A load compiling method and device for a durability test of a vehicle suspension system bench

Abstract

The application relates to a load compiling method and device for a bench durability test of an automobile suspension system, and relates to the technical field of suspension systems, and comprises the following steps: obtaining a characteristic road load spectrum at a wheel center of a suspension system; obtaining a same-phase load spectrum at the wheel center of the suspension system; obtaining a first fatigue damage ratio between the same-phase load spectrum at the wheel center of the suspension system and an initial equivalent load corresponding to the same-phase load spectrum, and performing first-stage optimization so that the first fatigue damage ratio is within a preset range of the first-stage optimization; and based on a bench durability fatigue total damage corresponding to a dangerous area of the suspension system and a road test durability fatigue total damage, performing second-stage optimization so that a second fatigue damage ratio is within a preset range of the second-stage optimization. The application establishes damage consistency correlation between a vehicle test field working condition and a bench durability test working condition, improves the reliability of equivalent load compilation, and overcomes the defects of the existing bench durability test of the suspension system.

Description

Technical Field

[0001] This application relates to the field of suspension system technology, specifically to a method and apparatus for compiling loads for bench durability tests of automotive suspension systems. Background Technology

[0002] The suspension system is a crucial component of a vehicle, its function being to transmit road excitations and loads to the vehicle body and to buffer and dampen impacts and vibrations caused by road unevenness, ensuring smooth vehicle operation. To guarantee its reliable and durable performance, OEMs conduct virtual durability simulation analysis and experimental verification during the design phase. Experimental verification generally falls into two categories: full-vehicle road durability testing at a proving ground and indoor bench durability testing. Road durability testing at a proving ground is time-consuming, costly, influenced by numerous factors, and yields highly variable results. In contrast, indoor bench durability testing is faster, less costly, offers more controllable processes, and provides more consistent results. Therefore, accurate and thorough bench durability testing of the suspension system is a vital means of shortening the vehicle development cycle and reducing R&D costs.

[0003] Currently, the loading methods for suspension system bench durability testing mainly include single-axle loading and multi-axle loading, each with its own shortcomings, failing to meet the actual needs of load compilation for automotive suspension system bench durability testing. Therefore, to meet this technical requirement, a new load compilation technique for automotive suspension system bench durability testing is presented. Summary of the Invention

[0004] This application provides a method and apparatus for compiling loads for bench durability tests of automotive suspension systems, establishing a correlation between damage consistency between vehicle test track conditions and bench durability test conditions, improving the reliability of equivalent load compilation, and overcoming the shortcomings of existing bench durability tests for suspension systems.

[0005] To achieve the above objectives, this application provides the following solution.

[0006] In a first aspect, this application provides a method for compiling loads for bench durability tests of automotive suspension systems, the method comprising the following steps:

[0007] The characteristic road load spectrum at the wheel center of the suspension system corresponding to different road surface characteristics within the test track road was obtained by extracting the characteristic road load spectrum at the wheel center of the suspension system.

[0008] Based on the phase difference of the characteristic road load spectrum at the wheel center of the suspension system corresponding to the left and right wheel centers of different road surfaces, the corresponding in-phase load spectrum at the wheel center of the suspension system is obtained.

[0009] Based on the in-phase load spectrum at the wheel center of the suspension system and the corresponding initial equivalent load, the first fatigue damage ratio corresponding to the bench durability fatigue damage of the two is obtained, and the initial equivalent load is optimized in the first level so that the first fatigue damage ratio is within the preset range of the first level optimization.

[0010] The bench durability analysis results under the first-level optimized initial equivalent load for each load component are linearly superimposed to obtain the total bench durability fatigue damage corresponding to the dangerous area of ​​the suspension system.

[0011] Based on the total bench fatigue damage corresponding to the hazardous area of ​​the suspension system and the total road test fatigue damage obtained from the test field load spectrum at the wheel center of the suspension system, the initial equivalent load is optimized in the second stage, so that the ratio of the total bench fatigue damage to the total road test fatigue damage is within the preset range of the second stage optimization.

[0012] Furthermore, the step of linearly superimposing and recombining the same load components with the same phase difference at the left and right wheel centers corresponding to different road surface characteristics to obtain the corresponding in-phase load spectrum at the wheel center of the suspension system includes the following steps:

[0013] For the characteristic road load spectrum at the wheel center of the suspension system corresponding to the left and right wheel centers of different road surfaces, phase division is performed to obtain the phase difference corresponding to three preset load components;

[0014] Based on the phase difference corresponding to the three preset load components, the corresponding load phase table is obtained by integration.

[0015] The cycle number of different road surface characteristics is added to the load phase table; wherein...

[0016] The three preset load components are FX, FY, and FZ;

[0017] Phase differences include 0°, 180°, and "△". A 0° phase difference indicates that the left and right wheels move in the same phase, a 180° phase difference indicates that the left and right wheels move in opposite directions, and a "△" phase difference indicates that a single wheel moves and the other wheel only bears half of the vertical axle load.

[0018] Furthermore, based on the phase difference of the characteristic road surface load spectrum at the left and right wheel centers corresponding to different road surface features, the same load components with the same phase difference are linearly superimposed and recombined to obtain the corresponding in-phase load spectrum at the wheel center of the suspension system, including the following steps:

[0019] Based on the pseudo-damage of the load spectrum of the three preset load components corresponding to the left and right wheel centers of different road surfaces, the load spectrum of the wheel center with the largest pseudo-damage is selected as the in-phase wheel center load corresponding to the preset load component of the suspension system wheel center.

[0020] For in-phase wheel center loads, the in-phase load spectrum at the wheel center of the suspension system corresponding to each load component combination is obtained by linear superposition according to the number of cycles specified in the test track road spectrum acquisition specification.

[0021] Furthermore, based on the in-phase load spectrum at the wheel center of the suspension system and the initial equivalent load obtained by simulating damage according to the in-phase load spectrum at the wheel center of the suspension system, the first frame durability fatigue damage, the second frame durability fatigue damage, and the corresponding first fatigue damage ratio corresponding to the dangerous area of ​​the suspension system are obtained, including the following steps:

[0022] Road test durability simulation analysis of the suspension system was conducted to identify the hazardous areas of the suspension system;

[0023] Rainflow statistics were performed on the in-phase load spectrum at the wheel center of the suspension system to obtain the corresponding load amplitude-mean-order matrix;

[0024] The pseudo-damage corresponding to each matrix element in the load amplitude-mean-order matrix is ​​calculated;

[0025] Summing the pseudo-damage corresponding to each matrix element in the load amplitude-mean-order matrix yields the pseudo-damage corresponding to the in-phase load spectrum at the wheel center of the suspension system.

[0026] The number of cycles corresponding to the initial equivalent load is calculated based on the maximum load amplitude in the load amplitude-mean-cycle matrix.

[0027] Based on the pseudo-damage corresponding to the in-phase load spectrum at the wheel center of the suspension system and the cycle number corresponding to the initial equivalent load, the initial equivalent load corresponding to the in-phase load spectrum at the wheel center of the suspension system is obtained.

[0028] Based on the in-phase load spectrum at the wheel center of the suspension system, the first frame durability fatigue damage corresponding to the dangerous area of ​​the suspension system is obtained;

[0029] Based on the initial equivalent load obtained by performing pseudo-damage equivalence according to the in-phase load spectrum at the wheel center of the suspension system, the second frame durability fatigue damage corresponding to the dangerous area of ​​the suspension system is obtained.

[0030] Based on the first frame durability fatigue damage and the second frame durability fatigue damage corresponding to the dangerous area of ​​the suspension system, the first fatigue damage ratio corresponding to the dangerous area of ​​the suspension system is obtained.

[0031] Secondly, this application provides a load compilation device for bench durability testing of automotive suspension systems, the device comprising:

[0032] The characteristic road surface load spectrum acquisition module is used to extract and obtain the characteristic road surface load spectrum at the wheel center of the suspension system corresponding to different characteristic road surfaces in the test field road;

[0033] The in-phase load spectrum acquisition module is used to obtain the corresponding in-phase load spectrum at the wheel center of the suspension system based on the phase difference of the characteristic road surface load spectrum at the left and right wheel centers corresponding to different characteristic road surfaces.

[0034] The initial equivalent load first-level optimization module is used to obtain the first fatigue damage ratio corresponding to the bench durability fatigue damage of the two based on the in-phase load spectrum at the wheel center of the suspension system and the corresponding initial equivalent load, and to perform first-level optimization on the initial equivalent load so that the first fatigue damage ratio is within the preset range of the first-level optimization.

[0035] The total fatigue damage acquisition module for test bench is used to linearly superimpose the test bench durability analysis results under the first-level optimized initial equivalent load for each load component to obtain the total fatigue damage of the test bench corresponding to the dangerous area of ​​the suspension system.

[0036] The initial equivalent load secondary optimization module is used to perform a second-level optimization on the initial equivalent load based on the total bench durability fatigue damage corresponding to the dangerous area of ​​the suspension system and the total road test durability fatigue damage obtained from the test field load spectrum at the wheel center of the suspension system, so that the ratio of the second fatigue damage corresponding to the total bench durability fatigue damage to the total road test durability fatigue damage is within the preset range of the second-level optimization.

[0037] The beneficial effects of the technical solution provided in this application include:

[0038] The embodiments of this application can establish the damage consistency correlation between the vehicle test track conditions and the bench durability test conditions. It can accurately verify the durability performance of the suspension system through a simple dual-actuator bench. It overcomes the shortcomings of the five-condition multi-axis loading method, which has no correlation between the sinusoidal load input and the test track road spectrum load. It also overcomes the shortcomings of the single-axis loading load spectrum, which does not consider the phase relationship of the loads in each direction of the left and right wheel centers.

[0039] The load developed in this application embodiment can be applied using a simple dual-actuator bench. The loading method is simple and the test cost is low, overcoming the disadvantages of complexity and high cost of multi-axis road simulation methods. Attached Figure Description

[0040] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0041] Figure 1 This is a flowchart illustrating the steps of the method for compiling loads for bench durability tests of automotive suspension systems provided in this application embodiment;

[0042] Figure 2 This is a flowchart illustrating the principle of the method for compiling loads for bench durability tests of automotive suspension systems provided in this application embodiment;

[0043] Figure 3 This refers to the load phase table at the wheel center of the suspension system in the method for compiling loads for bench durability tests of automotive suspension systems provided in this application embodiment;

[0044] Figure 4 This is a structural block diagram of the load compilation device for the bench durability test of the automotive suspension system provided in the embodiments of this application. Detailed Implementation

[0045] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0046] The embodiments of this application will be further described in detail below with reference to the accompanying drawings.

[0047] This application provides a method and apparatus for compiling loads for bench durability tests of automotive suspension systems, establishing a correlation between damage consistency between vehicle test track conditions and bench durability test conditions, improving the reliability of equivalent load compilation, and overcoming the shortcomings of existing bench durability tests for suspension systems.

[0048] To achieve the aforementioned technical effects, the overall concept of this application is as follows:

[0049] A method for compiling loads for bench durability tests of automotive suspension systems, the method comprising the following steps:

[0050] S1. Extract the characteristic road load spectrum at the wheel center of the suspension system corresponding to different road surface characteristics within the test track road;

[0051] S2. Based on the phase difference of the characteristic road load spectrum at the left and right wheel centers corresponding to different road surface features, obtain the corresponding in-phase load spectrum at the wheel centers of the suspension system.

[0052] S3. Based on the in-phase load spectrum at the wheel center of the suspension system and the corresponding initial equivalent load, obtain the first fatigue damage ratio corresponding to the fatigue damage of the two on the test bench, and perform first-level optimization on the initial equivalent load so that the first fatigue damage ratio is within the preset range of the first-level optimization.

[0053] S4. Linearly superimpose the bench durability analysis results under the initial equivalent load after the first-level optimization of each load component to obtain the total bench durability fatigue damage corresponding to the dangerous area of ​​the suspension system.

[0054] S5. Based on the total fatigue damage of the test bench corresponding to the dangerous area of ​​the suspension system and the total fatigue damage of the road test obtained from the test field load spectrum at the wheel center of the suspension system, the initial equivalent load is optimized in the second stage so that the ratio of the total fatigue damage of the test bench to the total fatigue damage of the road test is within the preset range of the second stage optimization.

[0055] The embodiments of this application will be further described in detail below with reference to the accompanying drawings.

[0056] See Figures 1-3 As shown in the figure, this application provides a method for compiling loads for bench durability tests of automotive suspension systems. The method includes the following steps:

[0057] S1. Extract the characteristic road load spectrum at the wheel center of the suspension system corresponding to different road surface characteristics in the test field road;

[0058] S2. Based on the phase difference of the characteristic road load spectrum at the left and right wheel centers corresponding to different road surface features, obtain the corresponding in-phase load spectrum at the wheel centers of the suspension system.

[0059] S3. Based on the in-phase load spectrum at the wheel center of the suspension system and the corresponding initial equivalent load, obtain the first fatigue damage ratio corresponding to the fatigue damage of the two on the test bench, and perform first-level optimization on the initial equivalent load so that the first fatigue damage ratio is within the preset range of the first-level optimization.

[0060] S4. Linearly superimpose the bench durability analysis results under the initial equivalent load after the first-level optimization of each load component to obtain the total bench durability fatigue damage corresponding to the dangerous area of ​​the suspension system.

[0061] S5. Based on the total fatigue damage of the test bench corresponding to the dangerous area of ​​the suspension system and the total fatigue damage of the road test obtained from the test field load spectrum at the wheel center of the suspension system, the initial equivalent load is optimized in the second stage so that the ratio of the total fatigue damage of the test bench to the total fatigue damage of the road test is within the preset range of the second stage optimization.

[0062] It should be noted that existing technologies mostly employ single-axis loading and multi-axis loading, as follows:

[0063] First, single-axle loading: Single-axle loading uses a single hydraulic cylinder to sequentially apply sinusoidal loads in various directions to the wheel center of the suspension system;

[0064] This method is simple to operate, has low equipment cost, and low test cost. However, it simply transforms multi-axis problems into various independent single-axis loading problems. The sinusoidal load it applies is a pseudo-damage equivalent conversion of the road spectrum load of each channel. This load has a certain correlation with the road spectrum of the test field, but it does not consider the phase relationship of the loads in each direction of the left and right wheel centers, which is inconsistent with the actual stress situation in the test field. It also does not consider the load response of the component's own structural characteristics, resulting in low accuracy of the test results.

[0065] Second, multi-axis loading: Multi-axis road simulation uses axle-coupled bench test equipment to apply actual road spectrum loads to the left and right wheel centers of the suspension system. The test conditions are consistent with the road durability test at the test site.

[0066] This technical approach requires the acquisition of road spectrum data from a real vehicle test track. The acquired signals include not only the six-component force at the wheel center, but also the wheel center acceleration signal, the shock absorber tower acceleration signal, the spring displacement signal, and the strain signals at the measuring points of various suspension components. Before the test, the drive signal of the shaft coupling test equipment must be iterated based on these signals. The entire test process is very complex, and there is also the possibility that the drive signal iteration process will not converge. Furthermore, the shaft coupling bench test equipment is very expensive, resulting in a relatively high cost for shaft coupling bench testing.

