Design method and structure of shear band structure for non-pneumatic tire and non-pneumatic tire

Abstract

The invention discloses a design method and structure of a shear band structure for a non-pneumatic tire and the non-pneumatic tire, and relates to the technical field of data processing. The method comprises the following steps: 1, acquiring target performance, and defining a target function; 2, parameter information of the shear band structure for the non-pneumatic tire is obtained; 3, creating a finite element model of the non-pneumatic tire; 4, solving by utilizing ABAQUS software according to the finite element model of the non-pneumatic tire, and outputting key mechanical properties of the non-pneumatic tire; and 5, iterating a new key structure parameter combination of the non-pneumatic tire by taking the given parameter optimization interval as a limiting condition through a Bayesian optimization method, and repeating the step 3 and the step 4 until the iteration is finished, and outputting the optimal key structure parameter of the non-pneumatic tire meeting the target performance of the non-pneumatic tire to be designed. According to the optimization design method, the parameters meeting the performance requirements can be automatically iterated in the parameter range, so that the optimization design method is more efficient.

Description

Technical Field

[0001] The present invention relates to the technical field of finite element design, and particularly relates to a design method for a shear band structure for a non-pneumatic tire, a shear band structure for a non-pneumatic tire, and a non-pneumatic tire. Background Art

[0002] Due to advantages such as explosion-proof, not easily damaged, and strong designability, non-pneumatic tires have become the focus of the new round of tires. A non-pneumatic tire mainly consists of a tread, a shear band, spokes, and a hub. Among them, the function of the shear band is similar to the inflation structure of a pneumatic tire, ensuring the grounding performance of the non-pneumatic tire and providing a "top load-bearing" mechanism for the tire, which is crucial for the overall performance of the tire. However, the existing shear bands of non-pneumatic tires are mainly solid rubber or porous polyurethane materials. These designs are difficult to effectively provide a "top load-bearing" mechanism for the thickness of the inner reinforcement layer of the tire due to their low compression modulus, reducing the load-bearing efficiency of the tire. In addition, this type of shear band cannot be used in extreme environments, such as high temperature, radiation, etc.

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

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

[0005] To achieve the above purpose, the present application provides a design method for a shear band structure for a non-pneumatic tire, and the design method for the shear band structure for the non-pneumatic tire includes: Step 1: Obtain the target performance of the non-pneumatic tire to be designed and define the objective function, wherein the non-pneumatic tire to be designed includes a shear band structure for the non-pneumatic tire; Step 2: Define the non-pneumatic tire structure parameter information and initialize the key structure parameters of the non-pneumatic tire to be optimized, and give the parameter optimization interval, wherein the key structure parameters of the non-pneumatic tire to be optimized include the parameters of the shear band structure for the non-pneumatic tire, and the non-pneumatic tire structure parameter information includes fixed parameters and the key structure parameters of the non-pneumatic tire to be optimized; Step 3: Create a finite element model of the non-pneumatic tire according to the non-pneumatic tire structure parameter information; Step 4: Solve according to the finite element model of the non-pneumatic tire using ABAQUS software and output the key mechanical properties of the non-pneumatic tire; Step 5: Input the key structural parameters of the non-pneumatic tire to be optimized and the key mechanical properties of the non-pneumatic tire corresponding to the input key structural parameters of the non-pneumatic tire to be optimized into the Bayesian optimization method. Using the given parameter optimization interval as a constraint condition, iterate to obtain a new combination of key structural parameters of the non-pneumatic tire and repeat Step 3 and Step 4 until the optimal key structural parameters of the non-pneumatic tire that meet the target performance of the non-pneumatic tire to be designed are output after the iteration ends.

[0006] Optionally, the key structural parameters of the non-pneumatic tire to be optimized include at least one of the parameter information of the shear band structure for non-pneumatic tires, and the parameter information of the shear band structure for non-pneumatic tires includes: The thickness of the shear band structure for non-pneumatic tires, the number of the first support members, the number of the 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.

[0007] Optionally, the objective function is as follows: ; Wherein, is the objective function; is the magnitude of the maximum stress of the non-pneumatic tire in the finite element calculation result, is the weight corresponding to the maximum stress in the non-pneumatic tire, is the th target performance, is the th performance obtained from the current simulation calculation, is the weight of the th target performance, n represents the number of target performances.

[0008] Optionally, creating the non-pneumatic tire finite element model according to the non-pneumatic tire structure parameter information includes: Establish the hub, spokes, shear band structure for non-pneumatic tires, tread, and road surface of the non-pneumatic tire; among them, the spokes 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; Respectively assign material parameters to the hub, spokes, shear band, tread, and road surface of the non-pneumatic tire; Assemble each component together and set the interaction relationship to form the non-pneumatic tire finite element model.

