Non-pneumatic tire shear band structure design method, structure, and non-pneumatic tire

Abstract

The application discloses a design method and structure of a shear band for a non-pneumatic tire and a non-pneumatic tire, and relates to the technical field of data processing. The method comprises the following steps: step 1, obtaining target performance and defining a target function; step 2, obtaining parameter information of the shear band for the non-pneumatic tire; step 3, creating a finite element model of the non-pneumatic tire; step 4, solving the finite element model of the non-pneumatic tire by using ABAQUS software and outputting key mechanical performance of the non-pneumatic tire; and step 5, iteratively outputting a new combination of key structural parameters of the non-pneumatic tire by using a Bayesian optimization method with the given parameter optimization interval as a limiting condition, and repeating the steps 3 and 4 until the optimal key structural parameters of the non-pneumatic tire meeting the target performance of the non-pneumatic tire to be designed are outputted. The application can automatically iteratively output parameters meeting performance requirements in a parameter range, so that the optimization design method is more efficient.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of finite element design, in particular to a shear band structure design method for non-pneumatic tire, a shear band structure for non-pneumatic tire and a non-pneumatic tire. BACKGROUND

[0002] Non-pneumatic tire has become the focus of new tire due to its advantages of blowout prevention, damage resistance and strong designability. Non-pneumatic tire is mainly composed of tread, shear band, spoke and hub, wherein the function of shear band is similar to that of the inflation structure of pneumatic tire, which guarantees the ground performance of non-pneumatic tire and provides a "top load" mechanism for the tire, and is crucial to the overall performance of the tire. However, the existing shear band of non-pneumatic tire is mainly solid rubber or porous polyurethane material. These designs are difficult to effectively provide a "top load" mechanism for the thickness of the inner side of the tire reinforcement layer due to the low compression modulus, which reduces the load efficiency of the tire. In addition, this type of shear band cannot be used in extreme environments such as high temperature and radiation.

[0003] Therefore, it is desirable to have a technical solution to overcome or at least alleviate at least one of the above-mentioned defects of the prior art. SUMMARY

[0004] The purpose of the present application is to provide a shear band structure design method for non-pneumatic tire to overcome or at least alleviate at least one of the above-mentioned defects of the prior art.

[0005] To achieve the above-mentioned purpose, the present application provides a shear band structure design method for non-pneumatic tire, which comprises:

[0006] Step 1: obtaining the target performance of the non-pneumatic tire to be designed, and defining the objective function, wherein the non-pneumatic tire to be designed comprises a shear band structure for non-pneumatic tire;

[0007] Step 2: defining non-pneumatic tire structure parameter information and initializing non-pneumatic tire key structure parameters to be optimized, and giving parameter optimization interval, wherein the non-pneumatic tire key structure parameters to be optimized include parameters of the shear band structure for non-pneumatic tire, and the non-pneumatic tire structure parameter information includes fixed parameters and non-pneumatic tire key structure parameters to be optimized;

[0008] Step 3: creating a non-pneumatic tire finite element model according to the non-pneumatic tire structure parameter information;

[0009] Step 4: solving by ABAQUS software according to the non-pneumatic tire finite element model, and outputting the key mechanical properties of the non-pneumatic tire;

[0010] Step 5: input the non-pneumatic tire key structure parameters to be optimized and the non-pneumatic tire key mechanical properties corresponding to the input non-pneumatic tire key structure parameters to be optimized into the Bayesian optimization method, and iteratively output a new combination of non-pneumatic tire key structure parameters under the limitation of the given parameter optimization interval, and repeat steps 3 and 4 until the iteration is completed, and output the optimal non-pneumatic tire key structure parameters meeting the target performance of the non-pneumatic tire to be designed.

[0011] Optionally, the non-pneumatic tire key structure parameters to be optimized at least include one of the parameter information of the non-pneumatic tire shear band structure, and the parameter information of the non-pneumatic tire shear band structure includes:

[0012] The thickness of the non-pneumatic tire shear band structure, the number of first support members, the number of second support members, the distance from the end of the first support member to the end of the adjacent second support member, the thickness of the inner side reinforcing layer, the thickness of the outer side reinforcing layer, the stiffness of the elastic member, and the initial length of the elastic member.

[0013] Optionally, the objective function is as follows:

[0014] ;

[0015] Wherein, is the objective function; is the maximum stress of the non-pneumatic tire in the finite element calculation result, is the weight of the maximum stress in the non-pneumatic tire, is the i-th target performance, is the i-th performance obtained by the current simulation calculation, is the i-th target performance, is the weight of the i-th target performance, indicates the number of target performances. n

[0016] Optionally, the creation of the non-pneumatic tire finite element model according to the non-pneumatic tire structure parameter information comprises:

[0017] establishing the hub, spoke, non-pneumatic tire shear band structure, tread, and road surface of the non-pneumatic tire; wherein the spoke and the non-pneumatic tire shear band structure are beam element models, the tread is a two-dimensional shell element, and the road surface is one of a beam element, a shell element, and an analytical rigid body;

[0018] respectively, the hub, spoke, shear band, tread, and road surface of the non-pneumatic tire are given material parameters;

[0019] Assembling each component together and setting the interaction relationship to form the non-pneumatic tire finite element model.​​

[0020] Optionally, the shear band structure for non-pneumatic tire comprises:

[0021] an inner reinforcement layer connected with the spokes;

[0022] an outer reinforcement layer connected with the tire tread;

[0023] a shear band inner support body arranged between the inner reinforcement layer and the outer reinforcement layer, the shear band inner support body comprising a plurality of first support members arranged circumferentially along the inner reinforcement layer and a plurality of second support members arranged circumferentially along the outer reinforcement layer, one first support member being arranged adjacent to one second support member;

[0024] a plurality of elastic member groups, each group of elastic member groups comprising a plurality of elastic members, one elastic member being hingedly connected at one end to one first support member and at the other end to one second support member, each elastic member in the same group of elastic member groups being hingedly connected to the same first support member and the same second support member; wherein,

[0025] when the outer reinforcement layer is deformed under pressure, the elastic members are subjected to a tensile action, the elastic members providing the outer reinforcement layer with a force opposite to the direction of pressure of the non-pneumatic tire through the second support members, and the elastic members providing the inner reinforcement layer with a force in the same direction of pressure of the non-pneumatic tire through the first support members.

[0026] Optionally, each of the elastic members is the same elastic member.

[0027] each elastic member in the same group is uniformly distributed along the thickness direction of the shear band inner support body.

[0028] Optionally, each of the elastic members has a preset prestress after assembly, the preset prestress being obtained by the following formula:

[0029] wherein,

[0030] is the preset prestress; is the number of elastic members in each column of elastic member groups, k s is the stiffness of a single elastic member, l s is the initial length of the elastic member, d T is the distance from the end of the adjacent first support member to the end of the adjacent second support member.

[0031] Optionally, the elastic member also needs to meet the maximum equivalent shear strain requirement of the non-pneumatic tire shear band structure under the premise of ensuring the tire load capacity, that is, ; the maximum equivalent shear strain of the non-pneumatic tire shear band structure is ; wherein π is the ratio of the circumference of a circle, r S1 is the radius of the inner reinforcing layer, h is the thickness of the non-pneumatic tire shear band structure, n T is the number of first support members or the number of second support members in the non-pneumatic tire shear band structure, d s is the diameter of the elastic member.

[0032] The application also provides a non-pneumatic tire shear band structure obtained by the non-pneumatic tire shear band structure design method as described above.

[0033] The application also provides a non-pneumatic tire, which comprises spokes, a tire tread, and a non-pneumatic tire shear band structure as described above.

[0034] The non-pneumatic tire shear band structure design method of the application has the following advantages:

[0035] (1) The non-pneumatic tire shear band structure design method proposed by the application can be customized for different application scenarios to design the tire performance. That is, only the required performance of the tire and the range of geometric parameters and material properties allowed for processing and preparation need to be input. The method combines the finite element simulation software ABAQUS and the Bayesian optimization algorithm to automatically iterate the parameters that meet the performance requirements within the parameter range. This reduces the experimental test iteration process required for non-pneumatic tire design when facing different application scenarios. Thus, the optimization design method of the application is more efficient.

[0036] (2) The two adjacent first support members and the second support member of the non-pneumatic tire shear band structure of the application and the elastic member form a tensile structure. The tensile structure is used as the non-pneumatic tire shear band structure, and the tensile component in the tensile structure is replaced by a tensile spring. Thus, the non-pneumatic tire shear band structure has a low shear modulus but a high compression load capacity, and thus can meet the performance requirements of the non-pneumatic tire shear band structure for non-pneumatic tires. The design strategy proposed by the application at the structural level solves the problem that conventional materials cannot balance shear flexibility and high compression load, and ensures the "top load" mechanism of the non-pneumatic tire. Not only can the load capacity per unit mass of the non-pneumatic tire be greatly improved, but also the ground pressure of the tire can be reduced, and the comfort and stability during tire driving can be increased. BRIEF DESCRIPTION OF DRAWINGS

[0037] Figure 1 is a flowchart of a design method of a shear band structure for a non-pneumatic tire according to an embodiment of the present application.

[0038] Figure 2 is a structural diagram of a non-pneumatic tire according to an embodiment of the present application.

[0039] Figure 3 is a partial structural diagram of a shear band structure for a non-pneumatic tire according to an embodiment of the present application. xoy is a plan view.

[0040] Figure 4 is a partial structural diagram of a shear band structure for a non-pneumatic tire according to an embodiment of the present application.

[0041] Figure 5 is a deformation diagram of a non-pneumatic tire according to an embodiment of the present application.

[0042] Reference Signs

[0043] 1, hub; 2, spoke; 3, inner reinforcement layer; 4, outer reinforcement layer; 5, shear band inner support; 6, elastic member; 7, pin shaft. DETAILED DESCRIPTION

[0044] In order to make the purpose, technical solutions and advantages of the present application clearer, the technical solutions in the embodiments of the present application will be described in more detail below with reference to the drawings. In the drawings, the same or similar notations represent the same or similar elements or elements having the same or similar functions throughout. The described embodiments are some embodiments of the present application, not all embodiments. The embodiments described below with reference to the drawings are exemplary and are intended to explain the present application, and cannot be understood as a limitation of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative labor fall within the scope of protection of the present application. The embodiments of the present application will be described in detail below with reference to the drawings.

