Multi-axle vehicle axle load calculation method and device based on finite element simulation

Abstract

The invention provides a multi-axle vehicle axle load calculation method and device based on finite element simulation, and belongs to the technical field of vehicle design, a vehicle structure model comprising a frame, an axle housing, a suspension support and other components is established, and the components are assembled through rigid connection. Then, a suspension system model comprising a front spring, a rear spring and a tire spring is established, and corresponding rigidity and material attributes are set; by establishing a center-of-mass connection point of a cab, a power assembly and goods and applying corresponding mass, the degree of freedom of a tire spring grounding point is restrained, and gravitational acceleration is applied. And finally, carrying out static analysis on the model after grid division, and calculating to obtain the axle load of each axle by extracting the Z-direction counter-acting force at the tire spring constraint position. According to the method, the complex structure and load distribution of the multi-axle vehicle are simulated, and the axle load calculation precision is improved; reliable load distribution data are provided for the vehicle design stage, and the suspension and frame design is optimized.

Description

Technical Field

[0001] This invention belongs to the field of vehicle design technology, specifically relating to a method and apparatus for calculating the axle load of a multi-axle vehicle based on finite element simulation. Background Technology

[0002] In the design, matching, and verification of multi-axle vehicles (such as three-axle and four-axle trucks, trailers, and special vehicles), the axle load distribution (i.e., the vertical load borne by each axle) is a crucial parameter. A reasonable axle load distribution directly affects the vehicle's handling stability, braking performance, tire wear, and compliance with road regulations' axle load limits.

[0003] In related technologies, the spring installation direction in suspension system modeling is not vertical according to the Z-axis requirement; the front springs are installed along the Y-axis or at an angle, resulting in a mismatch between the spring force direction and the actual situation. If the structure of the front / rear connecting beams is ignored and the springs are directly connected to the axle housing, the overall load-bearing characteristics of the leaf springs cannot be simulated. If the tire spring length is not set according to the actual tire radius, the suspension height will be inconsistent with the actual vehicle. These problems cause significant deviations in the mechanical stiffness and force transmission efficiency of the suspension system from reality, and the axle load calculation loses its reliable suspension mechanics basis.

[0004] The relevant technology assigns the stiffness of the front leaf spring directly to a single front spring when setting the spring stiffness and material properties, without considering the coordinated load-bearing capacity of the left and right springs. All components use the same elastic modulus and Poisson's ratio, ignoring the requirement that the front / rear connecting beams be lightweight and have negligible deformation. This results in excessive deformation of the connecting beams or an excessive weight ratio, interfering with the actual load distribution and thus affecting the accuracy of axle load calculation.

[0005] The relevant technology only constrains the Z-axis translational degree of freedom of the tire spring contact point, ignoring the front-to-back and left-to-right constraints. This causes the model to wobble or shift laterally during simulation, disrupting the force balance. If no gravitational acceleration is applied or a non-standard gravity value is used, the components in the model are only subjected to mass loads without gravity effects. The stress environment is inconsistent with the real Earth's gravity field, and the calculated tire reaction force cannot reflect the actual load. Summary of the Invention

[0006] This invention provides a method for calculating the axle load of multi-axle vehicles based on finite element simulation, which can efficiently and accurately predict the axle load distribution of multi-axle vehicles during the design phase, providing a reliable basis for vehicle chassis design and optimization.

[0007] The methods include: S101: Establish a vehicle structure model, including the frame, subframe, front axle housing, rear axle housing, front spring front bracket, front spring rear bracket, balance shaft, cab mount and powertrain mount, and assemble them through rigid connections; S102: Based on the vehicle structure model, establish a suspension system model, including front spring, rear spring, tire spring, front connecting beam and rear connecting beam. The front spring and rear spring are installed vertically downward along the Z direction, the tire spring is installed vertically downward along the Z direction, the front connecting beam is connected to the lower point of the front spring, and the rear connecting beam is connected to the leaf spring mounting hole of the rear axle housing. S103: Set the spring stiffness and material properties of the suspension system model, where the front spring stiffness is set to half of the actual stiffness of the front leaf spring, the rear spring stiffness is set to half of the actual stiffness of the rear leaf spring, the tire spring stiffness is set to the actual stiffness of the tire, and set the material properties of the front connecting beam and the rear connecting beam. S104: Establish the center of gravity connection points, including the cab center of gravity, powertrain center of gravity and cargo center of gravity, and establish the force connection between the center of gravity and the corresponding components, as well as the rigid connection between the suspension system and the axle housing; S105: Apply cab mass, powertrain mass, and cargo mass at the center of gravity connection point, and apply unsprung mass at the axle housing end point; S106: Constrain the translational degrees of freedom of all tire spring contact points and apply gravitational acceleration across the entire model; S107: Mesh the model to generate a finite element model; S108: Perform static analysis to obtain the Z-direction reaction force at the tire spring constraint and calculate the axle load of each axle.

[0008] According to another embodiment of this application, an electronic device is also provided, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the steps of a multi-axle vehicle axle load calculation method based on finite element simulation.

[0009] As can be seen from the above technical solutions, the present invention has the following advantages: This invention provides a multi-axle vehicle axle load calculation method based on finite element simulation. By assembling all structural components such as the chassis, subframe, axle housing, and brackets, and using rigid connections to recreate the actual mounting hole relationships, the method achieves geometric consistency between the vehicle structural model and the real vehicle, avoiding distortion of the force transmission path caused by structural simplification. Based on the real structural model, front / rear springs and tire springs are established according to the Z-axis vertical installation requirements. The actual connection relationship of the suspension system is recreated through front / rear connecting beams, ensuring that the geometry, installation angle, and connection method of the suspension system are consistent with the real vehicle. The front spring stiffness is decomposed according to the actual stiffness of the front leaf spring, and the rear spring stiffness is decomposed according to the actual stiffness of the rear leaf spring. The tire springs are directly matched to the actual tire stiffness. Simultaneously, a high elastic modulus material is separately set for the connecting beams, and the remaining components match the actual material properties of the vehicle's metal parts, achieving precise matching of the suspension system's mechanical characteristics with the real components. Three types of centers of mass are established based on the actual mass distribution, and force connections are established with the corresponding suspension mounts and subframes. At the same time, each component of the suspension system is rigidly fixed to the axle housing and brackets, ensuring that the force transmission path is completely consistent with the real vehicle. Mass loads are applied to the cab, powertrain, and cargo, while supplementing the unsprung mass loads of the front and rear suspensions to achieve full coverage of all vehicle loads, ensuring that the simulated loads are consistent with the actual vehicle load conditions. The XYZ translational degrees of freedom of the tire spring contact point are constrained to simulate the real constraint state between the tire and the ground. Standard gravitational acceleration is applied to construct a force environment consistent with the Earth's gravitational field, ensuring computational convergence. Tetrahedral elements are used to adapt to complex structures, and the global mesh size is set according to the minimum feature size. Local mesh refinement is applied to areas of concentrated stress, and defective meshes are optimized through quality checks to ensure the discretization accuracy of the finite element model. This ensures both computational resolution in areas of concentrated stress and avoids computational inefficiency caused by excessively dense meshes. The Z-axis reaction force of the tire spring is solved through static analysis, and the axle load is calculated by summing the loads by axle group. The axle load is directly derived from the mechanical simulation results, ensuring the objectivity and accuracy of the axle load calculation results. Attached Figure Description

[0010] To more clearly illustrate the technical solution of the present invention, the accompanying drawings used in the description will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0011] Figure 1 This is a schematic diagram of a multi-axis leaf spring suspension. Figure 2 This is a schematic diagram of an embodiment of a multi-axis leaf spring suspension; Figure 3 This is a flowchart of a method for calculating axle loads of multi-axle vehicles based on finite element simulation. Figure 4This is a schematic diagram of an electronic device. Detailed Implementation

[0012] like Figure 1 and Figure 2 A schematic diagram of a multi-axle leaf spring suspension vehicle is shown. This invention provides a method for calculating the axle load of multi-axle vehicles based on finite element simulation. The method establishes finite element models of the frame, subframe, and axle housing. Spring elements are used to simplify and simulate the stiffness characteristics of the leaf springs. The sprung mass of the main components is concentrated at the center of mass, and the load is transferred by establishing force connections. The unsprung mass is distributed across both ends of the axle housing. Static finite element analysis is performed by applying full constraints and gravity loads at the tire contact points. Finally, the axle load of each axle is calculated by extracting the support reactions at the tire constraint points. This invention can efficiently and accurately predict the axle load distribution of multi-axle vehicles during the design phase, providing a reliable basis for vehicle chassis design and optimization.