[0009] Optionally, the shear band structure for non-pneumatic tires includes: An inner reinforcing layer, and the inner reinforcing layer is connected to the spokes; An outer reinforcing layer, which is connected to the tire tread; A shear band internal support body, which is arranged between the inner reinforcing layer and the outer reinforcing layer. The shear band internal support body includes a plurality of first support members arranged circumferentially along the inner reinforcing layer and a plurality of second support members arranged circumferentially along the outer reinforcing layer. One first support member is arranged adjacent to one second support member; An elastic member group, the number of the elastic member groups is multiple. Each elastic member group includes a plurality of elastic members. One end of an elastic member is hinged to one first support member, and the other end is hinged to one second support member. Each elastic member in the same elastic member group is hinged to the same first support member and the same second support member; wherein, When the outer reinforcing layer is compressed and deformed, the elastic member is stretched. The elastic member provides a force opposite to the compression direction of the non-pneumatic tire to the outer reinforcing layer through the second support member, and the elastic member provides a force in the same direction as the compression direction of the non-pneumatic tire to the inner reinforcing layer through the first support member.

[0010] Optionally, each of the elastic members is the same elastic member; Each of the elastic members in the same group is evenly distributed along the thickness direction of the shear band internal support body.

[0011] Optionally, each of the elastic members has a preset prestress after assembly. The preset prestress is obtained through the following formula: ; wherein, 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 an adjacent first support member to the end of an adjacent second support member.

[0012] Optionally, on the premise of ensuring the load-bearing capacity of the tire, the elastic member also needs to meet the maximum equivalent shear strain requirement of the non-pneumatic tire for the shear band structure of the non-pneumatic tire, that is ; the maximum equivalent shear strain of the shear band structure of the non-pneumatic tire is ; wherein, π is the pi, r S1 is the radius of the inner reinforcing layer, h is the thickness of the shear band structure of the non-pneumatic tire, n Tis the number of the first support members or the number of the second support members in the shear belt structure for non-pneumatic tires, d s and is the diameter of the elastic member.

[0013] The present application also provides a shear belt structure for non-pneumatic tires, and the shear belt structure for non-pneumatic tires is obtained by the design method of the shear belt structure for non-pneumatic tires as described above.

[0014] The present application also provides a non-pneumatic tire, and the non-pneumatic tire includes spokes, a tire tread, and the shear belt structure for non-pneumatic tires as described above.

[0015] The design method of the shear belt structure for non-pneumatic tires of the present application has the following advantages: (1) The design method of the shear belt structure for non-pneumatic tires proposed by the present application can customize the tire performance for different application scenarios. That is, only the required tire performance, the range of geometric parameters allowed for processing and preparation, and the range of material properties need to be input. The proposed method combines the finite element simulation software ABAQUS and the Bayesian optimization algorithm, and can automatically iterate out the parameters that meet the performance requirements within the parameter range. This reduces the experimental test iteration process required for non-pneumatic tire design for different application scenarios. Thus, the optimization design method of the present application is more efficient.

[0016] (2) Two adjacent first support members and second support members of the shear belt structure for non-pneumatic tires of the present application and the elastic member form a tension structure. The tension structure is used as the shear belt structure for non-pneumatic tires, and the tension member in the tension structure is replaced with a tension spring, so that the shear belt structure for non-pneumatic tires has a low shear modulus but a high compression bearing capacity. Therefore, it can meet the performance requirements of the shear belt structure for non-pneumatic tires for non-pneumatic tires. The design strategy proposed by the present application at the structural level solves the problem that conventional materials cannot balance shear flexibility and high compression bearing, and ensures the "top bearing" mechanism of non-pneumatic tires. It can not only greatly improve the bearing capacity per unit mass of non-pneumatic tires, but also reduce the ground contact pressure of the tires, and increase the comfort and stability during tire driving. Description of the Drawings

[0017] Figure 1 is a schematic flow chart of the design method of the shear belt structure for non-pneumatic tires according to an embodiment of the present application.

[0018] Figure 2 is a schematic structural diagram of the non-pneumatic tire according to an embodiment of the present application.

[0019] Figure 3 is the xoy plan front view of the shear belt structure for non-pneumatic tires of the non-pneumatic tire according to an embodiment of the present application.

[0020] Figure 4 This is a schematic cross-sectional view of the A-A section of the shear belt structure part for a non-pneumatic tire of an embodiment of the present application.

[0021] Figure 5 This is a schematic view of the deformation of the non-pneumatic tire of an embodiment of the present application.

[0022] Reference numerals 1, wheel hub; 2, spoke; 3, inner reinforcing layer; 4, outer reinforcing layer; 5, inner support body of shear belt; 6, elastic member; 7, pin shaft. Detailed implementation manners

[0023] To make the objectives, technical solutions, and advantages of the implementation 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 accompanying drawings in the embodiments of the present application. In the drawings, the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The described embodiments are some, but not all, of the embodiments of the present application. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to explain the present application and should not be construed as limiting the present application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present application without creative efforts 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 accompanying drawings.

