Air spring system structural component design method, device, equipment and storage medium

Abstract

The present invention belongs to the field of automobile technology, and specifically is a method, device, equipment and storage medium for designing air spring system structural parts. It includes: 1. Establishing a high-precision air spring axisymmetric finite element model; 2. Establishing a high-precision air spring solid finite element model; 3. Carrying out air suspension modeling and simulation analysis; 4. Structural part strength simulation analysis; 5. Structural part strength verification and optimization. The present invention adopts a combination of flexible body-assisted modeling + fluid-solid coupling solution to carry out structural strength analysis. Each incremental step of the simulation analysis adjusts the contact state and structural stiffness according to the analysis results to correctly describe the large deformation mechanical behavior of the flexible structure under load. Avoid the type and position of the connection unit in the finite element modeling and the resulting errors to ensure the simulation accuracy; and use system analysis instead of single-piece analysis to correctly reflect the changes in assembly clearance and contact relationship under load conditions, thereby improving the accuracy of structural simulation.

Description

Technical Field

[0001] The present invention belongs to the field of automobile technology, and in particular to an air spring system structural component design method, device, equipment and storage medium. Background Art

[0002] Air springs are becoming more and more popular in high-end passenger cars due to their good stiffness characteristics. However, compared with traditional suspensions in the form of coil springs, air springs can generally provide greater axial loads, so the load conditions of the structural parts on the spring channel are more severe. The spring channel mainly includes control arms, body, and air spring upper and lower covers. Among them, air spring structural parts are mostly made of non-metallic materials with low material strength, so it is necessary to conduct structural strength verification.

[0003] The first step is to determine the load conditions for strength verification of structural parts. Usually, the air spring load conditions are extracted by suspension load decomposition. Generally speaking, the axial stiffness and warping stiffness of the air spring are defined based on the stiffness curve. However, the warping stiffness of the air spring is related to many factors such as air pressure and length. The stiffness curve cannot represent the actual warping stiffness of the air spring. Therefore, the air spring strength analysis conditions obtained by load decomposition cannot support high-precision strength analysis.

[0004] The second method to obtain the load conditions for strength verification of structural parts is to obtain the displacement of the air spring under specified working conditions or postures based on the suspension DMU analysis, and use the displacement as the input condition for the analysis of the air spring system, or extract the corresponding load of the air spring based on the displacement of the air spring as the input condition. However, the DMU analysis does not consider the deformation of structural parts and the displacement of the hard points of the suspension bushing, and the displacement direction of the spring is not fixed and is not along the axial direction. Therefore, the displacement and load conditions of the air spring analysis obtained by this method are inaccurate and cannot support high-precision strength verification.

[0005] The second step is to check the structural strength. The finite element method is a common method in the industry. The loading points in the model are connected to the structural parts through rigid units, and the loads are transferred to the structural parts through rigid units. In actual working conditions, the upper and lower covers of the empty spring are in contact with the empty spring capsule. Under load conditions, the contact surface between the capsule and the structural part changes and does not remain axisymmetric. Therefore, the finite element model using ordinary rigid connection units cannot guarantee the analysis accuracy, and the general software lacks connection units that can change the connection position or adaptive stiffness in real time, so high-precision stress analysis of structural parts cannot be achieved.

[0006] In summary, it is concluded that there are two main problems in the analysis of air spring structural parts based on traditional analysis methods: 1. Insufficient accuracy of structural part loads; 2. Insufficient accuracy of structural part strength analysis models. Therefore, the stress analysis accuracy of passenger car air spring structural parts cannot support strength design, and new simulation methods need to be developed to improve analysis accuracy. Summary of the invention

[0007] The present invention provides a method, device, equipment and storage medium for designing air spring system structural parts based on the flexible body assisted method. The present invention adopts the flexible body assisted method modeling + fluid-solid coupling solution combined method to perform structural strength analysis. The contact state and structural stiffness are adjusted according to the analysis results in each incremental step of the simulation analysis to correctly describe the large deformation mechanical behavior of the flexible structure under load. The type and position of the connection unit in the finite element modeling are avoided to ensure the simulation accuracy; and the system analysis is used instead of the single-piece analysis, which can correctly reflect the changes in the assembly gap and contact relationship under load conditions and improve the structural simulation accuracy.

[0008] The technical solution of the present invention is described as follows in conjunction with the accompanying drawings:

[0009] In a first aspect, an embodiment of the present invention provides a method for designing a structural component of an air spring system, comprising the following steps:

[0010] Step 1: Establish a high-precision axisymmetric finite element model of the air spring;

[0011] Step 2: establishing a high-precision air spring solid finite element model based on the high-precision air spring axisymmetric finite element model established in step 1;

[0012] Step 3: Import the high-precision air spring solid finite element model established in step 2 into the suspension system for air suspension modeling and simulation analysis;

[0013] Step 4: Simulation analysis of structural component strength;

[0014] Step 5: Strength verification and optimization of structural parts.

[0015] Furthermore, the specific method of step one is as follows:

[0016] 11) Establish an axisymmetric analysis model of air spring;

[0017] Based on any symmetry surface of the air spring, mesh the air spring model, define the rigid body properties and rigid body reference points of the upper cover, lower cover and clamping ring of the air spring; define the contact surface and contact relationship between the rigid body and the elastic body in the air spring model; divide the bladder unit and the reinforcing cord unit, define the reinforcing rib properties of the cord unit, and establish the axisymmetric finite element model of the air spring;

[0018] 12) Establish auxiliary flexible body;

[0019] Define the hyperelastic material and flexible body properties, and associate the hollow spring capsule skin with the hyperelastic material and flexible body properties; define the fluid-solid coupling interface based on the capsule mesh and part of the structure mesh as the action surface between air and structure, and define the fluid-solid coupling properties of the interface; define the outer surface contact surface of the flexible body structure, and define the contact pairs associated with it;

[0020] 13) Define simulation conditions;

[0021] Set the boundary conditions for the simulation of the axisymmetric empty spring model and define the load step: the empty spring is inflated to the design target value P0, and the empty spring is subjected to the axial displacement load [-U1, U1] along the symmetry axis;

[0022] 14) Finite element model solution;

[0023] Solve the simplified analysis model of the air spring axisymmetric, extract the support reaction force F0 of the air spring along the symmetry axis, extract the relationship between the support reaction force and the axial displacement, generate the FU curve, and extract the support reaction force under the specified displacement condition, and obtain the stiffness of the specified displacement through post-processing;

[0024] 15) Determine the simulation accuracy;

[0025] Select several points on the FU curve according to the displacement conditions and calculate the air spring support reaction force difference △F according to formula (1) i " and air spring stiffness difference △K" i :

[0026]

[0027] In the formula, Fd i is the axial force on the design target curve; Kd i is the axial force and stiffness on the design target curve; F i ' is the axial force difference under the load condition corresponding to the empty spring simulation curve; K' i It is the stiffness difference of the empty spring simulation curve under corresponding load conditions.

[0028] a) If the following conditions are met:

[0029]

[0030] It is determined that the simulated empty spring axisymmetric model meets the simulation accuracy requirements;

[0031] b) If the conditions specified in formula (2) are not met, the simulation accuracy of the empty spring is determined to be unsatisfactory, and the process of steps 11)-13) needs to be repeated to redefine the materials, properties, and contact conditions until the accuracy specified in formula (2) is achieved. It is determined that the axisymmetric model of the empty spring meets the simulation accuracy requirements.

