Method, system and equipment for calculating contribution of tire component to torsional rigidity and storage medium

Abstract

The invention relates to the technical field of tire simulation design, in particular to a method, system and equipment for calculating contribution of tire parts to torsional rigidity and a storage medium. According to the method, under a unified finite element tire-rim-road surface model and inflation and load working conditions, the overall torsional rigidity Kmz1 of the tire is obtained firstly, then the Young modulus of a selected target part is reduced to 0.01%-5% of a design value, inflation and torsional load analysis is conducted again on the premise that geometric topology, a contact relation and boundary conditions are kept unchanged, and the overall torsional rigidity Kmz1 of the tire is obtained. The degenerated torsional rigidity Kmz2 is obtained; and calculating a torsional rigidity contribution value delta K = Kmz1-Kmz2 / n and a contribution rate eta = delta K / Kmz1 by combining the occurrence frequency n of the target part in the structure, thereby realizing quantitative decomposition of parts such as a tread, a belted layer and sidewall rubber on torsional rigidity. Compared with an existing overall rigidity prediction method, the method does not need to delete parts or rebuild a model, can control the contribution calculation error within about + / -2%, remarkably improves the refinement degree of torsion performance analysis, and provides a visual and reliable quantitative basis for tire structure optimization design and multi-performance cooperative matching.

Description

Technical Field

[0001] This invention relates to the field of tire simulation design technology, and in particular to a method, system, device and storage medium for calculating the contribution of tire components to torsional stiffness. Background Technology

[0002] As the only contact component between a vehicle and the road surface, the overall stiffness characteristics of the tire (including radial stiffness, longitudinal stiffness, lateral stiffness, and torsional stiffness) directly affect the vehicle's handling stability, comfort, and safety. With the development of finite element simulation technology, the industry has widely adopted finite element models to predict and calibrate the stiffness characteristics of tires under various working conditions such as inflation, load, and steering, in order to reduce the number and cost of physical tire tests. However, existing technologies mainly focus on obtaining and calibrating overall stiffness indicators, and there is still a lack of effective means to quantitatively decompose and evaluate the independent contribution of individual structural components (such as tread, belt layers, and sidewall rubber) to specific stiffness indicators, especially torsional stiffness.

[0003] For example, Chinese invention patent CN107103119B discloses an automated modeling method for tire finite element analysis. By analyzing the tire material distribution map, it automatically extracts closed rubber regions and cord structures, completing two-dimensional cross-sectional modeling, mesh generation, and contact surface establishment. Based on this, tire finite element analysis is performed, significantly improving the efficiency and consistency of tire finite element model establishment. This method solves the problem of automating tire geometric modeling and mesh generation, providing a basic model for subsequent stiffness simulation. However, it focuses on "how to quickly and accurately establish a tire finite element model" and does not address technical solutions for quantifying the contribution of a specific tire component to torsional stiffness.

[0004] For example, Chinese invention patent CN111191397A discloses a method for rapid prediction of the static radial stiffness of radial tires. This method obtains a small number of load-displacement data points through finite element simulation, establishes a mathematical model, and fits the model parameters to predict the static radial stiffness of the tire under different deflection amounts. This achieves efficient prediction of radial stiffness and reduces the need for extensive physical testing. However, this technology also focuses on the entire tire as a research object, addressing the question of "how to quickly obtain the overall radial stiffness curve of the tire." It does not separate and quantitatively calculate the contributions of different structural components to the formation of overall stiffness, nor does it address the stiffness decomposition in the torsional stiffness direction.

[0005] For example, Chinese invention patent CN108460180B discloses a simulation method for the longitudinal and lateral stiffness of tires considering elastic slip. By establishing a three-dimensional nonlinear tire finite element model, it introduces for the first time the maximum elastic slip in the contact patch region to correct the tangential contact constitutive model, improving the consistency between the simulation results and experimental results for longitudinal and lateral stiffness. This method focuses on the impact of tangential slip at the tire-road contact interface on longitudinal and lateral stiffness, emphasizing the improvement of the accuracy of the overall longitudinal and lateral stiffness simulation. It is still a "holistic stiffness calibration" for the entire tire and does not propose quantitatively decomposing the contribution of individual components to a certain stiffness index (especially torsional stiffness) by changing local material stiffness parameters.

[0006] In summary, existing technologies reveal two key characteristics: First, while current finite element modeling and stiffness simulation methods can accurately predict the overall radial, longitudinal, and lateral stiffness characteristics of tires, significant progress has been made in model automation, parameter calibration, and contact constitutive correction. Second, both automated modeling methods and rapid anisotropic stiffness prediction and correction methods only provide "overall stiffness" results, lacking a systematic algorithmic framework capable of isolating the independent contribution of a target component to overall torsional stiffness from the complex coupling effects of multi-layered composite structures through "controlled degradation" of the target component's material stiffness under unified finite element models and operating conditions. Existing technologies lack a specific method for "reducing the Young's modulus of the target component to a small fraction of its design value, rendering it mechanically ineffective, and then calculating the component's contribution value and contribution rate based on the difference in torsional stiffness before and after operating conditions," nor are there corresponding systematic solutions. This makes it difficult to provide a detailed "component-level" decomposition basis for tire structure optimization.

