Balance bridge type plate spring modeling method, electronic equipment and medium

Abstract

According to the balance bridge type plate spring modeling method, the electronic equipment and the medium provided by the invention, the gap unit is adopted to establish the plate spring sheet contact relation, and rigidity analysis considering the contact relation can be carried out on a plate spring system; the convergence problem of calculation can be avoided under the condition that the vertical movement and rigidity performance of the plate spring are not influenced; according to the method, the motion relation between the plate spring pieces is represented by establishing the rigid connection units at the two ends of the plate spring and releasing the translational freedom degrees of the rigid connection units, the actual motion behavior of the plate spring is better met, and the method has the advantages of being simple, convenient and good in practicability; by defining the contact area of the balance bridge type plate spring, the reasonability of the deformation behavior of the plate spring and the calculation precision and calculation efficiency of the rigidity of the plate spring can be considered.

Description

Technical Field

[0001] The invention belongs to the technical field of vehicle suspension systems, and in particular relates to a balanced bridge type leaf spring modeling method, electronic equipment and a medium. Background Art

[0002] For vehicle products using a balanced bridge, their posture and stiffness performance under vehicle operating conditions are closely related to the suspension and leaf spring assembly. In the simulation analysis of vehicle stiffness and strength, establishing a scientific and reliable leaf spring assembly model has an important impact on improving the reliability of simulation analysis. At present, most of the modeling and stiffness analysis research is carried out on the ear-type leaf spring, and there are relatively few studies on the balanced bridge leaf spring, which makes the boundary conditions imposed on the ear-type leaf spring not applicable to the balanced bridge leaf spring, and there are deficiencies in describing the motion behavior and contact relationship expression between leaf spring leaves.

[0003] Patent application CN115186369A discloses a leaf spring modeling method, which constructs a leaf spring model based on a three-dimensional data input and grid discretization method, and processes the contact between leaf spring leaves using a common node method. There is no relative movement between the leaf spring leaves, and only the static stiffness analysis of the entire leaf spring is performed, which is inconsistent with the actual movement behavior of the leaf spring. Summary of the invention

[0004] The purpose of the present invention is to address the deficiencies in the prior art and provide a balanced bridge type leaf spring modeling method, electronic equipment and medium, which are more targeted for the modeling and stiffness analysis of the balanced bridge type leaf spring.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is:

[0006] A balanced bridge leaf spring modeling method includes the following implementation process:

[0007] Obtaining three-dimensional data, stiffness value, elastic modulus, and material of a balanced bridge leaf spring; the three-dimensional data includes a plurality of leaf spring leaves, a U-shaped bolt, a center bolt, straight sections at both ends of the leaf spring, and end faces at both ends of the leaf spring;

[0008] Using hexahedron or tetrahedron units to establish a finite element model of the balanced bridge leaf spring;

[0009] Covering a layer of shell elements on the surface of the leaf spring;

[0010] Setting a contact area of ​​the balancing bridge leaf spring;

[0011] Disposing gap units between shell units on surfaces of adjacent leaf spring pieces in the contact area to establish a contact relationship between the leaf spring pieces;

[0012] Establish multiple rigid connection units of the balanced bridge leaf spring, the rigid connection units include: a rigid connection unit in the middle of the leaf spring, a rigid connection unit on the end surface of the leaf spring, and a rigid connection unit between the leaf spring leaves; release the translational freedom of the main point and the slave point of the rigid connection unit between the leaf spring leaves along the front-rear direction of the balanced bridge leaf spring;

[0013] A degree of freedom constraint condition is established at the principal point of the rigid connection unit at the end face of the leaf spring at the bottom layer, and a load is applied vertically at the principal point of the rigid connection unit in the middle of the leaf spring;

[0014] Performing simulation analysis to determine whether the stiffness of the balanced bridge leaf spring meets preset conditions;

[0015] If so, it is determined that the balanced bridge leaf spring modeling is completed.