[0013] The following describes in detail the method for calculating axle loads of multi-axle vehicles based on finite element simulation, as described in this application. Specific details, such as particular system structures and technologies, are presented for illustrative purposes and not for limitation, in order to provide a thorough understanding of the embodiments of this application. However, those skilled in the art will understand that this application can also be implemented in other embodiments without these specific details.

[0014] It should be understood that, when used in this specification, the term "comprising" indicates the presence of the described feature, integral, step, operation, element, and / or component, but does not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components, and / or collections thereof. The terms "comprising," "including," "having," and variations thereof all mean "including but not limited to," unless otherwise specifically emphasized.

[0015] It should be understood that "one or more" as mentioned in this application refers to one, two, or more, and "multiple" as mentioned in this application refers to two or more. In the description of this application, unless otherwise stated, " / " means "or," for example, A / B can mean A or B. The "and / or" in this document is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone.

[0016] The terms "one embodiment" or "some embodiments" used in this application mean that one or more embodiments of this application include the specific features, structures, or characteristics described in that embodiment. Therefore, the phrases "in one embodiment," "in some embodiments," "in other embodiments," "in still other embodiments," etc., appearing in different parts of this application do not necessarily refer to the same embodiment, but rather mean "one or more, but not all, embodiments," unless otherwise specifically emphasized.

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

[0018] Please see Figure 3 The diagram shows a flowchart of a multi-axle vehicle axle load calculation method based on finite element simulation in a specific embodiment. The method includes: S101: Establish a vehicle structural model, including the frame, subframe, front axle housing, rear axle housing, front spring front bracket, front spring rear bracket, balance shaft, cab mount, and powertrain mount, and assemble these components through rigid connections.

[0019] S101 specifically includes the following methods: S1011: Place the frame 1, subframe 2, front axle housing 3, rear axle housing 4, front spring front bracket 5, front spring rear bracket 6, balance shaft 7, cab mount 8, and power system mount 9 in their actual installation positions, and complete the assembly by using a rigid connection method through the corresponding mounting holes of each component to ensure that the spatial position of each component is consistent with the actual vehicle.

[0020] According to the embodiments of this application, a three-dimensional model of a component that is completely identical to that of an actual vehicle is selected. The frame 1 is confirmed as the main load-bearing structure, and the installation position of the subframe 2 matches the corresponding interface of the frame. The mounting hole positions of the front axle housing 3 and the rear axle housing 4 must completely correspond to the geometric dimensions and spacing of the connection holes of the frame and the subframe. The front spring front bracket 5 and the front spring rear bracket 6 are respectively aligned with the leaf spring mounting area of ​​the front axle housing 3. The installation position of the balance shaft 7 must meet the connection requirements of the rear suspension spring. The mounting holes of the cab mount 8 and the power system mount 9 are precisely matched with the corresponding mounting positions of the frame 1 or the subframe 2. When rigidly connected, the fixing effect of the actual bolt connection is simulated by constraining the degrees of freedom of each mounting hole.

[0021] S1012: At the leaf spring mounting hole A of the front spring bracket 5, a front spring 13 is installed, extending vertically downward along the Z direction to point A1, so that the vertical distance between A and A1 is equal to the actual height of the front suspension, thereby determining the installation length of the front spring 13 in the Z direction.

[0022] According to an embodiment of this application, the spatial coordinates of the hole A on the front spring bracket 5 for mounting the leaf spring are identified, and the upper node of the front spring 13 is created at the center of the hole; the front spring 13 is stretched vertically downward along the negative Z-axis, and the stretching length is the actual height of the front suspension, i.e., the distance from A to A1. During the stretching process, the spring cross-sectional shape is kept consistent with the actual shape; after completion, it is checked whether the vertical distance between A and A1 is completely consistent with the front suspension height parameters in the design drawings. If there is a deviation, the stretching length is adjusted.

[0023] This embodiment specifies the installation height and positioning point of the front spring along the Z direction, so that the compression and tension of the front spring in the digital model are consistent with the force state of the actual vehicle during driving, ensuring the accuracy of the simulation of the dynamic characteristics of the suspension in the vertical direction.

[0024] S1013: At the leaf spring mounting hole B of the front spring rear bracket 6, a front spring 13 is installed, extending along the negative Z-axis to point B1, so that the vertical distance between B and B1 is equal to the actual height of the front suspension, thereby determining the installation length of the front spring 13 in the Y direction.

[0025] According to the embodiments of this application, the spatial coordinates of the hole B corresponding to the leaf spring installation on the front spring rear bracket 6 are found, and the upper node of the front spring 13 is created; the front spring 13 body is stretched vertically downward along the negative Y-axis, and the stretching length is the actual height of the front suspension, i.e., the distance from B to B1, to ensure that the stretching direction is consistent with the negative Y-axis direction; after completion, the vertical distance between B and B1 is measured to verify whether it is equal to the actual height of the front suspension, ensuring that the spring installation height matches the actual front suspension height of the vehicle.

[0026] This embodiment defines the installation height and positioning point of the front spring along the Y direction to adapt to the arrangement requirements of the front axle housing in the vehicle's lateral direction, i.e., the Y direction, ensuring that the direction of the front spring's support force on the front axle is consistent with the actual vehicle, accurately simulating the lateral mechanical behavior of the front suspension.

[0027] S1014: Establish a front connecting beam 12, and connect its two ends to points A1 and B1 at the lower end of the front spring 13 respectively, forming an assembly structure of the spring and connecting beam in the front suspension system.

[0028] According to an embodiment of this application, a three-dimensional model of the front connecting beam 12 is created using points A1 and B1 at the lower end of the front spring 13 as connection endpoints. The length of the connecting beam is determined by the spatial distance between A1 and B1. The cross-sectional shape of the front connecting beam 12 is set, which can be such as a circle or a rectangle, consistent with the actual vehicle front connecting beam. The two ends of the front connecting beam 12 are bound to points A1 and B1 by rigid connection or solid contact, ensuring that the force of the front spring 13 can be transmitted through the connecting beam.

[0029] In this embodiment, the front connecting beam connects to the lower end of the front spring, integrating the force transmission of the front springs on both sides into the front axle housing. This simulates the enhancing effect of the connecting beam on the lateral stability and force transmission of the front suspension in an actual vehicle, thereby improving the mechanical integrity of the front suspension system in the digital model.

[0030] S1015: At the center point E of the end face of the front axle housing 3, establish a tire spring 14, extending vertically downward along the Z direction. The spring length is equal to the actual radius of the tire, completing the installation of the tire spring on one side of the front suspension. Repeat the installation of the front spring front bracket 5, front spring rear bracket 6, front spring 13, front connecting beam 12, tire spring 14 and their connection relationship on the other side of the front suspension according to the principle of vehicle symmetry, to ensure that the left and right front suspension structures are consistent.