[0032] Furthermore, the specific method of step 2 is as follows:

[0033] 21) generating a solid finite element mesh; rotating the air spring axisymmetric finite element model established in step 1 around the axis of symmetry to generate a solid unit air spring mesh, and deleting the original axisymmetric mesh;

[0034] 22) defining an auxiliary flexible body; defining the flexible body properties of the capsule mesh in the solid model and associating it with the hyperelastic material;

[0035] 23) Update model parameters; update the deformable body properties of the structural 3D unit, the reinforcing rib properties of the planar cord unit, redefine the structural rigid body properties based on the 3D unit, and update the contact surface of the empty spring component surface;

[0036] 24) Update the coupling action area; redefine the closed fluid-solid interface area, including the inner surface of the bladder skin, upper cover, and lower cover structure as the interaction surface between the air and the structure; redefine the contact surface of the outer surface of the bladder skin, and the mutual contact relationship between the air-spring structure remains unchanged;

[0037] 25) Update boundary and load conditions; define the overall boundary conditions in all degrees of freedom, the boundary conditions of the inflation load step, and the boundary conditions in the axial displacement load step;

[0038] 26) Finite element model solution; solve the air spring entity analysis model, extract the relationship between the support reaction force and axial displacement of the air spring along the symmetry axis, generate the FU curve, extract the support reaction force under the specified displacement load condition, and solve the stiffness value of the air spring under the specified displacement load condition;

[0039] 27) Determine the simulation accuracy; Based on the empty spring support reaction force and stiffness values ​​solved in step 26), calculate the support reaction force difference and stiffness difference according to formula (1):

[0040]

[0041] In the formula, △F i " is the difference in the reaction force of the air spring support; △K" i Is the air spring stiffness difference: Fd i is the axial force on the design target curve; Kd i is the axial force and stiffness on the design target curve; F i ' is the axial force difference under the load condition corresponding to the empty spring simulation curve; K' i It is the stiffness difference of the empty spring simulation curve under the corresponding load condition;

[0042] a) If the difference in support reaction force and stiffness meets the condition of formula (2), it is determined that the empty spring solid finite element model meets the simulation accuracy requirements;

[0043] b) If the difference in the support reaction force and the difference in the stiffness do not meet the conditions of formula (2), it is determined that the solid finite element model of the air spring does not meet the simulation accuracy requirements, and it is necessary to repeat the process of steps 21)-27) to redefine the mesh size, contact, and boundary conditions until the accuracy specified in formula (2) is achieved, and it is determined that the solid finite element model of the air spring meets the simulation accuracy requirements;

[0044]

[0045] Furthermore, the specific method of step three is:

[0046] 31) Importing the solid model; Selecting the suspension model under the specified posture, and importing the high-precision air spring solid finite element model in step 2;

[0047] 32) Correction of the posture of the air spring model; coincide the reference point of the rigid structure of the lower cover of the air spring with the lower point of the spring, measure the angle formed by the upper point of the spring, the lower point of the spring, and the reference point of the upper cover rigid body, and rotate the air spring model according to the measured angle on the plane formed by the three points to ensure that the axis of the air spring solid model including the auxiliary flexible body is consistent with the design axis of the spring;

[0048] 33) Correction of the position of the air spring model; move the empty spring along the axial direction of the spring until the lower cover of the spring coincides with the designed position, and the upper cover is also at the designed position;

[0049] 34) Adjust the air spring model; modify the rigid body definition in the finite element model of the air spring, update the lower point of the spring to the rigid body reference point of the lower cover, and update the upper point of the spring to the rigid body reference point of the upper cover;

[0050] 35) Loading the air suspension: The air suspension is loaded in two load steps according to the following process;

[0051] 351) Define the air spring inflation load step; constrain the 1-6 degrees of freedom of the air spring upper point, the shock absorber upper point, the subframe and the body connection point, and constrain the vertical freedom of the wheel center. The air spring is inflated to the specified attitude pressure target P0, and the vertical support reaction force Fzw0 of the wheel center at this time is extracted;

[0052] 352) define the suspension displacement load step; release the vertical constraint at the wheel center position, and apply the vertical displacement load Uzw, extract the vertical support reaction force Fzw of the wheel center, the displacement of the lower point of the shock absorber Uj, the support reaction force Fj of the upper point of the shock absorber, the displacement of the lower point of the air spring Us, the support reaction force Fs of the upper point of the air spring, and the support reaction moment Ms, and generate the wheel center vertical load-displacement curve, i.e., the Uzw-Fzw curve, the shock absorber load curve, i.e., the Uzw-Fj curve, and the air spring load curve, i.e., the Uzw-Fs curve;

[0053] 36) Determine the simulation progress; Determine the simulation accuracy by comparing the air suspension system test with the system simulation results, and follow the following steps:

[0054] 361) Select several points on the wheel center vertical load-displacement curve according to the displacement condition, and calculate the difference between the wheel center load simulation and the test according to formula (3):

[0055] △F i =|Fzw i -Fzw' i | (3)

[0056] In the formula, Fzw i is the simulated value of the wheel center vertical load; Fzw' i is the test value of the wheel center vertical load; △Fzw i is the difference between the simulation and test of the wheel center vertical load;

[0057] a) If the following conditions are met:

[0058] △F i ≤0.01*Fzw' i (4)

[0059] It is determined that the wheel center vertical load simulation accuracy meets the requirements, and the process goes to step 362);

[0060] b) If the condition specified in formula (4) is not satisfied, it is determined that the simulation accuracy of the wheel center vertical load does not meet the requirement, and the operation of step 31) to step 35) needs to be repeated, and the stiffness property of the elastic connection unit in the model is adjusted until formula (4) is satisfied; at this time, it is determined that the simulation accuracy of the wheel center vertical load of the air suspension model meets the requirement, and go to step 362);

[0061] 362) Select several points on the shock absorber load curve and the air spring load curve, and calculate the difference between the shock absorber and spring load test and simulation according to formula (5):

[0062]

[0063] In the formula, Fj i and Fs i are the simulation values ​​of shock absorber and spring load respectively; Fj' i and Fs' i are the test values ​​of shock absorber and spring load respectively; △Fj i is and △Fs are the differences between the simulation and test of shock absorber and spring loads, respectively;

[0064] a) If the following conditions are met:

[0065]

[0066] It is determined that the simulation accuracy of the air suspension meets the requirements;

[0067] b) If the conditions specified in formula (6) are not met, it is determined that the distribution of the vertical load in the spring and shock absorber channels is not in line with reality, and the air suspension simulation accuracy does not meet the requirements. It is necessary to repeat the operations of steps 31) to 35), focusing on adjusting the shock absorber channel stiffness curve in the model until formula (6) is met. At this time, it is determined that the air suspension model meets the simulation accuracy requirements.

[0068] Furthermore, the specific method of step 4 is as follows:

[0069] 41) Model replacement: Divide the mesh based on the geometric model of the air spring system structure, import the mesh into the air suspension model, and adjust the position and posture, keeping the auxiliary flexible body mesh unchanged;

[0070] 42) Delete the rigid body; delete the rigid body model and reference points not involved in the structural strength simulation analysis model;

[0071] 43) Introduce auxiliary analysis structure; in addition to the analysis object, the structural grid required for the strength analysis of the air spring system structure is introduced into the air suspension model;

[0072] 44) defining contact; defining the contact surface for the model introduced in step 41) and step 43), and all contact pairs involved in the contact surface;

[0073] 45) Material and property definition: Introduce the model for step 41) and step 43), define the actual material properties, and define the properties according to the structure and mesh characteristics;

[0074] 46) Model solving; loading, the loading process is as follows:

[0075] 461) Define the air spring inflation load step; constrain the 1-6 degrees of freedom of the air spring upper point, the shock absorber upper point, the subframe and the body connection point, and constrain the vertical freedom of the wheel center. The air spring is inflated to the specified attitude pressure target P0, and the vertical support reaction force Fzw0 of the wheel center at this time is extracted;

[0076] 462) define the suspension displacement load step; release the vertical constraint at the wheel center position, and apply the vertical displacement load Uzw, extract the vertical support reaction force Fzw of the wheel center, the displacement of the lower point of the shock absorber Uj, the support reaction force Fj of the upper point of the shock absorber, the displacement of the lower point of the air spring Us, the support reaction force Fs of the upper point of the air spring, and the support reaction moment Ms, and generate the wheel center vertical load-displacement curve, i.e., the Uzw-Fzw curve, the shock absorber load curve, i.e., the Uzw-Fj curve, and the air spring load curve, i.e., the Uzw-Fs curve;

[0077] Among them, the suspension displacement is defined as the vertical upward jump limit of the wheel center. After solving the strength analysis model, the stress field S of the structural components in the second load step is extracted.

