A two-point control arm structure stability design method and device

Abstract

The present application belongs to the field of automobile technology, and in particular to a two-point control arm structure stability design method and device. It comprises: 1. Establishing a finite element model of a two-force rod control arm structure; 2. Obtaining the natural frequency of the two-force rod control arm; 3. Obtaining the axial force-natural frequency relationship curve; 4. Obtaining the instability load; 5. Judging whether the structure stability design requirements are met; 6. Selecting and designing the control arm section; 7. Optimizing the control arm section size; 8. Designing the control arm; 9. Obtaining the instability load of the optimized structure; 10. Evaluating the stability of the control arm structure; 11. Detailed designing the specific size of the control arm structure; 12. Optimizing the control arm. The present application is based on structural dynamics simulation analysis, and the simulation accuracy can meet the product development requirements of structural parts, has a wide range of practical engineering applications, and solves the problem of low analysis accuracy caused by the deviation between theoretical assumptions and actual situations in buckling analysis.

Description

Technical Field

[0001] This invention belongs to the field of automotive technology, specifically a method and device for designing the stability of a two-point control arm structure. Background Technology

[0002] Two-force bar structures are widely used in automotive chassis, such as control arms in suspension systems, tie rods in steering systems, and half-shafts in drivetrains. These two-force bar structures primarily bear and transmit vehicle loads and guide the chassis's motion. Structural stability design is a challenge for two-force bar structures, and the critical buckling load is a crucial structural design parameter. Unlike ideal compression member stability, most two-force bar structures in real-world vehicles do not satisfy the assumptions of slender straight bars and coaxial loads. Stability verification is performed using CAE (Computer-Aided Engineering) methods, primarily two: buckling eigenvalue analysis and post-buckling analysis. Buckling eigenvalue analysis relies on structural buckling theory, but real-world structures rarely meet the conditions for using buckling theory, such as the straight bar assumption, slender bar assumption, and coaxial load assumption, resulting in extremely low accuracy. Post-buckling analysis can depict the buckling failure form of control arms, but in actual structures, buckling conditions depend more on the deformation at both ends of the control arm and inherent structural defects. Relying solely on buckling simulation analysis is unlikely to accurately reflect reality. Therefore, it is necessary to conduct accurate structural stability analysis and, based on this analysis, perform structural stability design. Summary of the Invention

[0003] This invention provides a two-point control arm structure stability design method and device. Based on structural dynamics, the structural simulation analysis has the simulation accuracy to meet the requirements of structural component product development and has a wider range of practical engineering applications. It solves the problem of low analysis accuracy caused by the deviation between theoretical assumptions and actual conditions in buckling analysis.

[0004] The technical solution of this invention is described below in conjunction with the accompanying drawings:

[0005] In a first aspect, embodiments of the present invention provide a method for designing the stability of a two-point control arm structure, comprising the following steps:

[0006] Step 1: Establish a finite element model of the two-force bar control arm structure;

[0007] Step 2: Obtain the natural frequency of the two-force bar control arm;

[0008] Step 3: Obtain the axial force-natural frequency relationship curve;

[0009] Step 4: Obtain the instability load F cr ;

[0010] Step 5: Determine whether the structural stability design requirements are met. If the structural stability design requirements are met, the process ends. If the structural stability design requirements are not met, proceed to Step 6.

[0011] Step 6: Select and design the control arm cross-section. After completing the cross-section selection, proceed to Step 7.

[0012] Step 7: Optimize the cross-sectional dimensions of the control arm;

[0013] Step 8: Design the control arm based on the size optimization values ​​obtained in Step 7, and output the 3D structure;

[0014] Step 9: Repeat steps 1-4 to obtain the instability load F of the optimized structure. cr-op ;

[0015] Step 10: Evaluate the stability of the control arm structure;

[0016] Step 11: Design the specific dimensions of the control arm structure in detail;

[0017] Step 12: Optimize the control arm design based on the optimization parameters from Step 11; repeat Steps 8 to 11 until the requirements are met and a control arm structure meeting the stability design requirements is obtained, then end the process.

[0018] Furthermore, the specific method for step one is as follows:

[0019] 11) Mesh the control arm structure and check the mesh quality;

[0020] 12) Model the connection structure; among which, the bushing connection is modeled using a hexahedral mesh for bushing sleeve modeling, and the ball head structure is modeled using finite element methods for ball cup, ball seat, and ball head, and the contact relationship and friction characteristics between different structures are defined;

[0021] 13) Define the connection relationship; among which, define the motion coupling constraint between the hard point of the bushing structure and the node on the inner surface of the bushing metal outer tube, and reflect the stiffness characteristics of the connection structure; define the motion coupling constraint between the hard point of the ball head structure and the node on the outer surface of the ball head.