[0007] Therefore, based on existing tire finite element stiffness simulation technology, how to propose a method and system that can quantitatively calculate the contribution value and contribution rate of each tire component to torsional stiffness under a unified simulation framework is a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0008] The technical objective of this invention is to provide a method and system for quantitatively calculating and separating the contribution value and contribution rate of each tire component to the overall torsional stiffness under unified working conditions and a unified model, based on existing tire finite element simulation technology. By controlling the degradation of the Young's modulus of the target component into a mechanically "ineffective component", the difference in torsional stiffness of the component before and after is accurately obtained, thereby realizing the torsional stiffness decomposition analysis at the component level, providing an intuitive and quantitative engineering basis for tire structure optimization design and performance matching.

[0009] To achieve the objectives of this invention, the following technical solution is adopted:

[0010] A method for calculating the contribution of a tire component to torsional stiffness, characterized by comprising the following steps:

[0011] S1. Establish a finite element model of the tire and perform a two-dimensional axisymmetric inflation analysis:

[0012] S11. Divide the tire body cross section into grids according to the tire material distribution map, and assign corresponding material properties to each grid, including Young's modulus and Poisson's ratio of the rubber material and Young's modulus and Poisson's ratio of the skeleton material.

[0013] S12. Establish a rigid rim model, define the contact pair and friction coefficient between the tire and the rim, apply the rated inflation pressure to the inner boundary layer of the tire, and solve for the inflation equilibrium state.

[0014] S2. Generate a three-dimensional tire model based on the inflation balance results and establish load conditions:

[0015] S21. Rotate the two-dimensional axisymmetric tire model 360° along the tire circumference to generate a three-dimensional tire model;

[0016] S22. Arrange a rigid road surface model at a preset gap from the lower surface of the tire, define the contact pair and friction coefficient between the tire and the rigid road surface, fix the rim, apply the rated vertical load to the rigid road surface, and solve for the load balance state of the tire under the rated load.

[0017] S3. Obtain the overall torsional stiffness of the tire under balanced load conditions:

[0018] S31. Rotate the rigid road surface around the radial axis of the tire within a preset angle range, record the data of the reaction torque of the rigid road surface in the radial axis direction as a function of the rotation angle, and obtain the torque-rotation angle curve.

[0019] S32. Calculate the torsional stiffness K_mz1 of the tire under the target working condition within the linear interval of the torque-rotation curve;

[0020] S4. Construct a degradation model of the target component and repeat the torsional stiffness calculation:

[0021] S41. Select at least one tire target component in the finite element model, replace the material properties of the target component, set its Young's modulus to an equivalent low modulus value of 0.01% to 5% of the designed Young's modulus, while keeping the Poisson's ratio of the target component consistent with the original material, and keeping the material properties and boundary conditions of other components unchanged, thereby degrading the target component into a mechanical "ineffective component" that has basically no effect on torsional stiffness.

[0022] S42. Repeat the inflation analysis step and load analysis step on the degradation model to obtain the resolved torque-angle curve, and calculate the torsional stiffness K_mz2 of the tire after changing the target component in the corresponding linear interval.

[0023] S5. Calculate the contribution value and contribution rate of tire components to torsional stiffness:

[0024] S51. Calculate the torsional stiffness contribution value ΔK of the target component according to the formula ΔK=|K_mz1-K_mz2| / n, where n is the number of times the target component appears in the tire structure;

[0025] S52. Calculate the torsional stiffness contribution rate η of the target component according to the formula η=ΔK / K_mz1;

[0026] S53. Output the contribution value ΔK and contribution rate η to characterize the independent contribution of the target component to the overall torsional rigidity of the tire, and complete the calculation of the tire component's contribution to torsional rigidity.

[0027] Preferably, the coefficient of friction between the tire and the rim in step S12 is in the range of 0.01 to 1.0.

[0028] Preferably, the coefficient of friction between the tire and the rigid road surface in step S22 is in the range of 0.1 to 1.0.

[0029] According to the method described in claim 1, the upper limit of the rotation angle of the rigid road surface in step S31 is 5°, the linear interval is selected as 0° to 0.5°, and the torsional rigidity K_mz1 and K_mz2 are obtained by linear fitting of the torque and rotation angle data within the linear interval.

[0030] Preferably, the target component includes at least one of tread compound, belt layer, crown layer, and sidewall compound. The variable n is determined according to the number of times the target component is symmetrically repeated in the tire structure, wherein n = 1 for the tread compound and the base compound of the tire body, and n = 2 for the left and right sidewall compounds.

[0031] Preferably, in step S41, the Young's modulus of the target component is gradually reduced from the design value to the equivalent low modulus value of 0.01% to 5%. Steps S42 and S5 are repeated under each segment modulus until the rate of change of torsional stiffness K_mz2 obtained from two adjacent calculations is lower than the preset convergence threshold. At this point, it is determined that the Young's modulus of the target component has degenerated to the mechanical "ineffective component" state, and K_mz2 at this time is used to participate in the calculation of the contribution value ΔK and contribution rate η.

[0032] Furthermore, the present invention also provides a system for calculating the contribution of a tire component to torsional stiffness, the system being used to implement the method, comprising:

[0033] The model building module is used to mesh the tire body section based on the tire material distribution map, assign material properties to each component, and build a rigid rim model and the contact relationship between the tire and the rim.