[0078] Furthermore, the specific method of step five is as follows:

[0079] 51) Strength check: Perform structural strength check according to formula (7):

[0080] n=σ max / [σ] (7)

[0081] In the formula, σ max is the maximum stress value in the stress field S of the structural component; [σ] is the allowable stress of the structural component; n is the safety factor of the empty spring structural component under the limit use condition;

[0082] a) If the following conditions are met:

[0083] n>1 (8)

[0084] It is determined that the structural parts meet the strength design requirements and the process ends;

[0085] b) If the condition specified in formula (8) is not met, it is determined that the strength of the empty spring structure does not meet the design requirements, and the process goes to step 52);

[0086] 52) Structural optimization iteration: Structural optimization is performed on the structural parts, and the operations of step 41) to step 51) are repeated for the optimized structure until the requirements of formula (8) are met, and the design is terminated.

[0087] In a second aspect, an embodiment of the present invention further provides an air spring system structural component design device, comprising:

[0088] The first modeling module is used to establish a high-precision axisymmetric finite element model of the air spring;

[0089] The second modeling module is used to establish a high-precision air spring solid finite element model;

[0090] Modeling and simulation analysis module, used to import high-precision air spring solid finite element model into the suspension system for air suspension modeling and simulation analysis;

[0091] Strength simulation analysis module, used to simulate and analyze the structural parts in the air spring system;

[0092] Strength verification and optimization module, used to verify and perform high-strength design on structural parts in air-spring systems.

[0093] Furthermore, the first modeling module includes:

[0094] Establish an air spring axisymmetric analysis model module, which is used to establish an air spring axisymmetric analysis model;

[0095] Establishing an auxiliary flexible body model module, used for establishing an auxiliary flexible body model;

[0096] Define simulation conditions module, used to define simulation conditions;

[0097] The first finite element model solving module is used to solve the axisymmetric simplified parting model of the air spring;

[0098] A simulation accuracy determination module is used to determine whether the simulated air spring axisymmetric model meets the simulation accuracy requirements;

[0099] The second modeling module comprises:

[0100] Generate solid finite element mesh model module, used to generate solid finite element network model;

[0101] Define an auxiliary flexible body module to define the flexible body properties of the capsule mesh and associate it with the hyperelastic material;

[0102] Update model parameter module, which is used to update model parameters, including the deformable body properties of 3D units, the reinforcing rib properties of planar cord units, redefine the structural rigid body properties based on 3D units, and update the contact surface of the empty spring component surface;

[0103] Update boundary and load condition module, which is used to update the overall boundary conditions in all degrees of freedom directions, the boundary conditions of the inflation load step, and the boundary conditions in the axial displacement load step;

[0104] The second finite element model solving module is used to solve the air conditioning spring entity analysis model;

[0105] The first simulation accuracy determination module is used to determine whether the air spring entity finite element model meets the simulation accuracy requirements;

[0106] The modeling and simulation analysis module includes:

[0107] Import solid model module, used to import high-precision air spring solid model;

[0108] An air spring model posture correction module is used to correct the posture of the air spring model;

[0109] An air spring model position correction module is used to correct the position of the air spring model;

[0110] A first air suspension loading module, used for loading the air suspension;

[0111] The second simulation accuracy determination module is used to determine whether the vertical load of the wheel center of the air suspension model meets the accuracy requirements;

[0112] The strength simulation analysis module includes:

[0113] Model replacement module, used to import the mesh into the air suspension model and adjust it to the correct position and posture, keeping the auxiliary flexible body mesh unchanged;

[0114] Delete rigid body module, which is used to delete rigid body models and reference points not involved in the structural strength simulation analysis model;

[0115] Introducing the auxiliary analysis structure module, which is used to import the structural mesh required for the strength analysis of the air spring system structure into the air suspension model in addition to the analysis object;

[0116] Define contact module, which is used to define contact surface and all contact pairs involved in the contact surface;

[0117] Material and property definition module, used to define the actual material properties and define properties based on the structure and mesh characteristics;

[0118] Model solving module, used to extract the stress field S of the second load step structural component after solving the strength analysis model;

[0119] The strength verification and optimization module includes:

[0120] Strength verification module, used to verify the strength of air spring system components;

[0121] The structural optimization module is used to optimize the structural parts of the air spring system until the requirements are met.

[0122] In a third aspect, an embodiment of the present invention further provides a computer device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the program, an air spring system structural component design method as described in any one of the embodiments of the present invention is implemented.

[0123] In a fourth aspect, an embodiment of the present invention further provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements a method for designing a structural component of an air spring system as described in any one of the embodiments of the present invention.

[0124] The beneficial effects of the present invention are:

[0125] 1) The present invention adopts the combined method of flexible body assisted modeling + fluid-solid coupling solution to perform structural strength analysis. The contact state and structural stiffness are adjusted according to the analysis results in each incremental step of the simulation analysis to correctly describe the large deformation mechanical behavior of the flexible structure under load. The type and position of the connection unit in the finite element modeling are avoided to ensure the simulation accuracy.

[0126] 2) The present invention adopts system analysis instead of single-piece analysis, which correctly reflects the changes in assembly clearance and contact relationship under load conditions and improves the accuracy of structural simulation. BRIEF DESCRIPTION OF THE DRAWINGS

[0127] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0128] Figure 1 It is the membrane type air spring structure and the axisymmetric finite element model diagram;

[0129] Figure 2 It is a schematic diagram of air conditioning load-displacement curve;

[0130] Figure 3 The present invention is a flow chart of a design method for a structural component of an air spring system;

[0131] Figure 4 A schematic diagram of a design device for a structural component of an air spring system;

[0132] Figure 5 The figure is a schematic diagram of the structure of an electronic device. DETAILED DESCRIPTION

[0133] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0134] It should be noted that similar reference numerals and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further defined and explained in the subsequent drawings. At the same time, in the description of the present invention, the terms "first", "second", etc. are only used to distinguish the description and cannot be understood as indicating or implying relative importance.

[0135] Embodiment 1

[0136] Figure 3 This is a flow chart of a method for designing a structure of an air spring system provided in Embodiment 1 of the present invention. This embodiment is applicable to the design of a structure of an air spring system. The method can be executed by a device for designing a structure of an air spring system in an embodiment of the present invention. The device can be implemented in software and / or hardware. Figure 3 As shown, the method specifically comprises the following steps:

[0137] Step 1: Establish a high-precision axisymmetric finite element model of the air spring;

[0138] The specific method of step one is as follows:

[0139] 11) Establish an axisymmetric analysis model of air spring;

[0140] Based on any symmetry surface of the air spring, mesh the air spring model, define the rigid body properties and rigid body reference points of the upper cover, lower cover and clamping ring of the air spring; define the contact surface and contact relationship between the rigid body and the elastic body in the air spring model; divide the bladder unit and the reinforcing cord unit, define the reinforcing rib properties of the cord unit, and establish the axisymmetric finite element model of the air spring;

[0141] Among them, general finite element analysis software such as Abaqus or Mrac can be used to model the air spring. Ensure at least 4 layers of mesh in the thickness direction of the rubber bag skin. And ensure that the symmetry axis of the air spring axisymmetric model coincides with the coordinate axis, otherwise the posture of the model should be adjusted.

[0142] 12) Establish auxiliary flexible body;

[0143] Define the hyperelastic material and flexible body properties, and associate the hollow spring capsule skin with the hyperelastic material and flexible body properties; define the fluid-solid coupling interface based on the capsule mesh and part of the structure mesh as the action surface between air and structure, and define the fluid-solid coupling properties of the interface; define the outer surface contact surface of the flexible body structure, and define the contact pairs associated with it;

[0144] Among them, hyperelastic material parameters can be defined based on a variety of constitutive relations, and the required parameters are not exactly the same. Taking the Mooner Rivlin model as an example, three hyperelastic material parameters need to be defined: C10, C01, and D1. And it should be ensured that the interface between the air and the structure can be combined with the symmetry axis to form a closed cavity, otherwise the model should be adjusted to meet the requirements.