[0024] In the description of the present application, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "circumferential", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as limiting the scope of protection of the present application.

[0025] As Figure 1 shown, the shear belt structure design method for the non-pneumatic tire includes: Step 1: Obtain the target performance of the non-pneumatic tire to be designed and define the objective function, wherein the non-pneumatic tire to be designed includes a shear belt structure for the non-pneumatic tire; Step 2: Define the non-pneumatic tire structure parameter information, initialize the key structure parameters of the non-pneumatic tire to be optimized, and give the parameter optimization interval, wherein the key structure parameters of the non-pneumatic tire to be optimized include the parameters of the shear belt structure for the non-pneumatic tire, and the non-pneumatic tire structure parameter information includes fixed parameters and the key structure parameters of the non-pneumatic tire to be optimized; Step 3: Create a finite element model of the non-pneumatic tire according to the non-pneumatic tire structure parameter information; Step 4: Solve using the ABAQUS software based on the non-pneumatic tire finite element model, and output the key mechanical properties of the non-pneumatic tire; Step 5: Input the key structural parameters of the non-pneumatic tire to be optimized and the key mechanical properties of the non-pneumatic tire corresponding to the input key structural parameters of the non-pneumatic tire to be optimized into the Bayesian optimization method, and use the given parameter optimization interval as a limiting condition to iteratively generate a new combination of key structural parameters of the non-pneumatic tire and repeat Step 3 and Step 4 until the optimal key structural parameters that meet the target performance of the non-pneumatic tire to be designed are output after the iteration ends.

[0026] In this embodiment, the end of the iteration can be reaching a preset number of iteration rounds or reaching a preset iteration condition.

[0027] In this embodiment, the key structural parameters of the non-pneumatic tire to be optimized at least include one of the parameter information of the shear band structure for the non-pneumatic tire (it can be understood that in other embodiments, it can also include the thickness of the spoke), and the parameter information of the shear band structure for the non-pneumatic tire includes: The thickness of the shear band structure for the non-pneumatic tire, 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.

[0028] In this embodiment, the objective function is as follows: ; where where is the objective function; is the magnitude of the maximum stress of the non-pneumatic tire in the finite element calculation result, is the weight corresponding to the maximum stress in the non-pneumatic tire, is the th target performance, is the th performance obtained from the current simulation calculation, is the th weight of the target performance, n represents the number of target performances.

[0029] In this embodiment, creating the non-pneumatic tire finite element model according to the non-pneumatic tire structure parameter information includes: The hub, spokes, shear band structure for non-pneumatic tires, tread, and road surface of the non-pneumatic tire are established; the spokes and shear band structure for non-pneumatic tires are modeled as beam elements, the tread adopts two-dimensional shell elements, and the road surface adopts one of beam elements, shell elements, and analytical rigid bodies; Material parameters are given for the hub, spokes, shear band structure for the non-pneumatic tire, tread, and road surface of the non-pneumatic tire respectively. It should be emphasized that specific material properties can also be given to the tread and road surface for different usage environments, but this does not affect the design of the shear band structure for the non-pneumatic tire and the optimization of the overall performance of the non-pneumatic tire.

[0030] The various components are assembled together and interaction relationships are set to form the non-pneumatic tire finite element model.

[0031] See also Figures 2 to 4 In this embodiment, the shear band structure for a non-pneumatic tire includes an inner reinforcing layer 3, an outer reinforcing layer 4, a shear band internal support body 5, and an elastic member group. The inner reinforcing layer 3 is connected to the spoke 2; the outer reinforcing layer 4 is connected to the tire tread; the shear band internal support body 5 is arranged between the inner reinforcing layer 3 and the outer reinforcing layer 4, and the shear band internal support body 5 includes a plurality of first support members arranged along the circumference of the inner reinforcing layer 3 and a second support member arranged along the circumference of the outer reinforcing layer 4, a first support member and a second support member are arranged adjacent to each other; the number of elastic member groups is multiple, and each elastic member group is The elastic member group includes multiple elastic members 6, one end of an elastic member 6 is hinged to a first support member, and the other end is hinged to a second support member, and the elastic members in the same elastic member group are hinged to the same first support member and the same second support member; wherein, when the outer reinforcing layer 4 is compressed and deformed, the elastic member 6 is subjected to tension, and the elastic member 6 provides a force to the outer reinforcing layer 4 through the second support member in the opposite direction of the compression direction of the non-pneumatic tire, and the elastic member 6 provides a force to the inner reinforcing layer 3 through the first support member in the same direction as the compression direction of the non-pneumatic tire.

[0032] In this embodiment, the elastic members are identical elastic members; and the elastic members in the same group are evenly distributed along the thickness direction of the inner support body of the shear band.

[0033] In this embodiment, the first supporting member and the second supporting member have the same structure, except that one is connected to the inner reinforcement layer and the other is connected to the outer reinforcement layer.

[0034] In this embodiment, each of the elastic members has a preset prestress after assembly, and the prestress ensures that the elastic members do not shake after assembly. The preset prestress is obtained by the following formula: ;in, is the number of elastic members in each column of elastic member groups, is the stiffness of a single elastic member, is the initial length of the elastic member, is the distance from an adjacent first support member to the end of an adjacent second support member.

[0035] In this embodiment, on the premise of ensuring the load-bearing capacity of the tire, the diameter of the elastic member should be as small as possible to ensure sufficient space between the elastic member and the support body, allowing the shear band to generate a large shear deformation.

[0036] The present application also provides a shear band structure for a non-pneumatic tire. The non-pneumatic tire includes spokes and a tire tread. It is characterized in that the shear band structure for the non-pneumatic tire is obtained by the above-mentioned design method of the shear band structure for the non-pneumatic tire.

[0037] The present application also provides a non-pneumatic tire, which includes tire spokes, a tread, and the above-mentioned shear band structure for the non-pneumatic tire.

[0038] In this embodiment, the shear band structure for the non-pneumatic tire is located outside the tire spokes 2. The shear band structure for the non-pneumatic tire includes an inner reinforcing layer 3, an outer reinforcing layer 4, an internal support body 5 of the shear band, and an elastic member group. Among them, the inner reinforcing layer 3 is connected to the tire spokes 2, the outer reinforcing layer 4 is connected to the tread, and the inner reinforcing layer 3 and the outer reinforcing layer 4 are annular thin shells with uniform thickness. The internal support body 5 of the shear band is a "T"-shaped structure. A part of a first support member, a part of an adjacent second support member, and the elastic member connecting the two (the elastic member in the present application is a tension spring) constitute a tension structure unit. The characteristic of this unit is that when subjected to a compressive load, the elastic member undergoes tensile deformation, and the internal of the shear band structure for the non-pneumatic tire is obtained by circumferentially arraying the tension structure units.

[0039] In this embodiment, a groove is provided inside the internal support body 5 of the shear band, and a tension spring can be placed in the groove. The inner reinforcing layer 3, the outer reinforcing layer 4, the internal support body 5 of the shear band, and the elastic member 6 together constitute the shear band structure for the non-pneumatic tire. The internal support body 5 of the shear band and the elastic member 6 are hinged together by a pin shaft 7. An adjacent first support member, second support member, and the cooperating elastic member are combined into a tension structure unit. It should be emphasized in the present application that although the specific form of the internal support body of the shear band is not limited, it is necessary to ensure that the internal support body of the shear band and the tension spring together constitute a tension structure. This feature is manifested in the tire deformation that when the tire is compressed, the tension spring will be further stretched, while the internal support body of the shear band is in a compressed state.

[0040] In this embodiment, to ensure the uniformity of tire performance, all the tension springs are of the same specification, and the axis of the tension spring is along the radial direction of the tire. It should be emphasized that the initial length of the tension spring should be slightly less than the distance from the end of the first support member to the end of the second support member within the shear belt structure for non-pneumatic tires (see Figure 3 ), so as to ensure that the tension spring after assembly has a certain prestress and avoid the tension spring from shaking after assembly.

[0041] The magnitude of the prestress can be obtained from the formula where is the number of elastic members in each column of elastic member groups, is the stiffness of a single elastic member, is the initial length of the elastic member, is the distance from the end of the adjacent first support member to the end of the adjacent second support member. The tensile stiffness and number of the tension 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 sufficient stiffness of the tension spring, the diameter of the tension spring should be minimized as much as possible to ensure sufficient space between the tension spring and the internal support of the shear belt, which determines the maximum shear strain that the shear belt structure for non-pneumatic tires can generate. Assuming that the diameter of the tension spring is , the maximum effective shear strain that the shear belt structure for non-pneumatic tires can theoretically generate is .

[0042] where is the radius of the inner reinforcing layer, h is the thickness of the shear belt structure for non-pneumatic tires, n T is the number of tension structure units in the shear belt structure for non-pneumatic tires. In addition, rings should be provided at both ends of the tension spring to ensure the hinged connection mode between the tension spring and the internal support of the shear belt.

[0043] In this embodiment, the equivalent compression modulus of the tension structure unit is where d is the width of the non-pneumatic tire, π is the pi, r S1 is the radius of the inner reinforcing layer, h is the thickness of the shear belt structure for non-pneumatic tires, n T is the number of the first support members or the number of the second support members in the shear belt structure for non-pneumatic tires. Since the assembly mode between the tension spring and the internal support of the shear belt in the tension structure unit is hinged, the ideal equivalent shear modulus of the tension structure unitG e =0. However, it is understandable that due to the geometric assembly constraints of the tire itself, the initial equivalent shear modulus of the actual tensile structural unit is a value slightly greater than zero. The empirical formula for calculating the ground contact pressure of a non-pneumatic tire is: , where is the radius of the tire's outer reinforcement layer; P is the ground contact pressure of a non-pneumatic tire. Generally speaking, in order to reduce the ground contact pressure of the tire, the shear modulus of the shear band structure of the non-pneumatic tire is G e It should be as small as possible, which is consistent with this embodiment.

[0044] The shear belt structure design method for non-pneumatic tires of the present application has the following advantages: (1) The shear band structure design method for non-pneumatic tires proposed in this application can customize tire performance for different application scenarios. That is, it is only necessary to input the required tire performance and the range of geometric parameters and material properties that can be processed and prepared. The proposed method combines the commercial finite element simulation software ABAQUS and the Bayesian optimization algorithm to automatically iterate parameters that meet performance requirements within the parameter range. This reduces the experimental test iteration process required for non-pneumatic tire design for different application scenarios. This makes the optimization design method of this application more efficient.

[0045] (2) This application adopts a tensioning structure as the shear band structure for non-pneumatic tires, and replaces the tensioning components in the tensioning structure with tension springs, so that the shear band structure for non-pneumatic tires has a low shear modulus but a high compression bearing capacity, thereby meeting the performance requirements of non-pneumatic tires for shear band structures for non-pneumatic tires. The design strategy proposed in this application at the structural level solves the problem that conventional materials cannot take into account both shear flexibility and high compression bearing capacity, and ensures the "top load" mechanism of non-pneumatic tires, which can not only greatly improve the bearing capacity per unit mass of non-pneumatic tires, but also reduce the ground pressure of the tires, thereby increasing the comfort and stability of the tires during driving.

[0046] It is understandable that there is no restriction on the materials used in this embodiment, so rubber or even metal can be used according to actual needs. The non-pneumatic tire proposed here can be made of all nylon or metal by 3D printing, and then the tension spring is built into the shear band structure for the non-pneumatic tire. It is also possible to obtain the spokes, inner reinforcement layer, outer reinforcement layer and shear band internal support body separately by mechanical processing, and then assemble each component together by mechanical assembly. Similarly, this application does not limit the assembly method, and welding, riveting or bolting can be used according to the processing conditions.

[0047] It is understandable that in this embodiment, the structural characteristics of the spokes are not restricted, and the shape of the spokes can be Figure 2 a curved beam constructed by the spline curve shown, or a thin-walled honeycomb structure, or an intersecting curved beam structure, etc.

[0048] In this embodiment, the internal support body of the shear band connecting the elastic member has sufficient bending stiffness to ensure that no obvious deformation occurs under the load of the tire.

[0049] The shear band structure for non-pneumatic tires contains multiple adjustable parameters, and the relationship between these parameters and the performance of non-pneumatic tires is a "black box", so it is impossible to optimize the performance by solving the gradient. And because the time required for a single finite element calculation is relatively long, this means that methods that require a large amount of calculation for each iteration, such as ant colony algorithm and genetic algorithm, also fail. Bayesian optimization is a method that uses Bayes' theorem to guide the search to find the minimum or maximum value of the objective function. In each iteration, the surrogate function is updated using the results obtained previously and the next optimization is carried out, which has the advantages of fewer iterations and faster speed.

[0050] In this embodiment, defining the objective function according to the target performance includes: Given the target performance of the non-pneumatic tire, such as radial stiffness, lateral stiffness, tangential stiffness, etc.; Define the minimized objective function according to the target performance. When there are multiple target performances, set weights for each target performance according to actual needs, and then multiply the target performance by the weight and accumulate.

[0051]

[0052] Among them, is the th target performance, is the th performance obtained from the current simulation calculation, is the th weight of the target performance, n represents the number of target performances.

[0053] In order to make the performance of the tire meet the target requirements while minimizing the maximum stress of the material as much as possible, the objective function can be changed to: ;

[0054] Among them, is the magnitude of the maximum stress of the non-pneumatic tire in the finite element calculation result, is the weight corresponding to the maximum stress in the non-pneumatic tire, is the th target performance, is the th performance obtained from the current simulation calculation, is the weight of the th target performance, n represents the number of target performances.

[0055] In this embodiment, the parameters that the shear belt structure of the non-pneumatic tire can participate in optimization include the number of tension structure units (that is, the number of the first support members or the number of the second support members in the shear belt structure of the non-pneumatic tire), the thickness of the inner reinforcing layer , the thickness of the outer reinforcing layer , the thickness of the shear belt structure of the non-pneumatic tire h , the stiffness of the tension spring k s ; the parameters that the spoke can participate in optimization include the thickness of the spoke , the curvature of the spoke , but it can be understood that it is not limited to only these listed parameters.

[0056] The number of the tension structure units is an integer . The angle of the tension structure unit is the included angle between the two sides of the unit .

[0057] Creating a finite element model in this embodiment includes parametrically establishing components, specifying material parameters, assembling components, creating analysis steps, setting interaction relationships, applying load boundary conditions, element mesh generation, and submitting calculation tasks; The parametrically establishing components include the hub, spokes, shear belt structure of the non-pneumatic tire, tread, and road surface of the non-pneumatic tire. Among them, the hub, spokes, and shear belt structure of the non-pneumatic tire part can be simplified into a beam element model, the tread uses two-dimensional shell elements, and the road surface uses an analytical rigid body model. Specifically, the hub is a ring with a radius , and this radius can be defined according to the actual situation.

[0058] The spokes demonstrated in this embodiment are thin beams with a certain curvature. Its curvature can be defined by an offset angle . The offset angle is the included angle between the line connecting the spoke end point and the tire center and the line connecting the spoke midpoint and the tire center. It can be understood that when , the spoke is a straight line. The spokes can be obtained by connecting the end point - midpoint - end point in sequence through a spline curve. The modeling methods of the inner reinforcing layer and the outer reinforcing layer of the shear belt structure of the non-pneumatic tire are similar to that of the hub, and will not be elaborated here.

[0059] The internal support of the shear band can be modeled as a "T"-shaped beam. Half of the number of "T"-shaped internal supports of the shear band are connected to the inner reinforcement layer (i.e., the first support), and the other half are connected to the outer reinforcement layer (i.e., the second support). This part of the structure is determined by three geometric parameters, namely the number of tensioning units , the distance from the end of the first support to the end of the adjacent second support and the thickness . Therefore, the radian of a "T"-shaped internal support of the shear band is . Among them, the thickness should be large enough to ensure that the deformation generated by the internal support of the shear band in the tire under load can be ignored compared to the deformation at the bottom of the tire. It can be understood that since the circumferential perimeter is related to the radius length, the circumferential lengths of the first support and the second support are different. The circumferential length of the internal support of the shear band connected to the inner reinforcement layer is , and the circumferential length of the internal support of the shear band connected to the outer reinforcement layer is .

[0060] On the premise of no self-contact, if the diameter of the tension spring is ignored, theoretically, the maximum shear strain of the shear band structure for non-pneumatic tires can reach . The tension springs inside the shear band structure for non-pneumatic tires are set in the Interaction module of ABAQUS and are not modeled here. It can be understood that the model can also be extended to three-dimensional geometry, but the geometric relationships between different components and the logical relationships between various parameters remain unchanged.

[0061] The given material parameters include the material properties of the spokes, reinforcement layers, shear layers, treads, and road surfaces. According to actual needs, the properties of the materials can be linear or hyperelastic, etc.

[0062] The described assembly components are to assemble the non-pneumatic tire model, tread, and road surface together according to the geometric relationships in the Assembly module.

[0063] The described creation of analysis steps can adopt the State General type. It should be emphasized here that due to the existence of prestress in the tension spring, at least two analysis steps are required. The first analysis step is for the tension spring to release a part of the strain energy into the tire to reach a self-equilibrium state. The subsequent analysis steps are for simulating the loading of the tire.

[0064] The setting of interaction relationships in this embodiment includes defining a tension spring with pre-tension, displacement coupling, and contact relationships. The steps for defining a tension spring with pre-tension include: 1) Create a line feature in the Interaction module of ABAQUS. The two endpoints of this line are the positions where the two ends of the tensile spring are located in practice.

[0065] 2) Define the connector properties. Here, it is necessary to select the basic Axial type of connector, and select Elasticity and Reference Length in the BehaviorOptions option, and assign the tensile spring stiffness and the initial length respectively.

[0066] The tensile spring stiffness here should be the sum of the stiffnesses of each column of tensile springs, that is n s k s The displacement coupling is to couple the displacements of all mesh elements on the wheel hub to the reference point at its geometric center through the Coupling or Tie command. The interaction relationship between the tread and the outer reinforcing layer can be set by adding the Embedded command, where 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 of the non-pneumatic tire and the road surface, such as the friction coefficient, etc.

[0067] The applied load boundary conditions in this embodiment are specifically to apply displacement or force loads on the reference point of the coupled wheel hub and fix the road surface. If the target performance is the radial stiffness of the non-pneumatic tire, then 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, then a downward force is first applied to the reference point, and then a horizontal displacement is applied.

[0068] The element mesh division in this embodiment can be operated according to the default parameters of the ABAQUS software.

[0069] The output calculation results in this embodiment involve the post-processing of the calculation results and the output of the results. 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 completed entirely within ABAQUS. In this embodiment, the performance results obtained from the simulation calculation are automatically written into the Result.txt or Result.csv file, which is used as the information transfer between the optimization program and the finite element calculation program. The information contained in the file is the result corresponding to the target performance obtained from the current calculation result. It can be understood that the finite element analysis program is similar to a black box function. Inputting geometric parameters will output the corresponding performance.

[0070] The optimization iteration process in this embodiment includes reading the current simulation results and obtaining the geometric parameters for the next cycle according to the Bayesian optimization method; In the iterative process of the described Bayesian optimization model, a prior distribution is first selected to represent the uncertainty of the objective function. Usually, models such as Gaussian processes or random forests are used. Then, a set of points is selected from the initial point set as the initial sampling points. In each iteration, according to the current prior distribution model, the objective function is sampled to obtain a new sampling point. Then, based on this sampling point, the prior distribution model is updated, and under the new prior distribution model, the next sampling point is selected. Through continuous iteration, the objective function is gradually optimized, and finally the optimal solution is found. In this implementation case, it is to obtain the minimum value of the objective function.

[0071] The described 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 and calculating the finite element model are separate. In the optimization iteration program, the Python program for simulation can be called through 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 loop. It should be emphasized that the updated parameters should be written into the Paremerer.txt or Paremerer.csv file to be passed to the finite element calculation program. In this implementation case, the two programs involved interact through parameter files and result files.

[0072] The embodiment of this application gives a demonstration case according to the proposed optimization algorithm for non-pneumatic tires based on tensile structures. The predefined geometric parameters are: the width of the non-pneumatic tire d = 50mm, the thickness of the shear band structure of the non-pneumatic tire h = 18mm, the radius of the inner reinforcing layer r S1 = 100mm, the radius of the outer reinforcing layer r S2 = 118mm, the width of the internal support in the shear band t T = 2mm, the length of the tension spring l s = 10mm, the number of spokes is 36, the number of tensile structure units n T = 36. The elastic modulus of the material is 72 GPa (the elastic modulus of conventional aluminum alloy). The parameters to be optimized: the thickness of the spokes 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 tension spring ks The parameter ranges are 0.1 - 0.6 mm, 0.1 - 0.6 mm, 0.1 - 0.6 mm, and 50 - 200 N / mm respectively, and let t S1 = t S2 . Performance requirements: When the non - pneumatic tire sinks by 6 mm, it reaches the rated load of 600 N, and it is required that the maximum stress of the part except the tensile spring is as small as possible. The weight factors of the load and the maximum stress are taken as 3000 and 1 respectively. Therefore, the objective function is , where is the maximum stress of the tire when the sinkage is 6 mm, is the corresponding load. The number of iterations is set to 100. The obtained optimal parameters are: the thickness of the spoke t sp = 0.46 mm, the thickness of the inner reinforcing layer and the thickness of the outer reinforcing layer t S1 = t S2 = 0.13 mm, and 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 .

[0073] The measured effective load of the non - pneumatic tire when the sinkage is 6 mm is 600.2 N, meeting the target performance requirements. At this time, the maximum stress of the non - pneumatic tire is 362 MPa, which is much smaller than the strength of high - strength aluminum alloy (>500 MPa). It can be understood that because the circumferential length of the inner reinforcing layer is shorter than that of the outer reinforcing layer, when the non - pneumatic tire bears a load, the shear - band structure of the non - pneumatic tire must undergo shear deformation to adapt to the difference in the circumferential lengths of the inner and outer sides. At this time, the internal support in the shear band tilts, and the shear - band structure of the non - pneumatic tire undergoes shear deformation. The contact between the bottom of the tire and the ground is relatively flat, ensuring uniform ground contact pressure. It can be seen that the spokes at the top and both sides of the non - pneumatic tire are straightened, which reflects the top - bearing mechanism of the tire.

[0074] Finally, it should be pointed out that: the above embodiments are only used to illustrate the technical solutions of the present application, and are not intended to limit them. Although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements for 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 each embodiment of the present application.

Claims

1. A design method for a shear belt structure of a non-pneumatic tire, characterized in that The structural design method of the shear band for non-pneumatic tires includes: Step 1: Obtain the target performance of the to-be-designed non-pneumatic tire and define the objective function. Among them, the to-be-designed non-pneumatic tire includes the shear band structure for non-pneumatic tires. Step 2: Define the non-pneumatic tire structure parameter information, initialize the key structure parameters of the non-pneumatic tire to be optimized, and give the parameter optimization interval. Among them, the key structure parameters of the non-pneumatic tire to be optimized include the parameters of the shear band structure for non-pneumatic tires. The non-pneumatic tire structure parameter information includes fixed parameters and the key structure parameters of the non-pneumatic tire to be optimized. Step 3: Create a non-pneumatic tire finite element model according to the non-pneumatic tire structure parameter information. Step 4: Solve according to the non-pneumatic tire finite element model using ABAQUS software and output the key mechanical properties of the non-pneumatic tire. Step 5: Input the key structure parameters of the non-pneumatic tire to be optimized and the key mechanical properties of the non-pneumatic tire corresponding to the input key structure parameters of the non-pneumatic tire to be optimized into the Bayesian optimization method, and use the given parameter optimization interval as the constraint condition to iterate out a new combination of key structure parameters of the non-pneumatic tire and repeat Step 3 and Step 4 until the optimal key structure parameters of the non-pneumatic tire that meet the target performance of the to-be-designed non-pneumatic tire are output after the iteration ends.