[0034] The inflation analysis module is used to apply the rated inflation pressure to the inner boundary layer of the tire and solve the inflation equilibrium state of a two-dimensional axisymmetric tire rim model.

[0035] The 3D modeling and load analysis module is used to rotate the 2D axisymmetric model along the tire circumference to generate a 3D tire model, arrange the rigid road surface model, define the contact relationship between the tire and the rigid road surface, apply the rated vertical load, and solve for the load balance state.

[0036] The torsional load solving module is used to drive the rigid road surface to rotate around the radial axis of the tire within a preset angle range under the load equilibrium state, collect data on the reaction torque of the rigid road surface in the radial axis direction as a function of the rotation angle, construct the torque-rotation angle curve, and calculate the reference torsional stiffness K_mz1 of the tire within its linear range.

[0037] The material degradation module is used to select at least one tire target component in the finite element model, replace the Young's modulus of the target component with an equivalent low modulus value of 0.01% to 5% of the designed Young's modulus, keep the Poisson's ratio unchanged, and keep the material properties and boundary conditions of other components unchanged, thereby generating a degradation model of the target component.

[0038] The degraded torsional solution module is used to call the inflation analysis module and the three-dimensional modeling and load analysis module on the degraded model of the target component to obtain the re-solved torque-angle curve, and calculate the torsional stiffness K_mz2 after changing the target component in the corresponding linear interval.

[0039] The contribution calculation module is used to calculate the torsional stiffness contribution value ΔK of the target component according to ΔK=|K_mz1-K_mz2| / n, and to calculate the torsional stiffness contribution rate η of the target component according to η=ΔK / K_mz1, where n is the number of times the target component appears in the tire structure, and outputs the contribution value ΔK and contribution rate η.

[0040] Preferably, the system further includes a convergence control module, which is electrically connected to the material degradation module and the degradation condition torsion solution module. The convergence control module controls the material degradation module to gradually reduce the Young's modulus of the target component in a preset step size, and obtains the corresponding torsional stiffness K_mz2 through the degradation condition torsion solution module at each step size. When the rate of change of torsional stiffness K_mz2 corresponding to two adjacent step sizes is lower than a preset threshold, a degradation termination command is sent to the material degradation module.

[0041] Furthermore, the present invention also provides an electronic device for calculating the contribution of a tire component to torsional stiffness, including a processor and a memory, wherein the memory stores a computer program that can run on the processor, and the processor executes the steps of the method when executing the computer program.

[0042] Furthermore, the present invention also provides a computer-readable storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, performs the steps of the method described thereon.

[0043] This invention reduces the Young's modulus of a target component to 0.01%–5% of its design value under a unified tire finite element model and unified boundary conditions, causing it to degenerate into a mechanically "ineffective component" in the torsional stiffness direction. By comparing the torsional stiffness K_mz1 and K_mz2 before and after degradation, the torsional stiffness contribution value ΔK and contribution rate η of the target component are directly obtained without changing the overall tire geometry, contact conditions, and load boundaries, thus achieving "component decomposition" of tire torsional stiffness. This method eliminates the need for repeated adjustments to the model topology or the creation of a separate comparative model with "removed components," avoiding additional errors introduced by mesh re-division and changes in contact pairs, ensuring the comparability of the conditions before and after calculation, and controlling the contribution calculation error within approximately ±2%. Furthermore, by combining progressive degradation and convergence criteria, it can automatically determine the critical modulus range at which a component degenerates into an "ineffective component," improving the robustness and versatility of the algorithm. Based on the calculation method and system of this invention, tire design engineers can not only quantitatively compare the relative contributions of different components such as tread, belt layer, and sidewall rubber to torsional stiffness and accurately identify the key structures most sensitive to torsional performance, but also make targeted adjustments to local material and structural parameters while ensuring overall performance constraints. This achieves synergistic optimization between torsional stiffness and multiple performance objectives such as handling and durability, significantly improving the refinement of tire structure design and development efficiency. Attached Figure Description

[0044] Figure 1 Tire material distribution diagram.

[0045] Figure 2 : Schematic diagram of tire cross-section grid and material component division.

[0046] Figure 3 : Cloud map of tire inflation deformation results.

[0047] Figure 4 : 3D tire circumferential mesh generation results.

[0048] Figure 5 Schematic diagram of torsional load-rotation angle curve.

[0049] Figure 6Schematic diagram of tire coordinate system and boundary conditions. Detailed Implementation

[0050] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present invention.

[0051] I. Definition of Terms and Coordinate System

[0052] See Figure 6 This invention uses the right-handed rectangular coordinate system commonly used in tire engineering to uniformly describe tire geometry and loading direction:

[0053] With the tire's rotation axis as the z-axis direction, the positive z-axis points from right to left.

[0054] The x-axis is defined by the direction in which the tires are moving, with the positive x-axis pointing in the direction the vehicle is moving.

[0055] With the vertically upward direction as the y-axis, the positive y-axis points away from the road surface;

[0056] The torsional stiffness of a tire corresponds to the reaction torque M caused by the rotation of a rigid road surface about the z-axis (radial axis). z The linear relationship between the angle θ and the rotation angle;

[0057] In this invention, "torsional stiffness" refers to the magnitude of the counter-torque caused by a unit rotation angle when the road surface rotates around the z-axis at a small angle under given vertical load and inflation pressure. Its dimensions can be expressed as N·mm / ° or N·m / rad.

[0058] In this coordinate system, the normal contact between the tire and the rigid road surface mainly acts along the y-axis, while the tangential contact varies in the x–z plane; this invention focuses on the relationship between torsional load and deformation about the z-axis.

[0059] II. Example 1: Calculation Method for the Contribution of 215 / 50R15 Tire Components to Torsional Stiffness

[0060] The following uses a 215 / 50R15 passenger car tire as an example to systematically explain the calculation method of this invention. This embodiment uses a self-developed tire finite element preprocessing and solution platform (for example, it can be combined with the automated preprocessing technology described in patents CN116451479A and CN117171882A), or it can be implemented based on commercial finite element software. This embodiment focuses on describing the unique "component degradation-contribution calculation" process of this invention; other finite element solution details can be implemented using conventional techniques in the field.

[0061] (I) Step S1: Establishment of a two-dimensional axisymmetric tire finite element model

[0062] 1. Geometric modeling and mesh generation (corresponding) Figure 1 , Figure 2 )

[0063] (1) Import material distribution map

[0064] Import the 215 / 50R15 material distribution diagram provided by the tire design department into the finite element preprocessing module. Figure 1 The information clearly provides details such as tread thickness, tire profile, sidewall geometry, and bead structure.

[0065] (2) Geometric contour recognition and closed region generation

[0066] The preprocessing module is used to perform topological analysis on the boundary lines of each material, dividing the tire cross section into multiple closed regions and binding each region to the corresponding component type, such as: tread rubber region, base rubber region, belt layer region, carcass ply region, sidewall rubber region, bead filler rubber region, etc.

[0067] (3) Two-dimensional mesh generation

[0068] Constrained by structural complexity and computational accuracy requirements, the closed region is meshed:

[0069] Quadrilateral or triangular solid elements (e.g., plane strain elements) are used for the rubber matrix region, and the element size is appropriately increased in stress concentration areas such as the tread and shoulder.

[0070] The anisotropic characteristics of the fabric layer and belt layer can be represented by equivalent shell elements or embedded reinforcement elements;

[0071] After mesh generation, as follows Figure 2 As shown, different components are marked with different colors or labels to facilitate the selection of material properties and target components.

[0072] 2. Assigning material properties

[0073] (1) Rubber materials

[0074] For rubber components such as tread, carcass, and sidewall, the Neo-Hookean hyperelastic model is used to describe their constitutive relations. Based on actual material test data (uniaxial tensile, biaxial tensile, and shear tests, etc.), the corresponding shear modulus G and bulk modulus K are first obtained, and then the parameters required for the Neo-Hookean model (such as C) are calculated. 10 (e.g., D1, etc.), and record the nominal Young's modulus E and Poisson's ratio ν corresponding to each component.

[0075] (2) Reinforcing materials

[0076] For reinforcing components such as the carcass ply, belt ply, and crown ply, a linear elastic anisotropic material model or an equivalent orthotropic material is applied, which can be described by warp and weft stiffness, shear stiffness, and density parameters. For ease of explanation, this embodiment simplifies it to an equivalent isotropic material, assigning a corresponding Young's modulus E. s And Poisson ratio ν s It meets the stiffness requirements of the actual structure.

[0077] 3. Rim Model and Contact Settings

[0078] (1) Establishment of rigid rim model

[0079] A two-dimensional axisymmetric rigid rim geometry is established based on the rim design parameters. By defining a rigid body reference node, all nodes of the rim are coupled to this reference node to simplify constraint settings.

[0080] (2) Tire-rim contact pair

[0081] A contact pair is established between the inner tire bead area and the rim seat, using a surface-to-surface contact configuration. The normal contact is set as "hard contact," and the tangential contact uses the Coulomb friction model, with an initial friction coefficient of 0.03. The reasonable range for the friction coefficient is 0.01 to 1.0, and the actual value can be determined based on the rim surface treatment and assembly conditions.

[0082] (II) Step S2: Inflation Analysis (corresponding to) Figure 3 )

[0083] 1. Apply the rated inflation pressure

[0084] A uniformly distributed air pressure load is applied to the boundary of the internal cavity of the tire (i.e., the inner surface of the tire liner). In this embodiment, the rated inflation pressure is taken as 250 kPa. The inflation process is solved using a static nonlinear analysis step, considering geometric nonlinearity and material nonlinearity.

[0085] 2. Solving and Result Checking

[0086] The equilibrium deformation and stress distribution of a two-dimensional axisymmetric tire under rated air pressure can be obtained by solving the problem, and the tire profile can be output for comparison with the design shape. Figure 3 The deformation cloud diagram of the tire cross section after inflation is given, which shows the tread arch height, sidewall bulge, etc. The results reasonably indicate that the inflation analysis converges and can be used as the initial state for subsequent 3D modeling and load analysis.

[0087] (III) Step S3: Generation of 3D Tire Model and Load Analysis (corresponding to) Figure 4 , Figure 6 )

[0088] 1. 3D mesh generation (corresponding to) Figure 4 )

[0089] Based on the inflation balance, the axisymmetric model is rotated 360° circumferentially to generate a three-dimensional tire model:

[0090] Circumferential discretization strategy: Divide 360° into several sectors (e.g., 72 segments, each 5°), copy and rotate the two-dimensional mesh for each sector to ensure consistent circumferential unit structure;

[0091] Unit topology: Two-dimensional planar units are extruded into three-dimensional solid units to form three-dimensional structures such as tread, carcass, sidewall, and bead;

[0092] The generated 3D tire model is as follows Figure 4 As shown, the tread is distributed in a ring shape in the circumferential direction, and local mesh refinement can be applied to the shoulder or tread area as needed.

[0093] 2. Rigid pavement model and contact settings (see...) Figure 6 )

[0094] (1) Rigid pavement construction

[0095] A rigid, straight pavement panel is placed approximately 1 mm from the lower surface of the tire tread after static load in the negative y-axis direction. Its geometry should cover the entire ground contact area plus a certain margin. The rigid pavement also controls the overall movement through rigid body reference nodes.

[0096] (2) Tire-road contact

[0097] A surface-to-surface contact pair is established between the outer surface of the tire tread and the rigid road surface. Normal contact uses hard contact, and tangential contact uses the Coulomb friction model. The friction coefficient is set to 0.5 in this embodiment, with a reasonable range of 0.1 to 1.0. The contact settings between the tire and rim inherit the configuration from the two-dimensional model.

[0098] 3. Boundary conditions and rated load application (see...) Figure 6 )

[0099] (1) Rim constraint

[0100] All translational degrees of freedom of the rigid body reference node of the wheel rim are constrained (displacement in the x, y, and z directions is 0), and the rotation about the x and y axes is also constrained to simulate the state of the wheel rim being fixed to the vehicle hub. The rotational degree of freedom about the z axis can be retained for other working conditions if needed, but this embodiment mainly focuses on road surface torsion, so the rotation of the wheel rim about the z axis is also constrained.

[0101] (2) Application of vertical load

[0102] A concentrated vertical load is applied through a rigid road surface reference node to bring the tire to the target normal load under rated conditions. Taking a passenger car tire as an example in this embodiment, the rated load can be taken as 4802N. Displacement control or load control methods can be used in the solution process to ultimately make the ground reaction force tend to the required rated load.

[0103] 4. Load Analysis Solution

[0104] Under the aforementioned contact and constraint conditions, static nonlinear analysis is performed to solve for the load equilibrium state of the tire-road system. Under this state, the shape of the contact imprint, the contact pressure distribution, and the tire stress level can all be used to verify the rationality of the model.

[0105] (iv) Step S4: Calculation of torsional stiffness (corresponding to) Figure 5 )

[0106] 1. Torsional operating condition settings

[0107] After achieving vertical load balancing, a torsional load condition is introduced:

[0108] Constrain the vertical displacement and x-axis translational degree of freedom of the reference node of the rigid pavement, and retain the rotational degree of freedom about the z-axis;

[0109] While keeping the vertical load constant, apply an angular boundary or torque load about the z-axis to the rigid pavement.

[0110] In this embodiment, a rotation angle control method is adopted to gradually rotate the road surface around the z-axis to 5°, and solve the nonlinear problem step by step.

[0111] 2. Obtaining the reaction torque-rotation angle curve (corresponding to) Figure 5 )

[0112] During the solution process, the reaction moment M of the rigid pavement reference node about the z-axis is recorded. z The relationship data with the corresponding rotation angle θ. Through the post-processing module, M... z – θ data points are plotted as a curve, such as Figure 5 As shown:

[0113] Within a small angular range (e.g., 0° to 0.5°), the curve is essentially linear;

[0114] As the rotation angle increases, the nonlinearity of the rubber material and contact nonlinearity gradually become apparent, and the curve will deviate from linearity.

[0115] 3. Overall torsional rigidity K mz1 Calculation

[0116] Linear fitting is performed within the linear range of the torque-rotation angle curve, and the slope is calculated as the overall torsional stiffness. Taking this embodiment as an example, the reaction torque measured at θ = 0.5° is 75.1 N·mm, then the torsional stiffness K of the tire is... mz1 The calculations are as follows (in N·mm / °):

[0117]

[0118] in:

[0119] K mz1 The overall torsional rigidity of the tire under the baseline operating conditions;

[0120] θ is the torsional angle of the rigid pavement;

[0121] M z It is the reaction torque about the z-axis.

[0122] (V) Step S5: Controlled Degradation and Repeatability Analysis of Young's Modulus of Target Component

[0123] One of the key innovations of this invention is that, without changing the tire geometry and mesh topology, the Young's modulus of the target component is reduced to a small fraction of the design value, making it approximately degenerate into a mechanically "ineffective component" in the torsional direction, and then the component's contribution is calculated by the difference in torsional stiffness between the front and rear.

[0124] 1. Target component selection

[0125] Firstly, from Figure 2 A target component is selected from the material components shown. In this embodiment, the tread compound is chosen as the target component because the tread area directly participates in the shearing and friction with the road surface and is one of the torsional rigidity sensitive parts. For other embodiments, components such as the belt layer and sidewall compound can also be selected as the target component.

[0126] 2. Target component Young's modulus replacement strategy

[0127] In the finite element model, the material properties of the tread rubber element are replaced by an equivalent low-modulus material instead of the original Young's modulus E0. d A small fraction of the original value:

[0128] E d =αE0;

[0129] in:

[0130] E0 is the Young's modulus of collagen design in the tire tread.

[0131] E d The equivalent Young's modulus after degradation;

[0132] α is the degradation ratio coefficient, and this invention suggests a range of 0.0001 to 0.05, i.e. 0.01.

[0133] To avoid numerical ill-conditioning, this invention preferably uses α = 0.01 to 0.05, which significantly reduces the load-bearing capacity of the target component without causing convergence difficulties for the solver. In this embodiment, α = 0.01, that is:

[0134] E d =0.01E0;

[0135] During the material replacement process, the Poisson's ratio ν of the tread compound remains unchanged to ensure that its volumetric deformation characteristics are consistent with those of the raw material, and it only degrades at the stiffness level.

[0136] 3. Repeated inflation and load analysis

[0137] After replacing the tread compound with an equivalent low-modulus material, keeping the material parameters of other components and all boundary conditions completely unchanged, the inflation analysis and load analysis procedures are repeated, i.e., steps S2 and S3 are repeated. This ensures the consistency of the operating conditions before and after degradation and avoids introducing additional errors due to changes in geometry or contact conditions.

[0138] 4. Torsional stiffness K mz2 Calculation

[0139] Under the new load equilibrium state, repeat step S4 to apply the same torsional load to the rigid road surface and obtain a new torque-rotation curve; perform linear fitting within the same linear range (e.g., 0° to 0.5°) to obtain the overall torsional stiffness K of the degraded tire. mz2 .

[0140] In this embodiment, the reaction torque was measured to be 68.1 N·mm at θ = 0.5°, therefore:

[0141]

[0142] in:

[0143] K mz2 To improve the overall torsional rigidity of the tire after the tread compound degrades into a low-modulus material.

[0144] contrast Figure 5 The two curves before and after degradation show that the slope decreases slightly within a small angle range, indicating that the contribution of tread torsional stiffness is partially stripped away.

[0145] (vi) Step S6: Calculation of the contribution value and contribution rate of torsional stiffness of tread components

[0146] 1. Calculation of contribution value ΔK

[0147] This invention uses a reference torsional stiffness K mz1With degraded torsional stiffness K mz2 The difference is used to calculate the torsional stiffness contribution value ΔK of the target component. Considering that the target component may appear multiple times in the tire structure (e.g., symmetrically appearing on the left and right sidewall rubbers), the occurrence number n is introduced for normalization. The calculation formula is:

[0148]

[0149] in:

[0150] ΔK is the contribution value of the torsional stiffness of the target component;

[0151] K mz1 The overall torsional stiffness is based on the baseline working condition;

[0152] K mz2 The overall torsional rigidity of the target component after degradation;

[0153] n represents the number of times the target component appears in the tire structure.

[0154] The tread component appears only once in the cross-section, therefore n=1. Substituting the data into this embodiment:

[0155]

[0156] 2. Calculation of contribution rate η

[0157] The contribution rate η of the target component to the overall torsional stiffness is defined as the ratio of the contribution value ΔK to the reference torsional stiffness K. mz1 The ratio:

[0158]

[0159] in:

[0160] η is the contribution rate of the target component to the overall torsional stiffness (expressed as a percentage).

[0161] 3. Results Analysis

[0162] The above calculations show that, under the operating conditions of this embodiment, the tread component contributes approximately 9% to the overall torsional rigidity. Figure 5 The spacing between the two torque-rotation curves before and after degradation in the small-angle linear segment also visually verifies this conclusion—after the stiffness of the tread rubber decreases, the overall torsional stiffness is significantly reduced.

[0163] Compared to the traditional approach of "directly deleting components," this invention maintains the overall tire geometry and contact boundaries unchanged through equivalent low-modulus degradation. This ensures that the before-and-after comparison only reflects the impact of changes in the stiffness of the target component, thereby significantly reducing numerical comparison errors. Under reasonable mesh and load settings, the contribution calculation error of this invention can be controlled within approximately ±2%, meeting the needs of engineering applications.

[0164] (vii) Step S7: Extended Applications and Multi-Component Analysis

[0165] 1. Sequential Analysis of Multiple Components

[0166] In practical engineering, designers can analyze multiple components sequentially in the following manner:

[0167] First, select the tread compound as the target component and calculate ΔK. 胎面 and η 胎面 ;

[0168] Then, the tread material was restored to its original design value, and the first belt layer was selected as the target component for degradation analysis to obtain ΔK. 带束 and η 带束 ;

[0169] The same degradation calculation process is applied sequentially to components such as the crown belt layer, carcass ply, sidewall rubber, and bead rubber.

[0170] This method yields a "component-torsional stiffness contribution matrix," providing a quantitative basis for structural optimization.

[0171] 2. Normalization of symmetrical components

[0172] For components such as the sidewall rubber that are symmetrical on both sides, the occurrence frequency n is usually 2. Taking the sidewall rubber as an example, if both sides of the sidewall rubber are simultaneously treated as target components for degradation, and the overall torsional stiffness change ΔK is obtained... 总 Then use the formula:

[0173]

[0174] This allows us to obtain the average contribution value of the rubber on one side of the tire, thus achieving accurate normalization of the contribution under a symmetrical structure.

[0175] 3. Sensitivity analysis under different operating conditions

[0176] The method of this invention can also be repeated under different vertical loads, different inflation pressures, or different friction coefficients:

[0177] 1) Perform torsional analysis under large vertical loads to assess the impact of the loads on the torsional contribution of each component;

[0178] 20. Adjust the tire-road friction coefficient and study the contribution changes of components such as tread and belt layer under different adhesion conditions (dry and wet road surfaces);

[0179] 3) Compare the differences in the contribution rates of each component under different tire structure (single-layer / double-layer cord).

[0180] Through these extended analyses, designers can identify key components that are most sensitive to torsional stiffness in specific usage scenarios (such as high speeds on dry ground or low temperatures in wet ground), thereby enabling more targeted material and structural optimization.

[0181] IV. Example 2: Implementation based on system architecture

[0182] In a preferred embodiment, the present invention can also be implemented as a software system, which can be deployed on a server or engineering workstation, and includes:

[0183] 1. Model Building Module: Implementation Figure 1 , Figure 2 The system includes geometry recognition and mesh generation, and automatic assignment of material partitions and component labels.

[0184] 2. Inflation Analysis Module: Automatically generates analysis steps based on the input rated air pressure, performs two-dimensional or three-dimensional inflation analysis, and outputs the balance status.

[0185] 3. 3D Modeling and Load Analysis Module: Generates by rotating a 2D model. Figure 4 The three-dimensional model shown is applied. Figure 6 Given the boundary conditions and vertical loads, solve for the load equilibrium state.

[0186] 4. Torsional Load Solving Module: Automatically applies torsional loads or angular boundaries around the z-axis and outputs... Figure 5 The torque-rotation curve is shown, and the reference torsional stiffness K is calculated. mz1 .

[0187] 5. Material Degradation Module: Based on the target component selected by the user, the Young's modulus is proportionally reduced to 0.01, and multi-step degradation and convergence criterion settings are available.

[0188] 6. Degraded Condition Torsional Solution Module: Automatically repeats inflation and load analysis and torsional analysis on the degraded model to calculate the torsional stiffness K after degradation. mz2 .

[0189] 7. Contribution Calculation and Visualization Module: Calculates ΔK and η according to the above formulas, and displays the torsional stiffness contribution of each component in the form of tables, bar charts or pie charts, etc., and supports exporting analysis reports.

[0190] Engineers only need to select tire specifications, input material parameters and operating conditions on the interface, and the system can automatically complete the above steps and output the torsional stiffness contribution results of each component, greatly reducing the workload of manual modeling and post-processing and improving R&D efficiency.

[0191] In summary, this invention, through a unified simulation framework of "low modulus degradation of target components + difference in torsional stiffness between front and rear parts," achieves component-level decomposition and quantitative evaluation of tire torsional stiffness while maintaining complete consistency between tire geometry and operating conditions. It not only has the advantages of simple implementation and easy integration into existing finite element processes, but also provides stable and reliable calculation results, offering a powerful engineering tool for tire structure optimization and performance matching.

[0192] The foregoing description of embodiments of the present invention, through which those skilled in the art are able to implement or use the present invention, will be readily apparent to those skilled in the art. Various modifications to these embodiments will be readily 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 is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novelty disclosed herein.

Claims

1. A method for calculating the contribution of a tire component to torsional stiffness, characterized in that, Includes the following steps: S1. Establish a finite element model of the tire and perform a two-dimensional axisymmetric inflation analysis: S11. Divide the tire body cross section into grids according to the tire material distribution map, and assign corresponding material properties to each grid, including Young's modulus and Poisson's ratio of the rubber material and Young's modulus and Poisson's ratio of the skeleton material. S12. Establish a rigid rim model, define the contact pair and friction coefficient between the tire and the rim, apply the rated inflation pressure to the inner boundary layer of the tire, and solve for the inflation equilibrium state. S2. Generate a three-dimensional tire model based on the inflation balance results and establish load conditions: S21. Rotate the two-dimensional axisymmetric tire model 360° along the tire circumference to generate a three-dimensional tire model; S22. Arrange a rigid road surface model at a preset gap from the lower surface of the tire, define the contact pair and friction coefficient between the tire and the rigid road surface, fix the rim, apply the rated vertical load to the rigid road surface, and solve for the load balance state of the tire under the rated load. S3. Obtain the overall torsional stiffness of the tire under balanced load conditions: S31. Rotate the rigid road surface around the radial axis of the tire within a preset angle range, record the data of the reaction torque of the rigid road surface in the radial axis direction as a function of the rotation angle, and obtain the torque-rotation angle curve. S32. Calculate the torsional stiffness Kmz1 of the tire under the target working condition within the linear range of the torque-angle curve; S4. Construct a degradation model of the target component and repeat the torsional stiffness calculation: S41. Select at least one tire target component in the finite element model, replace the material properties of the target component, set its Young's modulus to an equivalent low modulus value of 0.01% to 5% of the designed Young's modulus, while keeping the Poisson's ratio of the target component consistent with the original material, and keeping the material properties and boundary conditions of other components unchanged, thereby degrading the target component into a mechanical "ineffective component" that has basically no effect on torsional stiffness. S42. Repeat the inflation analysis step and load analysis step on the degradation model to obtain the resolved torque-angle curve, and calculate the torsional stiffness Kmz2 of the tire after changing the target component in the corresponding linear interval. S5. Calculate the contribution value and contribution rate of tire components to torsional stiffness: S51. According to the formula ΔK = |K mz1 -K mz2 | / n Calculate the torsional stiffness contribution value ΔK of the target component, where n is the number of times the target component appears in the tire structure; S52. According to the formula η = ΔK / K mz1 Calculate the torsional stiffness contribution rate η of the target component; S53. Output the contribution value ΔK and contribution rate η to characterize the independent contribution of the target component to the overall torsional rigidity of the tire, and complete the calculation of the tire component's contribution to torsional rigidity.