[0145] 13) Define simulation conditions;

[0146] Set the boundary conditions for the simulation of the axisymmetric empty spring model and define the load step: the empty spring is inflated to the design target value P0, and the empty spring is subjected to the axial displacement load [-U1, U1] along the symmetry axis;

[0147] 14) Finite element model solution;

[0148] Solve the simplified analysis model of the air spring axisymmetric, extract the support reaction force F0 of the air spring along the symmetry axis, extract the relationship between the support reaction force and the axial displacement, generate the FU curve, and extract the support reaction force under the specified displacement condition, and obtain the stiffness of the specified displacement through post-processing;

[0149] Among them, Abaqus or Mrac and other general finite element analysis software can be used to solve the air spring. Both implicit and explicit solvers can be used to simulate the air spring model. In addition, it is necessary to ensure that all reinforcing cord units are always located in the rubber bag skin unit during the loading process, otherwise the work from step 11) to step 13) should be repeated. In step 11), the unit embedding command is used to improve the model accuracy;

[0150] Generally speaking, the extracted support reaction force is the combined axial support reaction force of the upper cover and the upper retaining ring, or the combined support reaction force of the lower cover and the lower retaining ring, see Figure 1 To simplify the post-processing process, the upper cover and the upper clamping ring can be combined into a rigid structure in 11), and the lower cover and the lower clamping ring can also be processed into a rigid structure.

[0151] The stiffness under the specified displacement load U2 is obtained by post-processing the FU curve, such as Figure 2 As shown, the slope K2 of the curve at U2 is the stiffness of the air spring under this stroke.

[0152] 15) Determine the simulation accuracy;

[0153] Select several points on the FU curve according to the displacement conditions and calculate the air spring support reaction force difference △F according to formula (1) i " and air spring stiffness difference △K" i :

[0154]

[0155] In the formula, Fd i is the axial force on the design target curve; Kd i is the axial force and stiffness on the design target curve; F i ' is the axial force difference under the load condition corresponding to the empty spring simulation curve; K' i It is the stiffness difference of the empty spring simulation curve under corresponding load conditions.

[0156] a) If the following conditions are met:

[0157]

[0158] It is determined that the simulated empty spring axisymmetric model meets the simulation accuracy requirements;

[0159] b) If the conditions specified in formula (2) are not met, the simulation accuracy of the empty spring is determined to be unsatisfactory, and the process of steps 11)-13) needs to be repeated to redefine the materials, properties, and contact conditions until the accuracy specified in formula (2) is achieved. It is determined that the axisymmetric model of the empty spring meets the simulation accuracy requirements.

[0160] Among them, it is recommended to take the value position greater than 5 to ensure the accuracy of stiffness simulation.

[0161] Step 2: establishing a high-precision air spring solid finite element model based on the high-precision air spring axisymmetric finite element model established in step 1;

[0162] The specific method of step 2 is as follows:

[0163] 21) generating a solid finite element mesh; rotating the air spring axisymmetric finite element model established in step 1 around the axis of symmetry to generate a solid unit air spring mesh, and deleting the original axisymmetric mesh;

[0164] Among them, it is necessary to control the number of meshes in the circumferential direction of the air spring. Considering the simulation accuracy and the quality of the hexahedral mesh, it is recommended that the number of circumferential meshes be greater than 100.

[0165] 22) defining an auxiliary flexible body; defining the flexible body properties of the capsule mesh in the solid model and associating it with the hyperelastic material;

[0166] Among them, if the applicable unit type of the flexible body is different from that of other solid units, it needs to be modified to the correct type.

[0167] 23) Update model parameters; update the deformable body properties of the structural 3D unit, the reinforcing rib properties of the planar cord unit, redefine the structural rigid body properties based on the 3D unit, and update the contact surface of the empty spring component surface;

[0168] Among them, the structures such as the capsule skin, upper cover, and lower cover are defined as entity attributes, and rigid bodies are defined as needed, and it is ensured that the reference point of the rigid body is always on the symmetry axis of the model.

[0169] 24) Update the coupling action area; redefine the closed fluid-solid interface area, including the inner surface of the bladder skin, upper cover, and lower cover structure as the interaction surface between the air and the structure; redefine the contact surface of the outer surface of the bladder skin, and the mutual contact relationship between the air-spring structure remains unchanged;

[0170] In order to ensure the contact relationship between the flexible bag skin structure and other structural parts and the convergence of the model, it is recommended to characterize the complex contact relationship between the various components of the air spring system by defining a general contact.

[0171] 25) Update boundary and load conditions; define the overall boundary conditions in all degrees of freedom, the boundary conditions of the inflation load step, and the boundary conditions in the axial displacement load step;

[0172] In order to ensure the sealing of the fluid cavity, it is recommended that the bladder skin part where the clamp ring is pressed be treated with common nodes with the upper cover and lower cover structure grids.

[0173] 26) Finite element model solution; solve the air spring entity analysis model, extract the relationship between the support reaction force and axial displacement of the air spring along the symmetry axis, generate the FU curve, extract the support reaction force under the specified displacement load condition, and solve the stiffness value of the air spring under the specified displacement load condition;

[0174] Among them, it involves large deformation of hyperelastic material structure. In order to avoid convergence problems, it is recommended to use explicit solver analysis, and it is necessary to ensure that the ratio of kinetic energy to internal energy of the model during the analysis is less than 0.05.

[0175] 27) Determine the simulation accuracy; Based on the empty spring support reaction force and stiffness values ​​solved in step 26), calculate the support reaction force difference and stiffness difference according to formula (1):

[0176]

[0177] In the formula, △F i " is the difference in the reaction force of the air spring support; △K" i Is the air spring stiffness difference: Fd i is the axial force on the design target curve; Kd i is the axial force and stiffness on the design target curve; F i ' is the axial force difference under the load condition corresponding to the empty spring simulation curve; K' i It is the stiffness difference of the empty spring simulation curve under the corresponding load condition;

[0178] a) If the difference in support reaction force and stiffness meets the condition of formula (2), it is determined that the empty spring solid finite element model meets the simulation accuracy requirements;

[0179] b) If the difference in the support reaction force and the difference in the stiffness do not meet the conditions of formula (2), it is determined that the solid finite element model of the air spring does not meet the simulation accuracy requirements, and it is necessary to repeat the process of steps 21)-27) to redefine the mesh size, contact, and boundary conditions until the accuracy specified in formula (2) is achieved, and it is determined that the solid finite element model of the air spring meets the simulation accuracy requirements;

[0180]

[0181] Step 3: Import the high-precision air spring solid finite element model established in step 2 into the suspension system for air suspension modeling and simulation analysis;

[0182] The specific method of step three is:

[0183] 31) Importing the solid model; Selecting the suspension model under the specified posture, and importing the high-precision air spring solid finite element model in step 2;

[0184] Among them, the posture of the suspension model is determined by the posture corresponding to the equilibrium state of the air spring, that is, the suspension posture corresponding to when the air spring maintains an axisymmetric structure in the suspension. It is recommended that the analysis postures of step one and step two be kept consistent, otherwise the process of step one and step two should be repeated to update the physical air spring model.

[0185] The suspension model can be a finite element mesh model of solid elements or a simplified model composed of bar elements and connection sub-elements.

[0186] 32) Correction of the posture of the air spring model; coincide the reference point of the rigid structure of the lower cover of the air spring with the lower point of the spring, measure the angle formed by the upper point of the spring, the lower point of the spring, and the reference point of the upper cover rigid body, and rotate the air spring model according to the measured angle on the plane formed by the three points to ensure that the axis of the air spring solid model including the auxiliary flexible body is consistent with the design axis of the spring;

[0187] Among them, the angle measured through the upper point of the spring, the lower point of the spring, and the upper cover rigid body reference point is the angle formed by the axis of the solid empty spring model and the actual axis of the spring, with the lower point of the spring as the vertex; the central axis of rotation of the solid empty spring model is defined as a straight line perpendicular to the plane determined by the three points and passing through the lower point of the spring.