[0067] Multi-axis sinusoidal loading typically involves using two actuated cylinders to simultaneously apply a unidirectional sinusoidal load to the left and right wheel centers of the suspension system. This test method is simple to operate, has low equipment costs, and low test fees. This method usually considers the phase difference of the unidirectional load at the left and right wheel centers, but the correlation between the sinusoidal load it applies and the road spectrum load of the whole vehicle test track is not high, resulting in low accuracy of the test results.

[0068] There are currently two methods for defining multi-axis sinusoidal loads. One method is based on the experience of OEMs and defines five operating conditions: braking, lateral, longitudinal, vertical bump, and vertical rebound. The loads for each condition are determined by empirical formulas, and these loads are not directly related to the road loads at the vehicle test track.

[0069] One method is to obtain the load through pseudo-damage equivalent conversion of the road spectrum load of the whole vehicle test track. The load obtained by this method is related to the road spectrum load of the whole vehicle test track to a certain extent, but it does not consider the load response of the component's own structural characteristics, and does not have a consistent damage correlation. It may result in overload, insufficient assessment, and inconsistencies between the component failure mode and the road durability test at the test track.

[0070] In summary, the overall flow of the technical solution in this application embodiment is as follows:

[0071] Obtain the test field load spectrum at the wheel center of the suspension system corresponding to the test field road;

[0072] From the load spectrum at the wheel center of the suspension system in the test field, the characteristic road surface load spectrum at the wheel center of the suspension system corresponding to different characteristic road surfaces in the test field is obtained;

[0073] Based on the phase difference of the load spectrum of the characteristic road surface at the wheel center of the suspension system corresponding to the left and right wheel centers of different road surfaces, the corresponding phase difference is obtained, and the corresponding load phase table is obtained by integrating them.

[0074] Based on the load phase table, the same load components with phase difference are linearly superimposed and recombined to obtain the corresponding in-phase load spectrum at the wheel center of the suspension system.

[0075] Based on the in-phase load spectrum at the wheel center of the suspension system, pseudo-damage equivalence is performed to obtain the corresponding initial equivalent load;

[0076] Based on the in-phase load spectrum at the wheel center of the suspension system and the corresponding initial equivalent load, a virtual durability analysis is performed on the suspension system to obtain the first frame durability fatigue damage and the second frame durability fatigue damage corresponding to the dangerous area of ​​the suspension system.

[0077] Based on the first frame durability fatigue damage and the second frame durability fatigue damage corresponding to the dangerous area of ​​the suspension system, the first fatigue damage ratio corresponding to the durability fatigue damage of the two frames is obtained, and the initial equivalent load is optimized in the first level so that the first fatigue damage ratio is within the preset range of the first level optimization.

[0078] The bench durability analysis results under the first-level optimized initial equivalent load for each load component are linearly superimposed to obtain the total bench durability fatigue damage corresponding to the dangerous area of ​​the suspension system.

[0079] The total road test durability fatigue damage was obtained based on the test field load spectrum at the wheel center of the suspension system.

[0080] The initial equivalent load, which has undergone the first-level optimization, is then subjected to a second-level optimization, such that the ratio of the total fatigue damage of the test bench to the total fatigue damage of the road test corresponds to the second fatigue damage within the preset range of the second-level optimization.

[0081] The embodiments of this application can establish the damage consistency correlation between the vehicle test track conditions and the bench durability test conditions. It can accurately verify the durability performance of the suspension system through a simple dual-actuator bench. It overcomes the shortcomings of the five-condition multi-axis loading method, which has no correlation between the sinusoidal load input and the test track road spectrum load. It also overcomes the shortcomings of the single-axis loading load spectrum, which does not consider the phase relationship of the loads in each direction of the left and right wheel centers.

[0082] Furthermore, the load prepared based on the technical solution of this application embodiment can be applied by a simple dual-actuator bench, the loading method is simple and the test cost is low, overcoming the disadvantages of complexity and high cost of multi-axis road simulation methods.

[0083] It should be noted that, for ease of understanding of this technical solution, appropriate explanations are provided for the technical terms involved in the embodiments of this application:

[0084] First, damage: Fatigue failure of a structure is a linear cumulative process. When the accumulated damage approaches the material's inherent life, the component will fail due to fatigue. The material's SN curve formula is as follows:

[0085] S = C × N f b In the formula, S is the stress cycle range of the structure, and N f Failure cycle count, C is the fatigue strength coefficient, and b is the fatigue strength index.

[0086] Stress S at different levels i The corresponding failure cycle number is N fi Then the stress S at different levels i Function n i The cumulative damage value D corresponding to this time:

[0087]

[0088] In the formula

[0089] Second, pseudo-damage: Unlike the real damage mentioned above, pseudo-damage does not consider the structural response, but only takes generalized loads such as force, torque, acceleration and displacement as inputs, and calculates the relative damage of the load by combining the material's SN curve.

[0090] Third, pseudo-damage equivalence: Based on the principle of pseudo-damage equality, the random road spectrum of each channel obtained from the road durability test at the test site is converted into the equivalent load of the corresponding single-level or multi-level sinusoidal cycle.

[0091] Furthermore, the step of linearly superimposing and recombining the same load components with the same phase difference at the left and right wheel centers corresponding to different road surface characteristics to obtain the corresponding in-phase load spectrum at the wheel center of the suspension system includes the following steps:

[0092] For the characteristic road load spectrum at the wheel center of the suspension system corresponding to the left and right wheel centers of different road surfaces, phase division is performed to obtain the phase difference corresponding to three preset load components;

[0093] Based on the phase difference corresponding to the three preset load components, the corresponding load phase table is obtained by integration.

[0094] The cycle number of different road surface characteristics is added to the load phase table; wherein...

[0095] The three preset load components are FX, FY, and FZ;

[0096] Phase differences include 0°, 180°, and "△". A 0° phase difference indicates that the left and right wheels move in the same phase, a 180° phase difference indicates that the left and right wheels move in opposite directions, and a "△" phase difference indicates that a single wheel moves and the other wheel only bears half of the vertical axle load.

[0097] Furthermore, based on the phase difference of the characteristic road surface load spectrum at the left and right wheel centers corresponding to different road surface features, the same load components with the same phase difference are linearly superimposed and recombined to obtain the corresponding in-phase load spectrum at the wheel center of the suspension system, including the following steps:

[0098] Based on the pseudo-damage of the load spectrum of the three preset load components corresponding to the left and right wheel centers of different road surfaces, the load spectrum of the wheel center with the largest pseudo-damage is selected as the in-phase wheel center load corresponding to the preset load component of the suspension system wheel center.

[0099] For in-phase wheel center loads, the in-phase load spectrum at the wheel center of the suspension system corresponding to each load component combination is obtained by linear superposition according to the number of cycles specified in the test track road spectrum acquisition specification.

[0100] Furthermore, based on the in-phase load spectrum at the wheel center of the suspension system and the initial equivalent load obtained by simulating damage according to the in-phase load spectrum at the wheel center of the suspension system, the first frame durability fatigue damage, the second frame durability fatigue damage, and the corresponding first fatigue damage ratio corresponding to the dangerous area of ​​the suspension system are obtained, including the following steps:

[0101] Road test durability simulation analysis of the suspension system was conducted to identify the hazardous areas of the suspension system;

[0102] Rainflow statistics were performed on the in-phase load spectrum at the wheel center of the suspension system to obtain the corresponding load amplitude-mean-order matrix;

[0103] The pseudo-damage corresponding to each matrix element in the load amplitude-mean-order matrix is ​​calculated;

[0104] Summing the pseudo-damage corresponding to each matrix element in the load amplitude-mean-order matrix yields the pseudo-damage corresponding to the in-phase load spectrum at the wheel center of the suspension system.