[0016] The contact relationship of the leaf spring of the present invention uses a gap unit, and a stiffness analysis of the contact relationship can be performed on the leaf spring system, which can avoid the convergence problem of the calculation without affecting the vertical movement and stiffness performance of the leaf spring. The present invention characterizes the movement relationship between the leaf spring leaves by establishing a rigid connection unit at both ends of the leaf spring and releasing the translational freedom of the rigid connection unit, which is more in line with the actual movement behavior of the leaf spring and has the advantages of simplicity, convenience and good practicality.

[0017] Furthermore, the contact area of ​​the balanced bridge leaf spring includes straight sections at both ends of the leaf spring and an area extending to both sides by a first distance starting from the intersection of the outer contours of the two U-bolts along the side direction of the balanced bridge leaf spring and the middle horizontal plane of the balanced bridge leaf spring.

[0018] In the actual movement process, the leaf spring relies on the mutual contact between the leaf springs to achieve load transfer. A small contact area affects the authenticity of the leaf spring movement state. A large contact area makes the nonlinear contact detection and calculation process complicated, the calculation cycle is long, and even the calculation does not converge. The contact area definition method of the balanced bridge leaf spring proposed in the present invention can take into account the rationality of the leaf spring deformation behavior, the calculation accuracy and efficiency of the leaf spring stiffness.

[0019] Furthermore, taking the geometric center of the central bolt as the main point and all nodes between the intersections of the outer contours of the two U-bolts along the lateral direction of the balanced bridge leaf spring and the middle horizontal plane of the balanced bridge leaf spring as the secondary points, a rigid connection unit in the middle of the leaf spring is established;

[0020] On the end faces of both ends of each leaf spring, with the end face center of each leaf spring as the main point and all nodes on the end face of each leaf spring as the slave points, rigid connection units of the leaf spring end faces are established respectively; with the end face center point of the lower layer leaf spring as the main point and the end face center point of the adjacent upper layer leaf spring as the slave point, rigid connection units between the leaf springs are established.

[0021] The clamping effect of the U-bolt is simulated by the rigid connection unit in the middle of the leaf spring; the relative motion relationship of the leaf spring during the extension process is simulated by the rigid connection unit on the end face of the leaf spring and the rigid connection unit between the leaf springs.

[0022] Furthermore, the degree of freedom constraint condition includes that one end of the bottom leaf spring constrains the translational degrees of freedom along the vehicle coordinate system X, Y and Z and the rotational degrees of freedom around X and Z, and the other end constrains the translational degrees of freedom along the vehicle coordinate system Y, Z and the rotational degrees of freedom around X and Z.

[0023] Further, the load is equal to the design stiffness value.

[0024] Furthermore, the process of performing simulation analysis to determine whether the stiffness of the balanced bridge leaf spring meets a preset condition includes:

[0025] The vertical displacement of the main point of the rigid connection unit in the middle of the leaf spring is analyzed by simulation. If the vertical displacement is equal to 1 mm, the stiffness of the balanced bridge leaf spring meets the preset requirements. Otherwise, the elastic modulus of the balanced bridge leaf spring is adjusted to make the vertical displacement equal to 1 mm.

[0026] Stiffness = load / displacement. The present invention sets the load to be equal to the design stiffness value. Therefore, you only need to check whether the displacement is 1 mm to intuitively judge the difference between the actual stiffness and the design stiffness of the established leaf spring model, and understand the stiffness of the model simply and conveniently.

[0027] Based on the same inventive concept, the present invention also provides an electronic device, including:

[0028] one or more processors;

[0029] A memory having one or more programs stored thereon, which, when executed by the one or more processors, enable the one or more processors to implement the steps of the balanced bridge leaf spring modeling method.

[0030] Based on the same inventive concept, the present invention also provides a computer-readable storage medium storing a computer program, which implements the steps of the balanced bridge leaf spring modeling method when executed by a processor.

[0031] Compared with the prior art, the present invention has the following beneficial effects:

[0032] 1. The contact relationship of the leaf spring of the present invention uses a gap unit, and a stiffness analysis considering the contact relationship can be performed on the leaf spring system, which can avoid the convergence problem of the calculation without affecting the vertical movement and stiffness performance of the leaf spring.

