Load spectrum compilation method, system, readable storage medium and computer device

Abstract

The present invention provides a method, system, readable storage medium and computer equipment for compiling a load spectrum. The method is applied to the stabilizer bar of a vehicle to be tested, including: obtaining stress cloud maps of the finite element model of the stabilizer bar under various working conditions, and determining the position of the strain measurement point according to the stress cloud map and the failure position of the stabilizer bar; performing component bench calibration on the stabilizer bar to obtain a calibration curve, and performing linear verification; if the verification is passed, a road test is performed on the vehicle to be tested to obtain a first strain load spectrum and a wheel center acceleration load spectrum; a multi-body dynamics analysis is performed on the vehicle to be tested, and a hard point load spectrum and a second strain load spectrum are obtained according to a virtual test of the stabilizer bar; judging whether the damage strength of the stabilizer bar evaluated by each load spectrum is consistent; if consistent, each load spectrum is edited and processed, and a multi-level program load spectrum is compiled in combination with the calibration curve. The present invention solves the problem that the component bench durability test has high cost, long cycle and weak target basis.

Description

Technical Field

[0001] The present invention relates to the technical field of vehicle component testing, and in particular to a method and system for compiling a load spectrum, a readable storage medium and a computer device. Background Art

[0002] With the rapid development of the automobile industry and the improvement of people's living standards, cars have become an indispensable part of people's lives. Therefore, more and more people are beginning to pay attention to the safety performance of cars.

[0003] Structural durability is one of the important indicators of automobile safety performance. In order to ensure the structural durability of the vehicle, a large number of fatigue tests will be carried out on the vehicle components during the vehicle development process. The tests on structural durability mainly include road tests in the proving ground and indoor bench tests.

[0004] The key to structural durability performance analysis lies in the true load spectrum between components. For proving ground road tests, it is difficult to obtain the true load spectrum between components. In addition, due to the particularity of automotive components, the proving ground road test cycle is long and the cost is relatively high. For indoor bench tests, there is a weak target basis and it is impossible to obtain an accurate load spectrum through load decomposition, resulting in insufficient measurement accuracy of structural durability performance in the existing technology. Summary of the invention

[0005] Based on this, an object of the present invention is to provide a method, system, readable storage medium and computer device for compiling a load spectrum, so as to at least solve the deficiencies in the above-mentioned technology.

[0006] The present invention provides a method for compiling a load spectrum, which is applied to a stabilizer bar of a vehicle to be tested, comprising:

[0007] Obtaining stress cloud diagrams of the finite element model of the stabilizer bar under various working conditions, and determining the position of the strain measuring point of the stabilizer bar according to the hot spot position in the stress cloud diagram and the position information of the stabilizer bar when failure occurs in the road test;

[0008] Performing component bench calibration on the stabilizer bar to obtain a corresponding calibration curve, and performing linearity verification on the calibration curve;

[0009] If the linearity verification of the calibration curve passes, the stabilizer bar and the wheel center acceleration sensor are installed on the vehicle to be tested to perform a road test, and the first strain load spectrum of the strain measuring point position and the wheel center acceleration load spectrum of the vehicle to be tested are collected according to the road test specification of the road test;

[0010] Performing a multi-body dynamics analysis on the vehicle to be tested to obtain a hard point load spectrum of the stabilizer bar, and obtaining a second strain load spectrum at the strain measuring point position according to a virtual test of the stabilizer bar;

[0011] evaluating the damage strength of the stabilizer bar according to the first strain load spectrum and the wheel center acceleration load spectrum and the hard point load spectrum and the second strain load spectrum, respectively, and determining whether the damage strength evaluated by the first strain load spectrum and the wheel center acceleration load spectrum is consistent with the damage strength evaluated by the hard point load spectrum and the second strain load spectrum;

[0012] If the damage intensity evaluated by the first strain load spectrum and the wheel center acceleration load spectrum is consistent with the damage intensity evaluated by the hard point load spectrum and the second strain load spectrum, the first strain load spectrum, the wheel center acceleration load spectrum, the hard point load spectrum and the second strain load spectrum are edited and processed, and the multi-level program load spectrum of the stabilizer bar is compiled in combination with the calibration curve.

[0013] Furthermore, before the step of performing component bench calibration on the stabilizer bar, the method further comprises:

[0014] Determining the type of strain gauge at the position of the strain measuring point according to the type of load on the stabilizer bar;

[0015] Install corresponding strain gauges at the strain measuring point according to the strain gauge type.

