A radial tire bead pressure simulation method, system and program product

Abstract

The present invention relates to the field of tire simulation design technology, and in particular to a simulation method, system and program product for radial tire bead pressure. The method comprises: establishing an axisymmetric finite element model based on the material distribution diagram of the tire and the rim; generating a three-dimensional tire and rim model through a periodic rotation law, and automatically defining the "kill" unit and the retained unit of the rim active block in combination with the life and death unit technology; in the simulation process, different deformation constraints are applied after the rim expands to the nominal diameter to simulate the actual test conditions of the bead pressure. Compared with the prior art, the present invention improves the modeling efficiency, simplifies the model editing and result processing steps, and at the same time improves the simulation accuracy by more than 10%, and the error with the actual measured results is small. The invention is suitable for the design and optimization of radial tires, and has the characteristics of low cost, high precision and high efficiency.

Description

Technical Field

[0001] The invention relates to the technical field of tire simulation design, and in particular to a simulation method, system and program product for radial tire bead pressure. Background Art

[0002] The bead pressure of radial tires is a key technical indicator that affects the tightness of the connection between the tire and the rim and ensures driving safety. Too low bead pressure may lead to a loose connection between the tire and the rim, causing slow tire leakage and slippage, or even cause the tire to separate from the rim under extreme conditions such as high-speed driving or emergency braking, causing the vehicle to lose control and seriously threatening driving safety. On the contrary, although too high bead pressure can enhance the connection strength, it will make the tire difficult to install and remove, and may even damage the bead structure and shorten the tire service life. Therefore, reasonable prediction of bead pressure is an important issue in tire design.

[0003] In the prior art, the evaluation methods of tire bead pressure mainly include experimental methods and numerical simulation methods. Experimental methods usually rely on standardized test processes (such as group standard T / CRIA29002-2022), which require a series of complex steps such as mold development, tire molding, vulcanization and testing. They have the disadvantages of high cost and long cycle, which is not conducive to rapid iteration in the tire design stage. In contrast, numerical simulation methods have gradually become the mainstream means of predicting tire bead pressure due to their low cost and high efficiency.

[0004] The current numerical simulation methods mainly include the following two: 1. Axisymmetric model method: By establishing an axisymmetric finite element model of the tire and rim, the tire bead pressure under loading conditions is simulated. However, this method assumes that the rim radius changes during loading, which is inconsistent with the split rim structure in actual tests, resulting in low accuracy of the simulation results. 2. Three-dimensional model re-editing method: Use Abaqus / Standard software to convert the axisymmetric model into a three-dimensional model, redefine the material direction, material parameters, boundary conditions and rim contact surface, etc., to simulate the tire bead pressure under real working conditions. Although this method can simulate the tire bead pressure distribution more accurately, it takes a lot of time and effort to edit the three-dimensional model, the modeling efficiency is low, and the post-processing steps are complicated, which is not conducive to rapid iteration.

[0005] Although the Chinese invention patents applied by the applicant (such as Patent 2021116135564, Patent 2022100923567 and Patent 2022105620611) have proposed several simulation analysis methods for tire performance, it is difficult for existing numerical simulation methods to strike a balance between accuracy and efficiency, especially the three-dimensional model re-editing method, which is difficult for general tire designers to quickly master due to its high modeling difficulty and low efficiency. These problems limit the promotion and application of tire bead pressure simulation technology. Therefore, there is an urgent need for a tire bead pressure simulation method that can maintain high accuracy, low modeling difficulty and high efficiency. Summary of the invention

[0006] In order to solve the above technical problems, the present invention provides an improved radial tire bead pressure simulation method, which generates a three-dimensional model by establishing an axisymmetric model and combining the periodic rotation law, and automatically processes the unit state of the rim active block by applying the birth-death unit technology, which not only improves the modeling efficiency, but also simplifies the post-processing process, and significantly improves the accuracy and practicality of the simulation results. This method provides tire designers with an efficient and easy-to-use simulation tool, which has important application value and promotion prospects.

[0007] In order to achieve the above-mentioned purpose, the present invention adopts the following technical solutions:

[0008] A method for simulating radial tire bead pressure, comprising the following steps:

[0009] 1) An axisymmetric finite element model is established based on the material distribution diagram of the tire and rim. The reinforcement components such as the carcass, cap and belt are divided into axisymmetric quadrilateral units, and linear elastic material parameters and density are assigned.