[0033] 2. The present invention characterizes the motion relationship between the leaf spring leaves by establishing a rigid connection unit at both ends of the leaf spring and releasing the translational freedom of the rigid connection unit, which is more in line with the actual motion behavior of the leaf spring and has the advantages of simplicity, convenience and good practicality.

[0034] 3. The definition of the contact area of ​​the balanced bridge leaf spring of the present invention can take into account the rationality of the leaf spring deformation behavior, the calculation accuracy and calculation efficiency of the leaf spring stiffness. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 It is a schematic diagram of the structure of the balanced bridge suspension of the present invention;

[0036] Figure 2 It is a schematic diagram of the structure of the balanced bridge leaf spring of the present invention;

[0037] Figure 3 It is a schematic diagram of calculating the stiffness of the balanced bridge leaf spring of the present invention;

[0038] Figure 4 It is a schematic diagram of the contact area of ​​the balanced bridge leaf spring of the present invention;

[0039] Figure 5 A schematic diagram of the contact relationship of the balanced bridge leaf spring of the present invention;

[0040] Figure 6 It is a schematic diagram of the end surface rigid connection unit of the balanced bridge type leaf spring of the present invention;

[0041] Figure 7 It is a schematic diagram of the middle rigid unit of the balanced bridge type leaf spring of the present invention.

[0042] In the figure: 1-balance bridge leaf spring, 2-straight sections at both ends of the leaf spring, 3-end faces at both ends of the leaf spring, 4-U-bolt, 5-balance bridge, 6-center bolt, 11-first leaf spring leaf, 12-second leaf spring leaf, 13-third leaf spring leaf. DETAILED DESCRIPTION

[0043] The present invention will be described in detail below in conjunction with the embodiments. It should be noted that the embodiments and features of the embodiments of the present invention can be combined with each other without conflict. For the convenience of description, if the words "upper", "lower", "left" and "right" appear in the following, they only indicate that the upper, lower, left and right directions are consistent with the drawings themselves, and do not limit the structure.

[0044] Example

[0045] A balanced bridge leaf spring modeling method of this embodiment is as follows:

[0046] (1) Input condition confirmation: The method of this embodiment requires the input of complete three-dimensional data of the balanced bridge leaf spring in the clamped free state, leaf spring drawings containing stiffness information (stiffness value, elastic modulus), and material information of each component of the leaf spring. The balanced bridge suspension, balanced bridge leaf spring 1, and stiffness calculation diagram are shown in the following figure. Figure 1 , Figure 2 , Figure 3 The three-dimensional data includes three leaf springs (a first leaf spring 11, a second leaf spring 12, and a third leaf spring 13), a U-shaped bolt 4, a center bolt 6, straight sections 2 at both ends of the leaf spring, end surfaces 3 at both ends of the leaf spring, and a balance bridge 5.

[0047] (2) Leaf spring modeling: Based on the input three-dimensional data, the leaf spring is meshed using hexahedron or tetrahedron units, and the mesh size is controlled at about 8 mm, so as to ensure the reliability of the analysis results while taking into account the model scale and computational efficiency. After the leaf spring meshing is completed, a layer of shell units is covered on the surface of each leaf spring, and the thickness is set to 0.01 mm. This layer of shell units is used to further generate surface contact relationships. The completed leaf spring model is assigned material properties, and model unit interference and penetration checks are performed to ensure that there is no initial penetration problem in the contact area units between the leaf springs.

[0048] (3) Establishment of surface contact relationship: For a balanced bridge leaf spring, the contact area is mainly located in the straight sections at both ends and in the forward and backward areas of the U-bolt compression part in the middle. Combined with the actual application of the current balanced bridge leaf spring, the straight sections at both ends of the balanced bridge leaf spring and the intersection of the outer contour of the U-bolt along the side direction of the balanced bridge leaf spring and the middle horizontal plane of the balanced bridge leaf spring are defined as the starting point, and the area extending 200 mm on both sides is defined as the contact area. The contact relationship between the surface shell elements of the leaf spring is established using gap elements in the contact area.