[0016] Furthermore, the step of performing component bench calibration on the stabilizer bar to obtain a corresponding calibration curve includes:

[0017] Fixing a stabilizing rod equipped with a strain gauge on a test bench, applying a load to the stabilizing rod equipped with the strain gauge by using an actuator at a preset time, and collecting a displacement signal of the actuator and a strain signal on the stabilizing rod equipped with the strain gauge at a preset number of times;

[0018] The collected multiple displacement signals and strain signals are linearly fitted to obtain a corresponding calibration curve.

[0019] Further, the step of respectively evaluating the damage strength of the stabilizer bar according to the first strain load spectrum and the wheel center acceleration load spectrum and the hard point load spectrum and the second strain load spectrum comprises:

[0020] Preprocessing the first strain load spectrum and the wheel center acceleration load spectrum to remove invalid signals in the first strain load spectrum and the wheel center acceleration load spectrum;

[0021] The preprocessed first strain load spectrum and wheel center acceleration load spectrum are simplified into a number of load cycles consisting of load amplitudes and load means;

[0022] The first strain load spectrum and the wheel center acceleration load spectrum are calculated by using the load cycle to evaluate the damage strength of the stabilizer bar.

[0023] Furthermore, the step of editing the first strain load spectrum, the wheel center acceleration load spectrum, the hard point load spectrum and the second strain load spectrum, and compiling a multi-level program load spectrum of the stabilizer bar in combination with the calibration curve includes:

[0024] Stepwise performing load spectrum mathematical statistics and load spectrum extrapolation on the first strain load spectrum, the wheel center acceleration load spectrum, the hard point load spectrum and the second strain load spectrum;

[0025] After the load spectrum extrapolation is completed, the corresponding two-dimensional damage matrix is ​​established according to the load spectrum damage statistics;

[0026] Establishing a corresponding one-dimensional damage matrix using a load stress function, the first strain load spectrum, the wheel center acceleration load spectrum, the hard point load spectrum, and the second strain load spectrum;

[0027] A multi-level programmed load spectrum of the stabilizer bar is compiled according to the two-dimensional damage matrix, the one-dimensional damage matrix and the calibration curve.

[0028] The present invention further proposes a load spectrum compilation system, which is applied to a stabilizer bar of a vehicle to be tested. The load spectrum compilation system comprises:

[0029] a first processing module, for obtaining stress cloud diagrams of the finite element model of the stabilizer bar under various working conditions, and determining the position of the strain measuring point of the stabilizer bar according to the hot spot position in the stress cloud diagram and the position information of the stabilizer bar when failure occurs in the road test;

[0030] A bench calibration module, used for performing a component bench calibration on the stabilizer bar to obtain a corresponding calibration curve, and performing a linear verification on the calibration curve;

[0031] a second processing module, configured to install the stabilizer bar and the wheel center acceleration sensor on the vehicle to be tested to perform a road test if the linear verification of the calibration curve passes, and collect a first strain load spectrum of the strain measuring point position and a wheel center acceleration load spectrum of the vehicle to be tested according to a road test specification of the road test;

[0032] An analysis module, used for performing a multi-body dynamics analysis on the vehicle to be tested to obtain a hard point load spectrum of the stabilizer bar, and obtaining a second strain load spectrum at the strain measuring point position according to a virtual test of the stabilizer bar;

[0033] an evaluation module, configured to evaluate the damage strength of the stabilizer bar according to the first strain load spectrum and the wheel center acceleration load spectrum and the hard point load spectrum and the second strain load spectrum, respectively, and determine whether the damage strength evaluated by the first strain load spectrum and the wheel center acceleration load spectrum is consistent with the damage strength evaluated by the hard point load spectrum and the second strain load spectrum;

[0034] A compilation module is used to edit the first strain load spectrum, the wheel center acceleration load spectrum, the hard point load spectrum and the second strain load spectrum if the damage intensity evaluated by the first strain load spectrum and the wheel center acceleration load spectrum is consistent with the damage intensity evaluated by the hard point load spectrum and the second strain load spectrum, and compile a multi-level program load spectrum of the stabilizer bar in combination with the calibration curve.

[0035] Furthermore, the system also includes:

[0036] A determination module, used to determine the type of strain gauge at the position of the strain measurement point according to the type of load on the stabilizer bar;

[0037] The third processing module is used to install the corresponding strain gauge at the strain measuring point according to the strain gauge type.

[0038] Furthermore, the bench calibration module includes:

[0039] A processing unit, used for fixing a stabilizing bar equipped with a strain gauge on a test bench, applying a load to the stabilizing bar equipped with the strain gauge by using an actuator at a preset time, and collecting a displacement signal of the actuator and a strain signal on the stabilizing bar equipped with the strain gauge at a preset number of times;

[0040] The fitting unit is used to perform linear fitting on the collected multiple displacement signals and the strain signals to obtain a corresponding calibration curve.