[0010] 2) Based on the axisymmetric model, a three-dimensional finite element model of the tire and rim is generated through a periodic rotation rule, wherein a rim section with an angle θ is reserved adjacent to each 45° rim active block of the rim as a unit to be "killed";

[0011] 3) Define the unit number after the axisymmetric unit is rotated according to the formula, and define the units to be "killed" and the units to be retained as sets respectively;

[0012] 4) In the simulation calculation, the birth and death unit technology is applied, and the properties of the rim section unit to be "killed" are set to "dead", and the remaining units participate in the calculation;

[0013] 5) According to the test conditions, apply expansion and constraint conditions to the rim, simulate the tire bead pressure and extract the results.

[0014] Preferably, in the step 1), an axisymmetric rebar unit is used to characterize the reinforcement structure, and an axisymmetric shell unit is used to establish a rim with an unexpanded rim radius of D and a nominal diameter d after the rim is expanded; the outer surface of the tire bead is set as the contact surface; linear elastic material parameters and density are assigned to the rubber unit and the skeleton unit according to actual tire material tests; full fixed constraints are applied to all nodes of the axisymmetric model in the Abaqus finite element program, and the calculation is completed.

[0015] Preferably, in step 3), a three-dimensional tire and rim model is automatically generated by a Python program, and the number of the unit to be "killed" is calculated according to the following formula:

[0016]

[0017] Among them, N ijs is the unit number, n i is the axisymmetric element number, n s is the section number, n j is the number of the jth 45° rim joint, m is the unit number offset, n is t It is the total number of sections inside the 45° rim snap block.

[0018] Preferably, in step 3), the unit retained by the rim flexible block is bound to the reference point of the tire axis center point through a coupling instruction.

[0019] Preferably, in step 4), the simulation process uses the birth and death unit technology of Abaqus software to process the "killed" units, ensuring that these units do not participate in the calculation.

[0020] Preferably, in step 5), the constraints imposed on the rim include two working conditions of reducing the nominal diameter d by 0.29 mm and increasing the nominal diameter d by 0.38 mm.

[0021] Furthermore, the present invention also provides a system for simulating radial tire bead pressure, wherein the system implements the method, including:

[0022] A modeling module for building an axisymmetric finite element model based on material distribution maps of the tire and rim;

[0023] The 3D model generation module is used to generate 3D tire and rim models from the axisymmetric model, and automatically define the rim active blocks and the units that need to be "killed";

[0024] The unit management module is used to define the set according to the units to be "killed" and the units to be retained, and to set the coupling relationship with the tire axis reference point;

[0025] Simulation module, used to apply expansion constraints and life-death unit technology for simulation calculation;

[0026] The post-processing module is used to extract simulation results and compare and analyze them with measured data.

[0027] As is already known, the modeling module automatically generates simulation models and calculation files through Python scripts; the unit management module can automatically calculate the number and status of the units in the 45° rim active block based on the formula, and classify them into a "killed" unit set and a retained unit set respectively; the simulation module combines Abaqus software to simulate the changes in tire bead pressure under different expansion conditions to evaluate the contact tightness and safety performance between the tire bead and the rim.

[0028] Furthermore, the present invention also provides a computer-readable storage medium having a computer program or instruction stored thereon, and the method is implemented when the computer program or instruction is executed by a processor.

[0029] Furthermore, the present invention also provides a computer program product, comprising a computer program or instructions, which implement the method when executed by a processor.

[0030] The present invention adopts the above technical solution and proposes a simulation method and system for radial tire bead pressure. By improving the modeling process and optimizing the simulation calculation, the simulation efficiency and accuracy are significantly improved, and the following technical effects are achieved:

[0031] 1. Improve modeling efficiency: The present invention establishes an axisymmetric finite element model and automatically generates a three-dimensional model based on the periodic rotation law, eliminating the need to manually edit the three-dimensional tire and rim models, thus avoiding the complex process of resetting the material direction, boundary conditions, and contact relationships in the traditional three-dimensional model re-editing method. At the same time, the Python script is used to realize automated operation, and the model can be established in only about 5 minutes. The modeling efficiency is 16 times higher than that of the traditional three-dimensional model re-editing method, reaching a high efficiency comparable to that of the axisymmetric method.

[0032] 2. Reduce the difficulty of modeling: The present invention uses the life and death unit technology to automatically define the "kill" unit of the rim active block, and quickly processes the units that need to be involved in the calculation and excluded through the collection management method. Designers only need to input basic parameters without in-depth operation of complex three-dimensional model editing tools, thereby reducing the modeling threshold and enabling general tire designers to quickly master the simulation process.

[0033] 3. Improve simulation accuracy: In the process of generating the three-dimensional model, the present invention automatically defines the rim active block structure and nonlinear contact model to accurately simulate the distribution characteristics of the tire bead pressure under actual test conditions. The simulation results show that compared with the axisymmetric method, the method of the present invention improves the tire bead pressure simulation accuracy by more than 10%, and its accuracy is within a relatively low range compared to the actual measurement results, meeting the requirements of engineering applications.

