An electric vehicle tire safety factor improvement method, system, storage medium and software product

Abstract

The present application relates to the technical field of tire simulation design, and particularly relates to an electric vehicle tire safety factor improvement method and system, a storage medium and a software product. yy By establishing and calibrating a finite element model, the present application introduces a belt tension measure T=σ yy / cosθ under uniform air pressure / load, mainly compensates for the reduction of auxiliary drum circumference ΔC and the flatness of the crown ΔW, constructs a multi-objective optimization to reduce T and meet the ground threshold, and outputs the production parameters. The sample tire verification shows that the anti-foreign object penetration capability can be significantly improved without changing the material and the number of layers, the five-point penetration index is ≥130%, and the shape and static deflection are kept within the allowable range.

Description

Technical Field

[0001] This invention relates to the field of tire simulation design technology, and in particular to a method, system, storage medium, and software product for improving the safety factor of electric vehicle tires. Background Technology

[0002] Electric vehicle tires, operating in commercial vehicle conditions, must balance load-bearing capacity, durability, handling stability, and resistance to indentation (puncture). In engineering, the "plunger / puncture load—force-displacement curve integral" is commonly used to obtain the breaking energy, which is then compared to a baseline energy to characterize the "puncture strength index." However, in practice, it has been found that simply increasing the index (e.g., ≥130%) at the expense of ground uniformity or belt tension field balance may lead to the contradiction of being "more easily punctured" in real-world driving. This is related to the mismatch between the tire's tread force path, belt angle, and ground morphology. Existing patents mostly improve one aspect of the structure or process, lacking a systematic and coordinated optimization approach that involves "simulation calibration—using molding parameters as primary variables—constrained by ground / geometric thresholds."

[0003] From a structural reinforcement perspective, early literature focused on improving tread stability and durability by addressing issues such as belt layer stiffness distribution and zero-degree / small-angle belts. For example, Chinese patent CN201863645U, "A High-Strength Belt Layer Tire," proposes setting an annular reinforcing belt at the belt shoulder to improve shoulder stiffness and durability. Its specification also discusses the impact of zero-degree (0–15°) belt structures on tread stability and rolling resistance, as well as their manufacturing complexity and insufficient central stiffness, suggesting that simply increasing local stiffness may introduce new imbalance risks (such as shoulder stress concentration). A similar approach is illustrated in Chinese patent CN101927664A, which also emphasizes the side effects of zero-degree helical belts forming a "cylindrical" structure after vulcanization and the tendency for shoulder stress concentration, highlighting the necessity for belt angle and stiffness distribution to be coordinated with the ground contact topography.

[0004] Regarding the consistency between the tire carcass / bead and manufacturing, the "steel-wire carcass MT tire" disclosed in Chinese patent CN210416098U starts from the process details such as pre-forming pressure and drum inflation, emphasizing that the cords should be fully stretched and the bonding strength should be improved by appropriate inflation pressure to avoid local weakness and early failure caused by manufacturing defects. This kind of process control helps the "bottom-line reliability" of subsequent puncture resistance, but it does not establish a quantitative coupling framework of "forming geometry - belt tension - grounding threshold - puncture index".

[0005] Patents related to the molding process and equipment mostly focus on process routes such as drum switching, bead positioning, and low-pressure inflation bonding, aiming to improve bonding quality and increase production efficiency. For example, Chinese patent CN109421299B "Method for Manufacturing Tires" proposes to inflate the tire under low pressure to join the tire carcass with the belt / tread assembly, and simultaneously move the bead axially inward to improve molding bonding and geometric consistency; however, these disclosures do not use the geometry of the auxiliary drum / forming drum (such as equivalent circumference and axial width) as a quantifiable optimization variable for the system design of anti-indentation performance. Similarly, Chinese patent CN111491786B, "Process and Equipment for Producing Tires for Vehicle Wheels," focuses on optimizing the cycle time of the dual-drum transfer and tire carcass sleeve station to improve manufacturing consistency and cycle time, but still lacks parametric optimization centered on performance constraints; while Chinese patent CN207594372U, "Multi-Drum Tire Molding Machine," provides a multi-drum collaborative feeding / reverse wrapping / pressing path at the equipment level, which is more geared towards equipment structure innovation and still has a distance to go in terms of parametric optimization of puncture performance.

[0006] Regarding puncture / pressure puncture evaluation methods, existing Chinese patent CN105393103A mainly focuses on "pressure retention / leakage resistance after puncture" or pressure relief evaluation process under road nail / screw conditions. For example, "Method for testing tire pressure loss resistance" calculates the "pressure loss resistance index" by inserting a nail / screw and driving at a set speed. It focuses on pressure relief resistance "after being punctured" and is not geared towards the molding / structural linkage design of "plunger indentation energy and index optimization". Therefore, it is difficult to directly guide the mechanism and avoidance strategy of ">130% index but easy to puncture on actual road".

[0007] In summary, the common shortcomings of existing technologies are mainly as follows: 1. They mostly start from single-point structures (belt stabilization, local stiffening) or single-stage processes (pre-forming / inflation / transfer / bonding), lacking a publicly available framework for quantitatively coupling and optimizing forming geometric parameters (such as the equivalent circumference of the auxiliary drum ΔC, the flat width of the tire crown ΔW) as "first variables"; nor have we seen a method for measuring belt tension T=σ under unified working conditions after finite element simulation and bidirectional calibration of profile / grounding. yy / cosθ and grounding threshold (rectangular / conical) together serve as hard constraints to guide the parameter optimization scheme (see the limitations of the disclosed bundle structure and forming / equipment categories); 2. Most of the disclosures related to puncture / pressure penetration focus on the pressure relief resistance after puncture or the air leakage resistance assessment of road nail conditions, which is difficult to directly map to the collaborative design requirements between plunger energy-exponential and grounding uniformity / bundle angle / tension field. Therefore, when enterprises use methods such as "strong negative drum shrinkage or unbalanced crown width compensation" to increase the index by a single objective (≥130%), it is easy to break the grounding threshold and change the belt tension distribution, resulting in the paradox of "higher test index but easier to penetrate in actual road". How to solve the optimal range of ΔC–ΔW under multiple thresholds of grounding / geometry / tension and verify it in closed loop has not yet been systematically solved. Summary of the Invention

[0008] The technical objective of this invention is to provide a method for improving the safety margin of electric vehicle tires. By parametrically optimizing key parameters such as drum circumference and crown width, the method reduces belt layer tension and improves crown structure safety margin and resistance to foreign object indentation while meeting ground uniformity and dimensional error thresholds.

[0009] To achieve the above objectives, the present invention adopts the following technical solution: A method for improving the safety factor of electric vehicle tires includes the following steps: S1. Establish a finite element simulation model of the target tire model, and obtain the simulation-measurement error and ground uniformity threshold by bidirectional calibration with the measured profile / ground pressure index. S2. Calculate the longitudinal stress σ of the belt layer under gas-filled steady state. yy and the belt angle θ, based on the tension criterion T=σ yy / cosθ measures the tension of the belt layer and the safety margin; S3. Using "reduction of auxiliary drum circumference ΔC and increase of tire crown width compensation ΔW" as coupled design variables, construct a multi-objective optimization problem with "reducing inflation belt tension and improving the breakdown index" as the main objective and the simulation-measurement error and ground uniformity threshold in step S1 as constraints. The target threshold for the breakdown strength index is set to be no less than 130%. S4. Under the premise of satisfying the constraints, solve for ΔC and ΔW, where ΔC is located between -20mm and -45mm and ΔW is positively compensated between +5mm and +12mm; and perform trial production and pressure-break test verification according to the solution set. S5. When the verification results meet the requirements of a breakdown strength index of not less than 130% and grounding uniformity of rectangular coefficient ≥ 0.92 and tapered coefficient ≤ 0.25, the final production parameters are determined. If they do not meet the requirements, return to step S3 for iterative optimization until they are met.

[0010] Preferably, the model calibration in step S1 includes at least the following: matching the grounding shape with the multi-point grounding width under 770kPa / specified load, and controlling the simulation-measurement error within 3%–6% respectively; The grounding uniformity thresholds are as follows: the simulation test deviations of grounding length and multi-point grounding width are both ≤6%, the rectangular coefficient is ≥0.92, the tapered coefficient is ≤0.25, and the errors of the inflatable outer diameter, cross-sectional width, and settlement are ≤1%, ≤3%, and ≤2%, respectively.

[0011] Preferably, the preferred solution in step S4 satisfies the following: the reduction in the circumference of the auxiliary drum ΔC is between -25mm and -40mm, and the compensation for the flat width of the tire crown ΔW is a positive compensation of +8mm to +12mm, thereby obtaining a puncture strength index of not less than 133% in the five-point puncture test; preferably, the preferred solution in step S4 satisfies the following: ΔC = -40mm and ΔW = +8mm or +12mm, with the corresponding puncture strength indices reaching not less than 156% and not less than 134%, respectively.

[0012] As a preferred embodiment, the linkage constraint of steps S2-S4 is as follows: compared with the original scheme, the tension of the first and second belt layers is reduced by at least about 10%, preferably reduced to a quantization level of about 268.3 and about 264.3; at the same time, the minimum belt angle of the first and second belt layers is reduced by at least about 2° compared with the original scheme.

[0013] As a preferred option, while reducing ΔC, the expansion rate is reduced by 0-1% compared to the original scheme, further reducing the tension of the belt layer and keeping the grounding index within the range of rectangular coefficient ≥ 0.92 and tapered coefficient ≤ 0.25.

[0014] As a preferred option, the shoulder thickness is finely adjusted within the range of +0 to +3.5 mm, or the cross-sectional width is compensated at the level of ±5 mm, as a secondary optimization variable in addition to ΔC and ΔW, so as to improve grounding uniformity without sacrificing durability.

[0015] As a preferred option, the grounding uniformity criterion in step S5 adopts a combined judgment of rectangular coefficient and tapered coefficient: if the rectangular coefficient is lower than 0.92 or the tapered coefficient is higher than 0.25, even if the breakdown strength meets the standard, it is judged as unqualified and reverts to the suboptimal solution.

[0016] Furthermore, the present invention also provides a tire forming parameter collaborative optimization system for implementing the method, comprising: Parameter input module: Obtains target model, five-point compression strength target threshold, ΔC and ΔW boundary and material / wire parameters; Simulation calibration module: Executes S1 and outputs the error and threshold determination results; Tension assessment module: Calculates σ under steady-state inflation. yy θ and T=σ yy / cosθ, and give the safety factor; Multi-objective optimization module: With the goal and constraint of reducing T and satisfying "breakdown index ≥ 130% and grounding threshold", solve for ΔC and ΔW; Solution verification module: Outputs the optimal / alternative molding parameters that meet the threshold and the trial production verification process.

[0017] Furthermore, the present invention also provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the method.

[0018] Furthermore, the present invention also provides a computer program product, including a computer program or instructions that, when executed by a processor, implement the method.

[0019] By employing the aforementioned technical solution, this invention significantly reduces the comprehensive tension metric T=σyy / cosθ of the tire crown belt layer and simultaneously optimizes the rectangularity / tapering and peak contact pressure distribution of the ground contact patch. This mechanistically weakens the stress concentration of plunger load and local shear in risk areas such as the belt end and shoulder groove bottom. Under optimized parameters, the tension of the first / second belt layer can be reduced by approximately 10% compared to the original scheme (i.e., the initial design scheme for the same target tire model under the conditions of ΔC=0 and ΔW=0), and the minimum belt angle decreases by ≥2°. Ground contact uniformity remains within the preset threshold, and dimensional-stiffness indicators such as outer diameter / section width / static deflection remain essentially unchanged. Thus, without sacrificing durability, the safety margin of the tire crown structure and resistance to foreign object indentation are significantly improved. Furthermore, the performance improvement is solidified into a reproducible parameter window that is insensitive to manufacturing tolerances, reducing the number of sample tires and testing costs. Attached Figure Description

[0020] Figure 1 This is a picture of a tire puncture test.

[0021] Figure 2 This is a simulation model of a certain series of tires.

[0022] Figure 3 The diagram shows the ground pressure distribution test shape for a normal tire under three different scenarios.

[0023] Figure 4 This is a test shape diagram of the grounding pressure distribution for the -28mm +8mm scheme.

[0024] Figure 5 The simulation diagram shows the grounding pressure distribution for the -28mm +8mm scheme.

[0025] Figure 6 This is a coordinate graph of the tension on the belt. Detailed Implementation

[0026] 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.

[0027] The method of the present invention includes the following steps: S1. Establish a finite element simulation model of the target tire model, and perform bidirectional calibration with the measured profile / ground pressure index to ensure that the key errors meet the following requirements: the simulation test deviations of ground contact length and multi-point ground contact width are both ≤6%, the rectangular coefficient is ≥0.92, the tapered coefficient is ≤0.25, and the errors of inflation outer diameter, cross-sectional width, and sinking are ≤1%, ≤3%, and ≤2%, respectively. S2. Calculate the longitudinal stress σ of the belt layer under gas-filled steady state. yy and the belt angle θ, based on the tension criterion T=σ yy / cosθ measures the tension of the belt layer and the safety margin; S3. Using "reducing the circumference of the auxiliary drum ΔC and increasing the flat width of the tire crown ΔW" as coupled design variables, construct a multi-objective optimization problem with "reducing the inflation belt tension and increasing the five-point indentation index" as the main objective and the matching threshold and ground uniformity threshold mentioned in step S1 as constraints. The target threshold for the five-point indentation strength index is set to be no less than 130%. S4. Under the premise of satisfying the constraints, find the optimal interval solutions for ΔC and ΔW, where ΔC is located between -20mm and -45mm and ΔW is positively compensated between +5mm and +12mm; and verify the solution by prototyping and five-point pressure-break test according to the solution set. S5. When the verification results meet the requirement that the five-point breakdown strength index is not less than 130% and the grounding uniformity meets the requirements that the rectangular coefficient is ≥0.92 and the tapered coefficient is ≤0.25, the final production parameters are determined. If they do not meet the requirements, return to step S3 for iterative optimization until they are met.

[0028] The inputs of this invention are the structure and material list, molding / vulcanization process specifications, test conditions and benchmarking data of the target specification (taking 7.00R16 model as an example); the outputs are the optimal combination of ΔC and ΔW that meets the constraints (grounding uniformity threshold, geometric / stiffness error threshold) and the mass production window, and include comparative examples and secondary compensation strategies.

[0029] I. Establishment of Three-Dimensional Finite Element Model and Multi-Index Calibration 1.1 Modeling Objects and Layered Structures like Figure 2As shown, a three-dimensional laminated model is constructed using an electric vehicle tire as the object, comprising the tire carcass, first / second belt layers (±θ crossover), overlay / reinforcing belt, tread, and bead. The rubber components of the tire carcass and tread are represented using hyperelastic or viscoelastic constitutive models (such as Ogden, Yeoh, or Prony temporal relaxation). The steel / fiber reinforcement layers are expressed using anisotropic reinforcements (rebar / fiber-reinforced shell / solid equivalent), defined by the commonly used engineering triplet of "material orientation, geometric orientation, and layup thickness / volume fraction". The cord angles are defined with the circumferential direction as the reference for the crossover angle ±θ.

[0030] 1.2 Mesh and Contact The tread and belt / covering area use a solid or shell / solid hybrid mesh with quadrilaterals as the main structure, with denser meshes in key areas such as the belt end / shoulder groove bottom. Contact with the road surface is surface-to-surface, with the friction coefficient determined based on the material of the company's test bench. The rim and bead geometry are constrained using a binding / contact combination to reproduce the actual assembly state.

[0031] 1.3 Operating Conditions and Boundary Conditions The analysis follows a sequence of "static inflation → static grounding / quasi-steady-state rolling". Calibration is performed using commonly used benchmark conditions: inflation pressure 770 kPa, load 13200 N (corresponding to actual measurements of the same diameter); constraints are applied to a uniform rim, and grounding is achieved using a rigid plate or equivalent platform, maintaining the same displacement / force control strategy as in the experiment.

[0032] The specific analysis is as follows: First, regarding the test grounding shape (e.g.) Figure 4 ) and the simulated contour (e.g. Figure 5 Matching with grounding pressure.

[0033] Table 1. Profile and Grounding Pressure Matching

[0034] Table 1 shows the overall matching (error) between the simulation results and the actual test data as follows: the grounding length is 3.11%; the grounding widths L1-L6 are 3.57%, 5.26%, 5.88%, 1.82%, 5.84%, and 5.04%, respectively; both the rectangular coefficient and the tapered coefficient are within the required range; the inflatable outer diameter is 0.57%; the cross-sectional width is 2.47%; and the settlement is 1.34%. These results indicate that the simulation results have high reliability.

[0035] 1.4 Multi-index calibration and error threshold The model was iteratively calibrated using three types of indices: geometry, grounding, and stiffness. Examples of target error and typical convergence results are shown below (those skilled in the art can equivalently replace them with their own thresholds): External geometry: Inflatable outer diameter error ≤ approximately 1% (e.g., 379.8mm in test, 382mm in simulation, error approximately 0.57%); cross-sectional width error ≤ approximately 3% (e.g., 193.3mm in test, 198.0mm in simulation, error approximately 2.47%).

[0036] Static deflection: The settlement error under the specified load is ≤ 2% (e.g., 22.4mm vs 22.1mm, error is about 1.34%).

[0037] Grounding spot: Grounding length error ≤ approximately 3.1% (e.g., 161 vs 166); Multi-point grounding width error ≤ approximately 6%; Derived rectangular coefficient ≥ 0.92, tapered coefficient ≤ 0.25.

[0038] Once the aforementioned error meets the threshold, the model can proceed to the mechanism analysis and parameter optimization stage.

[0039] II. Mechanism Identification of Belt Layer Tension and Belt Angle 2.1 Evaluation Quantity like Figure 6 As shown, during the vulcanization process of a tire, due to the large modulus of the steel wires, the angle is mainly changed to match the increase in the actual expansion rate. Since the mold size is fixed, the final tire size is fixed, so the longitudinal stress (s) yy The value of ) is fixed. When the circumference of the auxiliary drum decreases, the angle of the belt layer will decrease to match the actual expansion rate, which matches the simulation results. The longitudinal stress σ of the first / second belt layer is extracted under steady-state inflation. yy Combined with the belt angle θ, and the comprehensive tension metric T=σ is calculated. yy / cosθ is used to compare the load-bearing path and safety margin of the tire crown under different structural / process settings.

[0040] 2.2 Root Cause Localization Comparing different designs of the same specification (e.g., the EZ series, which uses UT steel wire and meets the compression test standard, and the AZ series, which does not meet the standard), it can be observed that: the T-value of the first / second belt layer of AZ is significantly higher than that of the control model, and the safety factor is correspondingly lower, indicating that the excessive tension of the belt layer in the initial inflation state is the main reason for insufficient resistance to foreign object indentation; reducing θ and / or reducing σ yy Both can effectively reduce T, but changing the material / layout (such as directly changing the corner or the number of layers) will introduce cost and consistency risks. Therefore, we should prioritize the optimization of the process with "equal materials" by considering the molding side parameters.

[0041] III. Optimization of Molding Parameters (ΔC, ΔW) 3.1 Design Variables and Constraints The main variables are: the reduction in the circumference of the auxiliary drum by ΔC (-40~+40mm) and the compensation for the flatness of the tire crown by ΔW (+0~+12mm), which are optimized in conjunction with each other; Objectives and constraints: The main objective is to "reduce T and improve the distribution of grounding peak values"; the constraints are a rectangular coefficient ≥ 0.92, a tapered coefficient ≤ 0.25, and geometric / stiffness errors not worse than the calibration threshold; at the same time, the enterprise's bottom-line strength index (such as "five-point breakdown index ≥ 130%) is used as the standard threshold (only used for convergence verification and not directly entered into the optimization process).

[0042] 3.2 Variable Response Laws With a baseline of 0, the values ​​of ΔC were scanned at -40 / -30 / -20 / 0 / +20 / +30 / +40 mm, and the following patterns were observed: ΔC increases (+): Belt angle θ increases slightly, belt longitudinal stress σ increases. yy As T increases, the grounding spot becomes more elliptical and the shoulder peak becomes more sensitive—which is detrimental to resisting indentation and equalizing voltage. ΔC decreases (-): θ and σ yy As the temperature decreases in the same direction, T decreases significantly, resulting in a more favorable path for the tread bending stiffness, which theoretically improves resistance to indentation.

[0043] While ΔC is negative, ΔW needs to be positively compensated (+8~+12mm) to maintain the rectangular tendency and width of the grounding spot and avoid excessive concentration due to bulging.

[0044] 3.3 Representative Combinations and Simulation Screening like Figure 3 As shown, after simulation screening, three representative combinations entered the prototype stage: Option A: ΔC = -28mm, ΔW = +8mm (recorded as "-28 / +8"); Option B: ΔC = -40mm, ΔW = +8mm (recorded as "-40 / +8"); Option C: ΔC = -40mm, ΔW = +12mm (recorded as "-40 / +12").

[0045] In simulations, all three schemes showed a decrease in the first / second belt layer T, a reduction in the minimum belt angle of ≥ 2°, and a more balanced distribution of grounding peak values; the stress concentration of the plunger-type load path is expected to be alleviated.

[0046] IV. Verification of the prototype and indoor test bench 4.1 Prototype Production Prototype tires were made according to the ΔC and ΔW combinations output by simulation. The geometric circumference reduction set by the auxiliary drum was accurately implemented on the molding side, and the flat width of the tire crown was controlled according to the formula increment. Other materials and lay-up were kept consistent with the baseline to achieve the comparison of "equal materials, equal structure, only the molding parameters were changed".

[0047] 4.2 Indoor Test Items and Criteria Profile / Geometry: Outer diameter, cross-sectional width; Static deflection: The amount of settlement under a specified load; Grounding spot: length, width at multiple points, rectangular / conical shape; Bottom line strength spot check: five-point crushing index (for threshold verification only).

[0048] The criteria used are the same as the calibration thresholds: geometric / stiffness error not worse than S2.4; rectangularity coefficient ≥ 0.92, tapering coefficient ≤ 0.25; strength index ≥ 130%.

[0049] 4.3 Test Results Option A (-28 / +8): Strength index approximately 133%; Rectangular coefficient approximately 0.95, Taper coefficient approximately 0.13; Geometry and deflection are within the threshold – optimal overall. Option B (-40 / +8): Strength index is about 156%, but the grounding uniformity and durability side boundary are too tight (shoulder stress sensitive). Option C (-40 / +12): Strength index approximately 134%, rectangularity coefficient approximately 0.91 (below the recommended threshold), mass production is not recommended.

[0050] V. Secondary Compensation and Comparison 5.1 Shoulder thickness and cross-sectional width compensation When the grounding derivative of the first piece / small batch deviates slightly from the threshold, a small compensation using non-major variables is adopted: shoulder thickness 0~+3.5mm, cross-sectional width ±5mm. Excessive increase in shoulder thickness may lead to a decrease in the rectangularity coefficient, and it is not used as the main path, but only for fine-tuning the equalization.

[0051] 5.2 Comparison of Direct Corner / Layer Modification While changing ±θ directly to a smaller angle or altering the number of belt layers can reduce θ or change the bending stiffness, it significantly impacts material inventory, process consistency, and cost, and imposes additional verification burden on handling stability / durability. Comparative results show that the molding parameter path (ΔC / ΔW) for equal materials can achieve the same or better T improvement and grounding uniformity at a lower cost.

[0052] VI. Conclusion While keeping the materials and ply unchanged, by negative reduction of ΔC and positive compensation of ΔW, the θ and T of the first / second belt layer are significantly reduced, the minimum belt angle is reduced by ≥ about 2°, and T is reduced by about 10% compared with the original scheme (i.e. the initial design scheme of the same target tire under the conditions of ΔC=0 and ΔW=0), and even higher reduction can be achieved, which homogenizes the grounding peak and weakens the stress concentration at the belt end / shoulder groove bottom; Taking -28 / +8 as an example, the sample test bench shows that while the grounding uniformity meets the standard (rectangular / conical coefficient meets the threshold) and the geometric / stiffness error is not worse than the calibration threshold, the bottom line strength sampling inspection reaches or exceeds the threshold of ≥130%, achieving a significant improvement in the ability to resist foreign object indentation. The solution of this invention does not require changes to the materials and the number of belt layers, and takes into account the certainty of cost, manufacturing consistency and performance improvement. It has been verified by tolerance expansion and DOE to have good robustness and is suitable for large-scale mass production and promotion.

[0053] 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 improving the safety factor of electric vehicle tires, characterized in that, Includes the following steps: S1. Establish a finite element simulation model of the target tire model, and obtain the simulation-measurement error and ground uniformity threshold by bidirectional calibration with the measured profile / ground pressure index. S2, calculate the longitudinal stress σ of the belt in the inflated steady state yy and the belt angle θ, based on the tension criterion T = σ yy / cos θ to measure the belt tension and the safety margin; S3. Using "reduction of auxiliary drum circumference ΔC and increase of tire crown width compensation ΔW" as coupled design variables, construct a multi-objective optimization problem with "reducing inflation belt tension and improving the breakdown index" as the main objective and the simulation-measurement error and ground uniformity threshold in step S1 as constraints. The target threshold for the breakdown strength index is set to be no less than 130%. S4. Under the premise of satisfying the constraints, solve for ΔC and ΔW, where ΔC is located between -20 mm and -45 mm, and ΔW is positively compensated between +5 mm and +12 mm; and perform trial production and pressure-break test verification according to the solution set. S5. When the verification results meet the requirements of a breakdown strength index of not less than 130% and grounding uniformity of rectangular coefficient ≥ 0.92 and tapered coefficient ≤ 0.25, the final production parameters are determined. If they do not meet the requirements, return to step S3 for iterative optimization until they are met.

2. The method according to claim 1, characterized in that, The model calibration in step S1 includes at least the following: matching the grounding shape with the multi-point grounding width under 770 kPa / specified load, and controlling the simulation-measurement error within 3%–6% respectively; The grounding uniformity thresholds are as follows: the simulation test deviations of grounding length and multi-point grounding width are both ≤6%, the rectangular coefficient is ≥0.92 and the tapered coefficient is ≤0.25, and the errors of the inflatable outer diameter, cross-sectional width, and settlement are ≤1%, ≤3%, and ≤2%, respectively.

3. The method according to claim 1, characterized in that, In step S4, the ΔC and ΔW are solved to satisfy the following conditions: the circumference reduction ΔC of the auxiliary drum is between -25 mm and -40 mm, and the flat width compensation ΔW of the tire crown is positively compensated to +8 mm to +12 mm, thereby obtaining a puncture strength index of not less than 133% in the puncture test.

4. The method according to claim 1, characterized in that, In step S4, ΔC and ΔW are solved to satisfy: ΔC = -40mm and ΔW = +8mm or +12mm, and the corresponding indentation strength index reaches not less than 156% and not less than 134%, respectively.

5. The method according to claim 1, characterized in that, The linkage constraints in steps S2-S4 are as follows: compared with the original scheme, the tension of the first and second belt layers is reduced by at least 10% respectively; at the same time, the minimum belt angle of the first and second belt layers is reduced by at least 2° respectively compared with the original scheme.

6. The method according to claim 1, characterized in that, While reducing ΔC, the expansion rate is reduced by 0–1% compared to the original scheme, reducing the belt layer tension and keeping the grounding index within the range of rectangularity coefficient ≥ 0.92 and taper coefficient ≤ 0.25; And / or, fine-tune the shoulder thickness within the range of +0 to +3.5 mm or compensate the cross-sectional width at the ±5 mm level as a secondary optimization variable in addition to ΔC and ΔW, to improve grounding uniformity without sacrificing durability.

7. The method according to claim 1, characterized in that, In step S5, the grounding uniformity criterion adopts the combined judgment of rectangular coefficient and tapered coefficient: if the rectangular coefficient is lower than 0.92 or the tapered coefficient is higher than 0.25, even if the breakdown strength meets the standard, it is judged as unqualified and reverts to the suboptimal solution.

8. A system for improving the safety factor of electric vehicle tires to implement the method of any one of claims 1-7, characterized in that, include: Parameter input module: Obtains target model, target threshold for compression puncture strength, ΔC and ΔW boundaries, and material / wire parameters; Simulation calibration module: Executes S1 and outputs the error and threshold determination results; Tension assessment module: Calculates σ under steady-state inflation. yy θ and T=σ yy / cosθ, and give the safety factor; Multi-objective optimization module: With the goal and constraint of reducing T and satisfying "breakdown index ≥ 130% and grounding threshold", solve for ΔC and ΔW; Solution verification module: Outputs the optimal / alternative molding parameters that meet the threshold and the trial production verification process.

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

10. A computer program product, comprising a computer program or instructions, characterized in that, When the computer program or instructions are executed by a processor, they implement the method of any one of claims 1-7.

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