[0022] 14) Define materials and properties; define the materials of control arms, bushing outer tubes, ball heads, ball cups, and ball seats, and define the properties of solid or sheet metal structural parts, associating the structural parts with the corresponding properties.

[0023] Furthermore, the specific method for step two is as follows:

[0024] 21) Establish a local coordinate system for the analysis of the two-force member structure, and define the boundary conditions of the control arm in the local coordinate system;

[0025] 22) Define the axial loading analysis step; apply an axial compressive load Fx1 to the loading end of the control arm;

[0026] 23) Define the constraint modal analysis step; Based on the axial loading, define the constraint modal analysis of the control arm;

[0027] 24) Solve for the natural frequency; submit the control arm natural frequency analysis model for solution to obtain the axial constraint and axial load F. x1 The natural frequency f1 under the action;

[0028] 25) Repeat steps 23)-24) to obtain several sets of axial loads F xn and the corresponding natural frequency f n ;

[0029] The specific method for step three is as follows:

[0030] The axial compressive load F applied by the control arm x The x-axis represents the square of the first-order natural frequency f of the control arm, and the y-axis represents the values ​​of the several sets of F obtained in step two. x n and f n The data is linearly fitted in the coordinate system to obtain F. x -f 2 The curve represents the axial load-frequency curve of a two-force member structure. 2 Relationship curve;

[0031] The specific method for step four is as follows:

[0032] The intersection point of the linear fitting curve in step three and the abscissa is the abscissa value corresponding to the intersection point, which is the instability load F of the two-force member control arm structure. cr .

[0033] Furthermore, the specific method for step five is as follows:

[0034] If the instability load F of the control arm cr If the following requirement is met, the process ends; otherwise, proceed to step six.

[0035] F crl ≤F cr ≤F cru

[0036] In the formula, F crl It is the lower limit of the control arm's instability load; F cru It is the design upper limit of the control arm's instability load.

[0037] Furthermore, the specific method for step seven is as follows:

[0038] 71) Define optimization parameters; select several sections on the control arm, and define the dimensional optimization parameter d for each section. v1 d v2 ... d vn ;

[0039] 72) Define the optimization objective; define the buckling load design objective of the two-force bar control arm structure as the optimization objective;

[0040] 73) Optimization solution; Solve the dimensional optimization analysis model to obtain the optimized values ​​O of the dimensional parameters. p -d v1 O p -d v2 O p -d vn And the sensitivity of dimensional parameters to the instability load of the control arm, S(d) v1 ), S(d v2 ), ..., S(d) vn ).

[0041] Furthermore, the specific method for step ten is as follows:

[0042] 101) The process ends if the conditions specified in the following formula are met;

[0043] F crl ≤F cr ≤F cru ;

[0044] 102) If the conditions specified in step 101) are not met, but the conditions specified in the following formula are met:

[0045] min{|F crl -F cr-op |,|F crl -F cr-op |}>0.05*F crl

[0046] Proceed to step seven, adjust the design parameters and optimization objectives, and optimize the cross-sectional dimensions of the control arm.

[0047] 103) If the conditions specified in step 101) are not met, but the conditions specified in the following formula are met, proceed to step eleven to perform detailed dimensional design;

[0048] min{|F crl -F cr-op |,|F crl -F cr-op |}<0.05*F crl .

[0049] Furthermore, the specific method for step eleven is as follows:

[0050] 111) Determine the instability load increment; if the instability load F obtained in step nine... cr-op Less than F crl The increment is determined according to the following formula:

[0051] △F cr =F crl -F cr-op ;

[0052] If the instability load F obtained in step nine cr-op Greater than F cru The increment is determined according to the following formula:

[0053] △F cr =F cr-op -F cru ;

[0054] 112) Determine the optimization parameters, and optimize the size parameter d that has the highest sensitivity to the instability load of the control arm. vi Defined as an optimization parameter, satisfying the conditions specified in the following formula:

[0055] S(dvi)=max{S(dv1) S(dv2) ... S(dvn)};

[0056] 113) To obtain the increment of dimensional parameters, the following conditions must be met:

[0057] S(dvi)*△(dvi)=△F cr .

[0058] Secondly, embodiments of the present invention also provide a two-point control arm structure stability design device, comprising:

[0059] The model building module is used to build a finite element model of a two-force bar control arm structure.

[0060] The first acquisition module is used to obtain the natural frequency of the two-force bar control arm;

[0061] The second acquisition module is used to obtain the axial force-natural frequency relationship curve;

[0062] The third acquisition module is used to obtain the instability load Fcr;

[0063] The judgment module is used to determine whether the structural stability design requirements are met. If the structural stability design requirements are met, the process ends; otherwise, the design continues.