[0034] 4. Simplify post-processing steps: The present invention simplifies the simulation post-processing process by defining a cylindrical coordinate system and automated programming technology, eliminating the need to establish a special coordinate system or convert calculation results. The simulation results can be directly output in the form of tire bead pressure distribution diagrams, contact force distribution diagrams, etc., greatly reducing the time and workload of post-processing.

[0035] 5. More in line with actual working conditions: During the simulation process, the present invention fully simulates the changes in tire bead pressure under actual test conditions by applying expansion and two deformation constraints (reduction of 0.29mm and increase of 0.38mm) to the rim diameter. The simulation results show that the distribution of tire bead pressure can be accurately predicted under both rim expansion and deformation conditions, which has strong engineering practicality.

[0036] 6. Save cost and time: Compared with traditional experimental methods, this invention avoids tedious processes such as mold development, tire molding, vulcanization and testing. It can quickly complete tire bead pressure prediction only through numerical simulation, which significantly reduces development costs and shortens the design cycle, providing strong support for the rapid iteration of tire design.

[0037] In summary, the present invention reduces the difficulty of modeling, improves modeling efficiency, simplifies post-processing steps, and significantly shortens the time required for tire bead pressure simulation while ensuring high-precision simulation. It provides an efficient, accurate, and easy-to-use tool for the design and optimization of radial tires, and has broad application value and promotion prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 Assembly diagram for axisymmetrical tire and rim;

[0039] Figure 2 This is a schematic diagram of the rim structure for tire bead pressure testing;

[0040] Figure 3 It is a schematic diagram of the cross section with a reserved angle θ;

[0041] Figure 4 The three-dimensional finite element model of the rim joint block after the "killing" section;

[0042] Figure 5 Assembly drawings for three-dimensional tires and rims;

[0043] Figure 6 This is the simulation result of the d-0.29mm working condition;

[0044] Figure 7 This is the simulation result of the d+0.38mm working condition. DETAILED DESCRIPTION

[0045] The following is a clear and complete description of the technical solutions in the embodiments of the present invention in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0046] The present invention provides an improved radial tire bead pressure simulation method, which generates a three-dimensional model by establishing an axisymmetric model and combining the periodic rotation law, and automatically processes the unit state of the rim active block by using the birth-death unit technology, which not only improves the modeling efficiency, but also simplifies the post-processing process, and significantly improves the accuracy and practicality of the simulation results. The method provides tire designers with an efficient and easy-to-use simulation tool, which has important application value and promotion prospects.

[0047] The first step is to divide the tire material distribution map into grids, where the crown band, belt, carcass and other parts containing reinforcement materials are axisymmetric quadrilateral units, axisymmetric rebar units are used to characterize the reinforcement structure, and axisymmetric shell units are used to establish a rim with an unexpanded rim radius of D and a nominal diameter of d after the rim is expanded; the outer surface of the bead is set as the contact surface; according to the actual tire material test, the rubber unit and the skeleton unit are given linear elastic material parameters and density. In the Abaqus finite element program, all nodes of the axisymmetric model are fully fixed and the calculation is completed.

[0048] In the second step, according to the structural characteristics of the eight rim active blocks, the tire and rim will be generated by rotating one circle based on the calculation results of the first step. When the rim is rotated and generated, a rim section with an angle of θ will be reserved at each adjacent 45° rim block boundary as the rim unit to be "killed" in the subsequent calculation process. In order to facilitate the viewing of the tire bead pressure results, the coordinate data of the starting surface of the tire and rim rotating around the Y axis is defined according to the following formula.

[0049]

[0050]

[0051] In the third step, based on the three-dimensional model of the tire and rim generated in the second step, a rim section to be "killed" and the rim model between two adjacent rim sections to be "killed" are defined as the rim models to be retained at approximately 45° intervals, and the unit number definition formula is as follows:

[0052]

[0053] Among them, N ijs is the axisymmetric element number n i The rotation generated by the nth j The nth 45° rim joint s The unit number of the section, m is the offset of the unit number, n is t is the total number of sections in the 45° rim snap block, n j The value range is an integer between 1 and 8. s =n t When is the number of the unit killed by the current rim active block, when n s <n t This is the number of the unit that needs to be retained in the current active block.

[0054] Define a set for all the units that need to be "killed". Define a set for each unit retained by the rim flexible block (such as Figure 4 ), establish a reference point for each rim active block at the center of the tire axis, couple each reference point with the corresponding active block, and set the contact surface of each rim active block and the contact relationship with the tire bead.

[0055] According to the above formulas and requirements, the python programming language can be used to automatically implement the above requirements and write them into the tire bead pressure calculation file.

[0056] In the fourth step, all degrees of freedom of all nodes are fixed in the first analysis step of tire bead pressure, and the unit properties of the rim section units that need to be "killed" in the third step are set to "dead" using the life and death unit technology of Abaqus simulation software, that is, these units no longer participate in the calculation (three-dimensional model of tire bead pressure, and local enlarged image).

[0057] In the fifth step, based on the calculation results of the fourth step, the rim diameter is first expanded to the nominal diameter d, and then according to the actual test conditions of the tire bead pressure, the eight reference points are simultaneously constrained to reduce the nominal diameter by 0.29 mm and increase it by 0.38 mm (e.g. Figure 6 , Figure 7 ).

[0058] Taking 245 / 60R18 as an example, the implementation steps of the present invention are as follows:

[0059] The first step is to divide the tire material distribution map into grids, where the cap, belt, carcass and other parts containing reinforcement materials are axisymmetric quadrilateral elements, and axisymmetric rebar elements are used to characterize the reinforcement structure (such as Figure 1), using axisymmetric shell elements to establish a rim with an unexpanded radius of D = 454.62 mm and a nominal diameter of d = 460.62 mm after rim expansion (such as Figure 2 ); Set the outer surface of the tire bead as the contact surface; assign linear elastic material parameters and density to the rubber unit and the skeleton unit according to the actual tire material test. Apply full fixed constraints to all nodes of the axisymmetric model in the Abaqus finite element program and complete the calculation.

[0060] In the second step, according to the actual structural characteristics of the eight rim active blocks, the tire and rim will be rotated and generated based on the calculation results of the first step. When the rim is rotated and generated, a cross-section area with an angle of θ=0.2° will be reserved at the boundary of each adjacent 45° rim block as the rim section to be "killed" in the subsequent calculation process (such as Figure 3 ). To facilitate viewing of tire bead pressure results, the data defining the starting surface of the tire and rim rotation around the Y axis is obtained according to the following formula.

[0061]

[0062]

[0063] In the third step, based on the three-dimensional model of the tire and rim generated in the second step, a rim section to be "killed" and the rim model between two adjacent rim sections to be "killed" are defined as the rim models to be retained at approximately 45° intervals, and the unit number definition formula is as follows:

[0064]

[0065] Among them, N ijs is the axisymmetric element number n i The rotation generated by the nth j The nth of the 45° rim joints s The unit number of each section, m is the offset of the unit number, n t is the total number of sections in the 45° rim snap block, n j The value range is an integer between 1 and 8. s =n t When is the number of the unit killed by the current rim active block, when n s <n t This is the number of the unit that needs to be retained in the current active block.

[0066] Define a set for all the units that need to be "killed". Define a set for each unit reserved for the rim flexible block (such as Figure 4), establish a reference point for each rim joint block at the center point of the tire axis, and couple each reference point and the corresponding joint block using the *Coupling command to set the contact surface of each rim joint block and its contact relationship with the tire bead.

[0067] According to the above formulas and requirements, the python programming language can be used to automatically implement the above requirements and write them into the tire bead pressure calculation file.

[0068] In the fourth step, based on the file written in the third step, all degrees of freedom of all nodes are fixed in the first analysis step of the tire bead pressure, and the element properties of the rim section elements that need to be "killed" in the third step are set to "dead" using the death and life element technology of the Abaqus simulation software, that is, these elements are no longer involved in the calculation (such as Figure 5 ).

[0069] In the fifth step, based on the calculation results of the fourth step, the rim diameter is first expanded to the nominal diameter, and then according to the actual test conditions of the tire bead pressure, the eight reference points are simultaneously constrained to reduce the nominal diameter by 0.29 mm and increase the nominal diameter by 0.38 mm (e.g. Figure 6 , Figure 7 ).

[0070] The above technology has been used to realize the rapid modeling and application of tire bead pressure. It can be seen from Table 1 that the modeling time of the method of this patent is comparable to that of the axisymmetric model method, and the accuracy of the measured results is improved by more than 10%, and it is more in line with the actual test conditions. Table 1 also shows that compared with the three-dimensional model re-editing method mentioned above, the method of this patent has greatly shortened the tire bead pressure modeling time, and the post-processing is simple. Compared with the measured results, the calculation accuracy is basically consistent. Therefore, the method of this patent application can well simulate the actual test conditions of tire bead pressure, while ensuring the accuracy of tire bead pressure simulation, reducing the difficulty of modeling, shortening the modeling time, and improving the modeling efficiency.

