A method for designing the service life of an automobile chassis component

Abstract

The application relates to a life design method for automobile chassis parts, which comprises the following specific steps: S1: determining the simulation life target L of the parts goal : S2: calculating the simulation life of each part, and outputting the minimum simulation life L of the part in combination with a failure condition fmin : S3: fatigue life result determination. The application aims to provide a life design method for automobile chassis parts, which can more comprehensively determine the simulation life target of the parts, solve the problem that the simulation life target is only defined according to material performance in the past, more accurately evaluate the fatigue life performance of the chassis parts, and perform life design on each part of the chassis, so that the durability performance can be more reasonably controlled through simulation means in the early stage of design of iterative products of the same type of vehicle, so as to meet the requirements of road test.

Description

Technical Field

[0001] This invention relates to the field of automotive component life design technology, and specifically to a method for designing the life of automotive chassis components. Background Technology

[0002] The chassis system plays a crucial role in vehicle operation. To meet the demands of rapid new vehicle development and reduce development costs, virtual verification of chassis component durability is of paramount importance. The performance of chassis components directly impacts the safety of the entire vehicle; therefore, some automakers have imposed higher requirements on the design of chassis components. Durability analysis of chassis components is conducted based on vehicle development plans, load conditions, and physical verification plans, defining durability analysis and life evaluation targets at the individual component, system, and vehicle levels.

[0003] The durability of a component is the result of a combination of factors, such as load, materials, and manufacturing processes. Currently, some automotive OEMs use CAE analysis to assess lifespan, typically defining lifespan targets based on a 50% fatigue limit for material properties, with a safety margin added. This current method of defining lifespan targets only considers the influence of material properties, neglecting the combined impact of load, manufacturing processes, and materials on lifespan. Furthermore, it sets the same safety margin for different chassis components, failing to differentiate between the unique characteristics of each component.

[0004] A Chinese patent discloses a method for predicting the structural strength and lifespan of hollow automotive chassis components. It uses finite element analysis to simulate the automotive operating environment and observe whether the components fail. Traditionally, component failure refers to a component's inability to perform its function, such as bending or fracture. However, this requires actual testing to visually observe the failure. In software simulations, only certain parameters are input to obtain a target value, which is then compared to a standard to assess whether the simulation results indicate failure. This patent focuses on the simulation process but doesn't mention the standard for component failure. Therefore, it can be inferred that it is similar to existing technologies, defining the lifespan evaluation target based on a 50% survival rate fatigue limit of material properties, with a safety margin reserved.

[0005] The failure of any one component can lead to the failure of the entire vehicle. Since the failure of the entire vehicle cannot be used to deduce the failure criteria of each component applied to the vehicle, the method disclosed in this patent can only predict the lifespan of the weakest component of the car during a certain period of use, but cannot assess the lifespan of the other components. Therefore, it cannot provide guidance for the design and selection of components, resulting in significant safety hazards in the design of the car chassis. Summary of the Invention

[0006] The purpose of this invention is to provide a life design method for automotive chassis components, which can more comprehensively determine the simulation life target of the components, solving the problem of defining the simulation life target only based on material properties in the past. It can more accurately evaluate the fatigue life performance of chassis components, and can perform life design for each chassis component. Thus, in the iterative product design of the same type of vehicle, the durability performance can be reasonably controlled in the early stage of design through simulation, so as to meet the requirements of road testing.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A method for designing the lifespan of automotive chassis components, characterized by the following specific steps: S1: Determine the simulation life target for the components. : Determine the target average life of components L gp Then, the simulated life target of the components is obtained by combining bench tests. ; S2: Calculate the simulated lifespan of each component and output the minimum simulated lifespan of the component based on the failure conditions. : The simulated lifespan of each component is calculated using simulation methods, and the minimum simulated lifespan of the component is output based on the material fatigue limit. ; S3: Fatigue life result determination: The minimum simulated lifespan of the component in step S2. Simulation life target of the component in step S1 If a comparison is made, > If the lifespan design of the component is satisfactory, then the component is deemed to have met the design requirements; otherwise, the component is deemed to have failed the design requirements.