[0064] The first design module is used to select and design the cross-section of the control arm. After the cross-section selection is completed, proceed to step seven.

[0065] The second design module is used to optimize the cross-sectional dimensions of the control arm;

[0066] The third design module is used to design the control arm based on the obtained size optimization values ​​and output the 3D structure;

[0067] The fourth module is used to obtain the instability load Fcr-op of the optimized structure;

[0068] The evaluation module is used to evaluate the stability of the control arm structure;

[0069] The fourth design module is used for detailed design of the specific dimensions of the control arm structure;

[0070] The fifth design module is used to optimize the control arm design based on the optimization parameters, and the process ends after obtaining the control arm structure that meets the stability design requirements.

[0071] Thirdly, a terminal is provided, including:

[0072] One or more processors;

[0073] Memory for storing the one or more processor-executable instructions;

[0074] Wherein, the one or more processors are configured as follows:

[0075] Perform the method described in the first aspect of the embodiments of the present invention.

[0076] Fourthly, a non-transitory computer-readable storage medium is provided, wherein when instructions in the storage medium are executed by a processor of a terminal, the terminal is able to perform the method described in the first aspect of the present invention.

[0077] Fifthly, an application product is provided, which, when running on a terminal, causes the terminal to execute the method described in the first aspect of the present invention.

[0078] The beneficial effects of this invention are as follows:

[0079] 1) This invention is based on structural simulation analysis of structural dynamics, avoiding the limitations of various assumptions in buckling analysis, and has a wider range of practical engineering applications;

[0080] 2) This invention avoids the problem of low analysis accuracy caused by the deviation between theoretical assumptions and actual conditions in buckling analysis, and the simulation accuracy can meet the requirements of structural component product development. Attached Figure Description

[0081] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0082] Figure 1 This is a flowchart of a two-point control arm structure stability design method according to the present invention;

[0083] Figure 2 Axial load-frequency of a two-force lever control arm 2 Relationship diagram;

[0084] Figure 3 This is a schematic diagram of a two-point control arm structure stability design device according to the present invention;

[0085] Figure 4 This is a schematic block diagram of a terminal structure. Detailed Implementation

[0086] 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.

[0087] It should be noted that similar reference numerals and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. Furthermore, in the description of this invention, terms such as "first," "second," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0088] Example 1

[0089] Figure 1 This is a flowchart of a two-point control arm structure stability design method provided in Embodiment 1 of the present invention. This embodiment is applicable to the stability design of two-point control arm structures. The method can be executed by a two-point control arm structure stability design device in this embodiment of the present invention, which can be implemented in software and / or hardware.

[0090] A method for designing the stability of a two-point control arm structure includes the following steps:

[0091] Step 1: Establish a finite element model of the two-force bar control arm structure;

[0092] 11) Mesh the control arm structure and check the mesh quality;

[0093] Finite element modeling of the control arm is performed using a mesh size of 3-5mm. If the control arm is a sheet metal forming structure, it is divided into quadrilateral meshes. For key feature locations, such as chamfers, there should be more than 4 rows of meshes. If the control arm is a cast or forged control arm hook, the surface is divided into triangular meshes, and a second-order tetrahedral solid mesh is generated based on the surface mesh. The mesh is refined at key feature locations, and at least two layers of mesh are ensured in all directions.

[0094] For sheet metal forming structures, the welding between different sheet metal parts is achieved through shared nodes between the main structure of the control arm and the connecting structure mesh.

[0095] 12) Model the connection structure; among which, the bushing connection is modeled using a hexahedral mesh for bushing sleeve modeling, and the ball head structure is modeled using finite element methods for ball cup, ball seat, and ball head, and the contact relationship and friction characteristics between different structures are defined;

[0096] For the bushing structure, the model should reflect the interference fit between the bushing metal outer tube and the control arm structure.

[0097] 13) Define the connection relationship; among which, define the motion coupling constraint between the hard point of the bushing structure and the node on the inner surface of the bushing metal outer tube, and reflect the stiffness characteristics of the connection structure; define the motion coupling constraint between the hard point of the ball head structure and the node on the outer surface of the ball head.

[0098] For bushing connection structures, connection units need to be defined and the actual bushing stiffness needs to be assigned to the connection units.

[0099] 14) Define materials and properties; define the materials of control arms, bushing outer tubes, ball heads, ball cups, and ball seats, and define the properties of solid or sheet metal structural parts, associating the structural parts with the corresponding properties.