[0049] The gap unit is a general-purpose gap unit from the node to the wall, which can simulate the contact and separation between units, transfer loads when in contact, and not transfer loads when separated. The characteristic of the gap unit is that its stiffness in both contact and separation states can be defined in the properties, so that when in contact, the gap unit has a larger unit stiffness, and the contact load can be transferred through the gap unit at this time; when separated, the gap unit adopts a small, close to 0 unit stiffness, and the load transferred through the gap unit is close to 0 at this time. The determination of the contact and separation states is determined by the software during the analysis process based on the relationship between the gap unit length and the initial length. When the length in the analysis is less than the initial length, it means that the gap unit is compressed, which is manifested as contact; when the unit length in the analysis is greater than the initial length, it means that the gap unit is separated, indicating that there is no contact. The definition of the contact area and the creation of the contact relationship are as follows: Figure 4 and Figure 5 shown.

[0050] (4) Characterization of the motion relationship of leaf springs: First, a rigid connection unit in the middle of the leaf spring is established with all nodes between the two intersection points determined in (3) as slave points and the geometric center of the center bolt as the master point to simulate the clamping effect of the U-bolt. Then, on the end faces of both ends of each leaf spring, a rigid connection unit of the leaf spring is established with the center of the end face as the master point and all nodes of the end face as slave points. Next, a rigid connection unit between leaf springs is established with the center point of the end face of the lower leaf spring as the master point and the center point of the end face of the upper leaf spring as the slave point. Only the degrees of freedom of the master point and the slave point of the rigid connection unit along the forward and backward extension direction of the balanced bridge leaf spring are released, thereby simulating the relative motion relationship of the balanced bridge leaf spring during the extension process. The rigid connection unit of the leaf spring is shown in the figure below. Figure 6 , Figure 7 shown.

[0051] (5) Boundary condition application: For the balanced bridge leaf spring model established in (1)-(4), freedom constraint conditions are established at the principal points of the rigid connection unit between the leaf spring leaves at the bottom of both ends in (4). One end constrains the translational freedom along the vehicle coordinate system X, Y and Z and the rotational freedom around X and Z, and the other end constrains the translational freedom along the vehicle coordinate system Y, Z and the rotational freedom around X and Z. A load equal to the design stiffness value of the leaf spring is applied vertically to the principal point of the rigid unit in the middle of the leaf spring established in (4).

[0052] (6) Leaf spring stiffness analysis: Based on the constraints and load conditions determined in (5), a nonlinear static solution condition is created to perform simulation analysis. The software is set to automatically determine the contact relationship between the leaf spring leaves according to the calculation process, and to determine whether the displacement of the main point of the rigid connection unit in the middle of the leaf spring in the load loading direction is 1 mm after the calculation is completed. The nonlinear static solution condition means that the stiffness of the leaf spring is continuously checked according to the shape change and the contact between the leaf spring leaves during the analysis process, and the deformation is calculated based on the results of the check, which reflects the process of the leaf spring stiffness being continuously tracked by the software.

[0053] (7) Leaf spring model adjustment: Read whether the vertical displacement of the principal point in (6) is 1 mm. If it is 1 mm, it indicates that the leaf spring stiffness meets the design requirements. If it does not meet the 1 mm target, the elastic modulus of the leaf spring needs to be appropriately scaled and solved again until the displacement in the stiffness analysis result is 1 mm. At this time, the adjusted leaf spring model is the final model that meets the stiffness design requirements.

[0054] Stiffness = load / displacement. In this embodiment, the load value is set equal to the design stiffness value of the leaf spring. Therefore, you only need to check whether the displacement is 1 mm to intuitively judge the difference between the actual stiffness and the design stiffness of the established leaf spring model, and understand the stiffness of the model simply and conveniently.