[0008] Compared to existing technologies, this invention adds a target for the simulated lifespan of components. The determination process, in obtaining the simulated lifetime target In the process, it is necessary not only to determine the target average lifespan L of the components. gp Furthermore, bench testing was also required to obtain the simulated life target. Next, the simulated lifetime target will be... As a standard for judging fatigue life results, this invention solves the problem of defining simulation life targets solely based on material properties. It can more accurately assess the fatigue life performance of chassis components. Furthermore, this invention can perform life design for every chassis component, rather than just for the most vulnerable components. This allows for more reasonable control of durability performance through simulation in the early stages of iterative product design for similar vehicle models. This provides a reference for component selection and lays the groundwork for meeting road test requirements after component assembly.

[0009] Furthermore, the specific operation of step S1 is as follows: S11: Severity S is defined based on the cause of potential component failure, and maintenance difficulty M is defined based on the replacement cost of the component; S12: Calculate the life risk level D of the component using the severity S and maintenance difficulty M, and obtain the average life target L of the component based on the life risk level D. gp ; S13: Set the average lifespan target L for components gp The simulated life target of the components is obtained by combining bench tests. .

[0010] Furthermore, in step S13, the simulated lifetime target The specific steps to obtain it are as follows: S131: Draw the 3D model of each component for bench testing; S132: Generate a mesh model based on the 3D model of the bench test; S133: Apply a single-channel quantitative load to one loading point, constrain the remaining loading points, and calculate the simulated life of the test bench. ; S134: Conduct bench tests, with the boundary conditions and loads of the tests consistent with the simulation conditions for calculating the simulated life. S135: Apply cyclic loads until fatigue cracks appear on the component, and record the number of cycles at which cracks appear; this is the test life. ; S136: Determine whether the number of trials has reached the preset value. If yes, proceed to the next step; otherwise, return to step S134. S137: Statistics on the test life in each test To obtain the maximum test life L smax Minimum test life L smin The average lifespan L of the test was obtained by averaging the data. sp ; S138: Utilizing the maximum test lifespan L smax Minimum test life L sminAverage test life L sp Bench simulation life Calculate the safety factor N; S139: Based on the average lifespan target L gp Calculate the simulated life target with safety factor N .

[0011] Furthermore, the formula for calculating the safety factor N in step S138 is as follows:

[0012] Where N is the safety factor, L smax To test the maximum lifespan, L smin To test the minimum lifespan, For the test life, L sp The average lifespan of the test.

[0013] Furthermore, in step S139, the simulated lifetime target The calculation formula is as follows: = N in, To simulate the lifetime target, L gp The average lifespan target is N, where N is the safety factor.

[0014] Furthermore, the formula for calculating the life risk degree D in step S12 is as follows: D=S+M Where D represents life risk level, S represents severity level, and M represents maintenance difficulty.

[0015] Furthermore, the severity definition steps in step S11 are as follows: S111: Obtain the Design Failure Mode and Effects Analysis (DFMEA) table for the chassis; S112: Filter out items from DFMEA where the potential failure mode of each component is cracking and the potential failure cause is insufficient durability. S113: Select severity scores from the selection criteria in step S112; S114: The severity scores are reassigned according to the levels to increase the differentiation and obtain the redefined severity S.

[0016] Furthermore, the replacement cost of the parts in step S11 includes material costs and labor costs, and the replacement cost of the parts is obtained from the damage assessment quotation from the officially designated 4S store; the repair difficulty M is classified according to the replacement cost of the parts.