[0041] Furthermore, the evaluation module includes:

[0042] A preprocessing unit, used for preprocessing the first strain load spectrum and the wheel center acceleration load spectrum to remove invalid signals in the first strain load spectrum and the wheel center acceleration load spectrum;

[0043] A rain flow statistics unit is used to simplify the pre-processed first strain load spectrum and wheel center acceleration load spectrum into a load cycle consisting of a plurality of load amplitudes and load means;

[0044] A damage analysis unit is used to evaluate the damage intensity of the stabilizer bar by calculating the first strain load spectrum and the wheel center acceleration load spectrum using the load cycle.

[0045] Furthermore, the compilation module includes:

[0046] A first processing unit is used to gradually perform load spectrum mathematical statistics and load spectrum extrapolation on the first strain load spectrum, the wheel center acceleration load spectrum, the hard point load spectrum and the second strain load spectrum;

[0047] The first creation unit is used to establish a corresponding two-dimensional damage matrix according to the load spectrum damage statistics after the load spectrum extrapolation is completed;

[0048] a second processing unit, configured to establish a corresponding one-dimensional damage matrix using a load-stress function, the first strain load spectrum, the wheel center acceleration load spectrum, the hard point load spectrum, and the second strain load spectrum;

[0049] The second creation unit is used to compile a multi-level program load spectrum of the stabilizer bar according to the two-dimensional damage matrix, the one-dimensional damage matrix and the calibration curve.

[0050] The present invention also provides a readable storage medium on which a computer device program is stored. When the program is executed by a processor, the above-mentioned method for compiling a load spectrum is implemented.

[0051] The present invention also provides a computer device, comprising a memory, a processor, and a computer device program stored in the memory and executable on the processor, wherein the processor implements the above-mentioned method for compiling a load spectrum when executing the computer device program.

[0052] The load spectrum compilation method, system, readable storage medium and computer device of the present invention determine the strain measurement point position of the stabilizer bar by using a cloud map and the failure position of the stabilizer bar in a road test, and perform component bench calibration on the stabilizer bar to obtain a corresponding calibration curve, perform linear verification on the calibration curve, and when the linear verification passes, collect the first strain load spectrum and wheel center acceleration load spectrum of the strain measurement point position through a road test; obtain the hard point load spectrum of the stabilizer bar by performing a multi-body dynamics analysis on the vehicle to be tested, and obtain the second strain load spectrum of the strain measurement point position by performing a virtual test on the stabilizer bar, and make a consistency judgment based on the damage intensity evaluated by the load spectrum. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] Figure 1 is a flow chart of a method for compiling a load spectrum in a first embodiment of the present invention;

[0054] Figure 2 is a flow chart of a method for compiling a load spectrum in another embodiment of the present invention;

[0055] Figure 3 for Figure 1 Detailed flow chart of step S102;

[0056] Figure 4 for Figure 1 Detailed flow chart of step S105;

[0057] Figure 5 A schematic diagram of the rain flow statistics method in the first embodiment of the present invention;

[0058] Figure 6 for Figure 1 Detailed flow chart of step S106;

[0059] Figure 7 is a range distribution histogram in the first embodiment of the present invention;

[0060] Figure 8 is a mean distribution histogram in the first embodiment of the present invention;

[0061] Fig. 9 is a structural block diagram of a load spectrum compilation system in a second embodiment of the present invention;

[0062] Fig.10 It is a structural block diagram of a computer device in the third embodiment of the present invention.

[0063] Description of main component symbols:

[0064] Memory 10 Second processing module 13 processor 20 Analysis Module 14 Computer equipment programs 30 Evaluation Module 15 First processing module 11 Compilation module 16 Bench calibration module 12

[0065] The following specific implementation manner will further illustrate the present invention in conjunction with the above-mentioned drawings. DETAILED DESCRIPTION

[0066] In order to facilitate the understanding of the present invention, the present invention will be described more fully below with reference to the relevant drawings. Several embodiments of the present invention are given in the drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present invention more thorough and comprehensive.

[0067] It should be noted that when an element is referred to as being "fixed to" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only.