[0055] The modeling process of the present embodiment using gap units is relatively simple and efficient, avoiding the cumbersome creation process of master surface, slave surface and contact pair in the traditional contact modeling method. In addition, the technology of the present solution reduces the requirements for the initial leaf spring meshing. The traditional method often has higher requirements for the modeling process in order to ensure the convergence of subsequent calculations. In terms of accuracy, the calculation accuracy achieved by the technology of the present solution is highly consistent with that of the traditional method. In terms of calculating the leaf spring stiffness, both the modeling efficiency and the reliability of the results are taken into account, and the calculation convergence is higher.

[0056] The leaf spring assembly model established using the technology of this solution can be directly assembled into the vehicle model to further carry out vehicle-level simulation analysis without additional work and settings. Therefore, the leaf spring model established can be used for both system-level research and vehicle-level research, and has good versatility. Models established by traditional methods are generally limited to the system level or component level and cannot be directly applied to the whole vehicle. They either require complex format conversion, with the risk of unit errors during the conversion process, or bring very high computational costs, or even fail to converge, resulting in the inability to complete the analysis.

[0057] The leaf spring assembly relies on the mutual contact between the leaf springs to achieve load transfer during the actual movement process. A small contact area affects the authenticity of the leaf spring movement state. A large contact area makes the nonlinear contact detection and calculation process complicated, the calculation cycle is long, and even the calculation does not converge. The balanced bridge leaf spring contact area definition method proposed in this embodiment can take into account the rationality of the leaf spring deformation behavior, the calculation accuracy and efficiency of the leaf spring stiffness.

[0058] At present, most leaf spring modeling methods simplify the model, ignore the contact relationship between leaf springs, perform modeling and solve stiffness, or establish contact relationships based on specific nonlinear analysis software, etc., but this method can only carry out local systematic analysis. This embodiment proposes a contact relationship modeling method based on gap units, which can, on the one hand, perform stiffness analysis considering contact relationships for leaf spring systems, and at the same time, further carry out vehicle assembly and apply to vehicle-level simulation analysis, which is easy to operate and has better versatility.

[0059] The method proposed in this embodiment of characterizing the motion relationship between the leaf spring leaves by establishing end surface rigid connection units at both ends of the leaf spring and releasing the translational freedom of the rigid connection units has the advantages of being simple, convenient and practical.

[0060] This embodiment defines a method for constraining the degrees of freedom at both ends of the leaf spring in the stiffness analysis based on the movement characteristics of the balanced bridge leaf spring. It also defines loading according to a load that is the same as the design stiffness value of the leaf spring, and stipulates that whether the displacement of the loading point satisfies 1mm is used as the basis for determining whether the stiffness of the leaf spring meets the design requirements.

[0061] The modeling method for the balanced bridge leaf spring proposed in this embodiment makes the modeling and stiffness analysis of the balanced bridge leaf spring more targeted, and can quickly obtain a balanced bridge finite element leaf spring model that meets the design requirements.

[0062] The balanced bridge leaf spring method proposed in this embodiment is simple and convenient, and can take into account both the reliability and efficiency of the analysis results. The obtained leaf spring model can be used to carry out research and analysis of the leaf spring assembly, and can also be further directly assembled to the vehicle finite element model to carry out vehicle-level simulation analysis and evaluation, with good versatility.

[0063] Another embodiment of the present invention provides an electronic device, including:

[0064] one or more processors;

[0065] The memory stores one or more programs, and when the one or more programs are executed by one or more processors, the one or more processors implement the steps of the balanced bridge leaf spring modeling method.

[0066] In some implementations, the memory may be a high-speed random access memory (RAM), and may also include a non-volatile memory, such as at least one disk memory.

[0067] In some other implementations, the processor may be a central processing unit (CPU), a digital signal processor (DSP), or other general-purpose processors of various types, which are not limited herein.

[0068] Another embodiment of the present invention provides a computer-readable storage medium storing a computer program, which implements the steps of the balanced bridge leaf spring modeling method when executed by a processor.

[0069] The contents explained in the above embodiments should be understood as these embodiments are only used to more clearly illustrate the present invention, and are not used to limit the scope of the present invention. After reading the present invention, various equivalent forms of modifications to the present invention by those skilled in the art all fall within the scope defined by the claims attached to this application.