[0017] Furthermore, the specific operation of step S2 is as follows: S21: Establish a fatigue analysis road spectrum model for the components and perform stress calculations to obtain stress calculation results; S22: Determine the fatigue analysis loads of the components and obtain the road load spectrum; S23: Import the stress calculation results from step S21 into the fatigue analysis software, use the rainflow counting method to superimpose the road load spectrum from step S22, and combine it with the material fatigue limit to output the minimum simulated life of the components. .

[0018] Furthermore, the specific operation of step S21 is as follows: S211: Draw the 3D model of the road spectrum for each component; S212: Generate a mesh model based on the road spectrum 3D model; S213: If the component assembly is unconstrained or insufficiently constrained during vehicle operation, the inertial release method shall be used for analysis; if the component assembly is subject to explicit constraints during vehicle operation, fixed constraints shall be applied, and time-domain loads shall be applied at loading points outside the constraints; stress calculation shall be performed to obtain stress calculation results.

[0019] Furthermore, the specific operation of step S22 is as follows: S221: Use a laser scanner to scan the features of the test track road surface to obtain a digital 3D model of the road surface; S222: Establish a multi-body virtual prototype vehicle model and tire model; S223: The multibody dynamics software ADAMS is used to simulate the actual vehicle driving on the road, and the road load of the component at the load extraction point during the vehicle's movement is obtained by calculation. S224: Integrate road loads that change over time to obtain the road load spectrum.

[0020] Furthermore, the material fatigue limit in step 23 is obtained through material testing experiments.

[0021] Furthermore, if it is determined in step S3 that the life design of the component is unqualified, the structure is optimized and the process returns to step S2.

[0022] Furthermore, after step S3, step S4 is also included: detecting whether all chassis components are included; if so, the process ends; otherwise, it returns to step S1.

[0023] The beneficial effects of this invention are: This invention can more accurately assess the fatigue life performance of each component of the chassis, enabling more reasonable control over durability performance in the early stages of product design, reducing the need for later modifications due to unreasonable durability, and ensuring that the chassis meets the requirements for road testing. Attached Figure Description

[0024] Figure 1 This is a flowchart of a life design method for automotive chassis components according to the present invention; Figure 2 This is a partially expanded flowchart of a life design method for automotive chassis components according to the present invention. Figure 3 This is the load spectrum of the lateral control arm connection point on a specific road surface in an embodiment of the present invention; Figure 4 This is a lifetime distribution diagram of the lateral control arm path spectrum in an embodiment of the present invention.

[0025] Where A is the subframe connection point; B is the point in the weld area; and C is the steering knuckle connection point. Detailed Implementation

[0026] The embodiments of the present invention will be described below with reference to the accompanying drawings and preferred embodiments. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be understood that the preferred embodiments are only for illustrating the present invention and not for limiting the scope of protection of the present invention.