[0105] The number of cycles corresponding to the initial equivalent load is calculated based on the maximum load amplitude in the load amplitude-mean-cycle matrix.

[0106] Based on the pseudo-damage corresponding to the in-phase load spectrum at the wheel center of the suspension system and the cycle number corresponding to the initial equivalent load, the initial equivalent load corresponding to the in-phase load spectrum at the wheel center of the suspension system is obtained.

[0107] Based on the in-phase load spectrum at the wheel center of the suspension system, the first frame durability fatigue damage corresponding to the dangerous area of ​​the suspension system is obtained;

[0108] Based on the initial equivalent load obtained by performing pseudo-damage equivalence according to the in-phase load spectrum at the wheel center of the suspension system, the second frame durability fatigue damage corresponding to the dangerous area of ​​the suspension system is obtained.

[0109] Based on the first frame durability fatigue damage and the second frame durability fatigue damage corresponding to the dangerous area of ​​the suspension system, the first fatigue damage ratio corresponding to the dangerous area of ​​the suspension system is obtained.

[0110] Furthermore, in calculating the pseudo-damage corresponding to each matrix element in the load amplitude-mean-order matrix, taking the in-phase load spectrum FX-0° as an example, the formula for calculating the pseudo-damage corresponding to each matrix element in the load amplitude-mean-order matrix is ​​as follows:

[0111]

[0112] In the formula, in,

[0113] DFX_0° ij For the pseudo-damage corresponding to the matrix element, nX0° ij FX_0° represents the number of iterations corresponding to a matrix element. ij The load amplitude corresponding to the matrix element, b is the fatigue strength index, and C is the fatigue strength coefficient.

[0114] Furthermore, by summing the pseudo-damage corresponding to each matrix element in the load amplitude-mean-order matrix, the pseudo-damage corresponding to the in-phase load spectrum at the wheel center of the suspension system is obtained. Taking the in-phase load spectrum FX-0° as an example, the calculation formula for summing the pseudo-damage corresponding to each matrix element in the load amplitude-mean-order matrix is ​​also included:

[0115]

[0116] In the formula, b represents the fatigue strength index.

[0117] Furthermore, based on the maximum load amplitude in the load amplitude-mean-cycle matrix, the calculation of the cycle number corresponding to the initial equivalent load, taking the in-phase load spectrum FX-0° as an example, also includes the formula for calculating the cycle number corresponding to the initial equivalent load:

[0118] in,

[0119] LC_X0° is the cycle number corresponding to the initial equivalent load;

[0120] The initial equivalent load corresponding to the preset in-phase load spectrum FX_0° is FX_0°. eq =A*FX_0° max A is a pre-set load factor.

[0121] Furthermore, the linear superposition of the bench durability analysis results under the first-level optimized initial equivalent load for each load component to obtain the total bench durability fatigue damage corresponding to the dangerous area of ​​the suspension system also includes a linear superposition formula for the total bench durability fatigue damage:

[0122] D Ni test = w1 * D Ni X eq _0°+w2*D Ni X eq _180°+w3*D Ni X eq _Δ+w4*D Ni Y eq _0°+w5*D Ni Y eq _180°+w6*D Ni Y eq _Δ+w7*D Ni Z eq _0°+w8*D Ni Z eq _180°+w9*D Ni Z eq _Δ; where,

[0123] w1, w2...w9 are adjustment coefficients corresponding to the initial equivalent load, and the initial value of the adjustment coefficient is 1;

[0124] D Ni X eq _0° represents the bench durability fatigue damage under the initial equivalent load corresponding to the in-phase load spectrum FX-0°;

[0125] D Ni X eq _180° represents the bench durability fatigue damage under the initial equivalent load corresponding to the in-phase load spectrum FX-180°;

[0126] D Ni X eq _Δ represents the bench durability fatigue damage under the initial equivalent load corresponding to the in-phase load spectrum FX-Δ;

[0127] D Ni Y eq _0° represents the bench durability fatigue damage under the initial equivalent load corresponding to the in-phase load spectrum FY-0°;

[0128] D Ni Y eq _180° represents the bench durability fatigue damage under the initial equivalent load corresponding to the in-phase load spectrum FY-180°;

[0129] D Ni Y eq _Δ represents the bench durability fatigue damage under the initial equivalent load corresponding to the in-phase load spectrum FY-Δ;

[0130] D Ni Z eq _0° represents the bench durability fatigue damage under the initial equivalent load corresponding to the in-phase load spectrum FZ-0°;

[0131] D Ni Z eq _180° represents the bench durability fatigue damage under the initial equivalent load corresponding to the in-phase load spectrum FZ-180°;

[0132] D Ni Z eq _Δ represents the bench durability fatigue damage under the initial equivalent load corresponding to the in-phase load spectrum FZ-Δ;

[0133] D Ni test represents the total fatigue damage of the suspension system in the hazardous area under the initial equivalent load after the first-level optimization, based on each load component.

[0134] In summary, in order to obtain the bench durability test load of the suspension system, the technical solution of this application embodiment divides the test field road spectrum at the wheel center of the suspension system into phases, and divides the phase difference of the load components FX, FY and FZ at the wheel center of the suspension system corresponding to different road surface characteristics into three phase differences: 0°, 180° and "△".

[0135] A 0° phase difference indicates that the left and right wheels move in the same phase, a 180° phase difference indicates that the left and right wheels move in opposite directions, and a "△" phase difference indicates that a single wheel moves while the other wheel only bears half of the vertical axle load.

[0136] In addition, in the technical solution of this application embodiment, for the same load component of the same suspension system on the same characteristic road surface, the load spectrum of the wheel center on the side with larger pseudo-damage is selected as the in-phase wheel center load of the load component of the suspension system wheel center. Then, according to the number of cycles specified in the test field road spectrum acquisition specification, the in-phase load components with the same phase difference are linearly superimposed to form 9 types of in-phase load spectra at the wheel center of the suspension system: X-0°, FX-180°, FX-△, FY-0°, FY-180°, FY-△, FZ-0°, FZ-180° and FZ-△.

[0137] Based on the technical solution of the embodiments of this application, a specific implementation process is provided, and the specific operation process is as follows:

[0138] Step 1, Obtaining the test track road spectrum at the wheel center of the suspension system:

[0139] The six-component force acquisition device and various sensors such as acceleration signal, displacement signal and strain signal are installed on the actual vehicle. The wheel center six-component force signal is directly collected at the test site in accordance with the vehicle road durability test specifications. Alternatively, the road durability load at the wheel center can be directly extracted by manipulating the multibody dynamics model in combination with the vehicle road durability test specifications through virtual test site technology.

[0140] Step 2: Extraction of the test load spectrum at the wheel center of the suspension system corresponding to different road surface characteristics:

[0141] According to the test track road spectrum acquisition specifications, and in combination with GPS, road spectrum signal characteristics and vehicle speed information, the test track road spectrum load at the wheel center of the suspension system obtained in step 1 is used to extract load spectra of different road surfaces.

[0142] Step 3: The phase of the test field load spectrum at the left and right wheel centers of the suspension system corresponding to different road surface characteristics is different. In order to accurately simulate the actual driving conditions, it is necessary to divide the phase of the test field load spectrum at the left and right wheel centers of the suspension system corresponding to different road surface characteristics.

[0143] It should be noted that the specific steps for step 3 are as follows:

[0144] Step 31: Combining the test field road spectrum signals and road surface feature information at the left and right wheel centers, the phase differences of the load components FX, FY and FZ at the left and right wheel centers corresponding to different road surface features obtained in Step 2 are divided into three phase differences: 0°, 180° and "△".