[0045] In the description of the present application, it should be understood that the terms "center", "longitudinal", "transverse", "circumferential", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the purpose of facilitating the description of the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the scope of protection of the present application.

[0046] As Figure 1The non-pneumatic tire shear band structure design method shown comprises:

[0047] Step 1: obtaining target performance of a non-pneumatic tire to be designed, and defining a target function, wherein the non-pneumatic tire to be designed comprises a non-pneumatic tire shear band structure;

[0048] Step 2: defining non-pneumatic tire structure parameter information and initializing non-pneumatic tire key structure parameters to be optimized, and giving a parameter optimization interval, wherein the non-pneumatic tire key structure parameters to be optimized comprise parameters of the non-pneumatic tire shear band structure, and the non-pneumatic tire structure parameter information comprises fixed parameters and the non-pneumatic tire key structure parameters to be optimized;

[0049] Step 3: creating a non-pneumatic tire finite element model according to the non-pneumatic tire structure parameter information;

[0050] Step 4: solving by using ABAQUS software according to the non-pneumatic tire finite element model, and outputting non-pneumatic tire key mechanical properties;

[0051] Step 5: inputting the non-pneumatic tire key structure parameters to be optimized and the non-pneumatic tire key mechanical properties corresponding to the input non-pneumatic tire key structure parameters to be optimized into a Bayesian optimization method, taking the given parameter optimization interval as a limiting condition to iteratively output a new non-pneumatic tire key structure parameter combination and repeating the steps 3 and 4 until an optimal non-pneumatic tire key structure parameter meeting the target performance of the non-pneumatic tire to be designed is outputted after iteration ends.

[0052] In the embodiment, the iteration end can be reaching a preset iteration round or reaching a preset iteration condition.

[0053] In the embodiment, the non-pneumatic tire key structure parameters to be optimized at least comprise one of parameter information of the non-pneumatic tire shear band structure (it can be understood that, in other embodiments, the thickness of the spoke can also be included), and the parameter information of the non-pneumatic tire shear band structure comprises:

[0054] thickness of the non-pneumatic tire shear band structure, number of first support members, number of second support members, distance from an end of the first support member to an end of the adjacent second support member, thickness of the inner side reinforcing layer, thickness of the outer side reinforcing layer, stiffness of the elastic member, and initial length of the elastic member.

[0055] In the embodiment, the target function is as follows:

[0056] ; wherein,

[0057] wherein, is the target function. a maximum stress in the non-pneumatic tire in the finite element calculation result, a weight corresponding to the maximum stress in the non-pneumatic tire, a first target performance, a first performance obtained by the current simulation calculation, a first target performance, a weight of the first target performance, a first target performance, a weight of the first target performance, n a number of target performances.

[0058] In the embodiment, the creating the non-pneumatic tire finite element model according to the non-pneumatic tire structure parameter information comprises:

[0059] establishing a hub, a spoke, a shear band structure for non-pneumatic tires, a tread, and a road surface of the non-pneumatic tire; wherein the spoke and the shear band structure for non-pneumatic tires are beam element models, the tread is a two-dimensional shell element, and the road surface is one of a beam element, a shell element, and an analytical rigid body;

[0060] respectively giving material parameters to the hub, the spoke, the shear band structure for non-pneumatic tires, the tread, and the road surface of the non-pneumatic tire; it is emphasized that specific material properties can be given to the tread and the road surface for different use environments, but this does not affect the design of the shear band structure for non-pneumatic tires and the optimization of the overall performance of the non-pneumatic tire.

[0061] assembling the components together and setting interaction relationships to form the non-pneumatic tire finite element model.

[0062] Referring to Figures 2 to 4In the embodiment, the shear band structure for non-pneumatic tire comprises an inner reinforcing layer 3, an outer reinforcing layer 4, a shear band inner support 5, and a plurality of elastic element groups. The inner reinforcing layer 3 is connected with the spoke 2. The outer reinforcing layer 4 is connected with the tire tread. The shear band inner support 5 is arranged between the inner reinforcing layer 3 and the outer reinforcing layer 4. The shear band inner support 5 comprises a plurality of first supports arranged circumferentially along the inner reinforcing layer 3 and a plurality of second supports arranged circumferentially along the outer reinforcing layer 4. One first support is arranged adjacent to one second support. Each of the plurality of elastic element groups comprises a plurality of elastic elements 6. One end of one elastic element 6 is hinged to one first support, and the other end is hinged to one second support. Each elastic element in the same elastic element group is hinged to the same first support and the same second support. When the outer reinforcing layer 4 is deformed under pressure, the elastic element 6 is stretched. The elastic element 6 provides the outer reinforcing layer 4 with a force opposite to the pressure direction of the non-pneumatic tire through the second support. The elastic element 6 provides the inner reinforcing layer 3 with a force in the same direction as the pressure direction of the non-pneumatic tire through the first support.

[0063] In the embodiment, each of the elastic elements is the same. Each elastic element in the same group is uniformly distributed along the thickness direction of the shear band inner support.

[0064] In the embodiment, the first support and the second support have the same structure, and one is connected with the inner reinforcing layer and the other is connected with the outer reinforcing layer.

[0065] In the embodiment, each of the elastic elements has a preset prestress after assembly. The prestress ensures that the elastic element does not shake after assembly. The preset prestress is obtained by the following formula:

[0066] ; wherein, n is the number of elastic elements in each column of elastic element groups, k is the stiffness of a single elastic element, L is the initial length of the elastic element, d is the distance from the end of the adjacent first support to the end of the adjacent second support.

[0067] In the embodiment, the diameter of the elastic element should be as small as possible to ensure that there is enough space between the elastic element and the support to allow the shear band to produce large shear deformation under the premise of ensuring the load capacity of the tire.

[0068] The application also provides a shear band structure for a non-pneumatic tire. The non-pneumatic tire comprises a spoke and a tire tread. The shear band structure for the non-pneumatic tire is obtained by the shear band structure design method for the non-pneumatic tire.

[0069] This application also provides a non-pneumatic tire, which includes tire spokes, a tread, and a shear strip structure for non-pneumatic tires as described above.

[0070] In this embodiment, the shear band structure for non-pneumatic tires is located on the outside of the tire spokes 2. The shear band structure for non-pneumatic tires includes an inner reinforcing layer 3, an outer reinforcing layer 4, an internal support body 5, and an elastic element assembly. The inner reinforcing layer 3 is connected to the tire spokes 2, and the outer reinforcing layer 4 is connected to the tread. Both the inner and outer reinforcing layers 3 and 4 are uniformly thick annular thin shells. The internal support body 5 is a T-shaped structure. A portion of a first support member, a portion of an adjacent second support member, and an elastic element (in this application, the elastic element is a tension spring) connected to both constitute a tension structure unit. This unit is characterized by the elastic element undergoing tensile deformation under compressive load. The internal structure of the shear band for non-pneumatic tires is formed by a circumferential array of tension structure units.

[0071] In this embodiment, the internal support 5 of the shear band has a groove inside, and a tension spring can be placed in the groove. The inner reinforcing layer 3, the outer reinforcing layer 4, the internal support 5 of the shear band, and the elastic element 6 together constitute the shear band structure for a non-pneumatic tire. The internal support 5 of the shear band and the elastic element 6 are hinged together by a pin 7. Adjacent first support members, second support members, and cooperating elastic elements combine to form a tension structure unit. It should be emphasized that although the specific form of the internal support of the shear band is not limited, it is necessary to ensure that the internal support of the shear band and the tension spring together constitute a tension structure. This feature is reflected in tire deformation: when the tire is compressed, the tension spring will be further stretched, while the internal support of the shear band is in a compressed state.

[0072] In this embodiment, to ensure uniform tire performance, all tension springs are of the same specification, and the axis of the tension spring is along the radial direction of the tire. It is important to emphasize the initial length of the tension spring. It should be slightly smaller than the distance from the end of the first support member to the end of the second support member within the shear band structure for non-pneumatic tires. (See) Figure 3 This ensures that the assembled tension spring has a certain prestress, preventing the tension spring from shaking after assembly.

[0073] The magnitude of prestress can be determined by the formula Obtain, among which This represents the number of elastic elements in each group of elastic elements. For the stiffness of a single elastic element, The initial length of the elastic element. is the distance from the end of the adjacent first support to the end of the adjacent second support. The tensile spring's tensile stiffness and the number of tensile springs can be flexibly determined according to actual requirements. Assuming that the rated radial stiffness of the tire is , it is recommended that . In addition, while ensuring that the tensile spring has sufficient stiffness, the diameter of the tensile spring should be as small as possible to ensure that there is sufficient space between the tensile spring and the internal support of the shear band, which determines the maximum shear strain that can be generated by the shear band structure for the non-pneumatic tire. Assuming that the diameter of the tensile spring is , the maximum effective shear strain that can be generated by the shear band structure for the non-pneumatic tire in theory is .

[0074] wherein, is the radius of the inner reinforcing layer, h is the thickness of the shear band structure for the non-pneumatic tire, n T is the number of tensile structure units in the shear band structure for the non-pneumatic tire. In addition, the two ends of the tensile spring should be provided with a circular ring to ensure that the connection between the tensile spring and the internal support of the shear band is hinged.

[0075] In this embodiment, the equivalent compression modulus of the tensile structure unit is , wherein, d is the width of the non-pneumatic tire, and π is the circular constant, r S1 is the radius of the inner reinforcing layer, h is the thickness of the shear band structure for the non-pneumatic tire, n T is the number of first supports or the number of second supports in the shear band structure for the non-pneumatic tire. Since the assembly between the tensile spring in the tensile structure unit and the internal support of the shear band is hinged, the ideal equivalent shear modulus of the tensile structure unit is G e =0. However, it can be understood that due to the geometric assembly constraints of the tire itself, the initial equivalent shear modulus of the actual tensile structure unit is a value slightly greater than zero. The empirical formula for calculating the ground pressure of the non-pneumatic tire is , wherein, is the radius of the outer reinforcing layer of the tire; P is the ground pressure of the non-pneumatic tire. Generally, to reduce the ground pressure of the tire, the shear modulus of the shear band structure for the non-pneumatic tire G e should be as small as possible, which is consistent with the present embodiment.

[0076] The design method of the shear band structure for the non-pneumatic tire of the present application has the following advantages:

[0077] (1) The shear strip structure design method for non-pneumatic tires proposed in this application can customize tire performance for different application scenarios. That is, it only requires inputting the required tire performance and the range of geometric parameters and material properties allowed for processing and manufacturing. The proposed method, combined with the commercial finite element simulation software ABAQUS and Bayesian optimization algorithm, can automatically iterate within the parameter range to obtain parameters that meet the performance requirements. This reduces the experimental testing and iteration process required for non-pneumatic tire design when facing different application scenarios. Thus, the optimization design method of this application is more efficient.

[0078] (2) This application adopts a tensioned structure as the shear strip structure for non-pneumatic tires, and replaces the tensioned component in the tensioned structure with a tension spring, so that the shear strip structure for non-pneumatic tires has a low shear modulus but high compressive load capacity, thus meeting the performance requirements of non-pneumatic tires for shear strip structures. The design strategy proposed in this application at the structural level solves the problem that conventional materials cannot simultaneously achieve shear flexibility and high compressive load capacity, and ensures the "top load-bearing" mechanism of non-pneumatic tires. This not only greatly improves the load-bearing capacity per unit mass of non-pneumatic tires, but also reduces the tire's ground pressure, increasing the comfort and stability of the tire during driving.

[0079] It is understood that no restrictions are placed on the materials used in this embodiment, and rubber or even metal can be used as needed. The non-pneumatic tire proposed here can be fabricated using 3D printing to create an all-nylon or metal structure, and then the tension spring can be embedded in the shear band structure for the non-pneumatic tire. Alternatively, the spokes, inner reinforcing layer, outer reinforcing layer, and internal support of the shear band can be obtained separately through machining, and then each component can be assembled together mechanically. Similarly, this application does not limit the assembly method, and welding, riveting, or bolting can be used depending on the processing conditions.

[0080] It is understood that the structural characteristics of the spokes are not limited in this embodiment, and the shape of the spokes can be... Figure 2 The curved beams constructed from the spline curves shown can also be thin-walled honeycomb structures or cross-curved beam structures, etc.

[0081] In this embodiment, the internal support of the shear band connecting the elastic element has sufficient bending stiffness to ensure that no significant deformation occurs when the tire is under load.

[0082] The shear band structure used in non-pneumatic tires contains multiple adjustable parameters. The relationship between these parameters and the performance of the non-pneumatic tire is a "black box," making performance optimization impossible through gradient calculation. Furthermore, the long computation time required for a single finite element method (FEM) calculation renders algorithms like ant colony optimization and genetic algorithms, which require significant computation in each iteration, ineffective. Bayesian optimization, on the other hand, uses Bayes' theorem to guide the search for the minimum or maximum value of the objective function. In each iteration, it updates the surrogate function with the previously solved results and performs the next optimization, offering advantages such as fewer iterations and higher speed.

[0083] In this embodiment, the objective function defined according to the target performance includes:

[0084] Given the target performance of a non-pneumatic tire, such as radial stiffness, lateral stiffness, tangential stiffness, etc.;

[0085] The objective function is defined based on the target performance. When there are multiple target performance targets, a weight is set for each target performance target according to actual needs. Then, the target performance is multiplied by the weight and accumulated.

[0086]

[0087] in, For the first One target performance, The first result obtained from the current simulation calculation One performance, For the first The weights of each target performance, n Indicates the number of target performance metrics.

[0088] To ensure that tire performance meets target requirements while minimizing maximum material stress, the objective function can be modified as follows:

[0089] ;

[0090] in, This represents the magnitude of the maximum stress in the non-pneumatic tire as calculated by the finite element method. This represents the weight corresponding to the maximum stress in a non-pneumatic tire. For the first One target performance, The first result obtained from the current simulation calculation One performance, For the first The weights of each target performance, n Indicates the number of target performance metrics.

[0091] In this embodiment, the parameters that can be optimized for the shear band structure of non-pneumatic tires include the number of tension structural units. the number of first support members or the number of second support members in the shear band structure for non-pneumatic tire, the thickness of the inner reinforcement layer , the thickness of the outer reinforcement layer , the thickness of the shear band structure for non-pneumatic tire h , the stiffness of the tensile spring k s The parameters that can be optimized by the spokes include the thickness of the spokes , the curvature of the spokes , but it can be understood that it is not limited to the listed parameters.

[0092] The number of the tensile structure units is an integer . The angle of the tensile structure unit is the included angle of the two sides of the unit .

[0093] The finite element model created in this embodiment includes parameterized component establishment, given material parameters, component assembly, analysis step creation, interaction relationship setting, load boundary condition application, element meshing, and calculation task submission;

[0094] The parameterized component establishment includes the hub, spokes, and shear band structure for non-pneumatic tire, the tread, and the road surface of the non-pneumatic tire. Among them, the hub, spokes, and shear band structure for non-pneumatic tire part can be simplified into a beam element model, the tread adopts a two-dimensional shell element, and the road surface adopts an analytical rigid body model. Specifically, the hub is a circular ring with a radius which can be defined according to actual conditions.

[0095] The spokes demonstrated in this embodiment are thin beams with a certain curvature. The curvature can be defined by an offset angle . The offset angle is the included angle between the line connecting the endpoints of the spokes and the center of the tire and the line connecting the midpoint of the spokes and the center of the tire. It can be understood that when , the spokes are a straight line. The spokes can be obtained by connecting the endpoints-midpoint-endpoints in sequence through a spline curve. The modeling method of the inner reinforcement layer and the outer reinforcement layer of the shear band structure for non-pneumatic tire is similar to that of the hub, which will not be repeated here.

[0096] The shear band internal support body can be modeled as a "T"-shaped beam. Half of the "T"-shaped shear band internal support body is connected to the inner reinforcement layer (i.e., the first support member), and the other half is connected to the outer reinforcement layer (i.e., the second support member). This part of the structure has three geometric parameters, which are the number of tensile units , the distance from the end of the first support member to the end of the adjacent second support member , and the thickness Therefore the arc of the "T" shaped shear band inner support is Where the thickness Should be large enough to ensure that the deformation of the shear band inner support is negligible compared to the deformation of the tire bottom when the tire is under load. It is understood that the length of the first support in the hoop direction and the length of the second support in the hoop direction are different due to the relationship between the hoop circumference and the radius length. The length of the shear band inner support connected to the inner reinforcement layer in the hoop direction is The length of the shear band inner support connected to the outer reinforcement layer in the hoop direction is .

[0097] The maximum shear strain of the shear band structure for a non-pneumatic tire can theoretically reach The tensile spring inside the shear band structure for a non-pneumatic tire is set in the Interaction module of ABAQUS, which is not modeled here. It is understood that the model can be extended to three-dimensional geometry, but the geometric relationship between different components and the logical relationship between parameters remain unchanged.

[0098] The given material parameters include the material properties of the spokes, reinforcement layers, shear layers, tread, and road surface. Depending on actual needs, the properties of the materials can be linear or hyperelastic, etc.

[0099] The assembly component is to assemble the non-pneumatic tire model, tread, and road surface according to the geometric relationship in the Assembly module.

[0100] The analysis step can use the State General type. It is emphasized here that due to the presence of pre-stress in the tensile spring, at least two analysis steps are required. The first analysis step is used to release a portion of the strain energy in the tensile spring into the tire to achieve a self-balancing state. The subsequent analysis step is used to load the tire for simulation.

[0101] The setting of the interaction relationship in this embodiment includes defining the tensile spring with pre-stretch, displacement coupling, and contact relationship. The steps for defining the tensile spring with pre-stretch include:

[0102] 1) Create a line feature in the Interaction module of ABAQUS, and the two endpoints of the line are the positions of the two ends of the actual tensile spring.

[0103] 2) Define the connector properties. Here, the basic Axial type connector is selected, and in the BehaviorOptions option, Elasticity and Reference Length are selected to give the tensile spring stiffness and initial length, respectively.

[0104] The tensile spring stiffness here should be the sum of the stiffness of each column of tensile springs, i.e. n s k s The displacement coupling is to couple the displacement of all the grid elements on the hub through the Coupling or Tie command on the reference point at the geometric center thereof. The interaction relationship between the tread and the outer reinforcing layer can be set by adding the Embedded command, wherein the tread is the host region and the outer reinforcing layer is the embedded region. The contact relationship is mainly to set the contact properties between the tread and the road surface of the non-pneumatic tire, such as the friction coefficient and the like.

[0105] The load application boundary condition in the embodiment is specifically to apply displacement or force load on the reference point coupled with the hub, and to fix the road surface. If the target performance is the radial stiffness of the non-pneumatic tire, a downward displacement is applied to the reference point. If the target performance is the tangential stiffness of the non-pneumatic tire under the rated load, a downward force is first applied to the reference point, and then a horizontal displacement is applied.

[0106] The unit grid division in the embodiment can be operated according to the default parameters of the ABAQUS software.

[0107] The output calculation result in the embodiment involves the post-processing of the calculation result and the output of the result. Although ABAQUS has a built-in Python interpreter, the built-in functions are relatively few, especially lacking functions such as Bayesian optimization, so the optimization process cannot be directly and completely completed inside ABAQUS. In the embodiment, the performance results obtained by simulation calculation are automatically written into the Result.txt or Result.csv file, which is used as information transmission between the optimization program and the finite element calculation program. The information contained in the file is the result of the corresponding target performance obtained by the current calculation result. It can be understood that the finite element analysis program is like a black box function, which inputs the geometric parameters and outputs the corresponding performance.

[0108] The optimization iteration process in the embodiment includes reading the current simulation result and obtaining the geometric parameters of the next cycle according to the Bayesian optimization method;

[0109] The Bayesian optimization model first selects a prior distribution to represent the uncertainty of the objective function in the iteration process, usually using models such as Gaussian process or random forest. Then, a set of points is selected from the initial point set as the initial sampling points. In each iteration, the objective function is sampled according to the current prior distribution model to obtain a new sampling point. Then, according to this sampling point, the prior distribution model is updated, and the next sampling point is selected under the new prior distribution model. Through continuous iteration, the objective function is gradually optimized, and the optimal solution is finally found. In this embodiment, the minimum value of the objective function is obtained.

[0110] The Bayesian optimization function can be used by installing the skopt library in the Python interpreter and importing the gp_minimize function. It should be emphasized that the program containing the optimization iteration and the program for creating the finite element model and calculation are separate. In the optimization iteration program, the Python program for simulation can be called by the "abaqus cae noGUI=xx.py" command. After each iteration, the gp_minimize function updates the prior model and outputs the geometric parameters required for the next cycle. It should be emphasized that the updated parameters should be written into the Paremerer.txt or Paremerer.csv file to be passed to the program for finite element calculation. The two programs involved in this embodiment interact through parameter files and result files.

[0111] The present embodiment gives an example according to the proposed optimization algorithm for non-pneumatic tires based on tension structure. The pre-defined geometric parameters are: the width of the non-pneumatic tire d = 50 mm, the thickness of the shear band structure used by the non-pneumatic tire h = 18 mm, the radius of the inner reinforcing layer r S1 = 100 mm, the radius of the outer reinforcing layer r S2 = 118 mm, the width of the internal support of the shear band t T = 2 mm, the length of the tensile spring l s = 10 mm, the number of spokes is 36, and the number of tension structure units n T = 36. The elastic modulus of the material is 72 GPa (the elastic modulus of a conventional aluminum alloy). The parameters to be optimized are: the thickness of the spoke t sp , the thickness of the inner reinforcing layer t S1 , the thickness of the outer reinforcing layer t S2 , and the stiffness of the tensile spring ks , the parameter ranges are 0.1-0.6 mm, 0.1-0.6 mm, 0.1-0.6 mm, 50-200 N / mm, respectively, and let t S1 t S2 The performance requirement is that the non-pneumatic tire reaches the rated load of 600 N when the sinkage is 6 mm, and the maximum stress of the part except the tensile spring is required to be as small as possible. The weight factors of the load and the maximum stress are 3000 and 1, respectively. Therefore, the objective function is , wherein is the maximum stress of the tire when the sinkage is 6 mm, is the corresponding load. The iteration number is set to 100. The obtained optimal parameters are: the thickness of the spoke t sp = 0.46 mm, the thickness of the inner side reinforcing layer and the thickness of the outer side reinforcing layer t S1 t S2 = 0.13 mm, the stiffness of the tensile spring k s = 167.73 N / mm. The deformation diagram of the non-pneumatic tire when the sinkage is 6 mm can be obtained as Figure 5 .

[0112] The effective load of the non-pneumatic tire when the sinkage is 6 mm is measured to be 600.2 N, which reaches the target performance requirement. At this time, the maximum stress of the non-pneumatic tire is 362 MPa, which is far less than the strength (> 500 MPa) of the high-strength aluminum alloy. It can be understood that, because the circumferential length of the inner side reinforcing layer is shorter than that of the outer side reinforcing layer, when the non-pneumatic tire is loaded, the non-pneumatic tire shear band structure must adapt to the different circumferential lengths of the inner and outer sides through shear deformation. At this time, the inner support of the shear band is inclined, and the non-pneumatic tire shear band structure produces shear deformation. The contact between the bottom of the tire and the ground is relatively flat, which ensures uniform ground pressure. It can be seen that the spokes at the top and both sides of the non-pneumatic tire are straightened, which reflects the load mechanism at the top of the tire.

[0113] Finally, it should be pointed out that: the above embodiments are only used to illustrate the technical solutions of the present application, but not to limit them. Although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacements to some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.​​