[0100] Step 2: Obtain the natural frequency of the two-force bar control arm;

[0101] 21) Establish a local coordinate system for the analysis of the two-force member structure, and define the boundary conditions of the control arm in the local coordinate system;

[0102] The local coordinate system is defined by the direction of the line connecting the two hard points at both ends of the two-force member structure as the X-axis; if the control arm includes a bushing connection structure, the hard point at the bushing end is the origin, and the bushing axis is the Z-axis of the local coordinate system; if both ends of the control arm are ball joints, the hard point at one ball joint is the origin, and the Y and Z axes of the local coordinate system are not specifically defined.

[0103] Different connection methods at both ends of the control arm correspond to different boundary conditions. For example, if the control arm includes a bushing connection structure, the bushing constrains the external points of the connection unit to degrees of freedom 1-6, and the other side serves as the loading end, constraining degrees of freedom 2 and 3 in the local coordinate system; if the control arm has ball joints at both ends, the hard point at one end constrains degrees of freedom 1-4 in the local coordinate system, and the other end serves as the loading end, constraining degrees of freedom 2 and 3.

[0104] 22) Define the axial loading analysis step; apply an axial compressive load Fx1 to the loading end of the control arm;

[0105] 23) Define the constraint modal analysis step; based on axial loading, define the control arm constraint modal analysis; it can solve and output the first ten natural frequencies and mode shapes;

[0106] 24) Solve for the natural frequency; submit the control arm natural frequency analysis model for solution to obtain the axial constraint and axial load F. x1 The natural frequency f1 under the action;

[0107] 25) Repeat steps 23)-24) to obtain several sets of axial loads F xn and the corresponding natural frequency f n .

[0108] Step 3: Obtain the axial force-natural frequency relationship curve;

[0109] The axial compressive load F applied by the control arm x The x-axis represents the square of the first-order natural frequency f of the control arm, and the y-axis represents the values ​​of the several sets of F obtained in step two. x n and f n The data is linearly fitted in the coordinate system to obtain F. x -f 2 The curve represents the axial load-frequency curve of a two-force member structure. 2 Relationship curves, such as Figure 2 As shown.

[0110] Step 4: Obtain the instability load F cr ;

[0111] The intersection point of the linear fitting curve in step three and the abscissa is the abscissa value corresponding to the intersection point, which is the instability load F of the two-force member control arm structure. cr ,like Figure 2 As shown.

[0112] Based on the differential equation of the lateral small-amplitude motion of the compression member, the characteristic equation of the stable solution is as follows:

[0113]

[0114] That is, there is a linear relationship between the square of the natural frequency and the end load, when When the value of F approaches 0, the column becomes unstable. At this point, the value of F is different from that of F. cr The theoretical value is consistent.

[0115] Step 5: Determine whether the structural stability design requirements are met. If the structural stability design requirements are met, the process ends. If the structural stability design requirements are not met, proceed to Step 6.

[0116] If the instability load F of the control arm cr If the following requirement is met, the process ends; otherwise, proceed to step six.

[0117] F crl ≤F cr ≤F cru (2)

[0118] In the formula, F crl It is the lower limit of the control arm's instability load; F cru It is the design upper limit of the control arm's instability load.

[0119] Step 6: Select and design the cross-section of the control arm. Based on the structural stability design target of the two-force rod control arm, select the cross-section shape, such as circular cross-section, square cross-section, annular cross-section, I-beam cross-section, etc. After completing the cross-section selection, proceed to Step 7.

[0120] According to the formula for the critical pressure of instability of a simply supported beam, F cr =π 2 EI / l 2 It can be seen that under the same conditions, the critical load for the instability of a two-force bar structure is positively correlated with the moment of inertia of the cross section. Different cross section shapes within the same cross section design space have different moments of inertia, which can be optimized through cross section selection.

[0121] If the cross-sectional shape of the control arm is not selectable, skip step six and proceed to step seven for optimization after step five.

[0122] Step 7: Optimize the cross-sectional dimensions of the control arm;

[0123] 71) Define optimization parameters; select several sections on the control arm, and define the size optimization parameters dv1, dv2, and dv3 for each section. v2 ... d vn ;

[0124] You can select 3-5 cross-sections as needed to define dimensional optimization parameters;

[0125] For the profile structure control arm, all sections are completely consistent in the axial direction, so segmented optimization is not adopted, and the dimensional parameters are defined only for one section.

[0126] 72) Define the optimization objective; define the buckling load design objective of the two-force bar control arm structure as the optimization objective;

[0127] 73) Optimization solution; Solve the dimensional optimization analysis model to obtain the optimized values ​​O of the dimensional parameters. p -d v1 O p -d v2 O p -d vn And the sensitivity of dimensional parameters to the instability load of the control arm, S(d) v1 ), S(d v2 ), ..., S(d) vn ).

