of the tire reaches the qualified standard of 107h. The calculation results are in good agreement with the actual test results, which can accurately represent the tire durability level.

Example 2

Take the 12.00R20 tire as an example for illustration.

Step 1, grid division of tire material distribution map. The tire material distribution map is meshed, the rubber material is divided into triangular units or quadrilateral units, the rubber material where the skeleton material is located is divided into quadrilateral units, and the skeleton material is divided into 2-node one-dimensional units.

Step 2, material property definition. On the basis of step 1, assign material properties to the divided mesh area according to the actual situation. The linear elastic constitutive model is selected as the rubber material, and the MALLOW model is selected as the skeleton material. The model parameters of each component are obtained by fitting according to the material test data.

Step 3, boundary condition setting. On the basis of step 2, apply 0.9MPa air pressure to the inner surface of the tire inner liner; establish a rigid rim 2D model to constrain the position of the bead, and the rim uses a standard rim with a model of 8.5×20. Abaqus software was used to analyze the inflation, and the results are shown in Figure 8.

Step 4, 3D model establishment. On the basis of step 3, the tire section is rotated 360 degrees in the circumferential direction to obtain a 3D model of the tire and rim, and the section is divided in the circumferential direction. In order to improve calculation efficiency and ensure calculation accuracy, a week is divided into 74 sections, of which the angle between the sections in the grounding area is 2 degrees, and the angle between the sections away from the grounding area is 5-9 degrees. The specific angle distribution is shown in Figure 6 shown in the table. The rim of the analytical rigid body is constrained, and the road surface is displaced so that the load applied to the tire is a standard load of 37500N.

Step 5, grounding characteristic data extraction. On the basis of step 4, the stress distribution data of some nodes in the tire contact area (Table 3) and the contour distribution shape map are extracted, as shown in Figure 9, and the plane contour is divided according to the extracted data. Calculate the area S _K of each subsection and the total area S _t of the grounding area (Table 4).

Table 3 Stress distribution data of some nodes in the tire contact area of Example 2

Table 4 The area S _K of the enclosed area surrounded by the two plane contours of each stress section in Example 2, and the total area of the grounding area S _t

Step 6, on the basis of step 3, calculate the ratio of the closed area S _K enclosed by two adjacent plane contours of each stress section to the total ground area S _t (Table 4). Further calculate the durability evaluation index M, according to the calculation results show that |M|=0.28>0.1, did not reach the target value. The actual measurement through the bench test found that the tire durability did not reach the qualified standard of 97h. The calculation results are in good agreement with the actual test results, which can accurately represent the tire durability level.

Step 7, durability improvement. On the basis of step 4, the design of the tire of this specification is optimized, and the ratio of the closed area _S6 surrounded by the two-plane contours of the stress section to the total area _S of the ground contact area is increased (Table 5), which is increased from the original 72%. to 91%, the improved ground footprint is shown in Figure 10. At this time, the durability evaluation index M=0.09 (Table 5) was calculated, and the target value of |M|<0.1 was reached.

Table 5 Data of closed area _S6 occupied by the total area S _t of the grounding area surrounded by two adjacent plane contours in the increased stress section

It is further found through the bench test that the durability of the tire reaches the qualified standard of 125h. The M value is reduced by 0.19, and the durability time is increased by 28%. The calculation results are in good agreement with the actual test results, which can accurately characterize the relationship between the change of M value and the tire durability level.

The foregoing is a description of the embodiments of the present invention, and through the above descriptions of the disclosed embodiments, those skilled in the art can implement or use the present invention. Various modifications to these examples will be apparent to those skilled in the art. The general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the 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 (10)