Claims

1. A balanced bridge leaf spring modeling method, characterized in that: The implementation process includes the following: Obtaining three-dimensional data, stiffness value, elastic modulus, and material of a balanced bridge leaf spring; the three-dimensional data includes a plurality of leaf spring leaves, a U-shaped bolt, a center bolt, straight sections at both ends of the leaf spring, and end faces at both ends of the leaf spring; Using hexahedron or tetrahedron units to establish a finite element model of the balanced bridge leaf spring; Covering a layer of shell elements on the surface of the leaf spring; Setting a contact area of ​​the balancing bridge leaf spring; Disposing gap units between shell units on surfaces of adjacent leaf spring pieces in the contact area to establish a contact relationship between the leaf spring pieces; Establish multiple rigid connection units of the balanced bridge leaf spring, the rigid connection units include: a rigid connection unit in the middle of the leaf spring, a rigid connection unit on the end surface of the leaf spring, and a rigid connection unit between the leaf spring leaves; release the translational freedom of the main point and the slave point of the rigid connection unit between the leaf spring leaves along the front-rear direction of the balanced bridge leaf spring; A degree of freedom constraint condition is established at the principal point of the rigid connection unit at the end face of the leaf spring at the bottom layer, and a load is applied vertically at the principal point of the rigid connection unit in the middle of the leaf spring; Performing simulation analysis to determine whether the stiffness of the balanced bridge leaf spring meets preset conditions; If so, it is determined that the balanced bridge leaf spring modeling is completed.

2. The balanced bridge leaf spring modeling method according to claim 1, characterized in that: The contact area of ​​the balanced bridge leaf spring includes straight sections at both ends of the leaf spring and areas extending to both sides for a first distance starting from the intersection of the outer contours of the two U-bolts along the side direction of the balanced bridge leaf spring and the middle horizontal plane of the balanced bridge leaf spring.

3. The balanced bridge leaf spring modeling method according to claim 1, characterized in that: Taking the geometric center of the central bolt as the main point and all nodes between the intersection of the outer contours of the two U-bolts along the lateral direction of the balanced bridge leaf spring and the middle horizontal plane of the balanced bridge leaf spring as the secondary points, a rigid connection unit in the middle of the leaf spring is established; On the end faces of both ends of each leaf spring, with the end face center of each leaf spring as the main point and all nodes on the end face of each leaf spring as the slave points, rigid connection units of the leaf spring end faces are established respectively; with the end face center point of the lower layer leaf spring as the main point and the end face center point of the adjacent upper layer leaf spring as the slave point, rigid connection units between the leaf springs are established.

4. The balanced bridge leaf spring modeling method according to claim 1, characterized in that: The degree of freedom constraint condition includes that one end of the bottom leaf spring constrains the translational degrees of freedom along the vehicle coordinate system X, Y and Z and the rotational degrees of freedom around X and Z, and the other end constrains the translational degrees of freedom along the vehicle coordinate system Y, Z and the rotational degrees of freedom around X and Z.

5. The balanced bridge leaf spring modeling method according to claim 1, characterized in that: The load is equal to the design stiffness value.

6. The balanced bridge leaf spring modeling method according to claim 5, characterized in that: The process of performing simulation analysis to determine whether the stiffness of the balanced bridge leaf spring meets the preset conditions includes: The vertical displacement of the main point of the rigid connection unit in the middle of the leaf spring is analyzed by simulation. If the vertical displacement is equal to 1 mm, the stiffness of the balanced bridge leaf spring meets the preset requirements. Otherwise, the elastic modulus of the balanced bridge leaf spring is adjusted to make the vertical displacement equal to 1 mm.

7. An electronic device, characterized in that: include: one or more processors; A memory having one or more programs stored thereon, which, when the one or more programs are executed by the one or more processors, enables the one or more processors to implement the steps of the method according to any one of claims 1 to 6.

8. A computer-readable storage medium, characterized in that: The computer program is stored therein, and when the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 6 are implemented.

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