[0128] Step 8: Design the control arm based on the size optimization values ​​obtained in Step 7, and output the 3D structure;

[0129] Step 9: Repeat steps 1-4 to obtain the instability load F of the optimized structure. cr-op ;

[0130] Step 10: Evaluate the stability of the control arm structure;

[0131] 101) The process ends if the conditions specified in the following formula are met;

[0132] F crl ≤F cr ≤F cru ;

[0133] 102) If the conditions specified in equation (2) are not met, but the conditions specified in equation (3) are met:

[0134] min{|F crl -F cr-op |,|F crl -F cr-op |}>0.05*F crl (3)

[0135] Proceed to step seven, adjust the design parameters and optimization objectives, and optimize the cross-sectional dimensions of the control arm.

[0136] 103) If the conditions specified in step 101) are not met, but the conditions specified in formula (4) are met, proceed to step eleven to perform detailed dimensional design;

[0137] min{|F crl -F cr-op |,|F crl -F cr-op |}<0.05*F crl (4)

[0138] Step 11: Design the specific dimensions of the control arm structure in detail;

[0139] 111) Determine the instability load increment; if the instability load F obtained in step nine... cr-op Less than F crl The increment is determined according to the following formula:

[0140] △F cr =F crl -F cr-op (5)

[0141] If the instability load F obtained in step nine cr-op Greater than F cru The increment is determined according to the following formula:

[0142] △F cr =F cr-op -F cru (6)

[0143] 112) Determine the optimization parameters, and optimize the size parameter d that has the highest sensitivity to the instability load of the control arm. vi Defined as an optimization parameter, satisfying the conditions specified in the following formula:

[0144] S(dvi)=max{S(dv1) S(dv2) ... S(dvn)}; (7)

[0145] You can select more than one size optimization parameter.

[0146] 113) To obtain the increment of dimensional parameters, the following conditions must be met:

[0147] S(dvi)*△(dvi)=△F cr (8)

[0148] If there are more than one dimension optimization parameter, the increment of the dimension parameter should conform to the following formula:

[0149]

[0150] In the formula, a i For a real number greater than 0 and less than 1, the size increment of the size optimization parameter dvi is a. i *Δ(d vi ).

[0151] Step 12: Optimize the control arm design based on the optimization parameters from Step 11; repeat Steps 8 to 11 until the requirements are met and a control arm structure meeting the stability design requirements is obtained, then end the process.

[0152] Example 2

[0153] See Figure 3 A two-point control arm structure stability design device, comprising:

[0154] The model building module is used to build a finite element model of a two-force bar control arm structure.

[0155] The first acquisition module is used to obtain the natural frequency of the two-force bar control arm;

[0156] The second acquisition module is used to obtain the axial force-natural frequency relationship curve;

[0157] The third acquisition module is used to obtain the instability load Fcr;

[0158] The judgment module is used to determine whether the structural stability design requirements are met. If the structural stability design requirements are met, the process ends; otherwise, the design continues.

[0159] The first design module is used to select and design the cross-section of the control arm. After the cross-section selection is completed, proceed to step seven.

[0160] The second design module is used to optimize the cross-sectional dimensions of the control arm;

[0161] The third design module is used to design the control arm based on the obtained size optimization values ​​and output the 3D structure;

[0162] The fourth module is used to obtain the instability load Fcr-op of the optimized structure;

[0163] The evaluation module is used to evaluate the stability of the control arm structure;

[0164] The fourth design module is used for detailed design of the specific dimensions of the control arm structure;

[0165] The fifth design module is used to optimize the control arm design based on the optimization parameters, and the process ends after obtaining the control arm structure that meets the stability design requirements.

[0166] Example 3

[0167] Figure 4 This is a structural block diagram of a terminal provided in an embodiment of this application. The terminal can be the terminal described in the above embodiments. The terminal can be a portable mobile terminal, such as a smartphone or tablet computer. The terminal may also be referred to as user equipment, portable terminal, or other names.

[0168] Typically, a terminal includes a processor 301 and a memory 302.

[0169] Processor 301 may include one or more processing cores, such as a quad-core processor or an octa-core processor. Processor 301 may be implemented using at least one hardware form selected from DSP (Digital Signal Processing), FPGA (Field-Programmable Gate Array), and PLA (Programmable Logic Array). Processor 301 may also include a main processor and a coprocessor. The main processor, also known as a CPU (Central Processing Unit), is used to process data in the wake-up state; the coprocessor is a low-power processor used to process data in the standby state. In some embodiments, processor 301 may integrate a GPU (Graphics Processing Unit), which is responsible for rendering and drawing the content to be displayed on the screen. In some embodiments, processor 301 may also include an AI (Artificial Intelligence) processor, which is used to handle computational operations related to machine learning.

[0170] The memory 302 may include one or more computer-readable storage media, which may be tangible and non-transitory. The memory 302 may also include high-speed random access memory and non-volatile memory, such as one or more disk storage devices or flash memory devices. In some embodiments, the non-transitory computer-readable storage media in the memory 302 is used to store at least one instruction, which is executed by the processor 301 to implement a two-point control arm structure stability design method provided in this application.

[0171] In some embodiments, the terminal may also optionally include: a peripheral device interface 303 and at least one peripheral device. Specifically, the peripheral device includes at least one of: a radio frequency circuit 304, a touch display screen 305, a camera 306, an audio circuit 307, a positioning component 308, and a power supply 309.

[0172] The peripheral device interface 303 can be used to connect at least one I / O (Input / Output) related peripheral device to the processor 301 and the memory 302. In some embodiments, the processor 301, memory 302, and peripheral device interface 303 are integrated on the same chip or circuit board; in some other embodiments, any one or two of the processor 301, memory 302, and peripheral device interface 303 can be implemented on separate chips or circuit boards, which is not limited in this embodiment.

[0173] The radio frequency (RF) circuit 304 is used to receive and transmit RF (Radio Frequency) signals, also known as electromagnetic signals. The RF circuit 304 communicates with communication networks and other communication devices via electromagnetic signals. The RF circuit 304 converts electrical signals into electromagnetic signals for transmission, or converts received electromagnetic signals back into electrical signals. Optionally, the RF circuit 304 includes: an antenna system, an RF transceiver, one or more amplifiers, a tuner, an oscillator, a digital signal processor, a codec chipset, a user identity module card, etc. The RF circuit 304 can communicate with other terminals through at least one wireless communication protocol. This wireless communication protocol includes, but is not limited to: the World Wide Web, metropolitan area networks, intranets, various generations of mobile communication networks (2G, 3G, 4G, and 5G), wireless local area networks, and / or WiFi (Wireless Fidelity) networks. In some embodiments, the RF circuit 304 may also include circuitry related to NFC (Near Field Communication), which is not limited in this application.

[0174] The touch display screen 305 is used to display a UI (User Interface). This UI may include graphics, text, icons, videos, and any combination thereof. The touch display screen 305 also has the ability to collect touch signals on or above its surface. These touch signals can be input as control signals to the processor 301 for processing. The touch display screen 305 is used to provide virtual buttons and / or a virtual keyboard, also known as soft buttons and / or a soft keyboard. In some embodiments, there may be one touch display screen 305, which serves as the front panel of the terminal; in other embodiments, there may be at least two touch display screens, respectively disposed on different surfaces of the terminal or in a folded design; in still other embodiments, the touch display screen 305 may be a flexible display screen, disposed on a curved or folded surface of the terminal. Furthermore, the touch display screen 305 may be configured as a non-rectangular, irregular shape, i.e., a non-rectangular screen. The touch display screen 305 may be made of materials such as LCD (Liquid Crystal Display) or OLED (Organic Light-Emitting Diode).

[0175] Camera assembly 306 is used to acquire images or videos. Optionally, camera assembly 306 includes a front-facing camera and a rear-facing camera. Typically, the front-facing camera is used for video calls or selfies, and the rear-facing camera is used for taking photos or videos. In some embodiments, there are at least two rear-facing cameras, which are any one of a main camera, a depth-sensing camera, and a wide-angle camera, to achieve background blurring by fusion of the main camera and the depth-sensing camera, and panoramic shooting and VR (Virtual Reality) shooting by fusion of the main camera and the wide-angle camera. In some embodiments, camera assembly 306 may also include a flash. The flash can be a single-color temperature flash or a dual-color temperature flash. A dual-color temperature flash is a combination of a warm light flash and a cool light flash, which can be used for light compensation at different color temperatures.

[0176] Audio circuit 307 provides an audio interface between the user and the terminal. Audio circuit 307 may include a microphone and a speaker. The microphone is used to collect sound waves from the user and the environment, converting the sound waves into electrical signals that are input to processor 301 for processing, or input to radio frequency circuit 304 for voice communication. For stereo sound acquisition or noise reduction purposes, multiple microphones may be used, each located in a different part of the terminal. The microphone may also be an array microphone or an omnidirectional microphone. The speaker is used to convert electrical signals from processor 301 or radio frequency circuit 304 into sound waves. The speaker may be a conventional diaphragm speaker or a piezoelectric ceramic speaker. When the speaker is a piezoelectric ceramic speaker, it can convert electrical signals not only into audible sound waves but also into inaudible sound waves for purposes such as distance measurement. In some embodiments, audio circuit 307 may also include a headphone jack.