[0068] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0069] Embodiment 1

[0070] See also Figure 1 , which shows a method for compiling a load spectrum in a first embodiment of the present invention, and is applied to a stabilizer bar of a vehicle to be tested. The method for compiling a load spectrum specifically includes steps S101 to S106:

[0071] S101, obtaining stress cloud diagrams of a finite element model of the stabilizer bar under various working conditions, and determining the position of a strain measuring point of the stabilizer bar according to hot spot positions in the stress cloud diagram and position information of the stabilizer bar when failure occurs in a road test;

[0072] In the specific implementation, a finite element model of the stabilizer bar of the vehicle to be tested is established. When establishing the finite element model, the stabilizer bar can be first scanned as a whole, and the geometric model of the stabilizer bar can be pre-constructed based on the material of the stabilizer bar and the connection relationship between the stabilizer bar and other components as input conditions. The model is processed using finite element processing software to obtain the corresponding finite element model. It should also be added that the pre-processing software for modeling can use Hypermesh or ANSA for modeling.

[0073] It can be understood that in other embodiments, the finite element model can also be established by directly scanning the stabilizer bar or importing data through the finite element model.

[0074] After establishing the finite element model of the stabilizer bar, it is combined with the finite element (strength) analysis under typical working conditions to obtain the stress cloud map under the corresponding working conditions. Among them, the stabilizer bar is mainly subjected to torsion. The typical working condition generally refers to the forced displacement applied at both ends. First, the finite element analysis model is established, and then the finite element analysis is performed to obtain the stress distribution cloud map of the stabilizer bar, in which the stress concentration position is the hot spot.

[0075] The fracture position information of the stabilizer bar during the road test, i.e., the position information when the stabilizer bar fails during the road test, is obtained, and compared with the stress cloud map under the corresponding working condition obtained above, and the strain test area of ​​the stabilizer bar, i.e., the strain measurement point position, is determined according to the hot spot position in the stress cloud map. This step compares the stress concentration position with the road test failure position to determine the stress measurement point position, with the purpose of finding the position with high stress for bench calibration and road load spectrum collection.

[0076] See also Figure 2 In other embodiments, before step S102, the method further includes steps S201 to S202:

[0077] S201, determining the type of strain gauge at the strain measuring point position according to the type of load on the stabilizer bar;

[0078] S202: Install corresponding strain gauges at the strain measuring point according to the strain gauge type.

[0079] In the specific implementation, the load type of the load force on the stabilizer bar is analyzed, and then the type of strain gauge that needs to be installed at the strain measurement point is determined. Among them, strain gauges are mainly divided into single-piece, strain rosette and shear strain gauges, etc., to test different types of strain. It is necessary to determine whether the load on the part is compression or torsion. The stabilizer bar mainly bears torsional shear force. In this embodiment, a shear strain gauge is used.

[0080] The strain gauge of the strain gauge type obtained above is installed at the strain measuring point to facilitate the subsequent bench calibration test.

[0081] S102, performing component bench calibration on the stabilizer bar to obtain a corresponding calibration curve, and performing linearity verification on the calibration curve;

[0082] For further information, see Figure 3 In step S102, the stabilizer bar is calibrated on a component bench to obtain a corresponding calibration curve, which includes steps S1021 to S1022:

[0083] S1021, fixing a stabilizing bar equipped with a strain gauge on a test bench, applying a load to the stabilizing bar equipped with the strain gauge by using an actuator cylinder at a preset time, and collecting a displacement signal of the actuator cylinder and a strain signal on the stabilizing bar equipped with the strain gauge according to a preset number of times;

[0084] S1022: Perform linear fitting on the collected multiple displacement signals and the strain signals to obtain a corresponding calibration curve.

[0085] In specific implementation, the purpose of bench calibration is to obtain the linear relationship between the bench actuator and the part strain (y=kx+b). The test method is similar to the static bench calibration. First, the strain gauge obtained above is pasted on the stabilizer bar, and the stabilizer bar with the strain gauge installed is fixed on the test bench. The actuator is used to apply a load to the stabilizer bar for a certain period of time (in this embodiment, it is applied from position 0 to position 40mm in 5s), and the displacement signal (X) of the actuator and the strain signal (Y) on the stabilizer bar are collected at the same time. Generally, the data is collected three times, and the collected measurement points are linearly fitted respectively. When the fitting linearity is good, the three changes of k are not greater than 0.01, and the changes of b are not greater than 0.01, then the linear fitting is OK, and the dynamic calibration curve is obtained.

[0086] S103, if the linearity verification of the calibration curve passes, the stabilizer bar and the wheel center acceleration sensor are installed on the vehicle to be tested to perform a road test, and a first strain load spectrum of the strain measuring point position and a wheel center acceleration load spectrum of the vehicle to be tested are collected according to a road test specification of the road test;

[0087] In a specific implementation, if the linearity verification of the above-mentioned calibration curve is passed, the stabilizer bar and the wheel center acceleration sensor are installed on the vehicle to be tested for a road test, and the first strain load spectrum of the strain measuring point position and the wheel center acceleration load spectrum of the vehicle to be tested are collected according to the road test specifications of the road test.