[0145] Among them, 0° phase difference means that the left and right wheels move in the same phase, 180° phase difference means that the left and right wheels move in opposite directions, and "△" phase difference means that a single wheel moves and the other wheel only bears half of the vertical axle load.

[0146] Step 32: Compile and summarize the phase differences of the three load components at the wheel center of the suspension system corresponding to the different road surface characteristics determined in Step 31 to form a load phase table, and add the cycle number corresponding to the characteristic road surface to the load phase table in accordance with the road spectrum acquisition specifications of the test site.

[0147] Step 4: In order to reduce the number of load conditions in the bench test and further reduce the difficulty and cost of the bench test, it is necessary to linearly superimpose and recombine the same load components with phase differences according to the number of cycles specified in the test site road spectrum acquisition specification.

[0148] It should be noted that the specific steps for step 4 are as follows:

[0149] Step 41: For the same characteristic road surface, the load amplitude levels of the same load component at the left and right wheel centers of the same suspension system are different. Calculate the pseudo-damage of the load spectrum corresponding to the load components FX, FY and FZ at the left and right wheel centers of the suspension system for different characteristic road surfaces obtained in Step 2. Select the load spectrum of the wheel center with larger pseudo-damage as the in-phase wheel center load of the load component at the wheel center of the suspension system.

[0150] Step 42: For the same wheel center load component of the same suspension system, the wheel center loads determined in step 41 with the same phase difference are linearly superimposed according to the number of cycles specified in the test track road spectrum acquisition specification to form a total of 9 in-phase load spectra at the wheel center of the suspension system: FX-0°, FX-180°, FX-△, FY-0°, FY-180°, FY-△, FZ-0°, FZ-180° and FZ-△.

[0151] Step 5: Damage equivalence and load optimization of the in-phase load spectrum at the wheel center of the suspension system. First, conduct road test durability simulation analysis of the suspension system to determine its dangerous area.

[0152] Then, the initial equivalent load is determined by performing pseudo-damage equivalence on the in-phase load spectrum;

[0153] Then, by comparing and analyzing the damage values ​​of the dangerous area of ​​the suspension system under the virtual durability analysis results of the in-phase load spectrum and the corresponding initial equivalent load, if the first fatigue damage ratio is within the threshold range, the load is accepted; otherwise, the initial equivalent load needs to be optimized until its first fatigue damage ratio meets the threshold requirement.

[0154] It should be noted that the specific steps in step 5 are as follows:

[0155] Step 51: Conduct road test durability simulation analysis on the suspension system to determine the hazardous areas of the suspension system:

[0156] Finite element analysis software, such as Hyperworks, was used to establish a finite element analysis model of the suspension system. At the connection between the fully constrained suspension and the body-in-white, unit forces in six directions (X, Y, Z, TX, TY, TZ) were applied at the left and right wheel centers to obtain the unit force stress response results of the suspension system. These unit force response results were correlated with the test track road spectrum loads at the wheel centers corresponding to the characteristic road surface obtained in step 2. The test track road spectrum loads at the wheel centers corresponding to the characteristic road surface obtained in step 2 were then input. Combined with the material SN curve of the suspension system and the test track road spectrum acquisition specifications, the cycle number corresponding to the characteristic road surface was calculated using fatigue analysis software, such as Femfat. The fatigue damage of each part was calculated, and the node number N of the dangerous area in the road test durability analysis results was extracted. i and its corresponding fatigue damage value D Ni .

[0157] Step 52: Perform rainflow statistics on the in-phase load spectrum FX-0° at the wheel center of the suspension system obtained in Step 4 to obtain the corresponding load amplitude-mean-order matrix, which is used for load pseudo-damage analysis calculation in subsequent steps.

[0158] Similarly, taking FX-0° as an example, the corresponding in-phase load matrix is ​​given in Table 1 below:

[0159] Table 1

[0160]

[0161] Step 53: Calculate the pseudo-damage corresponding to the load of each element in the matrix obtained in Step 52. The load amplitudes corresponding to the matrix elements are FX_0°. ij The corresponding number of iterations is n x 0° ij Material S / N curve formula: S = C × N f b ,

[0162] In the formula, S represents the stress cycle range of the structure, and N... f Failure cycle count, C is the fatigue strength coefficient, and b is the fatigue strength index.

[0163] The stress S at different levels i The corresponding failure cycle number is N fi Then the stress S at different levels i Function n i The cumulative damage value D corresponding to this time:

[0164]

[0165] In the formula

[0166] The pseudo-damage corresponding to the load of each element in the matrix is:

[0167] Step 54: Calculate the pseudo-damage DX_0° corresponding to the in-phase load spectrum FX-0° at the wheel center of the suspension system, that is, sum the pseudo-damage corresponding to the load of each element in the matrix:

[0168] Step 55: Based on the load amplitude-mean-order matrix obtained in Step 52, extract the maximum load amplitude FX_0° from the load amplitude-mean-order matrix. max The initial equivalent load corresponding to the preset in-phase load spectrum FX-0° is FX_0°. eq =A*FX_0° max A is a pre-set load factor. The load is set to the number of bench durability test cycles LC_X0°. Based on the principle of spurious damage equivalence, we have:

[0169] Then calculate the number of cycles LC_X0° corresponding to the initial equivalent load:

[0170] Step 56: The initial equivalent load calculated in Step 54 using pseudo-damage only considers the load level. Further virtual durability simulation analysis of the suspension system's in-phase load spectrum FX-0° and its corresponding initial equivalent load FX-0° is required to account for the influence of the structure itself on the load response. Based on the finite element analysis model of the suspension system obtained in Step 51, finite element analysis is performed at the connection between the fully constrained suspension and the body-in-white, applying unit forces in the X direction at the left and right wheel centers to obtain the stress response results of the suspension system in the X direction. These results are then compared with the in-phase load spectrum FX-0° and its corresponding initial equivalent load FX_0°. eqBased on the correlation and the material SN curve of the suspension system, the road test durability analysis results of the in-phase load spectrum FX-0° of the suspension system and the fatigue damage of each part of the suspension system corresponding to the initial equivalent load are calculated. The fatigue damage value D of the in-phase load spectrum of the critical area node Ni determined in step 51 is extracted from the road test durability analysis results. Ni X_0° and its corresponding fatigue damage value D from bench durability analysis results Ni X eq _0°, which represents the ratio of the first fatigue damage to the second fatigue damage to the first fixture, and the first fatigue damage at node Ni. ΔR is a pre-set threshold value, indicating the error accuracy of the equivalent load; otherwise, the initial equivalent load needs to be optimized, i.e., the number of cycles and the corresponding load amplitude of the initial equivalent load are adjusted until the first fatigue damage ratio R of node Ni is reached. Ni X_0°≤ΔR.

[0171] Step 57: Repeat steps 52-56 to determine the initial equivalent loads of the in-phase load spectra FX-180°, FX-△, FY-0°, FY-180°, FY-△, FZ-0°, FZ-180° and FZ-△ in sequence.

[0172] Step 6: Optimization of the initial equivalent load corresponding to the in-phase load spectrum:

[0173] Since the initial equivalent loads of each load component obtained in step 5 only consider the damage equivalents under the individual action of each channel load, without considering the coupling effect between the loads of each channel, it is necessary to further compare and analyze the simulation analysis results of the overall bench durability and road test durability of the suspension system and optimize the initial equivalent loads.