[0031] According to an embodiment of this application, an upper node of the tire spring 14 is created at the center point E of the end face of the front axle housing 3. The tire spring 14 is stretched along the negative Z-axis, and the stretching length is equal to the actual radius of the tire, that is, the distance from the lower end of the spring to point E is equal to the tire radius. After completion, the above operation is repeated at the symmetrical position on the other end of the front axle housing 3. If it is a single-axle structure, symmetry is not required; for multiple axles, the actual number is used. For the other side of the left and right front suspensions, the front spring front bracket 5, front spring rear bracket 6, front spring 13, front connecting beam 12, tire spring 14 and their connection relationship on the completed side are copied and pasted to the symmetrical position of the vehicle. The coordinates are adjusted to make it precisely align with the mounting holes of the other side frame, subframe and other components to complete the rigid connection.

[0032] In this embodiment, the length of the tire spring along the Z direction matches the actual radius of the tire, simulating the contact reference between the tire and the ground, ensuring that the tire's support force and torque transmission to the axle are consistent with reality; the left and right suspension structures are replicated to ensure that the load distribution and mechanical response of the vehicle's left and right suspensions are symmetrical.

[0033] S102: Based on the vehicle structure model, establish a suspension system model, including front spring, rear spring, tire spring, front connecting beam and rear connecting beam. The front spring and rear spring are installed vertically downward along the Z direction, the tire spring is installed vertically downward along the Z direction, the front connecting beam is connected to the lower point of the front spring, and the rear connecting beam is connected to the leaf spring mounting hole of the rear axle housing.

[0034] S102 specifically includes the following methods: S1021: Create a 3D model of the front spring. Based on the spatial positions of the front spring bracket 5 leaf spring mounting hole A and the front spring rear bracket 6 leaf spring mounting hole B, establish the upper node of the front spring 13 at the front spring bracket 5 leaf spring mounting hole A, and extend it vertically downward along the Z direction to generate the front spring 13 solid, so that the spring length is equal to the actual height of the front suspension; establish the upper node of the front spring 13 at the front spring rear bracket 6 leaf spring mounting hole B, and extend it along the negative Z-axis to generate the front spring 13 solid, so that the spring length is equal to the actual height of the front suspension.

[0035] According to an embodiment of this application, the three-dimensional coordinates of the front spring front bracket 5 leaf spring mounting hole A and the front spring rear bracket 6 leaf spring mounting hole B are obtained, and two nodes are created in the software; the front spring front bracket side node is stretched along the negative Z-axis, and the stretching length is the actual height of the front suspension from A to A1, keeping the spring cross section consistent with the actual height; the front spring rear bracket side node is stretched along the vertically downward negative Y-axis, and the stretching length is the actual height of the front suspension from B to B1. After stretching, it is verified whether the vertical distances between A and A1 and between B and B1 match the design parameters. If there is a deviation, the stretching length or node coordinates are adjusted.

[0036] This embodiment models the three-dimensional structure and installation parameters of the front spring, ensuring that the elastic deformation and force transmission characteristics of the front spring digital model are consistent with those of the actual vehicle, thus ensuring accurate vertical dynamic analysis of the suspension.

[0037] S1022: Create a 3D model of the rear spring. Establish the upper node of the rear spring 10 at the center point C of the end face of the balance shaft 7, and extend it vertically downward along the Z direction to generate the solid of the rear spring 10, so that the spring length is equal to the actual height of the rear suspension; establish the lower node of the rear spring 10 at the lower point C1 of the rear spring, and complete the 3D model of the spring 10.

[0038] According to an embodiment of this application, the three-dimensional coordinates of the center point C of the end face of the balance shaft 7 are located, and the upper node of the rear spring 10 is created; the upper node is stretched along the negative direction of the vertically downward Z-axis, and the stretching length is the actual height of the rear suspension from C to C1, keeping the spring cross section consistent with the actual height; a lower node is created at the lower point C1 of the rear spring, and the upper and lower nodes are connected to form a solid; it is checked whether the vertical distance between C and C1 is equal to the actual height of the rear suspension to ensure that the installation height is consistent with the actual vehicle height.

[0039] This embodiment accurately reproduces the geometry and installation characteristics of the rear spring, adapts to the mechanical support requirements of the rear suspension balance shaft, simulates the elastic constraint of the rear spring on the balance shaft, ensures that the mechanical response of the rear suspension is consistent with reality, and provides a reliable model for the calculation of rear axle load.

[0040] S1023: Create a 3D model of the tire spring. Establish the upper node of the tire spring 14 at the center point E of the front axle housing end face. Extend it vertically downward along the Z direction to generate the tire spring 14 solid, making the spring length equal to the actual radius of the tire. This completes the modeling of the tire spring 14 on one side of the front axle. Repeat the above operation at the center point E of the rear axle housing end face to complete the modeling of the tire spring 14 on one side of the rear axle. The tire springs 14 on the left and right sides are copied and established according to the principle of vehicle symmetry.

[0041] According to the embodiments of this application, the three-dimensional coordinates of the center point E of the front axle housing end face are determined, and the upper node of the tire spring 14 is created. The upper node is extruded along the negative Z-axis direction downwards, and the extruded length is equal to the actual tire radius, which is the distance from the lower end of the spring to point E. The solid is generated. The operation is repeated on the other side of the front axle housing to create the other front axle tire spring 14. When modeling the rear axle housing tire spring 14, the center point E of the corresponding end face is used as the starting point, and the extruded length is equal to the actual tire radius. The spring lengths on the left and right sides are checked to ensure they are consistent with the tire radii.

[0042] In this embodiment, the tire spring is modeled according to the actual tire radius to simulate the tire's ground support characteristics. This ensures that the force transmission of the tire spring to the axle housing is consistent with the actual vehicle driving state, thus ensuring accurate axle load calculation. Symmetrical modeling guarantees the simulation accuracy of multi-axle tire load distribution.

[0043] S1024: Create a 3D model of the front connecting beam and establish a connection. Using points A1 and B1 at the lower end of the front spring 13 as connection endpoints, create a 3D model of the front connecting beam 12. Set the cross-sectional shape of the front connecting beam 12 to be consistent with the actual shape. Bind both ends of the front connecting beam 12 to points A1 and B1 respectively through rigid connection to ensure that the force transmission path is consistent with the actual vehicle.

[0044] According to an embodiment of this application, the spatial distance between points A1 and B1 is measured, and a solid front connecting beam 12 of equal length is created. The cross-sectional shape of the front connecting beam 12 is set to be consistent with the actual shape. The two ends are bound to points A1 and B1 respectively through rigid connection. It is verified whether the connecting beam effectively transmits force after connection. If there is a gap, the connection parameters are adjusted. The left and right front connecting beams 12 are copied according to the principle of symmetry to ensure that the geometric parameters and connection relationship are consistent.

[0045] In this embodiment, the front connecting beam connects to the lower end of the front spring, integrating and transmitting the spring forces on both sides to the front axle housing. This simulates the enhancing effect of the actual connecting beam on the lateral stability and force transmission of the front suspension, thereby improving the mechanical integrity of the front suspension system.

[0046] S1025: Create a 3D model of the rear connecting beam and establish the connection. Establish the connection endpoint of the rear connecting beam 11 at the mounting hole D of the leaf spring of the rear axle housing 4. Create a 3D model of the rear connecting beam 11. Set the cross-sectional shape of the rear connecting beam 11 to be consistent with the actual shape. Bind both ends of the rear connecting beam 11 to the mounting hole D of the leaf spring of the rear axle housing 4 and the lower point C1 of the rear spring 10 respectively through rigid connection. After the connection is completed, copy and establish the left and right rear connecting beams 11 according to the vehicle symmetry principle.

[0047] According to the embodiments of this application, the three-dimensional coordinates of the leaf spring mounting hole D and the rear spring under-sprung point C1 of the rear axle housing 4 are obtained, and connection nodes at both ends of the rear connecting beam 11 are created; the cross-sectional shape of the rear connecting beam 11 is set to be consistent with the actual shape, and the two ends are bound to the leaf spring mounting hole D and the rear spring under-sprung point C1 respectively through rigid connection; it is checked whether the connected rear connecting beam is completely fitted with the axle housing and the rear spring, and if there is any offset, the node coordinates are adjusted; the left and right rear connecting beams 11 are copied according to the principle of symmetry to ensure that the layout of the connecting beams of multi-axle vehicles is consistent with the actual shape.