2. The design method of the shear belt structure for a non-pneumatic tire according to claim 1, characterized in that, The key structure parameters of the non-pneumatic tire to be optimized include at least one of the parameter information of the shear band structure for non-pneumatic tires. The parameter information of the shear band structure for non-pneumatic tires includes: The thickness of the shear band structure for non-pneumatic tires, the number of the first support members, the number of the 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 design method of the shear belt structure for a non-pneumatic tire according to claim 2, characterized in that, The objective function is as follows: ； Among them, is the objective function; is the magnitude of the maximum stress of the non-pneumatic tire in the finite element calculation result, is the weight corresponding to the maximum stress in the non-pneumatic tire, is the th target performance, is the th performance obtained from the current simulation calculation, is the weight of the th target performance, n represents the number of target performances.

4. The structural design method of the shear band for non-pneumatic tires according to claim 3, characterized in that, The creation of the non-pneumatic tire finite element model according to the non-pneumatic tire structure parameter information includes: Establish the hub, spokes, shear band structure for non-pneumatic tires, tread, and road surface of the non-pneumatic tire; among them, the spokes 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. Assign material parameters to the hub, spokes, shear band, tread, and road surface of the non-pneumatic tire respectively. Assemble each component together and set the interaction relationship to form the non-pneumatic tire finite element model.

5. The structural design method of the shear band for a non-pneumatic tire according to claim 4, characterized in that, The shear band structure for non-pneumatic tires includes: An inner reinforcing layer (3), and the inner reinforcing layer (3) is connected to the spokes (2); An outer reinforcing layer (4), and the outer reinforcing layer (4) is connected to the tire tread; A shear band internal support body (5), and the shear band internal support body (5) is arranged between the inner reinforcing layer (3) and the outer reinforcing layer (4). The shear band internal support body (5) includes 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). A first support member and a second support member are arranged adjacent to each other. Elastic element group, the number of the elastic element groups is multiple, each elastic element group includes a plurality of elastic elements (6), one end of an elastic element (6) is hinged to a first support member, and the other end is hinged to a second support member. Each elastic element in the same elastic element group is hinged to the same first support member and the same second support member; wherein, When the outer reinforcing layer (4) is compressed and deformed, the elastic element (6) is subjected to a tensile force. The elastic element (6) provides a force to the outer reinforcing layer (4) in a direction opposite to the compression direction of the non-pneumatic tire through the second support member, and the elastic element (6) provides a force to the inner reinforcing layer (3) in the same direction as the compression direction of the non-pneumatic tire through the first support member.

6. The structural design method of the shear belt for non-pneumatic tires according to claim 5, characterized in that, Each of the elastic elements (6) is the same elastic element; Each of the elastic elements (6) in the same group is uniformly distributed along the thickness direction of the inner support body of the shear band.

7. The structural design method of the shear band for a non-pneumatic tire according to claim 6, characterized in that, Each of the elastic elements has a preset prestress after assembly, and the preset prestress is obtained by the following formula: ; wherein, is the preset prestress; is the number of elastic members (6) in each column of elastic member groups, k s is the stiffness of a single elastic member (6), l s is the initial length of the elastic member (6), d T is the distance from the end of an adjacent first support member to the end of an adjacent second support member.

8. The structural design method of the shear band for a non-pneumatic tire according to claim 7, wherein On the premise of ensuring the load-bearing capacity of the tire, the elastic member (6) also needs to meet the maximum equivalent shear strain requirement of the shear belt structure for non-pneumatic tires for non-pneumatic tires, that is ; the maximum equivalent shear strain of the shear belt structure for non-pneumatic tires is ; where, π is the pi,[[]] r S1 is the radius of the inner reinforcing layer,[[]] h is the thickness of the shear belt structure for non-pneumatic tires,[[]] n T is the number of the first support members or the number of the second support members in the shear belt structure for non-pneumatic tires,[[]] d s is the diameter of the elastic member.[[]] 9. A shear belt structure for a non-pneumatic tire, characterized in that, The shear band structure for non-pneumatic tires is obtained by the shear band structure design method for non-pneumatic tires as described in any one of claims 1 to 8.

10. A non-pneumatic tire, characterized in that, The non-pneumatic tire includes spokes, a tire tread, and the shear band structure for non-pneumatic tires as described in claim 9.

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