[0174] It should be noted that the specific steps for step 6 are as follows:

[0175] Step 61: Overall bench durability analysis of the suspension system, which involves linearly superimposing the bench durability analysis results under the initial equivalent loads corresponding to the in-phase load spectra FX-0°, FX-180°, FX-△, FY-0°, FY-180°, FY-△, FZ-0°, FZ-180°, and FZ-△ obtained in Step 5. Then, the overall bench durability fatigue damage corresponding to the critical area node Ni mentioned in Step 51 is D. Ni test, then:

[0176] D Ni test = w1 * D Ni X eq _0°+w2*D Ni X eq _180°+w3*D Ni Y eq_Δ+w4*D Ni Y eq _0°+w5*D Ni Y eq _180°+w6*D Ni Y eq _Δ+w7*D Ni Z eq _0°+w8*D Ni Z eq _180°+w9*D Ni Z eq _Δ

[0177] In the formula: w1, w2…w9 are adjustment coefficients corresponding to each equivalent load, specifically taking values ​​in the range of [0, 2]. These can be used to further reduce the bench test conditions and adjust the equivalent loads. When the adjustment coefficients are set to initial values: w1=w2=…=w9=1,

[0178] D Ni test refers to the total fatigue damage of the test bench under the initial equivalent load corresponding to node Ni in the dangerous area described in step 51.

[0179] Step 62: Calculate the total fatigue damage D of the test bench under the initial equivalent load corresponding to node Ni obtained in Step 61. Ni test, the total road test durability fatigue damage D corresponding to node Ni obtained in step 51. Ni Comparison, if the second fatigue damage ratio under the initial equivalent load corresponding to node Ni is... The initial equivalent load can then be output as the bench test load; otherwise, the coefficients corresponding to each equivalent load need to be adjusted until the second fatigue damage ratio R corresponding to node Ni is reached. Ni Meets the preset conditions;

[0180] Finally, based on the principle of equal damage, the amplitude or number of cycles of each equivalent load is optimized by combining adjustment coefficients, and the optimized equivalent load is output as the bench test load.

[0181] In order to simplify the equivalent load optimization process, the technical solution of this application embodiment keeps the equivalent load amplitude unchanged and only adjusts the number of cycles of the equivalent load. The optimized equivalent load cycle number is the product of the cycle number corresponding to the initial equivalent load and the adjustment coefficient. It realizes the transformation of the whole vehicle test track road spectrum load of the suspension system into the bench durability test load, and can establish the damage consistency correlation between the whole vehicle test track working conditions and the bench durability test working conditions.

[0182] It can accurately verify the durability performance of suspension systems using a simple dual-actuator bench, identify suspension problems in advance during vehicle road durability testing, reduce the repetition of testing, improve the first-pass yield of vehicle durability tests, shorten the testing cycle, and reduce testing costs. Furthermore, it can convert the road loads of the vehicle proving ground, applicable to all structural load-bearing components, into bench durability test loads, thus having a wide range of applications.

[0183] See Figure 4 As shown, based on the same inventive concept as the method embodiment, this device embodiment provides a load compilation device for bench durability testing of automotive suspension systems, the device comprising:

[0184] The characteristic road surface load spectrum acquisition module is used to extract and obtain the characteristic road surface load spectrum at the wheel center of the suspension system corresponding to different characteristic road surfaces in the test field road;

[0185] The in-phase load spectrum acquisition module is used to obtain the corresponding in-phase load spectrum at the wheel center of the suspension system based on the phase difference of the characteristic road surface load spectrum at the left and right wheel centers corresponding to different characteristic road surfaces.

[0186] The initial equivalent load first-level optimization module is used to obtain the first fatigue damage ratio corresponding to the bench durability fatigue damage of the two based on the in-phase load spectrum at the wheel center of the suspension system and the corresponding initial equivalent load, and to perform first-level optimization on the initial equivalent load so that the first fatigue damage ratio is within the preset range of the first-level optimization.

[0187] The total fatigue damage acquisition module for test bench is used to linearly superimpose the test bench durability analysis results under the first-level optimized initial equivalent load for each load component to obtain the total fatigue damage of the test bench corresponding to the dangerous area of ​​the suspension system.

[0188] The initial equivalent load secondary optimization module is used to perform a second-level optimization on the initial equivalent load based on the total bench durability fatigue damage corresponding to the dangerous area of ​​the suspension system and the total road test durability fatigue damage obtained from the test field load spectrum at the wheel center of the suspension system, so that the ratio of the second fatigue damage corresponding to the total bench durability fatigue damage to the total road test durability fatigue damage is within the preset range of the second-level optimization.

[0189] The embodiments of this application can establish the damage consistency correlation between the vehicle test track conditions and the bench durability test conditions. It can accurately verify the durability performance of the suspension system through a simple dual-actuator bench. It overcomes the shortcomings of the five-condition multi-axis loading method, which has no correlation between the sinusoidal load input and the test track road spectrum load. It also overcomes the shortcomings of the single-axis loading load spectrum, which does not consider the phase relationship of the loads in each direction of the left and right wheel centers.

[0190] Furthermore, the load prepared based on the technical solution of this application embodiment can be applied by a simple dual-actuator bench, the loading method is simple and the test cost is low, overcoming the disadvantages of complexity and high cost of multi-axis road simulation methods.

[0191] Furthermore, the load phase table integration module is also used to perform phase division on the characteristic road load spectrum at the wheel center of the suspension system corresponding to the left and right wheel centers of different characteristic road surfaces, and obtain the phase difference corresponding to three preset load components.

[0192] Based on the phase difference corresponding to the three preset load components, the corresponding load phase table is obtained by integration.

[0193] The cycle number of different road surface characteristics is added to the load phase table; wherein...

[0194] The three preset load components are FX, FY, and FZ;

[0195] Phase differences include 0°, 180°, and "△". A 0° phase difference indicates that the left and right wheels move in the same phase, a 180° phase difference indicates that the left and right wheels move in opposite directions, and a "△" phase difference indicates that a single wheel moves and the other wheel only bears half of the vertical axle load.

[0196] Furthermore, the in-phase load spectrum acquisition module is also used to perform phase division on the characteristic road surface load spectrum at the wheel center of the suspension system corresponding to the left and right wheel centers of different characteristic road surfaces, and obtain the phase difference corresponding to the three preset load components.

[0197] The in-phase load spectrum acquisition module is also used to integrate and obtain the corresponding load phase table based on the phase difference between the three preset load components.

[0198] The in-phase load spectrum acquisition module is also used to add the cycle number of different characteristic road surfaces to the load phase table; wherein,

[0199] The three preset load components are FX, FY, and FZ;

[0200] Phase differences include 0°, 180°, and "△". A 0° phase difference indicates that the left and right wheels move in the same phase, a 180° phase difference indicates that the left and right wheels move in opposite directions, and a "△" phase difference indicates that a single wheel moves and the other wheel only bears half of the vertical axle load.

[0201] Furthermore, the in-phase load spectrum acquisition module is also used to select the load spectrum of the wheel center with the largest pseudo-damage as the in-phase wheel center load corresponding to the preset load component of the suspension system wheel center based on the pseudo-damage of the load spectrum of the three preset load components corresponding to the left and right wheel centers of different road surface features.

[0202] The in-phase load spectrum acquisition module is also used to linearly superimpose the in-phase wheel center loads according to the number of cycles specified in the test track road spectrum acquisition specifications to obtain the in-phase load spectrum at the wheel center of the suspension system corresponding to each load component combination.

[0203] Furthermore, the initial equivalent load level 1 optimization module is also used to perform road test durability simulation analysis on the suspension system to determine the dangerous areas of the suspension system;

[0204] The initial equivalent load first-level optimization module is also used to perform rainflow statistics on the in-phase load spectrum at the wheel center of the suspension system to obtain the corresponding load amplitude-mean-order matrix;

[0205] The initial equivalent load first-level optimization module is also used to calculate the pseudo-damage corresponding to each matrix element in the load amplitude-mean-order matrix;

[0206] The initial equivalent load first-level optimization module is also used to sum the pseudo-damage corresponding to each matrix element in the load amplitude-mean-order matrix to obtain the pseudo-damage corresponding to the in-phase load spectrum at the wheel center of the suspension system.

[0207] The initial equivalent load first-level optimization module is also used to calculate the number of cycles corresponding to the initial equivalent load based on the largest load amplitude in the load amplitude-mean-degree matrix;

[0208] The initial equivalent load first-level optimization module is also used to obtain the initial equivalent load corresponding to the in-phase load spectrum at the wheel center of the suspension system based on the pseudo damage corresponding to the in-phase load spectrum at the wheel center of the suspension system and the number of cycles corresponding to the initial equivalent load.

[0209] The initial equivalent load first-level optimization module is also used to obtain the first frame durability fatigue damage corresponding to the dangerous area of ​​the suspension system based on the in-phase load spectrum at the wheel center of the suspension system.

[0210] The initial equivalent load first-level optimization module is also used to obtain the second frame durability fatigue damage corresponding to the dangerous area of ​​the suspension system based on the initial equivalent load obtained by pseudo-damage equivalence based on the in-phase load spectrum at the wheel center of the suspension system.

[0211] The initial equivalent load first-level optimization module is also used to obtain the first fatigue damage ratio corresponding to the dangerous area of ​​the suspension system based on the first frame durability fatigue damage and the second frame durability fatigue damage corresponding to the dangerous area of ​​the suspension system.

[0212] Furthermore, in calculating the pseudo-damage corresponding to each matrix element in the load amplitude-mean-order matrix, taking the in-phase load spectrum FX-0° as an example, the formula for calculating the pseudo-damage corresponding to each matrix element in the load amplitude-mean-order matrix is ​​as follows:

[0213]

[0214] In the formula, in,

[0215] DFX_0° ij For the pseudo-damage corresponding to the matrix element, nX0° ij FX_0° represents the number of iterations corresponding to a matrix element. ij The load amplitude corresponding to the matrix element, b is the fatigue strength index, and C is the fatigue strength coefficient.

[0216] Furthermore, by summing the pseudo-damage corresponding to each matrix element in the load amplitude-mean-order matrix, the pseudo-damage corresponding to the in-phase load spectrum at the wheel center of the suspension system is obtained. Taking the in-phase load spectrum FX-0° as an example, the calculation formula for summing the pseudo-damage corresponding to each matrix element in the load amplitude-mean-order matrix is ​​also included:

[0217]

[0218] In the formula, b represents the fatigue strength index.

[0219] Furthermore, based on the maximum load amplitude in the load amplitude-mean-cycle matrix, the calculation of the cycle number corresponding to the initial equivalent load, taking the in-phase load spectrum FX-0° as an example, also includes the formula for calculating the cycle number corresponding to the initial equivalent load:

[0220] in,

[0221] LC_X0° is the cycle number corresponding to the initial equivalent load;

[0222] The initial equivalent load corresponding to the preset in-phase load spectrum FX_0° is FX_0°. eq =A*FX_0° max A is a pre-set load factor.

[0223] Furthermore, the linear superposition of the bench durability analysis results under the first-level optimized initial equivalent load for each load component to obtain the total bench durability fatigue damage corresponding to the dangerous area of ​​the suspension system also includes a linear superposition formula for the total bench durability fatigue damage:

[0224] D Ni test = w1 * D Ni X eq _0°+w2*D Ni X eq _180°+w3*D Ni Y eq _Δ+w4*D Ni Y eq_0°+w5*4D Ni Y eq _180°+w6*D Ni Y eq _Δ+w7*D Ni Z eq _0°+w8*D Ni Z eq _180°+w9*D Ni Z eq _Δ; where the terminology can be explained in the method embodiments mentioned in the first aspect.

[0225] It should be noted that the technical problems, technical means and technical effects of the vehicle suspension system bench durability test load compilation device provided in this application embodiment are similar to the principle of the vehicle suspension system bench durability test load compilation method.

[0226] It should be noted that in this application, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes the element.

[0227] The above are merely specific embodiments of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A method for compiling loads for bench durability tests of automotive suspension systems, characterized in that, The method includes the following steps: The characteristic road load spectrum at the wheel center of the suspension system corresponding to different road surface characteristics within the test track road was obtained by extracting the characteristic road load spectrum at the wheel center of the suspension system. Based on the phase difference of the characteristic road load spectrum at the wheel center of the suspension system corresponding to the left and right wheel centers of different road surfaces, the corresponding in-phase load spectrum at the wheel center of the suspension system is obtained. Based on the in-phase load spectrum at the wheel center of the suspension system and the corresponding initial equivalent load, the first fatigue damage ratio corresponding to the bench durability fatigue damage of the two is obtained, and the initial equivalent load is optimized in the first level so that the first fatigue damage ratio is within the preset range of the first level optimization. The bench durability analysis results under the first-level optimized initial equivalent load for each load component are linearly superimposed to obtain the total bench durability fatigue damage corresponding to the dangerous area of ​​the suspension system. Based on the total bench durability fatigue damage corresponding to the dangerous area of ​​the suspension system and the total road test durability fatigue damage obtained from the test field load spectrum at the wheel center of the suspension system, the initial equivalent load is optimized in the second level so that the ratio of the total bench durability fatigue damage to the total road test fatigue damage is within the preset range of the second level optimization. The method involves the following steps: First, based on the phase difference of the load spectrum at the left and right wheel centers corresponding to different road surface characteristics, linearly superimpose and recombine the same load components with the same phase difference to obtain the corresponding in-phase load spectrum at the wheel centers of the suspension system. For the characteristic road load spectrum at the wheel center of the suspension system corresponding to the left and right wheel centers of different road surfaces, phase division is performed to obtain the phase difference corresponding to three preset load components; Based on the phase difference corresponding to the three preset load components, the corresponding load phase table is obtained by integration. Add the cycle number of different road surface features to the load phase table; The method of obtaining the corresponding in-phase load spectrum at the wheel center of the suspension system based on the phase difference of the characteristic road surface load spectrum at the left and right wheel centers corresponding to different road surface characteristics, and linearly superimposing and recombining the same load components with the same phase difference to obtain the corresponding in-phase load spectrum at the wheel center of the suspension system, also includes the following steps: Based on the pseudo-damage of the load spectrum of the three preset load components corresponding to the left and right wheel centers of different road surfaces, the load spectrum of the wheel center with the largest pseudo-damage is selected as the in-phase wheel center load corresponding to the preset load component of the suspension system wheel center. For in-phase wheel center loads, the in-phase load spectra at the wheel center of the suspension system corresponding to each load component combination are obtained by linear superposition according to the number of cycles specified in the test track road spectrum acquisition specifications; among which... The three preset load components are FX, FY, and FZ; Phase differences include 0°, 180°, and "△". A 0° phase difference indicates that the left and right wheels move in the same phase, a 180° phase difference indicates that the left and right wheels move in opposite directions, and a "△" phase difference indicates that a single wheel moves while the other wheel only bears half of the vertical axle load.