2. The method according to claim 1, characterized in that, In step S12, the coefficient of friction between the tire and the rim ranges from 0.01 to 1.

0.

3. The method according to claim 1, characterized in that, In step S22, the coefficient of friction between the tire and the rigid road surface ranges from 0.1 to 1.

0.

4. The method according to claim 1, characterized in that, In step S31, the upper limit of the rotation angle of the rigid pavement is 5°, the linear interval is selected as 0° to 0.5°, and the torsional rigidity K is obtained by linearly fitting the torque-rotation angle data within this linear interval. mz1 and K mz2 .

5. The method according to claim 1, characterized in that, The target component includes at least one of tread compound, belt layer, crown layer, and sidewall compound. The variable n is determined according to the number of times the target component is symmetrically repeated in the tire structure, wherein n = 1 for the tread compound and the base compound of the tire body, and n = 2 for the left and right sidewall compounds.

6. The method according to claim 1, characterized in that, In step S41, the Young's modulus of the target component is gradually reduced from the design value to the equivalent low modulus value of 0.01% to 5% in segments. Steps S42 and S5 are repeated under each segment modulus until the torsional stiffness K obtained from two consecutive calculations is obtained. mz2 When the rate of change is lower than the preset convergence threshold, it is determined that the Young's modulus of the target component has degenerated to the mechanical "ineffective component" state, and Kmz2 at this time is used to participate in the calculation of the contribution value ΔK and contribution rate η.

7. A system for calculating the contribution of tire components to torsional stiffness, characterized in that, The system is used to implement the method according to any one of claims 1-6, comprising: The model building module is used to mesh the tire body section based on the tire material distribution map, assign material properties to each component, and build a rigid rim model and the contact relationship between the tire and the rim. The inflation analysis module is used to apply the rated inflation pressure to the inner boundary layer of the tire and solve the inflation equilibrium state of the two-dimensional axisymmetric tire rim model. The 3D modeling and load analysis module is used to rotate the 2D axisymmetric model along the tire circumference to generate a 3D tire model, arrange the rigid road surface model, define the contact relationship between the tire and the rigid road surface, apply the rated vertical load, and solve for the load balance state. The torsional load solving module is used to drive the rigid road surface to rotate around the radial axis of the tire within a preset angle range under the load equilibrium state, collect data on the reaction torque of the rigid road surface in the radial direction as a function of the rotation angle, construct a torque-rotation angle curve, and calculate the tire's reference torsional stiffness K within its linear range. mz1 ; The material degradation module is used to select at least one tire target component in the finite element model, replace the Young's modulus of the target component with an equivalent low modulus value of 0.01% to 5% of the designed Young's modulus, keep the Poisson's ratio unchanged, and keep the material properties and boundary conditions of other components unchanged, thereby generating a degradation model of the target component. The degradation condition torsional solution module is used to call the inflation analysis module and the three-dimensional modeling and load analysis module on the degradation model of the target component to obtain the resolved torque-rotation curve, and calculate the torsional stiffness K of the target component after modification within the corresponding linear interval. mz2 ; The contribution calculation module is used to calculate the contribution based on ΔK = |K mz1- K mz2 | / n Calculate the torsional stiffness contribution value ΔK of the target component, according to η = ΔK / K mz1 Calculate the torsional stiffness contribution rate η of the target component, where n is the number of times the target component appears in the tire structure, and output the contribution value ΔK and the contribution rate η.

8. The system according to claim 7, characterized in that, The system further includes a convergence control module, which is electrically connected to the material degradation module and the degradation condition torsion solution module. The convergence control module controls the material degradation module to gradually reduce the Young's modulus of the target component in a preset step size, and obtains the corresponding torsional stiffness Kmz2 through the degradation condition torsion solution module at each step size. When the rate of change of torsional stiffness Kmz2 corresponding to two adjacent step sizes is lower than a preset threshold, a degradation termination command is sent to the material degradation module.

9. An electronic device for calculating the contribution of a tire component to torsional stiffness, characterized in that, The method includes a processor and a memory, wherein the memory stores a computer program that can run on the processor, and the processor, when executing the computer program, performs the steps of the method as described in any one of claims 1 to 6.

10. A computer-readable storage medium having a computer program stored thereon, the computer program, when executed by a processor, performing the steps of the method as described in any one of claims 1 to 6.

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