[0177] The positioning component 308 is used to determine the current geographic location of the terminal in order to enable navigation or LBS (Location Based Service). The positioning component 308 can be a positioning component based on the US GPS (Global Positioning System), China's BeiDou system, or Russia's Galileo system.

[0178] Power supply 309 is used to power the various components in the terminal. Power supply 309 can be AC ​​power, DC power, a disposable battery, or a rechargeable battery. When power supply 309 includes a rechargeable battery, the rechargeable battery can be a wired rechargeable battery or a wireless rechargeable battery. A wired rechargeable battery is a battery that is charged via a wired line, while a wireless rechargeable battery is a battery that is charged via a wireless coil. The rechargeable battery can also be used to support fast charging technology.

[0179] Those skilled in the art will understand that Figure 4The structure shown does not constitute a limitation on the terminal and may include more or fewer components than shown, or combine certain components, or use different component arrangements.

[0180] Example 4

[0181] In an exemplary embodiment, a computer-readable storage medium is also provided, on which a computer program is stored, which, when executed by a processor, implements a two-point control arm structure stability design method as provided in all embodiments of the present application.

[0182] Any combination of one or more computer-readable media may be used. A computer-readable medium can be a computer-readable signal medium or a computer-readable storage medium. A computer-readable storage medium can be, for example—but not limited to—an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples (a non-exhaustive list) of computer-readable storage media include: an electrical connection having one or more wires, a portable computer disk, a hard disk, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage device, magnetic storage device, or any suitable combination thereof. In this document, a computer-readable storage medium can be any tangible medium that contains or stores a program that can be used by or in connection with an instruction execution system, apparatus, or device.

[0183] Computer-readable signal media may include data signals propagated in baseband or as part of a carrier wave, carrying computer-readable program code. Such propagated data signals may take various forms, including—but not limited to—electromagnetic signals, optical signals, or any suitable combination thereof. Computer-readable signal media may also be any computer-readable medium other than computer-readable storage media, capable of transmitting, propagating, or transmitting programs for use by or in connection with an instruction execution system, apparatus, or device.

[0184] The program code contained on a computer-readable medium may be transmitted using any suitable medium, including—but not limited to—wireless, wire, optical fiber, RF, etc., or any suitable combination thereof.

[0185] Computer program code for performing the operations of this invention can be written in one or more programming languages ​​or a combination thereof, including object-oriented programming languages ​​such as Java, Smalltalk, and C++, as well as conventional procedural programming languages ​​such as "C" or similar programming languages. The program code can be executed entirely on the user's computer, partially on the user's computer, as a standalone software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In cases involving remote computers, the remote computer can be connected to the user's computer via any type of network—including a local area network (LAN) or a wide area network (WAN)—or can be connected to an external computer (e.g., via the Internet using an Internet service provider).

[0186] Example 5

[0187] In an exemplary embodiment, an application product is also provided, including one or more instructions that can be executed by the processor 301 of the aforementioned device to complete the aforementioned two-point control arm structure stability design method.

[0188] Although embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and embodiments. It can be applied to various fields suitable for the invention. Further modifications can be readily made by those skilled in the art. Therefore, without departing from the general concept defined by the claims and their equivalents, the invention is not limited to the specific details and illustrations shown and described herein.