[0088] S104, performing a multi-body dynamics analysis on the vehicle to be tested to obtain a hard point load spectrum of the stabilizer bar, and obtaining a second strain load spectrum at the strain measuring point position according to a virtual test of the stabilizer bar;

[0089] In the specific implementation, a corresponding multi-body dynamics model is established according to the whole vehicle information of the vehicle to be tested, and a multi-body dynamics analysis is performed on the multi-body dynamics model, and the hard point load spectrum of the stabilizer bar installed on the vehicle to be tested (the load spectrum of the stabilizer bar connection point) is extracted, a virtual test is performed on the stabilizer bar, and the second strain load spectrum of the above-mentioned strain measurement point position is extracted.

[0090] It can be understood that multi-body dynamics is the study of the motion laws of multi-body systems (generally composed of several flexible and rigid objects connected to each other), and is usually modeled and analyzed using ADAMS.

[0091] S105, evaluating the damage strength of the stabilizer bar according to the first strain load spectrum and the wheel center acceleration load spectrum and the hard point load spectrum and the second strain load spectrum, and determining whether the damage strength evaluated by the first strain load spectrum and the wheel center acceleration load spectrum is consistent with the damage strength evaluated by the hard point load spectrum and the second strain load spectrum;

[0092] See also Figure 4 , the step S105 specifically includes steps S1051 to S1053:

[0093] S1051, preprocessing the first strain load spectrum and the wheel center acceleration load spectrum to remove invalid signals in the first strain load spectrum and the wheel center acceleration load spectrum;

[0094] S1052, simplifying the preprocessed first strain load spectrum and wheel center acceleration load spectrum into a plurality of load cycles consisting of load amplitudes and load means;

[0095] S1053: Calculate the first strain load spectrum and the wheel center acceleration load spectrum using the load cycle to evaluate the damage strength of the stabilizer bar.

[0096] In specific implementation, the first strain load spectrum and the wheel center acceleration load spectrum are preprocessed, that is, the load spectrum is filtered and the connecting road surface signals between the deburring and shearing characteristic road surfaces are removed, in order to delete invalid signals in the load spectrum.

[0097] The pre-processed first strain load spectrum and wheel center acceleration load spectrum are simplified into a number of load cycles consisting of load amplitudes and averages, the purpose of which is to calculate fatigue life and compile load spectra. In this application, the rain flow statistics method is adopted, and its counting principle is applicable to the stress-strain behavior of metal parts under cyclic load conditions (such as Figure 5 As shown in the figure, using this method, you first need to draw the time axis of the load spectrum downward, imagining it as a series of pagoda-shaped roofs. The rain flow starts to flow down from the inside (of the roof) and can continue to flow downward. The load cycle is determined based on the trajectory of the rain flow.

[0098] The implementation of rainflow counting in the program is divided into two steps: data compression and cycle number extraction:

[0099] (1) Data compression

[0100] The peak and trough value detection is used to compress the data and delete invalid payloads. Then the original payload data is counted to calculate the number of peak and trough cycles in the payload data. This process is called data compression.

[0101] The peak and trough loads are extracted, and the equivalent data between adjacent loads are compressed at the same time. In addition, since the acquired dynamic load data contains many tiny loads that do not cause damage to the parts, that is, invalid amplitudes, in order to reduce the counting workload, these invalid loads need to be deleted before load counting.

[0102] (2) Extracting the Rainflow Count Cycle

[0103] The process of rainflow counting of load spectrum is roughly divided into two steps: the first step is to count the first rainflow of load spectrum, and then dock the load spectrum; the simplified step of retaining or removing the first and last points of the load spectrum is called docking. The load spectrum obtained after the first rainflow counting belongs to a standard divergent-convergent load spectrum, which makes the counting method unable to cycle. This method is to cut at the maximum or minimum load spectrum position, and then connect the first and last points. If these two points are not exactly closed, they can be processed according to the waveform selection; the second step is to count the second rainflow of load spectrum and extract all load cycles. The purpose of the second rainflow counting of load spectrum is to extract the load cycle again from the adjusted load spectrum until a complete cycle consisting of three maximum points is left. .

[0104] Furthermore, the first strain load spectrum and the wheel center acceleration load spectrum are calculated by the load cycle to evaluate the damage strength of the stabilizer bar. The process of gradual accumulation of damage and gradual consumption of life of the material under cyclic load loading conditions is usually called fatigue failure of the part. When the accumulated damage of the part in a certain area reaches the inherent life of the material, the part will suffer fatigue failure. According to the linear fatigue cumulative damage theory, when fatigue failure occurs,

[0105]

[0106] Where D i represents the damage caused under the i-th level stress condition; n i represents the rain flow statistics under the i-th level stress; N i Represents the life of the part under the i-th level stress condition.