[0188] 33) Correction of the position of the air spring model; move the empty spring along the axial direction of the spring until the lower cover of the spring coincides with the designed position, and the upper cover is also at the designed position;

[0189] 34) Adjust the air spring model; modify the rigid body definition in the finite element model of the air spring, update the lower point of the spring to the rigid body reference point of the lower cover, and update the upper point of the spring to the rigid body reference point of the upper cover;

[0190] 35) Loading the air suspension: The air suspension is loaded in two load steps according to the following process;

[0191] 351) Define the air spring inflation load step; constrain the 1-6 degrees of freedom of the air spring upper point, the shock absorber upper point, the subframe and the body connection point, and constrain the vertical freedom of the wheel center. The air spring is inflated to the specified attitude pressure target P0, and the vertical support reaction force Fzw0 of the wheel center at this time is extracted;

[0192] Among them, 351) is applicable to the spring-damper separated suspension. For the spring-damper integrated suspension, the spring channel and the shock absorber channel are on the same axis, and only the upper point of the shock absorber is constrained;

[0193] 352) define the suspension displacement load step; release the vertical constraint at the wheel center position, and apply the vertical displacement load Uzw, extract the vertical support reaction force Fzw of the wheel center, the displacement of the lower point of the shock absorber Uj, the support reaction force Fj of the upper point of the shock absorber, the displacement of the lower point of the air spring Us, the support reaction force Fs of the upper point of the air spring, and the support reaction moment Ms, and generate the wheel center vertical load-displacement curve, i.e., the Uzw-Fzw curve, the shock absorber load curve, i.e., the Uzw-Fj curve, and the air spring load curve, i.e., the Uzw-Fs curve;

[0194] Among them, when the direction of the spring and shock absorber is inconsistent with the vertical direction of the vehicle, it is necessary to extract the support reaction force in the specified direction, and the direction should be consistent with the direction defined in the test.

[0195] 36) Determine the simulation progress; Determine the simulation accuracy by comparing the air suspension system test with the system simulation results, and follow the following steps:

[0196] 361) Select several points on the wheel center vertical load-displacement curve according to the displacement condition, and calculate the difference between the wheel center load simulation and the test according to formula (3):

[0197] △F i =|Fzw i -Fzw' i | (3)

[0198] In the formula, Fzw i is the simulated value of the wheel center vertical load; Fzw' i is the test value of the wheel center vertical load; △Fzw i is the difference between the simulation and test of the wheel center vertical load;

[0199] a) If the following conditions are met:

[0200] △F i ≤0.01*Fzw' i (4)

[0201] It is determined that the wheel center vertical load simulation accuracy meets the requirements, and the process goes to step 362);

[0202] b) If the condition specified in formula (4) is not satisfied, it is determined that the simulation accuracy of the wheel center vertical load does not meet the requirement, and the operation of step 31) to step 35) needs to be repeated, and the stiffness property of the elastic connection unit in the model is adjusted until formula (4) is satisfied; at this time, it is determined that the simulation accuracy of the wheel center vertical load of the air suspension model meets the requirement, and go to step 362);

[0203] 362) Select several points on the shock absorber load curve and the air spring load curve, and calculate the difference between the shock absorber and spring load test and simulation according to formula (5):

[0204]

[0205] In the formula, Fj i and Fs i are the simulation values ​​of shock absorber and spring load respectively; Fj' i and Fs' i are the test values ​​of shock absorber and spring load respectively; △Fj i is and △Fs are the differences between the simulation and test of shock absorber and spring loads, respectively;

[0206] a) If the following conditions are met:

[0207]

[0208] It is determined that the simulation accuracy of the air suspension meets the requirements;

[0209] b) If the conditions specified in formula (6) are not met, it is determined that the distribution of the vertical load in the spring and shock absorber channels is not in line with reality, and the air suspension simulation accuracy does not meet the requirements. It is necessary to repeat the operations of steps 31) to 35), focusing on adjusting the shock absorber channel stiffness curve in the model until formula (6) is met. At this time, it is determined that the air suspension model meets the simulation accuracy requirements.

[0210] Among them, since the initial stage of the test loading, the load overcomes the system assembly gap, resulting in instability in the initial stage of the test curve, the unstable stage of the test signal should be avoided in the accuracy comparison.

[0211] Step 4: Simulation analysis of structural component strength;

[0212] The specific method of step 4 is as follows:

[0213] 41) Model replacement: Divide the mesh based on the geometric model of the air spring system structure, import the mesh into the air suspension model, and adjust the position and posture, keeping the auxiliary flexible body mesh unchanged;

[0214] Among them, the mesh of the air spring structure in step 41) needs to meet the following conditions:

[0215] a) For axisymmetric structures, use a first-order hexahedral grid, divide the surface of the chamfer into more than 3 rows of units, and ensure that the grid has more than 4 layers in the thickness direction of the structure.

[0216] b) For non-axisymmetric structures, a second-order tetrahedral grid is used with a grid angle between 15 and 120 degrees. The surface at the chamfer position is divided into more than 3 rows of units, and more than 2 layers of units are ensured at any position of the structure along the thickness direction.

[0217] 42) Delete the rigid body; delete the rigid body model and reference points not involved in the structural strength simulation analysis model;

[0218] Among them, in addition to the target structure for analysis, the rigid structure is retained as much as possible. Taking the upper cover strength analysis as an example, the lower cover model can be kept as a rigid body property, and similarly, the upper cover structure rigid body properties can be kept in the lower cover strength analysis.

[0219] 43) Introduce auxiliary analysis structure; in addition to the analysis object, the structural grid required for the strength analysis of the air spring system structure is introduced into the air suspension model;

[0220] Among them, the main purpose of introducing the necessary structures for the analysis of the air spring system structure is to provide a high-precision load transfer method and boundary conditions for the structural analysis. In particular, for the suspension model of the bar system unit, an auxiliary analysis structure must be introduced. Taking the upper cover analysis as an example, the local body structure connected to it can be introduced, and the boundary conditions can be defined at the edge of the body mesh. The lower cover analysis can introduce the control arm and related structural meshes assembled with it, and define the contact and connection relationship between them.

[0221] 44) defining contact; defining the contact surface for the model introduced in step 41) and step 43), and all contact pairs involved in the contact surface;

[0222] Among them, for structures with complex models or contact relationships, it is recommended to define general contact.

[0223] 45) Material and property definition: Introduce the model for step 41) and step 43), define the actual material properties, and define the properties according to the structure and mesh characteristics;

[0224] For auxiliary structures with high rigidity, such as the body connecting longitudinal beam in the upper cover analysis, it is recommended to define rigid body properties. For structures with low rigidity or involved in deformation, such as the lower control arm of the E-type multi-link, it is recommended to define them as deformable body properties.

[0225] 46) Model solving; loading, the loading process is as follows:

[0226] 461) Define the air spring inflation load step; constrain the 1-6 degrees of freedom of the air spring upper point, the shock absorber upper point, the subframe and the body connection point, and constrain the vertical freedom of the wheel center. The air spring is inflated to the specified attitude pressure target P0, and the vertical support reaction force Fzw0 of the wheel center at this time is extracted;

[0227] 462) define the suspension displacement load step; release the vertical constraint at the wheel center position, and apply the vertical displacement load Uzw, extract the vertical support reaction force Fzw of the wheel center, the displacement of the lower point of the shock absorber Uj, the support reaction force Fj of the upper point of the shock absorber, the displacement of the lower point of the air spring Us, the support reaction force Fs of the upper point of the air spring, and the support reaction moment Ms, and generate the wheel center vertical load-displacement curve, i.e., the Uzw-Fzw curve, the shock absorber load curve, i.e., the Uzw-Fj curve, and the air spring load curve, i.e., the Uzw-Fs curve;

[0228] Among them, the suspension displacement is defined as the vertical upward jump limit of the wheel center. After solving the strength analysis model, the stress field S of the structural components in the second load step is extracted.

[0229] Among them, the vertical upward jump stroke limit of the wheel center corresponds to the limit state of compression of the air spring. At this time, the air spring bears the maximum load under the design conditions.

[0230] Step 5: Strength verification and optimization of structural parts;

[0231] The specific method of step five is as follows:

[0232] 51) Strength check: Perform structural strength check according to formula (7):

[0233] n=σ max / [σ] (7)

[0234] In the formula, σ max is the maximum stress value in the stress field S of the structural component; [σ] is the allowable stress of the structural component; n is the safety factor of the empty spring structural component under the limit use condition;

[0235] a) If the following conditions are met:

[0236] n>1 (8)

[0237] It is determined that the structural parts meet the strength design requirements and the process ends;

[0238] b) If the condition specified in formula (8) is not met, it is determined that the strength of the empty spring structure does not meet the design requirements, and the process goes to step 52);

[0239] 52) Structural optimization iteration: Structural optimization is performed on the structural parts, and the operations of step 41) to step 51) are repeated for the optimized structure until the requirements of formula (8) are met, and the design is terminated.