Claims

1. A method for designing the stability of a two-point control arm structure, characterized in that, Includes the following steps: Step 1: Establish a finite element model of the two-force bar control arm structure; Step 2: Obtain the natural frequency of the two-force bar control arm; Step 3: Obtain the axial force-natural frequency relationship curve; Step 4: Obtain the instability load Fcr; Step 5: Determine whether the structural stability design requirements are met. If the structural stability design requirements are met, the process ends. If the structural stability design requirements are not met, proceed to Step 6. Step 6: Select and design the control arm cross-section. After completing the cross-section selection, proceed to Step 7. Step 7: Optimize the cross-sectional dimensions of the control arm; Step 8: Design the control arm based on the size optimization values ​​obtained in Step 7, and output the 3D structure; Step 9: Repeat steps 1-4 to obtain the instability load Fcr-op of the optimized structure; Step 10: Evaluate the stability of the control arm structure; Step 11: Design the specific dimensions of the control arm structure in detail; Step 12: Optimize the control arm design based on the optimization parameters from Step 11; repeat Steps 8 to 11 until the requirements are met and a control arm structure meeting the stability design requirements is obtained, then end the process. The specific method for step two is as follows: 21) Establish a local coordinate system for the analysis of the two-force member structure, and define the boundary conditions of the control arm in the local coordinate system; 22) Define the axial loading analysis step; apply an axial compressive load Fx1 to the loading end of the control arm; 23) Define the constraint modal analysis step; Based on the axial loading, define the constraint modal analysis of the control arm; 24) Solve for the natural frequency; Submit the control arm natural frequency analysis model to solve for the natural frequency f1 under axial constraint and axial load Fx1. 25) Repeat steps 23)-24) to obtain several sets of axial loads Fxn and their corresponding natural frequencies fn; The specific method for step three is as follows: Using the axial compressive load Fx applied by the control arm as the abscissa and the square of the first-order natural frequency f of the control arm as the ordinate, the several sets of Fxn and fn data obtained in step two are linearly fitted in the coordinate system to obtain Fx-f. 2 The curve represents the axial load-frequency curve of a two-force member structure. 2 Relationship curve; The specific method for step four is as follows: Take the intersection point of the linear fitting curve in step three with the horizontal axis. The horizontal axis value corresponding to the intersection point is the instability load Fcr of the two-force bar control arm structure. The specific method for step five is as follows: If the instability load Fcr of the control arm meets the following requirement, the process ends; otherwise, proceed to step six. In the formula, Fcrl is the lower limit of the control arm instability load; Fcru is the design upper limit of the control arm instability load. The specific method for step eleven is as follows: 111) Determine the instability load increment; if the instability load Fcr-op obtained in step nine is less than Fcrl, determine the increment according to the following formula: ； If the instability load Fcr-op obtained in step nine is greater than Fcru, the increment is determined according to the following formula: ； 112) Determine the optimization parameters. The optimal parameter dvi, which has the highest sensitivity to the instability load of the control arm, is defined as the optimal parameter and satisfies the following condition: ； 113) To obtain the increment of dimensional parameters, the following conditions must be met: 。 2. The stability design method for a two-point control arm structure according to claim 1, characterized in that, The specific method for step one is as follows: 11) Mesh the control arm structure and check the mesh quality; 12) Model the connection structure; among which, the bushing connection is modeled using a hexahedral mesh for bushing sleeve modeling, and the ball head structure is modeled using finite element methods for ball cup, ball seat, and ball head, and the contact relationship and friction characteristics between different structures are defined; 13) Define the connection relationship; among which, define the motion coupling constraint between the hard point of the bushing structure and the node on the inner surface of the bushing metal outer tube, and reflect the stiffness characteristics of the connection structure; define the motion coupling constraint between the hard point of the ball head structure and the node on the outer surface of the ball head. 14) Define materials and properties; define the materials of control arms, bushing outer tubes, ball heads, ball cups, and ball seats, and define the properties of solid or sheet metal structural parts, associating the structural parts with the corresponding properties.

3. The stability design method for a two-point control arm structure according to claim 1, characterized in that, The specific method for step seven is as follows: 71) Define optimization parameters; Select several sections on the control arm and define the size optimization parameters dv1, dv2, ..., dvn for each section; 72) Define the optimization objective; define the buckling load design objective of the two-force bar control arm structure as the optimization objective; 73) Optimize the solution; solve the size optimization analysis model to obtain the optimized values ​​of the size parameters Op-dv1, Op-dv2, ..., Op-dvn, as well as the sensitivity of the size parameters to the instability load of the control arm S(dv1), S(dv2), ..., S(dvn).

4. A two-point control arm structure stability design device, used to implement the two-point control arm structure stability design method according to claim 1, characterized in that, include: The model building module is used to build a finite element model of a two-force bar control arm structure. The first acquisition module is used to obtain the natural frequency of the two-force bar control arm; The second acquisition module is used to obtain the axial force-natural frequency relationship curve; The third acquisition module is used to obtain the instability load Fcr; The judgment module is used to determine whether the structural stability design requirements are met. If the structural stability design requirements are met, the process ends; otherwise, the design continues. The first design module is used to select and design the cross-section of the control arm. After the cross-section selection is completed, proceed to step seven. The second design module is used to optimize the cross-sectional dimensions of the control arm; The third design module is used to design the control arm based on the obtained size optimization values ​​and output the 3D structure; The fourth module is used to obtain the instability load Fcr-op of the optimized structure; The evaluation module is used to evaluate the stability of the control arm structure; The fourth design module is used for detailed design of the specific dimensions of the control arm structure; The fifth design module is used to optimize the control arm design based on the optimization parameters, and the process ends after obtaining the control arm structure that meets the stability design requirements.

5. A terminal, characterized in that, include: One or more processors; Memory for storing the one or more processor-executable instructions; Wherein, the one or more processors are configured as follows: Implement a two-point control arm structure stability design as described in any one of claims 1 to 3.

6. A non-transitory computer-readable storage medium, characterized in that, When the instructions in the storage medium are executed by the terminal's processor, the terminal is able to perform a two-point control arm structure stability design as described in any one of claims 1 to 3.

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