[0107] In engineering practice, since the real fatigue life curve (SN curve) of parts is affected by the material, the design structure and manufacturing process of the parts will affect the SN curve, so when evaluating the damage caused by the accumulation of cyclic loads on parts, fatigue pseudo-damage is often used as the evaluation standard. If the SN curve of the material is unknown, it is usually based on experience to select a SN curve corresponding to a material that is relatively close to the material of the part as a substitute. This method can retain the damage caused by cyclic loads to the material as completely as possible.

[0108] The fatigue pseudo damage calculation formula can be obtained from the fatigue linear cumulative damage theory:

[0109] S m N = c;

[0110] Among them, m represents a constant determined according to stress properties and materials; c represents a constant determined by known conditions.

[0111] The actual load stress is divided into l levels, and the corresponding generalized stress cycle rain flow matrix of a certain channel is:

[0112] N=[N1 N2…N i ] T ;

[0113] The corresponding generalized stress cycle rain flow matrix is:

[0114]

[0115] The total fatigue pseudo damage caused under fatigue load conditions is:

[0116]

[0117] S106: If the damage intensity evaluated by the first strain load spectrum and the wheel center acceleration load spectrum is consistent with the damage intensity evaluated by the hard point load spectrum and the second strain load spectrum, the first strain load spectrum, the wheel center acceleration load spectrum, the hard point load spectrum and the second strain load spectrum are edited and processed, and a multi-level program load spectrum of the stabilizer bar is compiled in combination with the calibration curve.

[0118] See also Figure 6 , the step S106 specifically includes steps S1061 to S1064:

[0119] S1061, gradually performing load spectrum mathematical statistics and load spectrum extrapolation on the first strain load spectrum, the wheel center acceleration load spectrum, the hard point load spectrum, and the second strain load spectrum;

[0120] S1062, after the load spectrum extrapolation is completed, a corresponding two-dimensional damage matrix is ​​established according to the load spectrum damage statistics;

[0121] S1063, establishing a corresponding one-dimensional damage matrix using a load-stress function, the first strain load spectrum, the wheel center acceleration load spectrum, the hard point load spectrum, and the second strain load spectrum;

[0122] S1064: compile a multi-level program load spectrum for the stabilizer bar according to the two-dimensional damage matrix, the one-dimensional damage matrix, and the calibration curve.

[0123] In the specific implementation, the first strain load spectrum, the wheel center acceleration load spectrum, the hard point load spectrum and the second strain load spectrum are gradually subjected to load spectrum mathematical statistics and load spectrum extrapolation. Since the above-extracted load spectrum is only the load spectrum of one test cycle, there is randomness in the load spectrum of each cycle, and the extracted load spectrum cannot fully represent the characteristics of the entire cycle. In order to further analyze the statistical characteristics of the load spectrum, it is necessary to extrapolate the load spectrum.

[0124] Before the load spectrum is extrapolated, it is necessary to examine the distribution law of the load spectrum range and mean under the entire cycle condition. The method for analyzing the load spectrum distribution characteristics is usually to use statistical methods to analyze the counting results to obtain the load spectrum distribution law. A large number of engineering practices have proved that under random excitation, the loads borne by automobile chassis components show significant random distribution characteristics. In general, the range of the load spectrum is Weibull distribution and the mean is normal distribution.

[0125] The load range distribution is statistically analyzed to obtain the load range frequency cumulative distribution histogram and the load mean frequency cumulative distribution histogram, such as Figures 7 and 8 As shown in the figure, it can be seen that the load range obeys the Weibull function distribution, and the load mean is normally distributed, which conforms to the load distribution law.

[0126] Furthermore, the load data obtained by the whole vehicle virtual test will be affected by the modeling accuracy. Usually, the virtual test only extracts the load data of one cycle, and the sample obtained is small. The load amount contained in the statistical data obtained is quite different from the load amount required for the bench test, and it cannot fully simulate most of the loads in the real test field test. Load spectrum extrapolation is to make up for this deficiency, and select appropriate extrapolation models and tools to obtain the equivalent load that can represent the complete fatigue endurance test.

[0127] The key point of fatigue load spectrum compilation is to ensure that the compiled load spectrum retains the fatigue characteristics of the original load spectrum. Since the length of the load spectrum obtained in the above steps is too short, the statistical characteristics of the load spectrum cannot be fully expressed. In order to make the load spectrum more in line with the actual situation, the load frequency needs to be extrapolated before starting to compile the load spectrum. In this embodiment, a parameter extrapolation method is used to extrapolate the load spectrum. The distribution law of the population is estimated based on the sample, and then the limited sample data is expanded and extrapolated according to the distribution law of the population.

[0128] In this application, GlyphWorks software is used to perform pseudo-damage calculations using the stress-life analysis method. Dividing the load spectrum into 8 levels can fully reflect the fatigue characteristics of the structure, and the range is graded according to the ratio coefficients of 1.000, 0.950, 0.850, 0.725, 0.575, 0.425, 0.275, and 0.125, and the mean is graded at equal intervals. Combined with the calculated damage histograms under different load amplitudes, the damage results of the stress spectrum are statistically analyzed to obtain an 8x8 two-dimensional damage matrix;

[0129] Through the load-stress relationship obtained by the above-mentioned bench calibration, the load-stress function, the first strain load spectrum, the wheel center acceleration load spectrum, the hard point load spectrum and the second strain load spectrum are calculated to obtain the load values ​​corresponding to each level of stress range. The fatigue damage caused by the random load spectrum under different load levels can be well quantified through fatigue damage calculation. According to the fatigue damage equivalence principle, the conversion relationship between the random fatigue matrix and the program load damage matrix is ​​obtained, and the damage corresponding to each level of load is calculated by GlyphWorks software. The load frequency required to cause the total damage of each load level is calculated according to the fatigue damage equivalence principle, and the load is compressed by omitting the low-level load method. It can be seen from the damage accumulation theory that stress below 60% of the fatigue limit has almost no effect on the fatigue result. In this embodiment, conservative compression is performed to eliminate the first three levels of load. After eliminating the small load, the load spectrum retains 99.84% of the damage, and the length is reduced to 1 / 16 of the original load spectrum, with obvious acceleration effect. Finally, a load spectrum using a low-high-low loading sequence is obtained, that is, a multi-level program load spectrum.

[0130] In summary, the method for compiling the load spectrum in the above embodiment of the present invention is to determine the strain measuring point position of the stabilizer bar by using the cloud map and the failure position of the stabilizer bar in the road test, and to perform component bench calibration on the stabilizer bar to obtain a corresponding calibration curve, and to perform linear verification on the calibration curve. When the linear verification passes, the first strain load spectrum and the wheel center acceleration load spectrum of the strain measuring point position are collected through the road test; the hard point load spectrum of the stabilizer bar is obtained by performing a multi-body dynamics analysis on the vehicle to be tested, and the second strain load spectrum of the strain measuring point position is obtained by performing a virtual test on the stabilizer bar, and the consistency of the damage intensity evaluated by the load spectrum is judged.

[0131] Embodiment 2

[0132] Another aspect of the present invention is to provide a system for compiling load spectra. Fig. 9 , which is a load spectrum compilation system in a second embodiment of the present invention, and is applied to a stabilizer bar of a vehicle to be tested. The load spectrum compilation system includes:

[0133] A first processing module 11 is used to obtain stress cloud diagrams of the finite element model of the stabilizer bar under various working conditions, and determine the position of the strain measurement point of the stabilizer bar according to the hot spot position in the stress cloud diagram and the position information of the stabilizer bar when the stabilizer bar fails in the road test;

[0134] A bench calibration module 12 is used to perform component bench calibration on the stabilizer bar to obtain a corresponding calibration curve and perform linear verification on the calibration curve;

[0135] Furthermore, the bench calibration module 12 includes:

[0136] A processing unit, used for fixing a stabilizing bar equipped with a strain gauge on a test bench, applying a load to the stabilizing bar equipped with the strain gauge by using an actuator at a preset time, and collecting a displacement signal of the actuator and a strain signal on the stabilizing bar equipped with the strain gauge at a preset number of times;

[0137] The fitting unit is used to perform linear fitting on the collected multiple displacement signals and the strain signals to obtain a corresponding calibration curve.

[0138] The second processing module 13 is used for installing the stabilizer bar and the wheel center acceleration sensor on the vehicle to be tested to perform a road test if the linear verification of the calibration curve passes, and collecting the first strain load spectrum of the strain measuring point position and the wheel center acceleration load spectrum of the vehicle to be tested according to the road test specification of the road test;

[0139] The analysis module 14 is used to perform a multi-body dynamics analysis on the vehicle to be tested to obtain a hard point load spectrum of the stabilizer bar, and obtain a second strain load spectrum at the strain measuring point position according to a virtual test of the stabilizer bar;

[0140] an evaluation module 15, configured to evaluate the damage strength of the stabilizer bar according to the first strain load spectrum and the wheel center acceleration load spectrum and the hard point load spectrum and the second strain load spectrum, respectively, and determine whether the damage strength evaluated by the first strain load spectrum and the wheel center acceleration load spectrum is consistent with the damage strength evaluated by the hard point load spectrum and the second strain load spectrum;

[0141] Furthermore, the evaluation module 15 includes:

[0142] A preprocessing unit, used for preprocessing the first strain load spectrum and the wheel center acceleration load spectrum to remove invalid signals in the first strain load spectrum and the wheel center acceleration load spectrum;

[0143] A rain flow statistics unit is used to simplify the pre-processed first strain load spectrum and wheel center acceleration load spectrum into a load cycle consisting of a plurality of load amplitudes and load means;

[0144] A damage analysis unit is used to evaluate the damage intensity of the stabilizer bar by calculating the first strain load spectrum and the wheel center acceleration load spectrum using the load cycle.

[0145] The compilation module 16 is used to edit the first strain load spectrum, the wheel center acceleration load spectrum, the hard point load spectrum and the second strain load spectrum if the damage intensity evaluated by the first strain load spectrum and the wheel center acceleration load spectrum is consistent with the damage intensity evaluated by the hard point load spectrum and the second strain load spectrum, and compile a multi-level program load spectrum of the stabilizer bar in combination with the calibration curve.

[0146] Furthermore, the compilation module 16 includes:

[0147] A first processing unit is used to gradually perform load spectrum mathematical statistics and load spectrum extrapolation on the first strain load spectrum, the wheel center acceleration load spectrum, the hard point load spectrum and the second strain load spectrum;

[0148] The first creation unit is used to establish a corresponding two-dimensional damage matrix according to the load spectrum damage statistics after the load spectrum extrapolation is completed;

[0149] a second processing unit, configured to establish a corresponding one-dimensional damage matrix using a load-stress function, the first strain load spectrum, the wheel center acceleration load spectrum, the hard point load spectrum, and the second strain load spectrum;

[0150] The second creation unit is used to compile a multi-level program load spectrum of the stabilizer bar according to the two-dimensional damage matrix, the one-dimensional damage matrix and the calibration curve.

[0151] In other embodiments, the system further comprises:

[0152] A determination module, used to determine the type of strain gauge at the position of the strain measurement point according to the type of load on the stabilizer bar;

[0153] The third processing module is used to install the corresponding strain gauge at the strain measuring point according to the strain gauge type.

[0154] The functions or operation steps implemented when the above modules and units are executed are generally the same as those in the above method embodiments, and will not be repeated here.

[0155] The load spectrum compilation system provided in the embodiment of the present invention has the same implementation principle and technical effects as those of the aforementioned method embodiment. For the sake of brief description, for matters not mentioned in the system embodiment, reference may be made to the corresponding contents in the aforementioned method embodiment.

[0156] Embodiment 3

[0157] The present invention also provides a computer device, see Fig.10 , shown is a computer device in the third embodiment of the present invention, including a memory 10, a processor 20, and a computer device program 30 stored in the memory 10 and executable on the processor 20. When the processor 20 executes the computer device program 30, the above-mentioned method for compiling a load spectrum is implemented.

[0158] The memory 10 includes at least one type of readable storage medium, and the readable storage medium includes a flash memory, a hard disk, a multimedia card, a card-type memory (e.g., an SD or DX memory, etc.), a magnetic memory, a magnetic disk, an optical disk, etc. In some embodiments, the memory 10 may be an internal storage unit of a computer device, such as a hard disk of the computer device. In other embodiments, the memory 10 may also be an external storage device, such as a plug-in hard disk, a smart memory card (Smart Media Card, SMC), a secure digital (Secure Digital, SD) card, a flash card, etc. Further, the memory 10 may also include both an internal storage unit of a computer device and an external storage device. The memory 10 may be used not only to store application software and various types of data installed in the computer device, but also to temporarily store data that has been output or is to be output.

[0159] Among them, in some embodiments, the processor 20 can be an electronic control unit (Electronic Control Unit, abbreviated as ECU, also known as a vehicle computer), a central processing unit (Central Processing Unit, CPU), a controller, a microcontroller, a microprocessor or other data processing chip, used to run the program code stored in the memory 10 or process data, such as executing access restriction programs, etc.

[0160] It should be pointed out that Figure 8 The structure shown does not constitute a limitation on the computer device. In other embodiments, the computer device may include fewer or more components than shown in the figure, or combine certain components, or arrange the components differently.

[0161] The embodiment of the present invention further provides a readable storage medium on which a computer device program is stored. When the program is executed by a processor, the method for compiling a load spectrum as described above is implemented.

[0162] