A method for designing a low rolling resistance high strength tire

Abstract

This invention belongs to the field of tire design technology and discloses a tire design method with low rolling resistance and high strength. The specific steps are as follows: Step 1, obtain the rated design basic parameters of the target tire. Through the integrated tire structure design method for all working conditions, the coordinated optimization of tire carcass contour, belt layer, bead reinforcement, and tread pattern is achieved, breaking the limitation of independent optimization of individual components in traditional design. It effectively takes into account the performance matching between various components. At the same time, by establishing a mechanical analysis model covering four core working conditions—inflated stationary, straight rolling, steering and lateral deviation, and emergency braking—the stress characteristics of the tire in actual use are fully matched, ensuring that the designed structure can achieve coordinated optimization of rolling resistance and structural strength under all working conditions. In addition, a closed-loop iterative mechanism for simulation verification and bench testing is established. The performance is verified in advance through multiphysics simulation, and the parameters are iteratively adjusted through measured data, thereby improving the design accuracy.

Description

Technical Field

[0001] This invention belongs to the field of tire design technology, specifically a tire design method with low rolling resistance and high strength. Background Technology

[0002] With the increasing demands for energy conservation and emission reduction in the global automotive industry, and the continuous growth in consumer demand for vehicle safety and fuel economy, tires, as the core component in contact with the road surface, have received widespread attention for their rolling resistance and load-bearing strength. The magnitude of rolling resistance directly affects the vehicle's fuel consumption and carbon emission levels, while the structural strength of the tire is directly related to the vehicle's load-bearing capacity, fatigue resistance, and safety stability during driving. The industry has been committed to improving the overall structural strength of tires while reducing rolling resistance, in order to meet the dual demands of the current market.

[0003] Currently, most tire designs for low rolling resistance and high strength in the industry adopt an independent optimization approach for individual components. This involves separately adjusting parameters for the tire carcass profile, belt layer structure, bead reinforcement structure, or tread pattern. The optimization process for each component is guided by its own performance goals. This decentralized design approach often fails to consider the performance matching between various components, and it is easy for the performance improvement of one component to affect the performance of other components. At the same time, most existing design processes do not fully consider the stress and deformation characteristics of tires under different driving conditions in actual use. The designed structures often only meet performance requirements under specific conditions and cannot achieve synergistic optimization of rolling resistance and structural strength under all conditions. Moreover, traditional tire design processes mostly rely on the experience of designers for positive parameter adjustments, lacking a closed-loop mechanism for systematic multi-physics simulation verification and experimental performance iteration. This results in long design cycles, insufficient precision in performance adjustments, and difficulty in simultaneously meeting the design goals of low rolling resistance and high structural strength. It also fails to guarantee that the designed tires will maintain stable performance under different usage scenarios. Summary of the Invention

[0004] The purpose of this invention is to provide a tire design method with low rolling resistance and high strength to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a tire design method with low rolling resistance and high strength, the specific steps of which are as follows: Step 1: Obtain the rated design parameters of the target tire, including the tire's nominal section width, nominal outer diameter, rim calibration diameter, rim calibration width, rated inflation pressure, rated single tire load, maximum continuous driving speed, maximum permissible value of rolling resistance coefficient, minimum permissible value of radial stiffness, minimum permissible value of torsional stiffness, maximum permissible value of ground pressure non-uniformity coefficient, minimum permissible value of bead resistance lateral force, and minimum required value of tread wear life. Step 2: Based on the obtained rated design parameters, establish a basic model for full-condition mechanical analysis of the target tire; Step 3: Based on the full-condition mechanical analysis model, carry out the isotension topology optimization design of the tire carcass profile; Step 4: Based on the optimized tire carcass profile structure, carry out the low-deformation, high-rigidity layout design of the tire belt layer structure; Step 5: Based on the optimized tire carcass profile structure, design the gradient density steel wire reinforcement structure in the tire bead area; Step 6: Based on the optimized tire carcass profile and belt layer structure, carry out the design of a gradient rigidity low rolling resistance structure for the tire tread pattern. Step 7: Import all optimized tire structure geometric parameters into multiphysics simulation software, establish a multi-field coupled simulation verification model of the overall tire structure, carry out full-condition simulation calculations and extract full-performance simulation data of the tire; Step 8: Compare and verify all extracted tire full performance simulation data with the rated design basic parameters one by one. If the simulation values ​​of all performance indicators meet the requirements, proceed to the next step. If there are unmet indicators, return to the optimization design step of the corresponding structural module, adjust the parameters, and repeat the simulation verification process. Step 9: Based on all the verified tire structural geometric parameters, fabricate tire test specimens, conduct full-performance bench tests on the test specimens under standard conditions, and obtain all measured performance data of the test specimens; Step 10: Compare and verify all the measured performance data of the obtained test specimens with the rated design parameters one by one. If all the measured values ​​of the performance indicators meet the requirements, organize all the data to form a formal tire design scheme and complete the entire design process. If there are any unmet indicators, return to the optimization design steps of the corresponding structural module, adjust the parameters, and repeat the simulation verification and bench test process.

[0006] Preferably, the basic model for full-condition mechanical analysis described in step two includes boundary condition settings for four core working conditions. The boundary conditions for the inflated static working condition are: the rim is completely fixed, a constant rated inflation pressure is applied inside the tire, and no external load is applied. The boundary conditions for the rated load straight rolling working condition are: the rim is subjected to a rated vertical load, a constant rated inflation pressure is applied inside the tire, the simulated road surface moves at a constant linear speed at the maximum continuous driving speed, and the rim rotates synchronously and uniformly with the simulated road surface. The boundary conditions for the rated load steady-state steering and lateral deflection working condition are: the rim is subjected to a rated vertical load, a constant rated inflation pressure is applied inside the tire, the simulated road surface moves at a constant linear speed at 60% of the maximum continuous driving speed, the rim is set with a fixed lateral deflection angle, and the rim rotates synchronously and uniformly with the simulated road surface. The boundary conditions for the rated load emergency braking working condition are: the rim is subjected to a rated vertical load, a constant rated inflation pressure is applied inside the tire, the simulated road surface moves at an initial constant linear speed at the maximum continuous driving speed, a constant braking torque is applied to the rim, and the simulated road surface and rim complete the entire process of deceleration to a standstill synchronously.

[0007] Preferably, the isotension topology optimization design of the tire carcass profile described in step three specifically involves first extracting the stress distribution data of the entire path of the tire carcass cords from the basic model of the full-condition mechanical analysis. The data includes the tension values ​​of the tire carcass cords along the entire path from the bead installation start point to the crown center end point under four core working conditions. Then, with the uniformity of the tension along the entire path of the tire carcass cords as the core optimization objective, and with the crown arc radius, sidewall transition arc radius, bead installation fit arc radius, and horizontal axis position of the tire carcass cross-section as optimization variables, a mathematical model for tire carcass profile optimization is established. Through iterative calculation and adjustment of the values ​​of all optimization variables, the deviation ratio between the maximum and minimum tension values ​​of the tire carcass cords along the entire path under the four core working conditions is controlled within 5%. Then, based on the optimized tire carcass profile curve, the total number of tire carcass ply layers, the cord spacing of each ply layer, the cord arrangement angle of each ply layer, and the cord arrangement direction of adjacent ply layers are determined to ensure that the overall load uniformity of the tire carcass ply layers under the four core working conditions meets the design requirements.

[0008] Preferably, the low-deformation, high-rigidity arrangement design of the belt layer structure described in step four specifically involves first extracting the stress distribution and deformation data of the crown area under four core operating conditions after the tire carcass contour optimization; then, with minimizing the circumferential and lateral deformation of the belt layer as the core optimization objective, and using the total number of belt layers, the width of the cord of each belt layer, the cord arrangement angle of each belt layer, the cord arrangement spacing of each belt layer, and the cord arrangement direction of adjacent belt layers as optimization variables, establishing a mathematical model for the optimization of the belt layer structure; and adjusting the values ​​of all optimization variables through iterative calculations to ensure that the maximum circumferential deformation and maximum lateral deformation of the belt layer under the four core operating conditions are both controlled within 1%. Then, based on the optimized main structure of the belt layer, a smooth transition structure is designed for the edges of both sides of the belt layer, determining the width, thickness, and extension curvature of the transition structure to eliminate stress concentration at the edges of the belt layer under the four core operating conditions.

[0009] Preferably, the gradient density steel wire reinforcement structure design for the bead region described in step five specifically involves first extracting the force transmission path and stress distribution data of the bead region under four core working conditions after the tire carcass contour optimization. Then, with minimizing radial and torsional deformation of the bead region as the core optimization objective, and using the number of steel wire layers, steel wire spacing, steel wire direction, number of steel wire bundles, and position of steel wire bundles as optimization variables, a mathematical model for bead reinforcement structure optimization is established. First, for the core stress area where the bead and rim meet, a high-density interwoven steel wire reinforcement layer is designed, determining the total number of steel wire reinforcement layers in this area and the density of each steel wire layer. The spacing between wires, the angle of each layer of wires, and the direction of adjacent wires were determined. Then, for the transition area of ​​the bead triangular rubber, a low-density, directional arrangement of wire bundles was designed as a reinforcement structure. The total number of wire bundles, the position of each individual wire bundle, the extension direction of the wire bundles, and the spacing between adjacent wire bundles were determined. Through iterative calculations, the values ​​of all optimization variables were adjusted to ensure that the maximum radial deformation and maximum torsional deformation of the bead area under the four core working conditions were both controlled within 0.5%. Based on the optimized reinforcement structure, all geometric parameters of the bead-rim mating surface were determined to ensure that the fit accuracy of the entire bead-rim mating surface was controlled within 0.1 mm.

[0010] Preferably, the gradient rigidity low rolling resistance structure design of the tread pattern described in step six specifically involves first extracting the pressure distribution data of the tire contact patch under four core operating conditions after optimizing the tire carcass contour and belt layer structure. Then, with maximizing the uniformity of tread pattern contact deformation as the core optimization objective, and using the overall layout parameters, tread block structure parameters, reinforcing rib structure parameters, buffer groove structure parameters, and main groove structure parameters of the tread pattern as optimization variables, a mathematical model for tread pattern structure optimization is established. First, the total number of continuous longitudinal rib structures in the tread center region, the width of a single rib, the height of the rib, and the longitudinal length of the rib are determined to ensure that the contact rigidity of the tread center region under straight rolling conditions meets the design requirements. Then, the total number of tread block structures in the shoulder regions on both sides of the tread, the length of a single tread block, the width of a single tread block, the height of a single tread block, and the spacing between adjacent tread blocks are determined to ensure that the lateral rigidity of the tread shoulder region under steering and lateral deviation conditions meets the requirements. To meet design requirements, the following steps were taken: First, determine the number of progressive reinforcing ribs within each tread block, the position of each rib, the cross-sectional width, height, and longitudinal extension length of each rib. This ensures a gradient increase in rigidity from the contact patch edge to the contact patch center. Second, determine the position, width, depth, and longitudinal extension length of the stress-relieving buffer grooves at the bottom of each tread block. This completely eliminates stress concentration during contact patching. Third, determine the total number of longitudinal main grooves, the cross-sectional width and depth of each main groove, the longitudinal extension path of each main groove, and the transition radius of the inner wall of each main groove. This ensures the tire's drainage performance meets design requirements during driving on flooded roads. Finally, through iterative calculations and adjustments to all optimization variables, the pressure distribution uniformity deviation of the tread contact patch under four core operating conditions is controlled within 8%.

[0011] Preferably, the full-condition simulation calculation in step seven specifically involves setting boundary conditions for four core operating conditions that are completely consistent with those in step two for the simulation verification model. Full-condition simulation calculations are then performed for the tire inflation stationary condition, rated load straight rolling condition, rated load steady-state steering and lateral deflection condition, and rated load emergency braking condition. The maximum number of iteration steps for a single operating condition is set to 1000 steps, and the convergence accuracy of the simulation calculation is set to 0.001. After the simulation calculation is completed, the extracted full-performance simulation data of the tire specifically includes the simulated values ​​of the tire's rolling resistance coefficient, radial stiffness, torsional stiffness, ground pressure non-uniformity coefficient, bead anti-bead lateral force, and tread pattern deformation uniformity.

[0012] Preferably, the step-by-step comparison and verification in step eight specifically involves sequentially determining whether the simulated value of the rolling resistance coefficient is less than or equal to the maximum allowable value of the rolling resistance coefficient, whether the simulated value of the radial stiffness is greater than or equal to the minimum allowable value of the radial stiffness, whether the simulated value of the torsional stiffness is greater than or equal to the minimum allowable value of the torsional stiffness, whether the simulated value of the ground pressure non-uniformity coefficient is less than or equal to the maximum allowable value of the ground pressure non-uniformity coefficient, whether the simulated value of the bead anti-bead lateral force is greater than or equal to the minimum allowable value of the bead anti-bead lateral force, and whether the simulated value of the tread pattern deformation uniformity meets the design requirements. If the simulated value of any performance index does not meet the requirements, the tire structure module corresponding to that performance index is located, and the optimization design steps of the corresponding structure module are returned to perform a second iteration adjustment of all optimization variables of the structure module.

[0013] Preferably, the full-performance bench test described in step nine specifically involves installing the test sample on a standard test rim that matches the design parameters, inflating the test sample with the rated inflation pressure, and allowing it to stand for 24 hours in a constant temperature environment at a standard ambient temperature of 25°C. Afterward, the installed test sample is fixed on a tire comprehensive performance bench testing machine, and the following tests are conducted sequentially according to national standard testing methods: tire rolling resistance performance test, radial stiffness performance test, torsional stiffness performance test, ground pressure distribution test, and bead anti-beading performance test. The ambient temperature is maintained at 25°C during the testing process, and the inflation pressure is maintained at the rated inflation pressure. The measured performance data obtained after the test specifically includes the measured values ​​of the tire rolling resistance coefficient, radial stiffness, torsional stiffness, ground pressure non-uniformity coefficient, and bead anti-beading lateral force.

[0014] Preferably, the step-by-step final comparison and verification in step ten specifically involves sequentially determining whether the measured value of the rolling resistance coefficient is less than or equal to the maximum allowable value of the rolling resistance coefficient, whether the measured value of the radial stiffness is greater than or equal to the minimum allowable value of the radial stiffness, whether the measured value of the torsional stiffness is greater than or equal to the minimum allowable value of the torsional stiffness, whether the measured value of the ground pressure non-uniformity coefficient is less than or equal to the maximum allowable value of the ground pressure non-uniformity coefficient, and whether the measured value of the bead anti-bead lateral force is greater than or equal to the minimum allowable value of the bead anti-bead lateral force. If the measured value of any performance index does not meet the requirements, the tire structure module corresponding to that performance index is located, and the optimization design steps of the corresponding structure module are returned to iterate and adjust all the optimization variables of the structure module again. After the adjustment is completed, the simulation verification and bench test process of steps seven to nine is repeated.

[0015] The beneficial effects of this invention are as follows: By employing an integrated tire structure design method covering all operating conditions, the tire carcass profile, belt layer, bead reinforcement, and tread pattern are synergistically optimized. This breaks through the limitations of independent optimization of individual components in traditional designs, effectively balancing the performance matching between various components. Furthermore, by establishing a mechanical analysis model covering four core operating conditions—inflated stationary, straight-line rolling, steering and lateral deviation, and emergency braking—the stress characteristics of the tire in actual use are fully matched, ensuring that the designed structure can achieve synergistic optimization of rolling resistance and structural strength under all operating conditions. A closed-loop iterative mechanism for simulation verification and bench testing is also established. Performance is verified in advance through multiphysics simulation, and parameters are iteratively adjusted using measured data, significantly improving design accuracy and effectively shortening the design cycle. This approach simultaneously achieves effective reduction of tire rolling resistance and synchronous improvement of structural strength, ensuring stable tire performance under different usage scenarios. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the process of the present invention. Detailed Implementation

[0017] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0018] like Figure 1 As shown in the figure, this embodiment of the invention provides a tire design method with low rolling resistance and high strength, and the specific steps are as follows: Step 1: Obtain the rated design parameters of the target tire, including the tire's nominal section width, nominal outer diameter, rim calibration diameter, rim calibration width, rated inflation pressure, rated single tire load, maximum continuous driving speed, maximum permissible value of rolling resistance coefficient, minimum permissible value of radial stiffness, minimum permissible value of torsional stiffness, maximum permissible value of ground pressure non-uniformity coefficient, minimum permissible value of bead resistance lateral force, and minimum required value of tread wear life. Step 2: Based on the obtained rated design parameters, establish a basic model for full-condition mechanical analysis of the target tire; Step 3: Based on the full-condition mechanical analysis model, carry out the isotension topology optimization design of the tire carcass profile; Step 4: Based on the optimized tire carcass profile structure, carry out the low-deformation, high-rigidity layout design of the tire belt layer structure; Step 5: Based on the optimized tire carcass profile structure, design the gradient density steel wire reinforcement structure in the tire bead area; Step 6: Based on the optimized tire carcass profile and belt layer structure, carry out the design of a gradient rigidity low rolling resistance structure for the tire tread pattern. Step 7: Import all optimized tire structure geometric parameters into multiphysics simulation software, establish a multi-field coupled simulation verification model of the overall tire structure, carry out full-condition simulation calculations and extract full-performance simulation data of the tire; Step 8: Compare and verify all extracted tire full performance simulation data with the rated design basic parameters one by one. If the simulation values ​​of all performance indicators meet the requirements, proceed to the next step. If there are unmet indicators, return to the optimization design step of the corresponding structural module, adjust the parameters, and repeat the simulation verification process. Step 9: Based on all the verified tire structural geometric parameters, fabricate tire test specimens, conduct full-performance bench tests on the test specimens under standard conditions, and obtain all measured performance data of the test specimens; Step 10: Compare and verify all the measured performance data of the obtained test specimens with the rated design parameters one by one. If all the measured values ​​of the performance indicators meet the requirements, organize all the data to form a formal tire design scheme and complete the entire design process. If there are any unmet indicators, return to the optimization design steps of the corresponding structural module, adjust the parameters, and repeat the simulation verification and bench test process.

[0019] By synergistically integrating structural optimizations of the tire carcass, belt layer, bead, and tread pattern, and establishing a closed-loop iterative mechanism combining simulation and actual testing, the limitations of independent optimization of individual components in traditional design are broken. This effectively balances the performance matching between various components and fully matches the stress characteristics of tires under all working conditions in actual use. It can simultaneously achieve effective reduction of tire rolling resistance and synchronous improvement of structural strength, significantly improving design accuracy, effectively shortening the design cycle, and ensuring that the tire maintains stable performance under different usage scenarios.

[0020] In step two, the basic model for full-condition mechanical analysis includes boundary condition settings for four core working conditions. The boundary conditions for the inflated static working condition are: the rim is completely fixed, a constant rated inflation pressure is applied inside the tire, and no external load is applied. The boundary conditions for the rated load straight rolling working condition are: the rim is subjected to a rated vertical load, a constant rated inflation pressure is applied inside the tire, the simulated road surface moves at a constant linear speed at the maximum continuous driving speed, and the rim rotates synchronously and uniformly with the simulated road surface. The boundary conditions for the rated load steady-state steering and lateral deflection working condition are: the rim is subjected to a rated vertical load, a constant rated inflation pressure is applied inside the tire, the simulated road surface moves at a constant linear speed at 60% of the maximum continuous driving speed, the rim is set with a fixed lateral deflection angle, and the rim rotates synchronously and uniformly with the simulated road surface. The boundary conditions for the rated load emergency braking working condition are: the rim is subjected to a rated vertical load, a constant rated inflation pressure is applied inside the tire, the simulated road surface moves at an initial constant linear speed at the maximum continuous driving speed, a constant braking torque is applied to the rim, and the simulated road surface and rim complete the entire process of deceleration to a standstill synchronously.

[0021] By clearly defining the boundary conditions for four core operating conditions, the system comprehensively covers the stress state of the tire in all scenarios, from stationary to moving, straight to turning, and normal driving to emergency braking. This fully restores the real stress environment of the tire during actual use and avoids design deviations caused by considering only a single operating condition.

[0022] In step three, the isotension topology optimization design of the tire carcass profile involves first extracting the stress distribution data of the entire path of the tire carcass cords from the basic model of the full-condition mechanical analysis. The data includes the tension values ​​of the tire carcass cords along the entire path from the bead installation start point to the crown center end point under four core working conditions. Then, with the uniformity of the tension along the entire path of the tire carcass cords as the core optimization objective, and with the crown arc radius, sidewall transition arc radius, bead installation fit arc radius, and horizontal axis position of the tire carcass cross-section as optimization variables, a mathematical model for tire carcass profile optimization is established. Through iterative calculation and adjustment of the values ​​of all optimization variables, the deviation ratio between the maximum and minimum tension values ​​of the tire carcass cords along the entire path under the four core working conditions is controlled within 5%. Then, based on the optimized tire carcass profile curve, the total number of tire carcass ply layers, the cord spacing of each ply layer, the cord arrangement angle of each ply layer, and the cord arrangement direction of adjacent ply layers are determined to ensure that the overall load uniformity of the tire carcass ply layers under the four core working conditions meets the design requirements.

[0023] By optimizing the uniformity of tension along the entire tire carcass cord path, the problem of uneven stress on the tire carcass cord is effectively eliminated. The tension deviation of the cord under all working conditions is controlled within 5%, which greatly improves the overall load uniformity of the tire carcass, effectively reduces local stress concentration in the tire carcass, and reduces deformation loss of the tire carcass during rolling. While improving the structural strength of the tire carcass, it also effectively reduces the rolling resistance of the tire.

[0024] In step four, the low-deformation, high-rigidity arrangement design of the belt layer structure involves first extracting the stress distribution and deformation data of the crown area under four core operating conditions after the tire carcass contour optimization. Then, with minimizing the circumferential and lateral deformation of the belt layer as the core optimization objective, a mathematical model for belt layer structure optimization is established using the total number of belt layers, the width of the cord in each belt layer, the cord arrangement angle of each belt layer, the cord arrangement spacing of each belt layer, and the cord arrangement direction of adjacent belt layers as optimization variables. Through iterative calculations, the values ​​of all optimization variables are adjusted so that the maximum circumferential and lateral deformation values ​​of the belt layer under the four core operating conditions are both controlled within 1%. Then, based on the optimized main structure of the belt layer, a smooth transition structure is designed for the two sides of the belt layer, determining the width, thickness, and extension curvature of the transition structure to eliminate stress concentration at the edges of the belt layer under the four core operating conditions.

[0025] The optimization aims to minimize the circumferential and lateral deformation of the belt layer, controlling the deformation of the belt layer to within 1% under all working conditions. This significantly improves the overall rigidity of the belt layer and effectively limits the deformation of the tire crown area. At the same time, the smooth transition structure at the edge of the belt layer eliminates the stress concentration problem at the edge of the belt layer, effectively improving the fatigue resistance of the belt layer. While improving the overall structural strength of the tire, it reduces the deformation loss of the belt layer and further reduces rolling resistance.

[0026] In step five, the gradient density steel wire reinforcement structure design for the bead region involves first extracting the force transmission path and stress distribution data of the bead region under four core working conditions after the tire carcass contour optimization. Then, with minimizing radial and torsional deformation of the bead region as the core optimization objective, and using the number of steel wire layers, spacing, direction, number of steel wire bundles, and position of the steel wire bundles as optimization variables, a mathematical model for bead reinforcement structure optimization is established. First, for the core stress area where the bead and rim meet, a high-density interwoven steel wire reinforcement layer is designed, determining the total number of steel wire reinforcement layers and the arrangement of steel wires in each layer. The spacing, the arrangement angle of each layer of steel wires, and the arrangement direction of adjacent layers of steel wires were determined. Then, for the transition area of ​​the bead triangular rubber, a low-density oriented steel wire bundle reinforcement structure was designed. The total number of steel wire bundles in this area, the arrangement position of a single steel wire bundle, the extension direction of the steel wire bundle, and the arrangement spacing of adjacent steel wire bundles were determined. Through iterative calculations, the values ​​of all optimization variables were adjusted so that the maximum radial deformation and maximum torsional deformation of the bead area under the four core working conditions were both controlled within 0.5%. Then, based on the optimized reinforcement structure, all geometric parameters of the bead and rim mating surface were determined to ensure that the full-section fitting accuracy of the bead and rim mating surface was controlled within 0.1 mm.

[0027] The gradient density steel wire reinforcement structure design of the tire bead effectively matches the force transmission characteristics of the tire bead area by designing reinforcement structures with different densities for different stress areas of the tire bead. It controls the deformation of the tire bead within 0.5% under all working conditions, greatly improves the radial and torsional rigidity of the tire bead, and ensures the fitting accuracy between the tire bead and the rim, effectively improving the tire bead's anti-beading performance.

[0028] In step six, the gradient rigidity and low rolling resistance structure design of the tread pattern involves first extracting pressure distribution data of the tire contact patch under four core operating conditions after optimizing the tire carcass contour and belt layer structure. Then, with maximizing the uniformity of tread pattern contact deformation as the core optimization objective, a mathematical model for tread pattern structure optimization is established using the overall layout parameters, tread block structure parameters, reinforcing rib structure parameters, buffer groove structure parameters, and main groove structure parameters of the tread pattern as optimization variables. First, the total number of continuous longitudinal ribs in the central tread region, the width of a single rib, the height of the rib, and the longitudinal length of the ribs are determined to ensure that the contact rigidity of the central tread region under straight rolling conditions meets design requirements. Then, the total number of tread block structures, the length, width, height of a single tread block, and the spacing between adjacent tread blocks in the shoulder areas on both sides of the tread are determined to ensure that the lateral rigidity of the shoulder areas under steering and lateral deviation conditions meets requirements. The design requirements were then determined, including the number of progressive reinforcing ribs within each tread block, the position of each rib, the cross-sectional width, the cross-sectional height, and the longitudinal extension length of each rib. This ensured a gradient increase in rigidity from the contact patch edge to the contact patch center. Next, the position, width, depth, and longitudinal extension length of the stress-relieving buffer grooves at the bottom of each tread block were determined to completely eliminate stress concentration during contact patching. Finally, the total number of longitudinal main grooves, the cross-sectional width and depth of each main groove, the longitudinal extension path of each main groove, and the transition radius of the inner wall of each main groove were determined to ensure the tire's drainage performance meets design requirements during driving on flooded roads. Through iterative calculations and adjustments to all optimization variables, the pressure distribution uniformity deviation of the tread contact patch under the four core operating conditions was controlled within 8%.

[0029] The gradient rigidity design of the tread blocks effectively improves the uniformity of tread contact pressure, controlling the deviation of contact pressure under all working conditions to within 8%, significantly reducing the contact deformation of the tread blocks. At the same time, the stress relief buffer grooves eliminate stress concentration in the tread blocks, improving the wear resistance of the tread. While improving the rigidity of the tread structure, it reduces the deformation loss of the tread blocks, lowers the rolling resistance of the tire, and ensures the water drainage performance of the tire.

[0030] In step seven, the full-condition simulation calculation specifically involves setting boundary conditions for four core operating conditions that are completely identical to those in step two for the simulation verification model. Full-condition simulation calculations are then performed for the following conditions: tire inflation stationary condition, rated load straight rolling condition, rated load steady-state steering and lateral deflection condition, and rated load emergency braking condition. The maximum number of iterations per operating condition is set to 1000 steps, and the convergence accuracy is set to 0.001. After the simulation calculation is completed, the extracted full-performance simulation data of the tire specifically includes the simulated values ​​of the tire's rolling resistance coefficient, radial stiffness, torsional stiffness, ground pressure non-uniformity coefficient, bead anti-bead lateral force, and tread pattern deformation uniformity.

[0031] By using boundary conditions consistent with the previous model, the accuracy and consistency of the simulation results are ensured. Multiphysics simulation can obtain the full performance data of the tire in advance, and the preliminary performance verification is completed before the prototype is made. This effectively avoids the blind trial and error of making prototypes first and then testing in traditional design, improves the efficiency of design, and reduces unnecessary prototype production costs.

[0032] Specifically, step eight involves comparing and verifying each item in turn. This includes checking whether the simulated value of the rolling resistance coefficient is less than or equal to the maximum allowable value of the rolling resistance coefficient, whether the simulated value of the radial stiffness is greater than or equal to the minimum allowable value of the radial stiffness, whether the simulated value of the torsional stiffness is greater than or equal to the minimum allowable value of the torsional stiffness, whether the simulated value of the ground pressure non-uniformity coefficient is less than or equal to the maximum allowable value of the ground pressure non-uniformity coefficient, whether the simulated value of the bead anti-bead lateral force is greater than or equal to the minimum allowable value of the bead anti-bead lateral force, and whether the simulated value of the tread pattern deformation uniformity meets the design requirements. If the simulated value of any performance indicator does not meet the requirements, the tire structure module corresponding to that performance indicator is located, and the optimization design steps of the corresponding structure module are returned to perform a second iteration adjustment of all optimization variables of that structure module.

[0033] The simulation verification step, by comparing and verifying the simulation data one by one, can quickly locate performance indicators that do not meet the requirements, and then accurately locate the corresponding structural modules, enabling targeted parameter adjustments.

[0034] The full-performance bench test in step nine involves installing the test sample on a standard test rim that matches the design parameters, inflating the test sample with the rated inflation pressure, and allowing it to stand for 24 hours in a constant temperature environment at a standard ambient temperature of 25°C. Afterward, the installed test sample is fixed on a tire comprehensive performance bench testing machine, and the following tests are conducted sequentially according to national standard testing methods: tire rolling resistance performance test, radial stiffness performance test, torsional stiffness performance test, ground pressure distribution test, and bead anti-beading performance test. The ambient temperature is maintained at 25°C during the testing process, and the inflation pressure is maintained at the rated inflation pressure. The measured performance data obtained after the test include the measured values ​​of the tire rolling resistance coefficient, radial stiffness, torsional stiffness, ground pressure non-uniformity coefficient, and bead anti-beading lateral force.

[0035] By using a standard testing environment and standard testing methods, we obtained real-world performance data of the tires, effectively verifying the accuracy of the simulation results. At the same time, we provided a real and reliable test basis for the final design verification, avoiding the deviation between simulation results and actual performance, and ensuring that the designed tires can meet performance requirements in actual use.

[0036] Specifically, the final comparison and verification in step ten involves sequentially determining whether the measured value of the rolling resistance coefficient is less than or equal to the maximum allowable value of the rolling resistance coefficient, whether the measured value of the radial stiffness is greater than or equal to the minimum allowable value of the radial stiffness, whether the measured value of the torsional stiffness is greater than or equal to the minimum allowable value of the torsional stiffness, whether the measured value of the ground pressure non-uniformity coefficient is less than or equal to the maximum allowable value of the ground pressure non-uniformity coefficient, and whether the measured value of the bead anti-bead lateral force is greater than or equal to the minimum allowable value of the bead anti-bead lateral force. If the measured value of any performance indicator does not meet the requirements, the tire structure module corresponding to that performance indicator is located, and the optimization design steps of the corresponding structure module are returned to iterate and adjust all the optimization variables of the structure module again. After the adjustment is completed, the simulation verification and bench test process of steps seven to nine is repeated.

[0037] By comparing the measured data one by one, the actual performance of the design scheme can be verified. At the same time, precise module positioning and parameter adjustment can be carried out for indicators that do not meet the requirements, forming a complete closed-loop iterative process.

[0038] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0039] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A tire design method with low rolling resistance and high strength, characterized in that, The specific steps are as follows: Step 1: Obtain the rated design parameters of the target tire, including the tire's nominal section width, nominal outer diameter, rim calibration diameter, rim calibration width, rated inflation pressure, rated single tire load, maximum continuous driving speed, maximum permissible value of rolling resistance coefficient, minimum permissible value of radial stiffness, minimum permissible value of torsional stiffness, maximum permissible value of ground pressure non-uniformity coefficient, minimum permissible value of bead resistance lateral force, and minimum required value of tread wear life. Step 2: Based on the obtained rated design parameters, establish a basic model for full-condition mechanical analysis of the target tire; Step 3: Based on the full-condition mechanical analysis model, carry out the isotension topology optimization design of the tire carcass profile; Step 4: Based on the optimized tire carcass profile structure, carry out the low-deformation, high-rigidity layout design of the tire belt layer structure; Step 5: Based on the optimized tire carcass profile structure, design the gradient density steel wire reinforcement structure in the tire bead area; Step 6: Based on the optimized tire carcass profile and belt layer structure, carry out the design of a gradient rigidity low rolling resistance structure for the tire tread pattern. Step 7: Import all optimized tire structure geometric parameters into multiphysics simulation software, establish a multi-field coupled simulation verification model of the overall tire structure, carry out full-condition simulation calculations and extract full-performance simulation data of the tire; Step 8: Compare and verify all extracted tire full performance simulation data with the rated design basic parameters one by one. If the simulation values ​​of all performance indicators meet the requirements, proceed to the next step. If there are unmet indicators, return to the optimization design step of the corresponding structural module, adjust the parameters, and repeat the simulation verification process. Step 9: Based on all the verified tire structural geometric parameters, fabricate tire test specimens, conduct full-performance bench tests on the test specimens under standard conditions, and obtain all measured performance data of the test specimens; Step 10: Compare and verify all the measured performance data of the obtained test specimens with the rated design parameters one by one. If all the measured values ​​of the performance indicators meet the requirements, organize all the data to form a formal tire design scheme and complete the entire design process. If there are any unmet indicators, return to the optimization design steps of the corresponding structural module, adjust the parameters, and repeat the simulation verification and bench test process.

2. The tire design method for low rolling resistance and high strength according to claim 1, characterized in that: The basic model for full-condition mechanical analysis described in step two includes boundary condition settings for four core working conditions. The boundary conditions for the inflated static working condition are: the rim is completely fixed, a constant rated inflation pressure is applied inside the tire, and no external load is applied. The boundary conditions for the rated load straight rolling working condition are: the rim is subjected to a rated vertical load, a constant rated inflation pressure is applied inside the tire, the simulated road surface moves at a constant linear speed at the maximum continuous driving speed, and the rim rotates synchronously and uniformly with the simulated road surface. The boundary conditions for the rated load steady-state steering and lateral deflection working condition are: the rim is subjected to a rated vertical load, a constant rated inflation pressure is applied inside the tire, the simulated road surface moves at a constant linear speed at 60% of the maximum continuous driving speed, the rim is set with a fixed lateral deflection angle, and the rim rotates synchronously and uniformly with the simulated road surface. The boundary conditions for the rated load emergency braking working condition are: the rim is subjected to a rated vertical load, a constant rated inflation pressure is applied inside the tire, the simulated road surface moves at an initial constant linear speed at the maximum continuous driving speed, a constant braking torque is applied to the rim, and the simulated road surface and rim complete the entire process of deceleration to a standstill synchronously.

3. The tire design method for low rolling resistance and high strength according to claim 1, characterized in that: The isotension topology optimization design of the tire carcass profile described in step three involves first extracting the stress distribution data of the entire path of the tire carcass cords from the basic model of the full-condition mechanical analysis. The data includes the tension values ​​of the tire carcass cords along the entire path from the bead installation start point to the crown center end point under four core working conditions. Then, with the uniformity of the tension along the entire path of the tire carcass cords as the core optimization objective, and with the crown arc radius, sidewall transition arc radius, bead installation fit arc radius, and horizontal axis position of the tire carcass cross-section as optimization variables, a mathematical model for tire carcass profile optimization is established. Through iterative calculation and adjustment of the values ​​of all optimization variables, the deviation ratio between the maximum and minimum tension values ​​of the tire carcass cords along the entire path under the four core working conditions is controlled within 5%. Then, based on the optimized tire carcass profile curve, the total number of tire carcass ply layers, the cord spacing of each ply layer, the cord arrangement angle of each ply layer, and the cord arrangement direction of adjacent ply layers are determined to ensure that the overall load uniformity of the tire carcass ply layers under the four core working conditions meets the design requirements.

4. The tire design method for low rolling resistance and high strength according to claim 1, characterized in that: The low-deformation, high-rigidity arrangement design of the belt layer structure described in step four involves first extracting the stress distribution and deformation data of the crown area under four core operating conditions after the tire carcass contour optimization. Then, with minimizing the circumferential and lateral deformation of the belt layer as the core optimization objective, a mathematical model for belt layer structure optimization is established using the total number of belt layers, the width of the cord in each belt layer, the cord arrangement angle of each belt layer, the cord arrangement spacing of each belt layer, and the cord arrangement direction of adjacent belt layers as optimization variables. Through iterative calculations, the values ​​of all optimization variables are adjusted so that the maximum circumferential deformation and the maximum lateral deformation of the belt layer under the four core operating conditions are both controlled within 1%. Then, based on the optimized main structure of the belt layer, a smooth transition structure is designed for the two sides of the belt layer, determining the width, thickness, and extension curvature of the transition structure to eliminate stress concentration at the edges of the belt layer under the four core operating conditions.

5. The tire design method for low rolling resistance and high strength according to claim 1, characterized in that: The gradient density steel wire reinforcement structure design in the bead area described in step five involves first extracting the force transmission path and stress distribution data of the bead area under four core working conditions after the tire carcass contour optimization. Then, with minimizing radial and torsional deformation in the bead area as the core optimization objective, and using the number of steel wire layers, spacing, direction, number of steel wire bundles, and position of the steel wire bundles as optimization variables, a mathematical model for bead reinforcement structure optimization is established. First, for the core stress area where the bead and rim meet, a high-density interwoven steel wire reinforcement layer is designed, determining the total number of steel wire reinforcement layers and the arrangement of steel wires in each layer. The spacing, the arrangement angle of each layer of steel wires, and the arrangement direction of adjacent layers of steel wires were determined. Then, for the transition area of ​​the bead triangular rubber, a low-density oriented steel wire bundle reinforcement structure was designed. The total number of steel wire bundles in this area, the arrangement position of a single steel wire bundle, the extension direction of the steel wire bundle, and the arrangement spacing of adjacent steel wire bundles were determined. Through iterative calculations, the values ​​of all optimization variables were adjusted so that the maximum radial deformation and maximum torsional deformation of the bead area under the four core working conditions were both controlled within 0.5%. Then, based on the optimized reinforcement structure, all geometric parameters of the bead and rim mating surface were determined to ensure that the full-section fitting accuracy of the bead and rim mating surface was controlled within 0.1 mm.

6. The tire design method for low rolling resistance and high strength according to claim 1, characterized in that: Step six describes the gradient rigidity and low rolling resistance structure design of the tread pattern. Specifically, it involves first extracting pressure distribution data of the tire contact patch under four core operating conditions after optimizing the tire carcass contour and belt layer structure. Then, with maximizing the uniformity of tread pattern contact deformation as the core optimization objective, and using the overall layout parameters, tread block structure parameters, reinforcing rib structure parameters, buffer groove structure parameters, and main groove structure parameters of the tread pattern as optimization variables, a mathematical model for tread pattern structure optimization is established. First, the total number of continuous longitudinal ribs in the tread center region, the width of a single rib, the height of the rib, and the longitudinal length of the ribs are determined to ensure that the contact rigidity of the tread center region under straight rolling conditions meets design requirements. Then, the total number of tread block structures, the length of a single tread block, the width of a single tread block, the height of a single tread block, and the spacing between adjacent tread blocks in the shoulder regions on both sides of the tread are determined to ensure that the lateral rigidity of the tread shoulder region under steering and lateral deviation conditions meets design requirements. The design requirements were then met. The number of progressive reinforcing ribs within each tread block, their location, cross-sectional width, height, and longitudinal extension length were determined to ensure a gradient increase in rigidity from the contact patch edge to the contact patch center. Next, the location, width, depth, and longitudinal extension length of the stress-relieving buffer grooves at the bottom of each tread block were determined to completely eliminate stress concentration during contact patching. Finally, the total number of longitudinal main grooves, their cross-sectional width, depth, longitudinal extension path, and transition radius of the inner wall of each main groove were determined to ensure the tire's drainage performance meets design requirements during driving on flooded roads. Through iterative calculations and adjustments to all optimization variables, the pressure distribution uniformity deviation of the tread pattern contact patch under the four core operating conditions was controlled within 8%.

7. The tire design method for low rolling resistance and high strength according to claim 1, characterized in that: The full-condition simulation calculation described in step seven specifically involves setting boundary conditions for the simulation verification model that are completely consistent with those in step two for four core operating conditions. Full-condition simulation calculations are then performed for the tire inflation stationary condition, rated load straight rolling condition, rated load steady-state steering and lateral deflection condition, and rated load emergency braking condition. The maximum number of iteration steps for a single operating condition is set to 1000 steps, and the convergence accuracy of the simulation calculation is set to 0.

001. After the simulation calculation is completed, the extracted full-performance simulation data of the tire specifically includes the simulated values ​​of the tire's rolling resistance coefficient, radial stiffness, torsional stiffness, ground pressure non-uniformity coefficient, bead anti-bead lateral force, and tread pattern deformation uniformity.

8. The tire design method for low rolling resistance and high strength according to claim 1, characterized in that: The step-by-step comparison and verification described in step eight specifically involves sequentially determining whether the simulated value of the rolling resistance coefficient is less than or equal to the maximum allowable value of the rolling resistance coefficient, whether the simulated value of the radial stiffness is greater than or equal to the minimum allowable value of the radial stiffness, whether the simulated value of the torsional stiffness is greater than or equal to the minimum allowable value of the torsional stiffness, whether the simulated value of the ground pressure non-uniformity coefficient is less than or equal to the maximum allowable value of the ground pressure non-uniformity coefficient, whether the simulated value of the bead anti-bead lateral force is greater than or equal to the minimum allowable value of the bead anti-bead lateral force, and whether the simulated value of the tread pattern deformation uniformity meets the design requirements. If the simulated value of any performance index does not meet the requirements, the tire structure module corresponding to that performance index is located, and the optimization design steps of the corresponding structure module are returned to perform a second iteration adjustment of all optimization variables of that structure module.

9. The tire design method for low rolling resistance and high strength according to claim 1, characterized in that: The full-performance bench test described in step nine specifically involves installing the test sample on a standard test rim that matches the design parameters, inflating the test sample with the rated inflation pressure, and allowing it to stand for 24 hours in a constant temperature environment at a standard ambient temperature of 25°C. Afterward, the installed test sample is fixed on a tire comprehensive performance bench testing machine, and the following tests are conducted sequentially according to national standard testing methods: tire rolling resistance performance test, radial stiffness performance test, torsional stiffness performance test, ground pressure distribution test, and bead anti-beading performance test. The ambient temperature is maintained at 25°C during the testing process, and the inflation pressure is maintained at the rated inflation pressure. The measured performance data obtained after the test specifically includes the measured values ​​of the tire's rolling resistance coefficient, radial stiffness, torsional stiffness, ground pressure non-uniformity coefficient, and bead anti-beading lateral force.

10. The tire design method for low rolling resistance and high strength according to claim 1, characterized in that: The final comparison and verification step 10 involves sequentially determining whether the measured value of the rolling resistance coefficient is less than or equal to the maximum allowable value of the rolling resistance coefficient, whether the measured value of the radial stiffness is greater than or equal to the minimum allowable value of the radial stiffness, whether the measured value of the torsional stiffness is greater than or equal to the minimum allowable value of the torsional stiffness, whether the measured value of the ground pressure non-uniformity coefficient is less than or equal to the maximum allowable value of the ground pressure non-uniformity coefficient, and whether the measured value of the bead anti-bead lateral force is greater than or equal to the minimum allowable value of the bead anti-bead lateral force. If the measured value of any performance indicator does not meet the requirements, the tire structure module corresponding to that performance indicator is located, and the optimization design steps of the corresponding structure module are returned to iterate and adjust all the optimization variables of the structure module again. After the adjustment is completed, the simulation verification and bench test process of steps 7 to 9 is repeated.

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