[0240] Among them, if the number of dangerous locations in the structure is small, it is recommended to perform structural optimization for the dangerous locations separately; if the number of locations that do not meet the design requirements is large, it is recommended to combine professional structural optimization simulation software for structural optimization. In the structural optimization simulation, stress conditions can be set as optimization constraints or optimization targets.

[0241] Embodiment 2

[0242] See also Figure 4 , a design device for a structural component of an air spring system, comprising:

[0243] The first modeling module is used to establish a high-precision axisymmetric finite element model of the air spring;

[0244] The first modeling module comprises:

[0245] Establish an air spring axisymmetric analysis model module, which is used to establish an air spring axisymmetric analysis model;

[0246] Establishing an auxiliary flexible body model module, used for establishing an auxiliary flexible body model;

[0247] Define simulation conditions module, used to define simulation conditions;

[0248] The first finite element model solving module is used to solve the axisymmetric simplified parting model of the air spring;

[0249] The simulation accuracy determination module is used to determine whether the axisymmetric model of the simulated air spring meets the simulation accuracy requirements.

[0250] The second modeling module is used to establish a high-precision air spring solid finite element model;

[0251] The second modeling module comprises:

[0252] Generate solid finite element mesh model module, used to generate solid finite element network model;

[0253] Define an auxiliary flexible body module to define the flexible body properties of the capsule mesh and associate it with the hyperelastic material;

[0254] Update model parameter module, which is used to update model parameters, including the deformable body properties of 3D units, the reinforcing rib properties of planar cord units, redefine the structural rigid body properties based on 3D units, and update the contact surface of the empty spring component surface;

[0255] Update boundary and load condition module, which is used to update the overall boundary conditions in all degrees of freedom directions, the boundary conditions of the inflation load step, and the boundary conditions in the axial displacement load step;

[0256] The second finite element model solving module is used to solve the air conditioning spring entity analysis model;

[0257] The first simulation accuracy determination module is used to determine whether the air spring entity finite element model meets the simulation accuracy requirement.

[0258] Modeling and simulation analysis module, used to import high-precision air spring solid finite element model into the suspension system for air suspension modeling and simulation analysis;

[0259] The modeling and simulation analysis module includes:

[0260] Import solid model module, used to import high-precision air spring solid model;

[0261] An air spring model posture correction module is used to correct the posture of the air spring model;

[0262] An air spring model position correction module is used to correct the position of the air spring model;

[0263] A first air suspension loading module, used for loading the air suspension;

[0264] The second simulation accuracy determination module is used to determine whether the vertical load of the wheel center of the air suspension model meets the accuracy requirement.

[0265] Strength simulation analysis module, used to simulate and analyze the structural parts in the air spring system;

[0266] The strength simulation analysis module includes:

[0267] Model replacement module, used to import the mesh into the air suspension model and adjust it to the correct position and posture, keeping the auxiliary flexible body mesh unchanged;

[0268] Delete rigid body module, which is used to delete rigid body models and reference points not involved in the structural strength simulation analysis model;

[0269] Introducing the auxiliary analysis structure module, which is used to import the structural mesh required for the strength analysis of the air spring system structure into the air suspension model in addition to the analysis object;

[0270] Define contact module, which is used to define contact surface and all contact pairs involved in the contact surface;

[0271] Material and property definition module, used to define the actual material properties and define properties based on the structure and mesh characteristics;

[0272] The model solving module is used to extract the stress field S of the structural components in the second load step after solving the strength analysis model.

[0273] Strength verification and optimization module, used to verify and perform high-strength design on structural parts in air-spring systems.

[0274] The strength verification and optimization module includes:

[0275] Strength verification module, used to verify the strength of air spring system components;

[0276] The structural optimization module is used to optimize the structural parts of the air spring system until the requirements are met.

[0277] Embodiment 3

[0278] Figure 5 This is a schematic diagram of the structure of a computer device in Embodiment 3 of the present invention. Figure 5 A block diagram of an exemplary computer device 102 suitable for use in implementing embodiments of the present invention is shown. Figure 5 The computer device 102 shown is only an example and should not bring any limitation to the functions and scope of use of the embodiments of the present invention.

[0279] like Figure 5 As shown, the computer device 102 is in the form of a general-purpose computing device. The components of the computer device 102 may include, but are not limited to: one or more processors or processing units 16, a system memory 28, and a bus 18 that connects various system components (including the system memory 28 and the processing unit 16).

[0280] Bus 18 represents one or more of several types of bus structures, including a memory bus or memory controller, a peripheral bus, an accelerated graphics port, a processor or a local bus using any of a variety of bus architectures. By way of example, these architectures include, but are not limited to, an Industry Standard Architecture (ISA) bus, a Micro Channel Architecture (MAC) bus, an Enhanced ISA bus, a Video Electronics Standards Association (VESA) local bus, and a Peripheral Component Interconnect (PCI) bus.

[0281] The computer device 102 typically includes a variety of computer system readable media. These media can be any available media that can be accessed by the computer device 102, including volatile and non-volatile media, removable and non-removable media.

[0282] The system memory 28 may include computer system readable media in the form of volatile memory, such as random access memory (RAM) 30 and / or cache memory 32. The computer device 102 may further include other removable / non-removable, volatile / non-volatile computer system storage media. By way of example only, the storage system 34 may be used to read and write non-removable, non-volatile magnetic media ( Figure 5 not shown, usually called a "hard drive"). Although Figure 5Not shown in the figure, a disk drive for reading and writing to a removable non-volatile disk (e.g., a "floppy disk"), and an optical disk drive for reading and writing to a removable non-volatile optical disk (e.g., a CD-ROM, a DVD-ROM, or other optical media) may be provided. In these cases, each drive may be connected to the bus 18 via one or more data medium interfaces. The memory 28 may include at least one program product having a set (e.g., at least one) of program modules that are configured to perform the functions of the various embodiments of the present invention.

[0283] A program / utility 40 having a set (at least one) of program modules 42 may be stored, for example, in the memory 28. Such program modules 42 include, but are not limited to, an operating system, one or more application programs, other program modules, and program data, each of which or some combination may include an implementation of a network environment. The program modules 42 generally perform the functions and / or methods of the embodiments described herein.

[0284] The computer device 102 may also communicate with one or more external devices 14 (e.g., keyboard, pointing device, display 24, etc.), may also communicate with one or more devices that enable a user to interact with the computer device 102, and / or communicate with any device that enables the computer device 102 to communicate with one or more other computing devices (e.g., network card, modem, etc.). Such communication may be performed through an input / output (I / O) interface 22. In addition, in the computer device 102 of the present embodiment, the display 24 is not present as an independent individual, but is embedded in the mirror surface, and when the display surface of the display 24 is not displayed, the display surface of the display 24 is visually integrated with the mirror surface. In addition, the computer device 102 may also communicate with one or more networks (e.g., local area network (LAN), wide area network (WAN) and / or public network, such as the Internet) through a network adapter 20. As shown in the figure, the network adapter 20 communicates with other modules of the computer device 102 through a bus 18. It should be understood that although not shown in the figure, other hardware and / or software modules can be used in conjunction with the computer device 102, including but not limited to: microcode, device drivers, redundant processing units, external disk drive arrays, RAID systems, tape drives, and data backup storage systems.

[0285] The processing unit 16 executes various functional applications and data processing by running the programs stored in the system memory 28 , for example, implementing a method for designing a structural component of an air spring system provided in an embodiment of the present invention.

[0286] Embodiment 4

[0287] Embodiment 4 of the present invention provides a computer-readable storage medium having a computer program stored thereon. When the program is executed by a processor, a method for designing a structural component of an air spring system as provided in all the embodiments of the present application is implemented.

[0288] Any combination of one or more computer-readable media may be used. A computer-readable medium may be a computer-readable signal medium or a computer-readable storage medium. A computer-readable storage medium may be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, device or device, or any combination thereof. More specific examples (a non-exhaustive list) of computer-readable storage media include: an electrical connection with one or more wires, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination thereof. In this document, a computer-readable storage medium may be any tangible medium containing or storing a program that may be used by or in conjunction with an instruction execution system, device, or device.

[0289] Computer-readable signal media may include a data signal propagated in baseband or as part of a carrier wave, which carries a computer-readable program code. Such propagated data signals may take a variety of forms, including, but not limited to, electromagnetic signals, optical signals, or any suitable combination of the above. Computer-readable signal media may also be any computer-readable medium other than a computer-readable storage medium, which may send, propagate, or transmit a program for use by or in conjunction with an instruction execution system, apparatus, or device.

[0290] Program code embodied on a computer readable medium may be transmitted using any appropriate medium, including but not limited to wireless, wireline, optical fiber cable, RF, etc., or any suitable combination of the foregoing.

[0291] Computer program code for performing the operations of the present invention may be written in one or more programming languages ​​or a combination thereof, including object-oriented programming languages ​​such as Java, Smalltalk, C++, and conventional procedural programming languages ​​such as "C" or similar programming languages. The program code may be executed entirely on the user's computer, partially on the user's computer, as a separate software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In the case of a remote computer, the remote computer may be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or may be connected to an external computer (e.g., via the Internet using an Internet service provider).

[0292] Note that the above are only preferred embodiments of the present invention and the technical principles used. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and that various obvious changes, readjustments and substitutions can be made by those skilled in the art without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in more detail through the above embodiments, the present invention is not limited to the above embodiments, and may include more other equivalent embodiments without departing from the concept of the present invention, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. A method for designing a structural component of an air spring system, characterized in that: The following steps are involved: Step 1: Establish a high-precision axisymmetric finite element model of the air spring; Step 2: establishing a high-precision air spring solid finite element model based on the high-precision air spring axisymmetric finite element model established in step 1; Step 3: Import the high-precision air spring solid finite element model established in step 2 into the suspension system for air suspension modeling and simulation analysis; Step 4: Simulation analysis of structural component strength; Step 5: Strength verification and optimization of structural parts; The specific method of step one is as follows: 11) Establish an axisymmetric analysis model of air spring; Based on any symmetry surface of the air spring, mesh the air spring model, define the rigid body properties and rigid body reference points of the upper cover, lower cover and clamping ring of the air spring; define the contact surface and contact relationship between the rigid body and the elastic body in the air spring model; divide the bladder unit and the reinforcing cord unit, define the reinforcing rib properties of the cord unit, and establish the axisymmetric finite element model of the air spring; 12) Establish auxiliary flexible body; Define the hyperelastic material and flexible body properties, and associate the hollow spring capsule skin with the hyperelastic material and flexible body properties; define the fluid-solid coupling interface based on the capsule mesh and part of the structure mesh as the action surface between air and structure, and define the fluid-solid coupling properties of the interface; define the outer surface contact surface of the flexible body structure, and define the contact pairs associated with it; 13) Define simulation conditions; Set the boundary conditions for the simulation of the axisymmetric empty spring model and define the load step: the empty spring is inflated to the design target value P0, and the empty spring is subjected to the axial displacement load [-U1, U1] along the symmetry axis; 14) Finite element model solution; Solve the simplified analysis model of the air spring axisymmetric, extract the support reaction force F0 of the air spring along the symmetry axis, extract the relationship between the support reaction force and the axial displacement, generate the FU curve, and extract the support reaction force under the specified displacement condition, and obtain the stiffness of the specified displacement through post-processing; 15) Determine the simulation accuracy; Select several points on the FU curve according to the displacement conditions and calculate the air spring support reaction force difference ΔF according to formula (1): i ” and the air spring stiffness difference ΔK i ”: In the formula, Fd i is the axial force on the design target curve; Kd i is the axial force and stiffness on the design target curve; F i ' is the axial force difference under the load condition corresponding to the empty spring simulation curve; K i ' is the stiffness difference of the empty spring simulation curve under the corresponding load condition; a) If the following conditions are met: It is determined that the simulated empty spring axisymmetric model meets the simulation accuracy requirements; b) If the conditions specified in formula (2) are not met, the simulation accuracy of the empty spring is determined to be unsatisfactory, and the process of steps 11)-13) needs to be repeated to redefine the materials, properties, and contact conditions until the accuracy specified in formula (2) is achieved. It is determined that the axisymmetric model of the empty spring meets the simulation accuracy requirements.

2. A method for designing a structural component of an air spring system according to claim 1, characterized in that: The specific method of step 2 is as follows: 21) generating a solid finite element mesh; rotating the air spring axisymmetric finite element model established in step 1 around the axis of symmetry to generate a solid unit air spring mesh, and deleting the original axisymmetric mesh; 22) Define auxiliary flexible body; Define the flexible body properties of the skin mesh in the solid model and associate it with the hyperelastic material; 23) Update model parameters; update the deformable body properties of the structural 3D unit, the reinforcing rib properties of the planar cord unit, redefine the structural rigid body properties based on the 3D unit, and update the contact surface of the empty spring component surface; 24) Update the coupling action area; redefine the closed fluid-solid interface area, including the inner surface of the bladder skin, upper cover, and lower cover structure as the interaction surface between the air and the structure; redefine the contact surface of the outer surface of the bladder skin, and the mutual contact relationship between the air-spring structure remains unchanged; 25) Update boundary and load conditions; define the overall boundary conditions in all degrees of freedom, the boundary conditions of the inflation load step, and the boundary conditions in the axial displacement load step; 26) Finite element model solution; solve the air spring entity analysis model, extract the relationship between the support reaction force and axial displacement of the air spring along the symmetry axis, generate the FU curve, extract the support reaction force under the specified displacement load condition, and solve the stiffness value of the air spring under the specified displacement load condition; 27) Determine the simulation accuracy; Based on the empty spring support reaction force and stiffness values ​​solved in step 26), calculate the support reaction force difference and stiffness difference according to formula (1): Where, ΔF i ” is the difference in the reaction force of the air spring; ΔK i " is the difference in air spring stiffness: Fd i is the axial force on the design target curve; Kd i is the axial force and stiffness on the design target curve; F i ' is the axial force difference under the load condition corresponding to the empty spring simulation curve; K i ' is the stiffness difference of the empty spring simulation curve under the corresponding load condition; a) If the difference in support reaction force and stiffness meets the condition of formula (2), it is determined that the empty spring solid finite element model meets the simulation accuracy requirements; b) If the difference in the support reaction force and the difference in the stiffness do not meet the conditions of formula (2), it is determined that the solid finite element model of the air spring does not meet the simulation accuracy requirements, and it is necessary to repeat the process of steps 21)-27) to redefine the mesh size, contact, and boundary conditions until the accuracy specified in formula (2) is achieved, and it is determined that the solid finite element model of the air spring meets the simulation accuracy requirements; 3. The method for designing a structural component of an air spring system according to claim 1, characterized in that: The specific method of step three is: 31) Importing the solid model; Selecting the suspension model under the specified posture, and importing the high-precision air spring solid finite element model in step 2; 32) Correction of the posture of the air spring model; coincide the reference point of the rigid structure of the lower cover of the air spring with the lower point of the spring, measure the angle formed by the upper point of the spring, the lower point of the spring, and the reference point of the upper cover rigid body, and rotate the air spring model according to the measured angle on the plane formed by the three points to ensure that the axis of the air spring solid model including the auxiliary flexible body is consistent with the design axis of the spring; 33) Correction of the position of the air spring model; move the empty spring along the axial direction of the spring until the lower cover of the spring coincides with the designed position, and the upper cover is also at the designed position; 34) Adjust the air spring model; modify the rigid body definition in the air spring finite element model, update the lower point of the spring to the rigid body reference point of the lower cover, and update the upper point of the spring to the rigid body reference point of the upper cover; 35) Loading the air suspension: The air suspension is loaded in two load steps according to the following process; 351) Define the air spring inflation load step; constrain the 1-6 degrees of freedom of the air spring upper point, the shock absorber upper point, the subframe and the body connection point, and constrain the vertical freedom of the wheel center. The air spring is inflated to the specified attitude pressure target P0, and the vertical support reaction force Fzw0 of the wheel center at this time is extracted; 352) define the suspension displacement load step; release the vertical constraint at the wheel center position, and apply the vertical displacement load Uzw, extract the vertical support reaction force Fzw of the wheel center, the displacement of the lower point of the shock absorber Uj, the support reaction force Fj of the upper point of the shock absorber, the displacement of the lower point of the air spring Us, the support reaction force Fs of the upper point of the air spring, and the support reaction moment Ms, and generate the wheel center vertical load-displacement curve, i.e., the Uzw-Fzw curve, the shock absorber load curve, i.e., the Uzw-Fj curve, and the air spring load curve, i.e., the Uzw-Fs curve; 36) Determine the simulation progress; Determine the simulation accuracy by comparing the air suspension system test with the system simulation results, and follow the following steps: 361) Select several points on the wheel center vertical load-displacement curve according to the displacement condition, and calculate the difference between the wheel center load simulation and the test according to formula (3): ΔFzw i =|Fzw i -Fzw i '| (3) In the formula, Fzw i is the simulated value of the wheel center vertical load; Fzw i ' is the test value of the wheel center vertical load; ΔFzw i is the difference between the simulation and test of the wheel center vertical load; a) If the following conditions are met: ΔFzw i ≤0.01*Fzw i ' (4) It is determined that the wheel center vertical load simulation accuracy meets the requirements, and the process goes to step 362); b) If the condition specified in formula (4) is not satisfied, it is determined that the simulation accuracy of the wheel center vertical load does not meet the requirement, and the operation of step 31) to step 35) needs to be repeated, and the stiffness property of the elastic connection unit in the model is adjusted until formula (4) is satisfied; at this time, it is determined that the simulation accuracy of the wheel center vertical load of the air suspension model meets the requirement, and go to step 362); 362) Select several points on the shock absorber load curve and the air spring load curve, and calculate the difference between the shock absorber and spring load test and simulation according to formula (5): In the formula, Fj i and Fs i are the simulation values ​​of shock absorber and spring load respectively; Fj i ' and Fs i ' are the test values ​​of shock absorber and spring load respectively; ΔFj i is and ΔFs are the differences between the simulation and the test for the shock absorber and spring loads, respectively; a) If the following conditions are met: It is determined that the simulation accuracy of the air suspension meets the requirements; b) If the conditions specified in formula (6) are not met, it is determined that the distribution of the vertical load in the spring and shock absorber channels is not in line with reality, and the air suspension simulation accuracy does not meet the requirements. It is necessary to repeat the operations of steps 31) to 35), focusing on adjusting the shock absorber channel stiffness curve in the model until formula (6) is met. At this time, it is determined that the air suspension model meets the simulation accuracy requirements.