2. The method for compiling loads for bench durability tests of automotive suspension systems as described in claim 1, characterized in that, Based on the in-phase load spectrum at the wheel center of the suspension system and the initial equivalent load obtained by pseudo-damage equivalence based on the in-phase load spectrum at the wheel center of the suspension system, the first frame durability fatigue damage, the second frame durability fatigue damage, and the corresponding first fatigue damage ratio corresponding to the dangerous area of ​​the suspension system are obtained, including the following steps: Road test durability simulation analysis of the suspension system was conducted to identify the hazardous areas of the suspension system; Rainflow statistics were performed on the in-phase load spectrum at the wheel center of the suspension system to obtain the corresponding load amplitude-mean-order matrix; The pseudo-damage corresponding to each matrix element in the load amplitude-mean-order matrix is ​​calculated; Summing the pseudo-damage corresponding to each matrix element in the load amplitude-mean-order matrix yields the pseudo-damage corresponding to the in-phase load spectrum at the wheel center of the suspension system. The number of cycles corresponding to the initial equivalent load is calculated based on the maximum load amplitude in the load amplitude-mean-cycle matrix. Based on the pseudo-damage corresponding to the in-phase load spectrum at the wheel center of the suspension system and the cycle number corresponding to the initial equivalent load, the initial equivalent load corresponding to the in-phase load spectrum at the wheel center of the suspension system is obtained. Based on the in-phase load spectrum at the wheel center of the suspension system, the first frame durability fatigue damage corresponding to the dangerous area of ​​the suspension system is obtained; Based on the initial equivalent load obtained by performing pseudo-damage equivalence according to the in-phase load spectrum at the wheel center of the suspension system, the second frame durability fatigue damage corresponding to the dangerous area of ​​the suspension system is obtained. Based on the first frame durability fatigue damage and the second frame durability fatigue damage corresponding to the dangerous area of ​​the suspension system, the first fatigue damage ratio corresponding to the dangerous area of ​​the suspension system is obtained.

3. The method for compiling loads for bench durability tests of automotive suspension systems as described in claim 2, characterized in that, Taking the in-phase load spectrum FX-0° as an example, the formula for calculating the pseudo-damage corresponding to each matrix element in the load amplitude-mean-order matrix is ​​as follows: ； In the formula, ,in, The pseudo-damage corresponding to the matrix element. This represents the number of iterations corresponding to a matrix element. The load amplitude corresponding to the matrix element, b is the fatigue strength index, and C is the fatigue strength coefficient.

4. The method for compiling loads for bench durability tests of automotive suspension systems as described in claim 2, characterized in that, The summation of pseudo-damage corresponding to each matrix element in the load amplitude-mean-order matrix yields the pseudo-damage corresponding to the in-phase load spectrum at the wheel center of the suspension system. Taking the in-phase load spectrum FX-0° as an example, the calculation formula for the summation of pseudo-damage corresponding to each matrix element in the load amplitude-mean-order matrix is ​​also included: ； b is the fatigue strength index.

5. The method for compiling loads for bench durability tests of automotive suspension systems as described in claim 2, characterized in that, Based on the maximum load amplitude in the load amplitude-mean-cycle matrix, the calculation of the cycle number corresponding to the initial equivalent load, taking the in-phase load spectrum FX-0° as an example, also includes the calculation formula for the cycle number corresponding to the initial equivalent load: ;in, This represents the number of cycles corresponding to the initial equivalent load. Preset in-phase load spectrum The corresponding initial equivalent load is A is a pre-set load factor.

6. The method for compiling loads for bench durability tests of automotive suspension systems as described in claim 1, characterized in that, The linear superposition of the bench durability analysis results under the initial equivalent load after first-level optimization of each load component to obtain the total bench durability fatigue damage corresponding to the dangerous area of ​​the suspension system also includes a linear superposition formula for the total bench durability fatigue damage: ;in, This is the adjustment factor corresponding to the initial equivalent load, and the initial value of the adjustment factor is 1; , , , , , , , as well as The table durability fatigue damage under the initial equivalent load corresponding to the in-phase load spectra FX-0°, FX-180°, FX-△, FY-0°, FY-180°, FY-△, FZ-0°, FZ-180° and FZ-△ are respectively. The total fatigue damage of the suspension system in the hazardous area is the test bench durability damage under the initial equivalent load after the first-level optimization of each load component.

7. A load compilation device for bench durability testing of automotive suspension systems, characterized in that, The device includes: The characteristic road surface load spectrum acquisition module is used to extract and obtain the characteristic road surface load spectrum at the wheel center of the suspension system corresponding to different characteristic road surfaces in the test field road; The in-phase load spectrum acquisition module is used to obtain the corresponding in-phase load spectrum at the wheel center of the suspension system based on the phase difference of the characteristic road surface load spectrum at the left and right wheel centers corresponding to different characteristic road surfaces. The initial equivalent load first-level optimization module is used to obtain the first fatigue damage ratio corresponding to the bench durability fatigue damage of the two based on the in-phase load spectrum at the wheel center of the suspension system and the corresponding initial equivalent load, and to perform first-level optimization on the initial equivalent load so that the first fatigue damage ratio is within the preset range of the first-level optimization. The total fatigue damage acquisition module for test bench is used to linearly superimpose the test bench durability analysis results under the first-level optimized initial equivalent load for each load component to obtain the total fatigue damage of the test bench corresponding to the dangerous area of ​​the suspension system. The initial equivalent load secondary optimization module is used to perform a second-level optimization on the initial equivalent load based on the total bench durability fatigue damage corresponding to the dangerous area of ​​the suspension system and the total road test durability fatigue damage obtained from the test field load spectrum at the wheel center of the suspension system, so that the ratio of the second fatigue damage corresponding to the total bench durability fatigue damage to the total road test fatigue damage is within the preset range of the second-level optimization. The same-phase load spectrum acquisition module is also used to perform phase division on the characteristic road load spectrum at the wheel center of the suspension system corresponding to the left and right wheel centers of different characteristic road surfaces, and obtain the phase difference corresponding to three preset load components; The in-phase load spectrum acquisition module is also used to integrate and obtain the corresponding load phase table based on the phase difference corresponding to the three preset load components. The same-phase load spectrum acquisition module is also used to add the cycle number of different characteristic road surfaces to the load phase table; The in-phase load spectrum acquisition module is also used to select the load spectrum of the wheel center with the largest pseudo-damage as the in-phase wheel center load corresponding to the preset load component of the suspension system wheel center based on the pseudo-damage of the load spectrum of the three preset load components corresponding to the left and right wheel centers of different road surface features. The in-phase load spectrum acquisition module is also used to linearly superimpose in-phase wheel center loads according to the number of cycles specified in the test track road spectrum acquisition specifications, to obtain the in-phase load spectrum at the wheel center of the suspension system corresponding to each load component combination; wherein... The three preset load components are FX, FY, and FZ; Phase differences include 0°, 180°, and "△". A 0° phase difference indicates that the left and right wheels move in the same phase, a 180° phase difference indicates that the left and right wheels move in opposite directions, and a "△" phase difference indicates that a single wheel moves while the other wheel only bears half of the vertical axle load.

8. The load compilation device for bench durability testing of automotive suspension systems as described in claim 7, characterized in that, The linear superposition of the bench durability analysis results under the initial equivalent load after first-level optimization of each load component to obtain the total bench durability fatigue damage corresponding to the dangerous area of ​​the suspension system also includes a linear superposition formula for the total bench durability fatigue damage: ;in, This is the adjustment factor corresponding to the initial equivalent load, and the initial value of the adjustment factor is 1; , , , , , , , as well as The table durability fatigue damage under the initial equivalent load corresponding to the in-phase load spectra FX-0°, FX-180°, FX-△, FY-0°, FY-180°, FY-△, FZ-0°, FZ-180° and FZ-△ are respectively. The total fatigue damage of the suspension system in the hazardous area is the test bench durability damage under the initial equivalent load after the first-level optimization of each load component.

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