1. A method for judging tire durability by tire contact pressure distribution, characterized in that: comprising the following steps: Step 1, establishing a two-dimensional tire finite element analysis model according to the tire material distribution map; Step 2. On the basis of step 1, rotate the two-dimensional tire finite element analysis model 360 degrees along the tire rotation axis to generate a 3D model after the tire and rim are matched; establish a rigid flat road model to make the rigid flat road The straight road faces the tire displacement until the contact load of the two reaches the standard load of the tire; the tire load analysis is performed, and the stress value δ _ij of each node of the tire crown in contact with the ground is output, and the stress nephogram of the ground contact area is output simultaneously; Step 3: Carry out segmental analysis on the stress nephogram of the tire tread contact area extracted in step 2: the tire pressure is P, _δij is the stress value of each node of the tire crown, and the contact area is divided into n sections according to the stress of the contact area , draw the plane isolines for the stress extremes of the nodes in the n sections respectively, and the area between two adjacent plane isovalues forms a closed area; The area of the closed area is denoted as S _K , K=1,2,3,...,n; Step 4. Obtain S _t = L/P according to the relationship between the tire pressure P, the tire load L and the total contact area S _t ; Step 5. According to the area S _K of each section, the stress value δ _ij of each node of the tire crown and the total ground contact area S _t , the average value of the actual ground contact pressure can be obtained:

Step 6. Define tire durability evaluation index

The tire durability under the ground pressure of each section can be characterized by the M value, and the two are negatively correlated. 2. A method for judging tire durability by tire contact pressure distribution according to claim 1, characterized in that: the specific steps of establishing a tire finite element analysis model in step 1 are: first establishing a tire two-dimensional axisymmetric analysis model , the tire material distribution map is meshed, and the mesh is divided according to the type of each component and the corresponding material properties are assigned to each component; the rigid rim 2D model is established, so that the tire and the rim are located in the same coordinate system, and the contact pair is set. , so that the tire bead and rim are combined to obtain the finite element analysis model of the tire, and then the rated inflation pressure is applied to the boundary layer on the inner surface of the tire to carry out the inflation analysis. 3. A method for judging tire durability through the distribution of tire contact pressure according to claim 1, characterized in that: in step 6, when M decreases by 0.1, the tire durability level increases by 13%-15%; When the pressure difference inside and outside each section tends to 0, the durability performance reaches the best. 4. A method for judging tire durability by tire contact pressure distribution according to claim 1, characterized in that: in step 3, the contact area is divided into 10 sections according to the stress, i.e. n=10, subsections The analysis method is as follows: first paragraph: δ _ij <0.1P; second paragraph: 0.1P≤δ _ij <0.3P; The third paragraph: 0.3P≤δ _ij <0.5P; the fourth paragraph: 0.5P≤δ _ij <0.7P; The fifth paragraph: 0.7P≤δ _ij <0.9P; the sixth paragraph: 0.9P≤δ _ij <1.1P; The seventh paragraph: 1.1P≤δ _ij <1.3P; the eighth paragraph: 1.3P≤δ _ij <1.5P; The ninth paragraph: 1.3P≤δ _ij <1.7P; the tenth paragraph: 1.7P≤δ _ij ; Plane isolines are drawn for the nodal stresses in the above ten sections respectively to form 10 closed areas. 5. A method for judging tire durability through _tire contact pressure distribution according to claim 4, characterized in that: let |M| The area of the closed area surrounded by the two-plane isolines in the stress section of this node is S ₆ , and |M| decreases with the increase of S ₆ , and the durability performance is improved at this time; if |M|>0.1, it means that the tire is durable There is room for improvement in performance and can be optimized until |M| reaches the target value. 6. A method for judging tire durability by tire contact pressure distribution according to claim 5, characterized in that: according to the conclusion drawn, the node stress _δij can be obtained from the two planes of [0.9P, 1.1P] The ratio of the area S ₆ of the enclosed area surrounded by the contour to the total ground area can determine the durability of the tire. To improve the durability of the tire, S ₆ must be increased. 7. An application of the method according to any one of claims 1-6 in tire simulation design. 8. A computer device comprising a memory, a processor, and a computer program or instruction stored on the memory, wherein the processor executes the computer program or instruction to realize any one of claims 1-6 the method. 9. A computer-readable storage medium, on which a computer program or instruction is stored, characterized in that, when the computer program or instruction is executed by a processor, the method according to any one of claims 1-6 is implemented. 10. A computer program product, comprising computer programs or instructions, characterized in that, when the computer program or instructions are executed by a processor, the method according to any one of claims 1-6 is implemented.

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