[0071] Table 1 Comparison of time and accuracy of this patented method with other methods

[0072]

[0073] The above is a description of the embodiments of the present invention. Through the above description of the disclosed embodiments, professionals and technicians in the field can implement or use the present invention. Various modifications to these embodiments will be apparent to professionals and technicians in the field. 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 in this article, but will conform to the widest range consistent with the principles and novelties disclosed herein.

Claims

1. A method for simulating radial tire bead pressure, characterized in that: The following steps are involved: 1) An axisymmetric finite element model is established based on the material distribution diagram of the tire and rim. The reinforcement components including the carcass, cap and belt are divided into axisymmetric quadrilateral elements, and linear elastic material parameters and density are assigned. 2) Based on the axisymmetric model, a three-dimensional finite element model of the tire and rim is generated through the periodic rotation law, in which a rim section with an angle of θ is reserved adjacent to each 45° rim flexible block of the rim as the unit to be "killed"; 3) Define the unit number after the axisymmetric unit is rotated according to the formula, and define the units to be "killed" and the units to be retained as sets respectively; The coordinate data of the starting surface of the tire and rim rotating around the Y axis is defined according to the following formula; Data 1 = Data 2 = ; According to the three-dimensional model of the tire and rim generated in step 2), a rim section to be "killed" and the rim model between two adjacent rim sections to be "killed" are defined every 45° as the rim model to be retained, and the unit number definition formula is as follows: Among them, N ijs is the unit number, n i is the axisymmetric element number, n s is the section number, n j is the number of the jth 45° rim joint, m is the unit number offset, n is t The total number of sections inside the 45° rim snap block; 4) In the simulation calculation, the birth and death unit technology is applied, and the properties of the rim section unit to be "killed" are set to "dead", and the remaining units participate in the calculation; 5) According to the test conditions, apply expansion and constraint conditions to the rim, simulate the tire bead pressure and extract the results.

2. The simulation method according to claim 1, characterized in that: In the step 1), an axisymmetric rebar unit is used to characterize the reinforcement structure, and an axisymmetric shell unit is used to establish a rim with an unexpanded rim radius of D and a nominal diameter d after the rim is expanded; the outer surface of the tire bead is set as the contact surface; linear elastic material parameters and density are assigned to the rubber unit and the skeleton unit according to actual tire material testing; full fixed constraints are applied to all nodes of the axisymmetric model in the Abaqus finite element program, and the calculation is completed.

3. The simulation method according to claim 1, characterized in that: In the step 3), a three-dimensional tire and rim model is automatically generated by a Python program.

4. The simulation method according to claim 1, characterized in that: In the step 3), the unit retained by the rim flexible block is bound to the reference point of the tire axis center point through a coupling instruction.

5. The simulation method according to claim 1, characterized in that: In step 4), the simulation process uses the birth and death unit technology of Abaqus software to process the "killed" units to ensure that these units do not participate in the calculation.

6. The simulation method according to claim 1, characterized in that: In step 5), the constraints imposed on the rim include two working conditions of reducing the nominal diameter d by 0.29 mm and increasing the nominal diameter d by 0.38 mm.

7. A system for simulating radial tire bead pressure, characterized in that: The system implements the method according to any one of claims 1 to 6, including: A modeling module for building an axisymmetric finite element model based on material distribution maps of the tire and rim; The 3D model generation module is used to generate 3D tire and rim models from the axisymmetric model, and automatically define the rim active blocks and the units that need to be "killed"; The unit management module is used to define a set according to the units to be "killed" and the units to be retained, and to set the coupling relationship with the tire axis reference point; Simulation module, used to apply expansion constraints and life-death unit technology for simulation calculation; The post-processing module is used to extract simulation results and compare and analyze them with measured data.

8. The system according to claim 7, characterized in that The modeling module automatically generates simulation models and calculation files through Python scripts; the unit management module can automatically calculate the number and status of the units in the 45° rim active block based on the formula, and classify them into a "killed" unit set and a retained unit set respectively; the simulation module combines Abaqus software to simulate the changes in tire bead pressure under different expansion conditions to evaluate the contact tightness and safety performance between the tire bead and the rim.

9. A computer-readable storage medium having a computer program or instruction stored thereon, characterized in that: When the computer program or instruction is executed by a processor, the method according to any one of claims 1 to 6 is implemented.

10. A computer program product comprising a computer program or instructions, characterized in that When the computer program or instruction is executed by a processor, the method according to any one of claims 1 to 6 is implemented.

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