4. The method for designing a structural component of an air spring system according to claim 1, characterized in that: The specific method of step 4 is as follows: 41) Model replacement: Divide the mesh based on the geometric model of the air spring system structure, import the mesh into the air suspension model, and adjust the position and posture, keeping the auxiliary flexible body mesh unchanged; 42) Delete the rigid body; delete the rigid body model and reference points not involved in the structural strength simulation analysis model; 43) Introduce auxiliary analysis structure; in addition to the analysis object, the structural grid required for the strength analysis of the air spring system structure is introduced into the air suspension model; 44) defining contact; defining the contact surface for the model introduced in step 41) and step 43), and all contact pairs involved in the contact surface; 45) Material and property definition: Introduce the model for step 41) and step 43), define the actual material properties, and define the properties according to the structure and mesh characteristics; 46) Model solving; loading, the loading process is as follows: 461) Define the air spring inflation load step; constrain the 1-6 degrees of freedom of the air spring upper point, the shock absorber upper point, the subframe and the body connection point, and constrain the vertical freedom of the wheel center. The air spring is inflated to the specified attitude pressure target P0, and the vertical support reaction force Fzw0 of the wheel center at this time is extracted; 462) define the suspension displacement load step; release the vertical constraint at the wheel center position, and apply the vertical displacement load Uzw, extract the vertical support reaction force Fzw of the wheel center, the displacement of the lower point of the shock absorber Uj, the support reaction force Fj of the upper point of the shock absorber, the displacement of the lower point of the air spring Us, the support reaction force Fs of the upper point of the air spring, and the support reaction moment Ms, and generate the wheel center vertical load-displacement curve, i.e., the Uzw-Fzw curve, the shock absorber load curve, i.e., the Uzw-Fj curve, and the air spring load curve, i.e., the Uzw-Fs curve; Among them, the suspension displacement is defined as the vertical upward jump limit of the wheel center. After solving the strength analysis model, the stress field S of the structural components in the second load step is extracted.

5. A method for designing a structural component of an air spring system according to claim 4, characterized in that: The specific method of step five is as follows: 51) Strength check: Perform structural strength check according to formula (7): n=σ max / [s] (7) In the formula, σ max is the maximum stress value in the stress field S of the structural component; [σ] is the allowable stress of the structural component; n is the safety factor of the empty spring structural component under the limit use condition; a) If the following conditions are met: n > 1 (8) It is determined that the structural parts meet the strength design requirements and the process ends; b) If the condition specified in formula (8) is not met, it is determined that the strength of the empty spring structure does not meet the design requirements, and the process goes to step 52); 52) Structural optimization iteration: Structural optimization is performed on the structural parts, and the operations of step 41) to step 51) are repeated for the optimized structure until the requirements of formula (8) are met, and the design is terminated.

6. The method for designing a structural component of an air spring system according to claim 1, characterized in that: This is achieved by a design device for an air spring system structure, the device comprising: The first modeling module is used to establish a high-precision axisymmetric finite element model of the air spring; The second modeling module is used to establish a high-precision air spring solid finite element model; Modeling and simulation analysis module, used to import high-precision air spring solid finite element model into the suspension system for air suspension modeling and simulation analysis; Strength simulation analysis module, used to simulate and analyze the structural parts in the air spring system; Strength verification and optimization module, used to verify and perform high-strength design on structural parts in air-spring systems.

7. A method for designing a structural component of an air spring system according to claim 6, characterized in that: The first modeling module comprises: Establish an air spring axisymmetric analysis model module, which is used to establish an air spring axisymmetric analysis model; Establishing an auxiliary flexible body model module, used for establishing an auxiliary flexible body model; Define simulation conditions module, used to define simulation conditions; The first finite element model solving module is used to solve the axisymmetric simplified parting model of the air spring; A simulation accuracy determination module is used to determine whether the simulated air spring axisymmetric model meets the simulation accuracy requirements; The second modeling module comprises: Generate solid finite element mesh model module, used to generate solid finite element network model; Define an auxiliary flexible body module to define the flexible body properties of the capsule mesh and associate it with the hyperelastic material; Update model parameter module, which is used to update model parameters, including the deformable body properties of 3D units, the reinforcing rib properties of planar cord units, redefine the structural rigid body properties based on 3D units, and update the contact surface of the empty spring component surface; Update boundary and load condition module, which is used to update the overall boundary conditions in all degrees of freedom directions, the boundary conditions of the inflation load step, and the boundary conditions in the axial displacement load step; The second finite element model solving module is used to solve the air conditioning spring entity analysis model; The first simulation accuracy determination module is used to determine whether the air spring entity finite element model meets the simulation accuracy requirements; The modeling and simulation analysis module includes: Import solid model module, used to import high-precision air spring solid model; An air spring model posture correction module is used to correct the posture of the air spring model; An air spring model position correction module is used to correct the position of the air spring model; A first air suspension loading module, used for loading the air suspension; The second simulation accuracy determination module is used to determine whether the vertical load of the wheel center of the air suspension model meets the accuracy requirements; The strength simulation analysis module includes: Model replacement module, used to import the mesh into the air suspension model and adjust it to the correct position and posture, keeping the auxiliary flexible body mesh unchanged; Delete rigid body module, which is used to delete rigid body models and reference points not involved in the structural strength simulation analysis model; Introducing the auxiliary analysis structure module, which is used to import the structural mesh required for the strength analysis of the air spring system structure into the air suspension model in addition to the analysis object; Define contact module, which is used to define contact surface and all contact pairs involved in the contact surface; Material and property definition module, used to define the actual material properties and define properties based on the structure and mesh characteristics; Model solving module, used to extract the stress field S of the structural parts in the second load step after solving the strength analysis model; The strength verification and optimization module includes: Strength verification module, used to verify the strength of air spring system components; The structural optimization module is used to optimize the structural parts of the air spring system until the requirements are met.

8. A computer device comprising a memory, a processor and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the program, an air spring system structural component design method as described in any one of claims 1-5 is implemented.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the program is executed by a processor, an air spring system structural component design method as described in any one of claims 1-5 is implemented.

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