[0027] It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. Therefore, the drawings only show the components related to the present invention and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0028] like Figure 1 As shown in the figure, this embodiment proposes a method for designing the lifespan of automotive chassis components, including the following specific steps: S1: Determine the simulation life target for the components. : Determine the target average life of components L gp Then, the simulated life target of the components is obtained by combining bench tests. ; S11: Severity S is defined based on the cause of potential component failure, and maintenance difficulty M is defined based on the replacement cost of the component; The steps for defining severity S are as follows: S111: Obtain the Design Failure Mode and Effects Analysis (DFMEA) table for the chassis; S112: Filter out items from DFMEA where the potential failure mode of each component is cracking and the potential failure cause is insufficient durability. Failure analysis methods were used to obtain DFMEA tables for chassis components. The tables contain all the functions of the components, and each function corresponds to relevant information such as potential failure modes, potential failure causes / mechanisms, and severity. S113: Select severity scores from the selection criteria in step S112; S114: The severity scores are reassigned according to the levels to increase differentiation and obtain a redefined severity S; If the severity differences between components are not readily apparent, appropriate scaling can be applied to highlight these differences, resulting in a redefined severity level for all chassis components. ; Repair difficulty The following is how it was obtained: The difficulty of repairing a component is determined by scoring it based on its repair cost, i.e., its replacement cost. The cost of replacing parts includes material costs and labor costs, and the cost of replacing parts is obtained from the damage assessment quotation from the officially designated 4S store; the repair difficulty M is classified into levels based on the cost of replacing parts. The rating range for maintenance difficulty M is 1 to 10 points, meaning that the chassis component with the highest maintenance cost receives 10 points and the lowest receives 1 point. S12: Calculate the life risk level D of the component using the severity S and maintenance difficulty M, and obtain the average life target L of the component based on the life risk level D. gp ; The formula for calculating the life risk factor D is as follows: D=S+M Where D represents life risk level, S represents severity level, and M represents maintenance difficulty; Obtain the life risk level of all chassis components The life risk level D is normalized by dividing the life risk level D of all chassis components by the minimum life risk level min{ The average life target L of all chassis components was obtained. gp ; S13: Set the average lifespan target L for components gp The simulated life target of the components is obtained by combining bench tests. ; Furthermore, in step S13, the simulated lifetime target The specific steps to obtain it are as follows: S131: Draw the 3D model of each component for bench testing; 3D models generally include the component body, welds, ball joints, bolt units, bushing connection units, etc. S132: Generate a mesh model based on the 3D model of the bench test; S133: Apply a single-channel quantitative load to one loading point, constrain the remaining loading points, and calculate the simulated life of the test bench. ; S134: Conduct bench tests, with the boundary conditions and loads of the tests consistent with the simulation conditions for calculating the simulated life. S135: Apply cyclic loads until fatigue cracks appear on the component, and record the number of cycles at which cracks appear; this is the test life. ; S136: Determine whether the number of trials has reached the preset value. If yes, proceed to the next step; otherwise, return to step S134. Preferably, the number of tests is at least 6, requiring at least 6 effective bench tests, and the test life of the components is recorded. , }; S137: Statistics on the test life in each test To obtain the maximum test life L smax Minimum test life L smin The average lifespan L of the test was obtained by averaging the data. sp ; Based on the test results of the components, obtain the statistical value of the test life of the components, and the maximum test life Max{ , The maximum value among the test life results for each component is denoted as}, and the minimum test life is denoted as the minimum value (Min{) among the test life results for each component. , The average lifespan (L) is obtained by averaging the test lifetimes obtained from six trials. sp ; S138: Utilizing the maximum test lifespan L smax Minimum test life L smin Average test life L sp Bench simulation life Calculate the safety factor N; The formula for calculating the safety factor N is as follows:

[0029] Where N is the safety factor, L smax To test the maximum lifespan, L smin To test the minimum lifespan, For the test life, L sp The average lifespan of the test; S139: Based on the average lifespan target L gp Calculate the simulated life target with safety factor N ; Simulated lifespan target The calculation formula is as follows: = N in, To simulate the lifetime target, L gp The average lifespan target is N, where N is the safety factor. S2: Calculate the simulated lifespan of each component and output the minimum simulated lifespan of the component based on the failure conditions. : The simulated lifespan of each component is calculated using simulation methods, and the minimum simulated lifespan of the component is output based on the material fatigue limit. ; The fatigue life analysis of chassis components is based on multibody dynamics virtual iteration, which decomposes the six-component force load spectrum of the wheel center to the components, and then performs fatigue analysis on individual components. S21: Establish a fatigue analysis road spectrum model for the components and perform stress calculations to obtain stress calculation results; S211: Draw the 3D model of the road spectrum for each component; The road spectrum 3D model generally includes the component body, weld, ball joint, bolt unit, bushing connection unit, etc., but the combined scenarios are different, so the road spectrum 3D model here is different from the bench test 3D model in step S131. S212: Generate a mesh model based on the road spectrum 3D model; S213: If the component assembly is unconstrained or insufficiently constrained during vehicle operation, the inertial release method shall be used for analysis; if the component assembly is subject to explicit constraints during vehicle operation, fixed constraints shall be applied, and time-domain loads shall be applied at loading points outside the constraints; stress calculation shall be performed to obtain stress calculation results. For example, control the arm and apply a unit load to all channels at the connection point; if the component assembly has explicit constraints during vehicle operation, such as the position where the steering knuckle connects to the wheel center, apply a fixed constraint and apply a unit load to the loading point other than the constraint in 6 channels; solve for the stress under the unit load in each channel; S22: Determine the fatigue analysis loads of the components and obtain the road load spectrum; S221: Use a laser scanner to scan the features of the test track road surface to obtain a digital 3D model of the road surface; S222: Establish a multi-body virtual prototype vehicle model and tire model; S223: The multibody dynamics software ADAMS is used to simulate the actual vehicle driving on the road, and the road load of the component at the load extraction point during the vehicle's movement is obtained by calculation. S224: Integrate road loads that vary over time to obtain the road load spectrum; Load extraction points refer to the connection points of various component assemblies. Each point has six component forces, and the load changes with time, which is called the road load spectrum. S23: Import the stress calculation results from step S21 into the fatigue analysis software, use the rainflow counting method to superimpose the road load spectrum from step S22, and combine it with the material fatigue limit to output the minimum simulated life of the components. ; The material fatigue limit is obtained through material testing. Here, the material fatigue limit can be calculated using the SN stress-life curve or EN strain-life curve under a 50% failure probability, calculating the fatigue damage and life of the simulated component, and outputting the minimum simulated life of the unit. .

[0030] S3: Fatigue life result determination: The minimum simulated lifespan of the component in step S2. Simulation life target of the component in step S1 If a comparison is made, > If the lifespan design of the component is satisfactory, then the lifespan design of the component is deemed acceptable; otherwise, the lifespan design of the component is deemed unacceptable. For non-compliant structures, targeting lifespans shorter than the simulated lifespan target. The region is optimized, and then the process returns to step S2 until the calculated value is reached. > ; S4: Check if all chassis components are included. If yes, end the process; otherwise, return to step S1.

[0031] The following examples illustrate the lateral control arm in detail: S1: Determine the simulation life target for the components. ; S11: Severity S is defined based on the cause of potential component failure, and maintenance difficulty M is defined based on the replacement cost of the component; The severity levels of control arms, subframes, and steering knuckles are categorized into three levels: 8, 9, and 10, as shown in Table 1. However, these three levels do not clearly highlight the differences in severity among these three types of components. Therefore, by appropriately scaling down the levels to emphasize their differences, this invention uses 10, 20, and 30 to characterize the severity of these three structural types: control arms, subframes, and steering knuckles. ; Table 1. Component severity obtained based on the DEFMA table.

[0032] The difficulty of repairing a component is determined by scoring it based on its repair cost. The difficulty of repair is rated on a scale of 1 to 10, with the highest repair cost for chassis components receiving 10 points and the lowest receiving 1 point. Table 2 shows the repair difficulty of the chassis components that are of particular concern for this model. Table 2. Repair Difficulty of Chassis Components Based on Repair Costs

[0033] S12: Calculate the life risk level D of the component using the severity S and maintenance difficulty M, and obtain the average life target L of the component based on the life risk level D. gp ; Life risk of components =Severity +Repair difficulty This yields the lifespan risk level of all chassis components. The life risk level is normalized by dividing the life risk level of all chassis components by the minimum life risk level (min{). The average life target L for the chassis components of this model was obtained. gp As shown in Table 3; Table 3 Average life target L for chassis components gp

[0034] S13: Set the average lifespan target L for components gp The simulated life target of the components is obtained by combining bench tests. ; During bench testing, The average value of the lifetime results from each test was calculated. The relevant lifetime data for the rear lateral control arm are shown in Table 4 below. Table 4. Relevant lifespan data of the rear lateral control arm

[0035] Life safety factor The calculation formula is as follows:

[0036] Where N is the safety factor, L smax To test the maximum lifespan, L smin To test the minimum lifespan, For the test life, L sp The average lifespan of the test; The safety factor N of the rear lateral control arm is calculated using the above formula, and combined with the target average lifespan L of the rear lateral control arm obtained in step S13. gp The simulated life target is calculated using the following formula.

[0037] Simulated lifespan target The calculation formula is as follows: = N in, To simulate the lifetime target, L gp The average lifespan target is N, where N is the safety factor. The simulation life target of the rear lateral control arm components is obtained as follows: .

[0038] S2: Calculate the simulated lifespan of each component and output the minimum simulated lifespan of the component based on the failure conditions. : In S22, fatigue analysis loads on components are determined, and the road load spectrum is obtained. The rear upper lateral control arm of this vehicle model has two connection points, connected to the rear subframe and the rear steering knuckle respectively. A structural schematic diagram can be referenced. Figure 4 A is the subframe connection point; B is the point in the weld area; C is the steering knuckle connection point. The load spectrum of subframe connection point A on a specific road surface is as follows: Figure 3 As shown.

[0039] Step S23: Calculate the minimum simulation lifetime. In the simulation, the fatigue life distribution of the rear lateral control arm of this vehicle model is calculated as follows: Figure 4 The minimum simulation life of the structure occurs in weld region B. .

[0040] S3. Determination of fatigue life results; The minimum lifetime calculated by S2 The simulated life target determined by S1 For comparison, due to the analysis life of the rear lateral control arm Greater than If the lifespan of the designed rear lateral control arm is satisfactory, then the lifespan of the component is deemed acceptable. If the component lifespan is unsatisfactory, then a lifespan shorter than the simulation target must be addressed. The region is optimized, and then the process returns to step S2 until the calculated value is reached. Greater than .

[0041] The above embodiments are merely preferred embodiments provided to fully illustrate the present invention, and the scope of protection of the present invention is not limited thereto. Equivalent substitutions or modifications made by those skilled in the art based on the present invention are all within the scope of protection of the present invention.

Claims

1. A method for designing the lifespan of automotive chassis components, characterized in that: The specific steps include the following: S1: Determine the simulation life target for the components. : Determine the target average lifespan L of the components gp Then, the simulated life target of the components is obtained by combining bench tests. ; The specific operation of step S1 is as follows: S11: Severity S is defined based on the cause of potential component failure, and maintenance difficulty M is defined based on the replacement cost of the component; S12: Calculate the life risk level D of the component using the severity S and maintenance difficulty M, and obtain the average life target L of the component based on the life risk level D. gp ; S13: Set the average lifespan target L for components gp The simulated life target of the components is obtained by combining bench tests. ; The simulated lifespan target in step S13 The specific steps to obtain it are as follows: S131: Draw the 3D model of each component for bench testing; S132: Generate a mesh model based on the 3D model of the bench test; S133: Apply a single-channel quantitative load to one loading point, constrain the remaining loading points, and calculate the simulated life of the test bench. ; S134: Conduct bench tests, with the boundary conditions and loads of the tests consistent with the simulation conditions for calculating the simulated life. S135: Apply cyclic loads until fatigue cracks appear on the component, and record the number of cycles at which cracks appear; this is the test life. ; S136: Determine whether the number of trials has reached the preset value. If yes, proceed to the next step; otherwise, return to step S134. S137: Statistics on the test life in each test To obtain the maximum test life L smax Minimum test life L smin The average lifespan L of the test was obtained by averaging the data. sp ; S138: Utilizing the maximum test lifespan L smax Minimum test life L smin Average test life L sp Bench simulation life Calculate the safety factor N; S139: Based on the average lifespan target L gp Calculate the simulated life target with safety factor N ; S2: Calculate the simulated lifespan of each component and output the minimum simulated lifespan of the component based on the failure conditions. : The simulated lifespan of each component is calculated using simulation methods, and the minimum simulated lifespan of the component is output based on the material fatigue limit. ; The specific operation of step S2 is as follows: S21: Establish a fatigue analysis road spectrum model for the components and perform stress calculations to obtain stress calculation results; S22: Determine the fatigue analysis loads of the components and obtain the road load spectrum; S23: Import the stress calculation results from step S21 into the fatigue analysis software, use the rainflow counting method to superimpose the road load spectrum from step S22, and combine it with the material fatigue limit to output the minimum simulated life of the components. ; S3: Fatigue life result determination: The minimum simulated lifespan of the component in step S2. Simulation life target of the component in step S1 If a comparison is made, > If the lifespan design of the component is satisfactory, then the component is deemed to have met the design requirements; otherwise, the component is deemed to have failed the design requirements.