[0048] In this embodiment, the rear connecting beam connects the rear axle housing and the rear spring, transmitting the rear suspension force and torque, simulating the supporting effect of the actual connecting beam on the structural strength of the rear suspension; symmetrical modeling ensures that the load distribution and mechanical behavior of the multi-axle rear suspension are consistent with reality, providing a structural basis for accurate calculation of the rear axle and multi-axle axle loads.

[0049] S103: Set the spring stiffness and material properties of the suspension system model, where the front spring stiffness is set to half of the actual stiffness of the front leaf spring, the rear spring stiffness is set to half of the actual stiffness of the rear leaf spring, the tire spring stiffness is set to the actual stiffness of the tire, and set the material properties of the front connecting beam and the rear connecting beam.

[0050] S103 specifically includes the following methods: S1031: Obtain the design parameters before the actual stiffness K of the front leaf spring, and substitute the actual stiffness value of the front leaf spring into the front spring stiffness calculation formula. Determine the stiffness K1 of the front spring 13.

[0051] According to embodiments of this application, the front spring stiffness matches the load-bearing and deformation characteristics of the front leaf spring. When multiple leaf springs are connected in parallel in the front suspension, a single spring bears half the stiffness of the front leaf spring. Therefore, it is used... Calculation. If the actual stiffness of the front leaf spring, Kfront, is 200 N / mm, then K1 = 100 N / mm. This value is directly assigned to the front spring entity in the finite element software to ensure that its deformation is consistent with half the characteristics of the actual leaf spring. The stiffness of the front leaf spring is then adjusted to accommodate the parallel characteristics of multiple leaves to ensure that the load-sharing ratio of the front spring is consistent with the actual values.

[0052] S1032: Assign material properties to the spring entities corresponding to the connection points of the front spring bracket 5 and the front spring 13, and the connection points of the rear spring bracket 6 and the front spring 13: set Poisson's ratio to 0.3 and elastic modulus to 210 Gpa.

[0053] According to the embodiments of this application, the elastic modulus of the front spring material, E=210Gpa, corresponds to the properties of steel, and Poisson's ratio, ν=0.3, is a typical value for isotropic materials. By binding the parameters to the front spring unit, it is ensured that the stress and strain of the spring under compression / tension conform to Hooke's law σ=Eε, accurately simulating elastic mechanical behavior.

[0054] S1033: After obtaining the actual stiffness K of the rear leaf spring, the design parameters are used to substitute the actual stiffness value of the rear leaf spring into the rear spring stiffness calculation formula K2=K. 后 Once the stiffness K2 of spring 10 is determined.

[0055] According to the embodiments of this application, the rear spring stiffness logic is the same as the front spring. In the rear suspension leaf spring combination, a single spring bears half of the stiffness of the rear leaf spring, that is, K2=K 后 If the actual stiffness of the rear leaf spring, Krear, is 300 N / mm, then K2 = 300 N / mm. The assignment method is the same as that of the front spring to ensure that the mechanical response of the rear spring matches the actual situation.

[0056] S1034: Assign material properties to the spring entity corresponding to the connection point between the balance shaft 7 and the rear spring 10, and the unsprung point C1: set Poisson's ratio to 0.3 and elastic modulus to 210 Gpa.

[0057] According to the embodiments of this application, the material properties of the rear spring are the same as those of the front spring. If the rear spring is made of steel, E=210Gpa and ν=0.3 are reasonable values. Assigning these parameters to the rear spring ensures that its deformation and stress calculations under the vertical load of the axle conform to the theory of material mechanics, supporting the transmission of axle loads in the rear suspension. Furthermore, matching the rear spring material to the actual material ensures that its deformation and strength characteristics under high loads conform to physical laws, guaranteeing the reliability of the rear axle load calculation.

[0058] S1035: Obtain the design parameters of the actual tire stiffness K wheel, and directly determine the actual tire stiffness value as the stiffness K3 of the tire spring 14.

[0059] According to the embodiments of this application, the tire spring stiffness is directly taken as the actual tire stiffness K_wheel. Since the tire is the core component for vertical elastic support, its stiffness is determined by the tire carcass structure. K3 is bound to the tire spring unit to reduce the vertical load on the wheel. δ represents tire deformation, which conforms to actual tire characteristics and accurately simulates load transmission. The tire springs directly adopt the actual stiffness to simulate the elastic contact characteristics between the tire and the ground, ensuring that the vertical load transmission of the wheel is consistent with reality and supporting the axle load calculation.

[0060] S1036: Assign material properties to the solid models of front connecting beam 12 and rear connecting beam 11: set the elastic modulus to 21000Gpa and the Poisson's ratio to 0.3; Assign material properties to all solid models of frame 1, subframe 2, front axle housing 3, rear axle housing 4, front spring front bracket 5, front spring rear bracket 6, balance shaft 7, cab mount 8, powertrain mount 9, rear spring 10, and tire spring 14, except for the front connecting beam and rear connecting beam: set the elastic modulus to 210Gpa and the Poisson's ratio to 0.3.

[0061] According to the embodiments of this application, the elastic modulus E of the front and rear connecting beams is 21000 Gpa to simulate lightweight, high-rigidity components, with negligible deformation; other structural components have an elastic modulus E of 210 Gpa to match the properties of steel. These parameters are assigned to the corresponding entities to ensure low deformation of the connecting beams and that the mechanical response of the load-bearing structures such as the frame / bridge shell is consistent with reality, providing a stiffness basis for the axle load path.

[0062] It can be seen that the high elastic modulus of the front and rear connecting beams simplifies the calculation and does not affect the accuracy, while the materials of other structural components are matched to the actual situation, ensuring the authenticity of the axle load transmission path of the entire suspension frame.

[0063] S104: Establish center of gravity connection points, including the cab center of gravity, powertrain center of gravity, and cargo center of gravity, and establish force connections between these centers of gravity and corresponding components, as well as establish rigid connections between the suspension system and the axle housing.

[0064] S104 specifically includes the following methods: S1041: Collect the mass and geometric center data of each component of the cab, and calculate the spatial coordinates of the cab's center of mass O1 using the mass weighting method; create a node in the currently constructed vehicle-suspension integrated structure that is consistent with the spatial position of the center of mass O1.

[0065] The currently constructed vehicle-suspension integrated structure is an integrated structure that combines the vehicle structure model and the suspension system model based on geometric assembly relationships and connection constraints.

[0066] According to an embodiment of this application, the driver's cab is composed of n components, and the mass of the i-th component is m. i The centroid coordinates are Then the coordinates of the cab's center of mass O1 are:

[0067] in The total mass of the cab. After obtaining the mass and coordinates of each component, substitute them into the formula to calculate the O1 coordinate. Accurately calculate the position of the cab's center of gravity to ensure that the applied position of the cab's mass load is consistent with the actual position.

[0068] S1042: Obtain the mass and geometric center data of each component of the powertrain, calculate the spatial coordinates of the powertrain center of mass O2 using the mass weighting method; create a node in the currently constructed vehicle-suspension integrated structure that is consistent with the spatial position of the center of mass O2.

[0069] According to an embodiment of this application, the powertrain center of gravity calculation logic is the same as that of the cab. Assume the powertrain contains m components, and the mass of the j-th component is m. j center of mass Then the coordinates of the powertrain's center of mass O2 are:

[0070] in, This represents the total mass of the powertrain. After calculation, nodes are created to verify the spatial relationship between the powertrain mounting holes and the suspension mounts, ensuring that the load transfer direction after the center of gravity connection is consistent with reality. This embodiment positions the powertrain center of gravity to match the load transfer path of the powertrain with the actual load-bearing characteristics of the vehicle's powertrain suspension mounts, ensuring accurate simulation of the front-rear and lateral loads of the powertrain on the chassis.

[0071] S1043: Based on the cargo mass distribution and loading location data, calculate the spatial coordinates of the cargo center of mass O3 using the mass weighting method; in the currently constructed vehicle-suspension integrated structure, create a node with the same spatial position as the center of mass O3.

[0072] According to the embodiments of this application, if the cargo is a concentrated load, the center of mass is the point of application of the load. If it is a distributed load, such as a uniformly loaded cuboid cargo, the center of mass is calculated by area weighting. After obtaining the cargo mass m and the coordinates of the loading position, a cargo center of mass node O3 is created. The distance and orientation between O3 and the upper wing surface of the subframe are checked to ensure that the gravity in the Z direction is consistent with the actual load direction. This embodiment reasonably establishes the force connection between the cargo center of mass and the subframe, simulating the vertical and longitudinal load transfer of the cargo to the subframe and frame during transportation, ensuring that the impact of the cargo mass on the axle load is consistent with reality.

[0073] S1044: Locate the spatial coordinates of the cab suspension 8 and the cab connection hole, establish a force connection between the cab center of mass node O1 and the corresponding node of the connection hole, define the connection method as a rigid body connection, and ensure that the force is transmitted from the center of mass to the cab structure.

[0074] According to an embodiment of this application, the coordinates of the cab suspension 8 and the cab connection hole are measured using a CAD model, and the connection hole node is set as... The center of mass O1 of the driver's cab is By simulating the elastic / rigid characteristics of the cab suspension through force connection, the system recreates the interaction between the cab's vibration and displacement during driving and the chassis, thereby improving the realism of the dynamic load calculations for the front suspension and chassis.

[0075] S1045: Determine the spatial coordinates of the powertrain mount and the powertrain mounting hole, and establish a force connection between the powertrain center of mass node O2 and the corresponding node of the mounting hole to ensure that the powertrain mass load can be transmitted to the powertrain mount through the connection.

[0076] According to an embodiment of this application, the coordinates of the powertrain mount and the mounting hole are determined, and the mounting hole node is defined as follows: The powertrain center of mass O2 node is When establishing a force connection, if it is simplified to a rigid connection, the force transmission satisfies F. O2 =F B Displacement coordination u O2 =u B This ensures that the inertial force, gravity, and other loads of the powertrain are transmitted to the suspension via the connection, and then to the chassis.

[0077] This embodiment establishes a connection between the powertrain and the suspension to transmit the inertial force, gravity, and other loads of the powertrain, ensuring that the axle load at the front end of the frame and the front axle includes the contribution of the powertrain, and avoiding load omission.

[0078] S1046: Determine the set of geometric nodes on the upper wing surface of the subframe, and establish a rigid connection between the cargo center of mass node O3 and the nodes on the upper wing surface of the subframe so that the cargo mass load is transferred to the vehicle-suspension integrated structure through this connection.

[0079] According to an embodiment of this application, the set of nodes on the upper wing surface of the subframe is determined. The core O3 node of the cargo is In this embodiment, the springs are rigidly connected to the brackets, crossbeams to the axle housing, etc., ensuring the instantaneous transmission of force between the suspension components and eliminating load calculation deviations caused by connection gaps.

[0080] S105: Apply cab mass, powertrain mass, and cargo mass at the center of gravity connection point, and apply unsprung mass at the axle housing end point.

[0081] S105 specifically includes the following methods: S1051: Apply a mass load equal to the actual mass of the cab at the cab's center of mass O1.

[0082] According to the embodiments of this application, the actual mass data of the cab is obtained by actual measurement, and the actual mass data is applied as a load to the cab center of mass O1 established in step S1041. The load direction is along the negative Z-axis direction to ensure that the application position coincides with the cab center of mass and no offset or additional torque is generated.

[0083] In this way, a load matching the actual mass of the cab is applied to the cab's center of gravity, simulating the mechanical process of the cab's own weight being transmitted to the frame through the cab's suspension. This ensures that the location and magnitude of the applied cab gravity load are consistent with the actual vehicle.

[0084] S1052: Apply a mass load equal to the actual mass of the powertrain at the center of mass O2 of the powertrain.

[0085] According to the embodiments of this application, the actual mass parameters of the powertrain, including the total mass of integrated components such as the engine and transmission, are collected. The actual mass parameters are then applied to the center of mass O2 of the powertrain established in step S1042, with the load direction along the negative Z-axis, consistent with the actual gravitational force acting on the powertrain.

[0086] This embodiment applies a corresponding mass load to the center of gravity of the powertrain to restore the actual stress state of the powertrain's gravity transmitted to the frame through the powertrain suspension, thereby improving the accuracy of axle load calculation.

[0087] S1053: Apply a mass load equal to the actual mass of the cargo at the cargo's core O3.

[0088] According to an embodiment of this application, the cargo mass value is determined based on the actual loaded weight of the cargo. If the cargo is uniformly distributed, it is applied according to the total weight. If it is non-uniformly distributed, it is applied to the cargo mass center O3 established in step S1043 after being divided according to the actual distribution ratio. The load direction is along the negative Z-axis direction.

[0089] This embodiment applies the actual mass load of the cargo to its center of gravity, simulating the mechanical path of the cargo's weight being transferred to the chassis via the subframe. It is adaptable to different cargo loading weights and distribution conditions, enhancing the method's versatility.

[0090] S1054: Apply a mass load corresponding to the actual unsprung mass of the front suspension at the end point E of the front axle housing 3.

[0091] According to the embodiments of this application, the unsprung mass of the front suspension, including the total mass of non-sprung components such as the front axle housing, tires, and wheel hubs, is calculated by weighing or design drawings. The mass value is then applied as a load to the end point E of the front axle housing 3, with the load direction along the negative Z-axis, to simulate the weight of the unsprung components of the front suspension.

[0092] In this embodiment, a front suspension unsprung mass load is applied to the end of the front axle housing to simulate the process where the weight of the unsprung components acts directly on the axle housing and is then transmitted to the ground through the tire springs. This compensates for the error caused by neglecting the unsprung mass in traditional axle load calculations and improves the accuracy of the calculation results.

[0093] S1055: Apply a mass load corresponding to the actual unsprung mass of the rear suspension at the end point E of the rear axle housing 4.

[0094] According to an embodiment of this application, the unsprung mass of the rear suspension, which includes the total mass of non-sprung components such as the rear axle housing, tires, and wheel hubs, is determined using the same method as for obtaining the unsprung mass of the front suspension. The mass load is then applied to the end point E of the rear axle housing 4, with the load direction along the negative Z-axis.

[0095] This embodiment applies a rear suspension unsprung mass load to the end of the rear axle housing to recreate the effect and transmission path of the gravity of the rear suspension unsprung components. This simulates the load configuration of the rear suspension system, ensuring the reliability of the rear axle load calculation.

[0096] S1056: Set all applied mass loads to be in the negative Z-axis direction.

[0097] According to the embodiments of this application, the direction of application of all mass loads is uniformly set to the negative direction of the Z-axis to ensure consistency with the direction of gravitational acceleration and conform to the law of vertical downward gravity.

[0098] This avoids additional horizontal or lateral forces caused by inconsistent load directions, ensuring that the stress state of the finite element model is completely consistent with that of the actual vehicle, and reducing systematic errors in mechanical simulation.

[0099] S106: Constrain the translational degrees of freedom of all tire spring contact points and apply gravitational acceleration across the entire model.

[0100] S106 specifically includes the following methods: S1061: Locate the grounding points of the six tire springs 14. The lower end of each tire spring 14 is the grounding point in contact with the ground.

[0101] According to an embodiment of this application, based on the established installation positions of the six tire springs 14, the endpoint of each tire spring 14 extending vertically downwards to the ground is determined. This endpoint is the grounding point, ensuring that the grounding point position completely corresponds to the actual grounding position of the tire. The six grounding points correspond to the actual grounding points of the two front axle tires and the four rear axle tires, respectively. By locating the tire spring grounding points, the specific position where the constraint is applied is clarified, ensuring that the constraint is consistent with the actual tire grounding position.

[0102] S1062: Apply a translational degree of freedom constraint in the X direction to the contact point of each tire spring 14, and set the constraint condition to UX=0.

[0103] According to the embodiments of this application, for each located tire spring grounding point, a translational degree of freedom constraint in the X direction of the vehicle's front-to-back direction is set in the finite element simulation software to restrict the displacement of the grounding point in the X direction. The constraint condition is explicitly set to UX=0 to prevent the vehicle model from moving forward and backward during the simulation process.

[0104] This embodiment constrains the translational degree of freedom of the grounding point in the X direction, limiting the displacement of the model in the forward and backward directions of the vehicle. This conforms to the actual physical characteristic that the tire cannot slide forward and backward after contacting the ground, thereby improving the dynamic stability and calculation accuracy of the model.

[0105] S1063: Apply a Y-direction translational degree of freedom constraint to the contact point of each tire spring 14, and set the constraint condition to UY=0.

[0106] According to an embodiment of this application, each tire spring contact point is further constrained by a translational degree of freedom in the Y direction of the vehicle's left and right directions. The constraint condition is set to UY=0 to limit the displacement of the contact point in the left and right directions, prevent the model from shifting laterally, and ensure the lateral stability of the vehicle model.

[0107] This embodiment constrains the translational degree of freedom of the grounding point in the Y direction, restricts the displacement of the model in the left and right directions, simulates the lateral constraint effect between the tire and the ground, conforms to the lateral support characteristics of the tire when the vehicle is in motion, ensures that the force direction of each component of the vehicle is always mainly in the vertical direction, and reduces the interference of lateral forces on the axle load calculation.

[0108] S1064: Apply a Z-direction translational degree of freedom constraint to the contact point of each tire spring 14, and set the constraint condition to UZ=0.

[0109] According to the embodiments of this application, after completing the constraints in the X and Y directions, a translational degree of freedom constraint in the Z direction is set for each tire spring contact point. The constraint condition is set to UZ=0 to simulate the actual state that the tire cannot penetrate downwards after contacting the ground, thus ensuring the rationality of the force transmission of the model.

[0110] S1065: Apply gravitational acceleration along the negative Z-axis throughout the finite element model. The magnitude of the gravitational acceleration is taken as the standard gravitational acceleration.

[0111] According to an embodiment of this application, in the global coordinate system of the finite element model, a gravitational acceleration along the negative Z-axis downwards is applied, with a value of 9.8 m / s². This value is consistent with the standard gravitational acceleration on the Earth's surface, so that all mass-bearing components in the model are subjected to gravity, thus restoring the actual stress environment of the vehicle.

[0112] In this way, applying gravitational acceleration causes all mass components in the model, such as the cab, powertrain, cargo, and unsprung parts, to be subjected to gravitational loads. Gravity, together with the mass load applied in step S105, works synergistically to restore the actual stress environment of the vehicle in the Earth's gravitational field, ensuring that the stress on all components conforms to physical laws. This allows the axle load calculation to reflect the actual load distribution under gravity, improving the realism and reliability of the calculation results.

[0113] S107: Mesh the model to generate a finite element model.

[0114] S107 specifically includes the following methods: Step S1071: Select the appropriate finite element type for different components in the vehicle structure model.

[0115] According to embodiments of this application, in the finite element software, appropriate element types are assigned based on the geometric characteristics and stress properties of each component. The frame and subframe are discretized using shell elements, specifically 4-node reducing shell elements. The front and rear axle housings are constructed using solid elements. The front and rear connecting beams are constructed using beam elements. Spring components are constructed using spring elements. This element allocation strategy is based on the mechanical behavior characteristics of each component during actual stress, ensuring a balance between computational accuracy and efficiency.

[0116] Step S1072: Set the mesh size parameters for each component in the vehicle structure model.

[0117] According to embodiments of this application, differentiated mesh sizes are set based on the importance and geometric complexity of the components. Major load-bearing structures such as the frame and subframe use a denser mesh with a basic size of 20mm; critical components such as the axle housing and balance shaft use a 15mm mesh size; and secondary components such as connecting beams use a 25mm mesh size. In terms of algorithm implementation, the Advancing Front Method is used for mesh generation. This algorithm generates the mesh by advancing it from the boundary inwards, thus better preserving geometric features.

[0118] Step S1073: Perform mesh generation operation on the vehicle structure model.

[0119] According to embodiments of this application, the entire assembly is discretized in finite element software according to preset element types and size parameters. During mesh generation, local mesh refinement technology is used to refine the mesh in stress concentration areas around mounting holes, reducing the mesh size in the refined areas to 1 / 3 of the basic size. For complex geometric regions, adaptive meshing technology is used, with error estimation guiding mesh refinement to ensure geometric boundary fitting accuracy. The process transforms a continuous geometric model into a discrete system composed of a finite number of elements and nodes.

[0120] This embodiment transforms a continuous geometric model into a set of finite elements through mathematical discretization. Each element is interconnected via nodes, forming a discrete system suitable for numerical computation. Local refinement techniques are used to accurately capture stress concentration phenomena.

[0121] Step S1074: Perform mesh generation on the spring components in the suspension system.

[0122] According to embodiments of this application, a specialized discretization method is employed for the spring component. Spring elements are directly generated as discrete units, each containing two nodes corresponding to the upper and lower endpoints of the spring. In the mathematical model, the spring elements do not participate in geometric discretization but instead directly participate in the assembly of the overall stiffness matrix through the stiffness matrix. This approach ensures both computational efficiency and accurate reflection of the spring's mechanical properties.

[0123] Based on the spring element as a special connecting unit, it does not participate in geometric discretization, but directly participates in the assembly of system equations through the stiffness matrix, accurately simulating the mechanical behavior of elastic elements.

[0124] Step S1075: Check the quality of the generated finite element mesh and make corrections.

[0125] According to the embodiments of this application, the mesh quality indicators, including element aspect ratio, Jacobian determinant value, and twist, are checked using the post-processing function of the finite element software. Quality acceptance criteria are set as follows: element aspect ratio not greater than 5, Jacobian determinant value greater than 0.6, and twist less than 45 degrees. Mesh optimization is performed on regions that do not meet the requirements. The Laplace smoothing algorithm is used to adjust the node positions. The Laplace smoothing algorithm optimizes the mesh quality by iteratively calculating the center position of the node's neighborhood. Multiple iterations are performed until the mesh quality meets the analysis requirements.

[0126] This embodiment utilizes the post-processing functions of finite element analysis software to check and optimize mesh quality, eliminate defective elements, and ensure the stability and accuracy of numerical calculations. An optimization algorithm is employed to improve node distribution and enhance element quality.

[0127] S108: Perform static analysis to obtain the Z-direction reaction force at the tire spring constraint and calculate the axle load of each axle.

[0128] S108 specifically includes the following methods: S1081: In finite element analysis software, select a solver suitable for structural statics based on the model characteristics, such as the Standard solver in ABAQUS or the Static Structural solver in ANSYS, to ensure support for linear / small deformation static analysis.

[0129] According to embodiments of this application, the solver can be the Standard solver of ABAQUS or the Static Structural solver of ANSYS. The solver selection matches the model characteristics. If the model contains nonlinear elements such as rubber bushings, a nonlinear solver is selected; however, in this model, the springs and connecting beams are linear elastic, so a linear static solver is selected, which has high computational efficiency and meets the accuracy requirements.

[0130] Different solvers have varying efficiency and accuracy for solving linear / nonlinear problems. Choosing a dedicated linear static solver can efficiently handle elastic deformation problems, ensuring the speed and accuracy of shaft load calculations.

[0131] S1082: Enable linear analysis unit in solver parameter settings.

[0132] According to the embodiments of this application, the linear statics analysis assumes small deformation and that the material obeys Hooke's law, which is consistent with the linear setting of spring stiffness and material elastic modulus in the model.

[0133] S1083: Execute the solution process. The solver performs calculations and generates a solution log file to record the iteration process and convergence status.

[0134] According to an embodiment of this application, when submitting a solution, the software converts nodes, elements, materials, loads, and constraints into a solver input file, and solves the linear equation system Ku=F using an internal algorithm, where K is the stiffness matrix, u is the displacement vector, and F is the load vector.

[0135] In this way, submitting the solution involves passing the model data to the solver kernel, which then solves the displacement field using numerical methods, ensuring the consistency of the calculations.

[0136] S1084: View the solution log in real time, pay attention to the residual and displacement increment indicators, and determine the solution is successful when the residual is lower than the set threshold and the number of iterations reaches the convergence condition.

[0137] According to embodiments of this application, the residual reflects the degree of balance between load and internal force; excessively large residuals can lead to displacement calculation errors. During monitoring, if the residual consistently exceeds a threshold, the mesh quality or constraint settings are checked. This ensures the reliability of displacement field and reaction force calculations, providing effective input for shaft load calculations.

[0138] S1085: Locate the constraint nodes of the 6 tire spring grounding points using the node selection tool, read their node reaction forces in the Z direction, and record them as FZ1 to FZ6.

[0139] According to an embodiment of this application, the nodal reaction force is obtained through the RFZ value output by the solver, confirming that the nodal number corresponds one-to-one with the tire spring contact point. For example, the nodal corresponding to the left front spring of the front axle is node N1, and its RFZ is FZ1. Here, the finite element solver calculates the reaction force through the nodal force balance equation, and extracts the RFZ value to obtain the spring's supporting force on the ground.

[0140] S1086: Based on the correspondence between the shaft and the spring, such as the front shaft corresponding to FZ1 / FZ2, the middle shaft corresponding to FZ3 / FZ4, and the rear shaft corresponding to FZ5 / FZ6, sum the reaction forces of the coaxial springs to obtain the first shaft load = FZ1 + FZ2, the second shaft load = FZ3 + FZ4, and the third shaft load = FZ5 + FZ6.

[0141] According to an embodiment of this application, the axle load calculation is based on the design in the physical model where each axle is supported by two springs. Therefore, the sum of the reaction forces of the coaxial springs is the total load on the bearing. The calculation verifies the correspondence between the springs and the axles, such as the left and right springs of the rear axle corresponding to FZ5 / FZ6.

[0142] In this way, based on the connection relationship between the axle and the spring, the axle load is obtained by summing the coaxial spring reaction forces. Mapping the spring load onto the actual axle accurately reflects the weight distribution of the vehicle on each bearing, providing key parameters for vehicle design.

[0143] It should be understood that the sequence number of each step in the above embodiments does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

[0144] like Figure 4 As shown, this application also provides an electronic device, including a display module 103, a memory 102, a processor 101, a communication module 104, and a computer program stored in the memory and executable on the processor 101. When the processor 101 executes the program, it implements the steps of a multi-axle vehicle axle load calculation method based on finite element simulation.

[0145] In embodiments of the present invention, electronic devices include, but are not limited to, laptop computers, desktop computers, workstations, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. Electronic devices may also refer to various forms of mobile devices, such as personal digital processors, cellular phones, smartphones, wearable devices, and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely illustrative and are not intended to limit the implementation of the embodiments described and / or claimed herein.

[0146] In this embodiment, processor 101 may be implemented using at least one of an application-specific integrated circuit, a programmable logic device, a field-programmable gate array, a processor, a controller, a microcontroller, a microprocessor, or an electronic unit designed to perform the functions described herein. In some cases, such an implementation may be implemented within a controller. For software implementation, implementations such as processes or functions may be implemented with separate software modules that allow the performance of at least one function or operation. Software code may be implemented by a software application (or program) written in any suitable programming language, and the software code may be stored in memory and executed by the controller.

[0147] The display module 103 is used to display information input by the user or information provided to the user. The display module 103 may include a display panel, which may be configured in the form of a liquid crystal display, an organic light-emitting diode, or the like.

[0148] The memory 102 can be used to store software programs and various data. The memory 102 may include high-speed random access memory, and may also include non-volatile memory, such as at least one disk storage device, flash memory device, or other volatile solid-state storage device.

[0149] The communication module 104 transmits radio signals to and / or receives radio signals from at least one of a base station, an external terminal, and a server. Such radio signals may include voice call signals, video call signals, or various types of data sent and / or received according to text and / or multimedia messages.

[0150] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for calculating axle load of multi-axle vehicles based on finite element simulation, characterized in that, The methods include: S101: Establish a vehicle structure model, including the frame, subframe, front axle housing, rear axle housing, front spring front bracket, front spring rear bracket, balance shaft, cab mount and powertrain mount, and assemble them through rigid connections. S102: Based on the vehicle structure model, establish a suspension system model, including front spring, rear spring, tire spring, front connecting beam and rear connecting beam. The front spring and rear spring are installed vertically downward along the Z direction, the tire spring is installed vertically downward along the Z direction, the front connecting beam is connected to the lower point of the front spring, and the rear connecting beam is connected to the leaf spring mounting hole of the rear axle housing. S103: Set the spring stiffness and material properties of the suspension system model, where the front spring stiffness is set to half of the actual stiffness of the front leaf spring, the rear spring stiffness is set to half of the actual stiffness of the rear leaf spring, the tire spring stiffness is set to the actual stiffness of the tire, and set the material properties of the front connecting beam and the rear connecting beam. S104: Establish the center of gravity connection points, including the cab center of gravity, powertrain center of gravity and cargo center of gravity, and establish the force connection between the center of gravity and the corresponding components, as well as the rigid connection between the suspension system and the axle housing; S105: Apply cab mass, powertrain mass, and cargo mass at the center of gravity connection point, and apply unsprung mass at the axle housing end point; S106: Constrain the translational degrees of freedom of all tire spring contact points and apply gravitational acceleration across the entire model; S107: Mesh the model to generate a finite element model; S108: Perform static analysis to obtain the Z-direction reaction force at the tire spring constraint and calculate the axle load of each axle.

2. The method for calculating the axle load of a multi-axle vehicle based on finite element simulation according to claim 1, characterized in that, S101 specifically includes the following methods: The chassis, subframe, front axle housing, rear axle housing, front spring front bracket, front spring rear bracket, balance shaft, cab mount, and power system mount are placed according to their actual installation positions. Assembly is completed by rigid connection through the corresponding mounting holes of each component, ensuring that the spatial position of each component is consistent with the actual vehicle. At the leaf spring mounting hole A of the front spring bracket, a front spring is installed, extending vertically downward along the Z direction to point A1, so that the vertical distance between A and A1 is equal to the actual height of the front suspension, thereby determining the installation length of the front spring in the Z direction; At the leaf spring mounting hole B of the front spring rear bracket, a front spring is installed, extending along the negative Z-axis to point B1, so that the vertical distance between B and B1 is equal to the actual height of the front suspension, thereby determining the installation length of the front spring in the Y direction. A front connecting beam is constructed, and its two ends are connected to points A1 and B1 at the lower end of the front spring, respectively, to form an assembly structure of the spring and the connecting beam in the front suspension system. At the center point E of the front axle housing end face, a tire spring is installed, extending vertically downwards along the Z direction. The spring length is equal to the actual radius of the tire, thus completing the installation of the tire spring on one side of the front suspension. The front spring front bracket, front spring rear bracket, front spring, front connecting beam, tire spring, and their connection relationships of the single-side front suspension are then repeated on the other side according to the principle of vehicle symmetry to ensure that the left and right front suspension structures are consistent.

3. The method for calculating the axle load of a multi-axle vehicle based on finite element simulation according to claim 1, characterized in that, S102 specifically includes the following methods: Create a 3D model of the front spring. Based on the spatial positions of the front spring front bracket leaf spring mounting hole A and the front spring rear bracket leaf spring mounting hole B, establish the upper node of the front spring at the front spring front bracket leaf spring mounting hole A, and extend it vertically downward along the Z direction to generate the front spring solid, so that the spring length is equal to the actual height of the front suspension; establish the upper node of the front spring at the front spring rear bracket leaf spring mounting hole B, and extend it along the negative Z-axis to generate the front spring solid, so that the spring length is equal to the actual height of the front suspension. Create a 3D model of the rear spring. Establish the upper node of the rear spring at the center point C of the balance shaft end face, and extend it vertically downward along the Z direction to generate the rear spring solid, making the spring length equal to the actual height of the rear suspension. Establish the lower node of the rear spring at the lower point C1. After completion, the 3D model of the spring is constructed. Create a 3D model of the tire spring. Establish the upper node of the tire spring at the center point E of the front axle housing end face, and extend it vertically downward along the Z direction to generate the tire spring solid. Make the spring length equal to the actual radius of the tire to complete the modeling of the tire spring on one side of the front axle. Repeat the above operation at the center point E of the rear axle housing end face to complete the modeling of the tire spring on one side of the rear axle. The tire springs on the left and right sides are copied and established according to the principle of vehicle symmetry. Create a 3D model of the front connecting beam and establish the connection. Use points A1 and B1 at the lower end of the front spring as the connection endpoints. Create a 3D model of the front connecting beam and set the cross-sectional shape of the front connecting beam to be consistent with the actual one. Bind both ends of the front connecting beam to points A1 and B1 respectively through rigid connection to ensure that the force transmission path is consistent with the actual vehicle. Create a 3D model of the rear connecting beam and establish the connection. Establish the connection endpoint of the rear connecting beam at the rear axle housing leaf spring mounting hole D. Create a 3D model of the rear connecting beam and set the cross-sectional shape of the rear connecting beam to be consistent with the actual shape. Bind both ends of the rear connecting beam to the rear axle housing leaf spring mounting hole D and the rear spring underpoint C1 respectively through rigid connection. After completing the connection, copy and create the left and right rear connecting beams according to the vehicle symmetry principle.

4. The method for calculating the axle load of a multi-axle vehicle based on finite element simulation according to claim 1, characterized in that, S103 specifically includes the following methods: Before obtaining the design parameters for the actual stiffness K of the front leaf spring, substitute the actual stiffness value of the front leaf spring into the front spring stiffness calculation formula. Determine the stiffness K1 of the front spring; Material properties are assigned to the spring entities corresponding to the connection points between the front spring bracket and the front spring, and between the rear spring bracket and the front spring. After obtaining the design parameters of the actual stiffness K of the rear leaf spring, substitute the actual stiffness value of the rear leaf spring into the rear spring stiffness calculation formula K2=K 后 Once the spring stiffness K2 is determined; Material properties are assigned to the spring entities corresponding to the connection point between the balance shaft and the rear spring, and the unsprung point of the rear spring. Obtain the design parameters of the tire's actual stiffness K wheel, and determine the actual stiffness value of the tire as the stiffness K3 of the tire spring; Assign material properties to the solid models of the front and rear connecting beams. Assign material properties to all solid models of the chassis, subframe, front axle housing, rear axle housing, front spring front bracket, front spring rear bracket, balance shaft, cab mount, powertrain mount, rear spring, and tire springs, except for the front and rear connecting beams.

5. The method for calculating the axle load of a multi-axle vehicle based on finite element simulation according to claim 1, characterized in that, S104 specifically includes the following methods: Collect the mass and geometric center data of each component of the cab, and use the mass weighting method to calculate the spatial coordinates of the cab's center of mass O1; in the currently constructed vehicle-suspension integrated structure, create a node with the same spatial position as the center of mass O1; Obtain the mass and geometric center data of each powertrain component, and calculate the spatial coordinates of the powertrain center of mass O2 using the mass weighting method; create a node in the currently constructed vehicle-suspension integrated structure that is consistent with the spatial position of the center of mass O2; Based on the cargo mass distribution and loading location data, calculate the spatial coordinates of the cargo center of mass O3 using the mass weighting method; in the currently constructed vehicle-suspension integrated structure, create a node with the same spatial location as the center of mass O3; Locate the spatial coordinates of the cab suspension 8 and the cab connection hole, establish a force connection between the cab center of mass node O1 and the corresponding node of the connection hole, define the connection method as a rigid body connection, and ensure that the force is transmitted from the center of mass to the cab structure. Determine the spatial coordinates of the powertrain mount and the powertrain mounting hole, and establish a force connection between the powertrain center of mass O2 node and the corresponding node of the mounting hole; Determine the set of geometric nodes on the upper wing surface of the subframe, and establish a rigid connection between the cargo center of mass node O3 and the nodes on the upper wing surface of the subframe so that the cargo mass load is transferred to the vehicle-suspension integrated structure through the connection.

6. The method for calculating the axle load of a multi-axle vehicle based on finite element simulation according to claim 1, characterized in that, S105 specifically includes the following methods: A mass load equal to the actual mass of the cab is applied at the cab's center of mass O1; A mass load equal to the actual mass of the powertrain is applied at the center of mass O2 of the powertrain. Apply a mass load equal to the actual mass of the cargo at the cargo's core O3; A mass load corresponding to the actual unsprung mass of the front suspension is applied at the end point E of the front axle housing. A mass load corresponding to the actual unsprung mass of the rear suspension is applied at the end point E of the rear axle housing. Set all applied mass loads to be in the negative Z-axis direction.

7. The method for calculating the axle load of a multi-axle vehicle based on finite element simulation according to claim 1, characterized in that, S106 specifically includes the following methods: Locate the grounding points of the six tire springs; the lower end of each tire spring is the grounding point that contacts the ground. Apply a translational degree of freedom constraint in the X direction to the contact point of each tire spring, and set the constraint condition to UX=0; Apply a Y-direction translational degree of freedom constraint to the contact point of each tire spring, and set the constraint condition to UY=0; Apply a Z-direction translational degree of freedom constraint to the contact point of each tire spring, and set the constraint condition to UZ=0; Gravitational acceleration is applied along the negative Z-axis throughout the finite element model, with the magnitude of the gravitational acceleration taken as the standard gravitational acceleration.

8. The method for calculating the axle load of a multi-axle vehicle based on finite element simulation according to claim 1, characterized in that, S107 specifically includes the following methods: Select the appropriate finite element type for different components in the vehicle structure model; Set the mesh size parameters for each component in the vehicle structure model; Perform mesh generation on the vehicle structure model; Mesh the spring components in the suspension system; Check the quality of the generated finite element mesh and make corrections.

9. The method for calculating the axle load of a multi-axle vehicle based on finite element simulation according to claim 1, characterized in that, S108 specifically includes the following methods: In finite element analysis software, a solver suitable for structural statics is selected based on the characteristics of the model; In the solver parameter settings, enable the linear analysis unit, execute the solution process, the solver performs calculations, and generates a solution log file to record the iteration process and convergence status; View the solution log in real time, pay attention to the residual and displacement increment indicators, and determine the solution is successful when the residual is lower than the set threshold and the number of iterations reaches the convergence condition; Locate the constraint nodes of the six tire spring grounding points using the node selection tool, read their node reaction forces in the Z direction, and record them as FZ1 to FZ6. Based on the correspondence between the shaft and the spring, the front shaft corresponds to FZ1 / FZ2, the middle shaft corresponds to FZ3 / FZ4, and the rear shaft corresponds to FZ5 / FZ6. By summing the reaction forces of the coaxial springs, we get the shaft load of the first shaft = FZ1 + FZ2, the shaft load of the second shaft = FZ3 + FZ4, and the shaft load of the third shaft = FZ5 + FZ6.

10. An electronic 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, it implements the steps of the multi-axle vehicle axle load calculation method based on finite element simulation as described in any one of claims 1 to 9.

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