Claims

1. A design method for a shear strip structure for a non-pneumatic tire, characterized in that, The non-pneumatic tire shear band structure design method comprises the following steps: Step 1: obtaining the target performance of a non-pneumatic tire to be designed, and defining a target function, wherein the non-pneumatic tire to be designed comprises a non-pneumatic tire shear band structure; Step 2: defining non-pneumatic tire structure parameter information and initializing non-pneumatic tire key structure parameters to be optimized, and giving parameter optimization intervals, wherein the non-pneumatic tire key structure parameters to be optimized comprise parameters of the non-pneumatic tire shear band structure, and the non-pneumatic tire structure parameter information comprises fixed parameters and the non-pneumatic tire key structure parameters to be optimized; Step 3: creating a non-pneumatic tire finite element model according to the non-pneumatic tire structure parameter information; the step of creating a non-pneumatic tire finite element model according to the non-pneumatic tire structure parameter information comprises the following steps: establishing a hub, spokes, a non-pneumatic tire shear band structure, a tire tread and a road surface of the non-pneumatic tire; wherein the spokes and the non-pneumatic tire shear band structure are beam element models, the tire tread is a two-dimensional shell element, and the road surface is one of a beam element, a shell element and an analytical rigid body; respectively giving material parameters of the hub, the spokes, the shear band, the tire tread and the road surface of the non-pneumatic tire; assembling the components together and setting interaction relationships to form the non-pneumatic tire finite element model; the non-pneumatic tire shear band structure comprises: an inner reinforcing layer (3) connected with the spokes (2); an outer reinforcing layer (4) connected with the tire tread; a shear band internal support body (5) arranged between the inner reinforcing layer (3) and the outer reinforcing layer (4), the shear band internal support body (5) comprising a plurality of first support members arranged circumferentially along the inner reinforcing layer (3) and a plurality of second support members arranged circumferentially along the outer reinforcing layer (4), one first support member being arranged adjacent to one second support member; a plurality of elastic member groups, each elastic member group comprising a plurality of elastic members (6), one end of one elastic member (6) being hinged to one first support member and the other end being hinged to one second support member, and each elastic member in the same elastic member group being hinged to the same first support member and the same second support member; wherein when the outer reinforcing layer (4) is deformed under pressure, the elastic members (6) are subjected to a tensile action, the elastic members (6) provide the outer reinforcing layer (4) with a force opposite to the pressure direction of the non-pneumatic tire through the second support members, and the elastic members (6) provide the inner reinforcing layer (3) with a force in the same direction as the pressure direction of the non-pneumatic tire through the first support members; Step 4: solving by using ABAQUS software according to the non-pneumatic tire finite element model, and outputting non-pneumatic tire key mechanical properties. Step 5: input the non-pneumatic tire key structure parameters to be optimized and the non-pneumatic tire key mechanical properties corresponding to the input non-pneumatic tire key structure parameters to be optimized into the Bayesian optimization method, and iterate out a new non-pneumatic tire key structure parameter combination with the given parameter optimization interval as a limiting condition, and repeat steps 3 and 4 until the iteration is completed and the optimal non-pneumatic tire key structure parameters meeting the target performance of the non-pneumatic tire to be designed are output.

2. The method of designing a shear band structure for a non-pneumatic tire of claim 1, wherein, The non-pneumatic tire key structure parameters to be optimized at least include one of the parameter information of the non-pneumatic tire shear band structure, and the parameter information of the non-pneumatic tire shear band structure includes: The thickness of the non-pneumatic tire shear band structure, the number of first support members, the number of second support members, the distance from the end of the first support member to the end of the adjacent second support member, the thickness of the inner reinforcing layer, the thickness of the outer reinforcing layer, the stiffness of the elastic member, and the initial length of the elastic member.

3. The method of designing a shear band structure for a non-pneumatic tire of claim 2, wherein, The objective function is as follows: ； in, The objective function is... This represents the magnitude of the maximum stress in the non-pneumatic tire as calculated by the finite element method. This represents the weight corresponding to the maximum stress in a non-pneumatic tire. For the first i One target performance, The first result obtained from the current simulation calculation i One performance, For the first i The weights of each target performance, n Indicates the number of target performance metrics.

4. The method of designing a shear band structure for a non-pneumatic tire of claim 1, wherein, Each of the elastic members (6) is the same elastic member; Each elastic member (6) in the same group is uniformly distributed along the thickness direction of the shear band internal support body.

5. The method of designing a shear band structure for a non-pneumatic tire of claim 4, wherein, Each of the elastic members has a preset prestress after assembly, and the preset prestress is obtained by the following formula: ; wherein, F Pre is a predetermined prestress; n s is the number of elastic elements (6) in each column of elastic element groups, k s is the stiffness of a single elastic element (6), l s is the initial length of an elastic element (6), d T is the distance of the end of an adjacent first support element to the end of an adjacent second support element.

6. The method of designing a shear band structure for a non-pneumatic tire of claim 5, wherein, The elastic member (6) needs to meet the maximum equivalent shear strain requirement of the shear band structure for non-pneumatic tires on the premise of ensuring the load bearing capacity of the tire, that is ; the maximum equivalent shear strain of the shear band structure for non-pneumatic tires is ; wherein π is the circular constant, r S1 is the radius of the inner reinforcing layer, h is the thickness of the shear band structure for non-pneumatic tires, n T is the number of the first support member or the number of the second support member in the shear band structure for non-pneumatic tires, d s is the diameter of the elastic member.

7. A shear band structure for a non-pneumatic tire, characterized by, The non-pneumatic tire shear band structure is obtained by the non-pneumatic tire shear band structure design method according to any one of claims 1 to 6.

8. A non-pneumatic tire characterized by, The non-pneumatic tire includes spokes, a tire tread, and the non-pneumatic tire shear band structure according to claim 7.

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