2. The method for designing the lifespan of automotive chassis components according to claim 1, characterized in that: The formula for calculating the safety factor N in step S138 is as follows: Where N is the safety factor, L smax To test the maximum lifespan, L smin To test the minimum lifespan, For the test life, L sp The average lifespan of the test.

3. The method for designing the lifespan of automotive chassis components according to claim 1, characterized in that: Simulated lifetime target in step S139 The calculation formula is as follows: = N in, To simulate the lifetime target, L gp The average lifespan target is N, where N is the safety factor.

4. The method for designing the lifespan of automotive chassis components according to claim 1, characterized in that: The formula for calculating the life risk degree D in step S12 is as follows: D=S+M Where D represents life risk level, S represents severity level, and M represents maintenance difficulty.

5. The method for designing the lifespan of automotive chassis components according to claim 1, characterized in that: The steps for defining severity in step S11 are as follows: S111: Obtain the Design Failure Mode and Effects Analysis (DFMEA) table for the chassis; S112: Filter out items from DFMEA where the potential failure mode of each component is cracking and the potential failure cause is insufficient durability. S113: Select severity scores from the selection criteria in step S112; S114: The severity scores are reassigned according to the levels to increase the differentiation and obtain the redefined severity S.

6. The method for designing the lifespan of automotive chassis components according to claim 1, characterized in that: The replacement cost of the parts in step S11 includes material costs and labor costs. The replacement cost of the parts is obtained from the damage assessment quotation from the officially designated 4S store. The repair difficulty M is classified according to the replacement cost of the parts.

7. The method for designing the lifespan of automotive chassis components according to claim 1, characterized in that: The specific operation of step S21 is as follows: S211: Draw the 3D model of the road spectrum for each component; S212: Generate a mesh model based on the road spectrum 3D model; S213: If the component assembly is unconstrained or insufficiently constrained during vehicle operation, the inertial release method shall be used for analysis; if the component assembly is subject to explicit constraints during vehicle operation, fixed constraints shall be applied, and time-domain loads shall be applied at loading points outside the constraints. Stress calculations are performed to obtain stress calculation results.

8. The method for designing the lifespan of automotive chassis components according to claim 1, characterized in that: The specific operation of step S22 is as follows: S221: Use a laser scanner to scan the features of the test track road surface to obtain a digital 3D model of the road surface; S222: Establish a multi-body virtual prototype vehicle model and tire model; S223: The multibody dynamics software ADAMS is used to simulate the actual vehicle driving on the road, and the road load of the component at the load extraction point during the vehicle's movement is obtained by calculation. S224: Integrate road loads that change over time to obtain the road load spectrum.

9. The method for designing the lifespan of automotive chassis components according to any one of claims 1 to 8, characterized in that: If the life design of a component is deemed unqualified in step S3, the process returns to step S2 after structural optimization.

10. The method for designing the lifespan of automotive chassis components according to any one of claims 1 to 8, characterized in that: After step S3, step S4 is also included: detect whether all chassis components are included. If so, the process ends; otherwise, return to step S1.

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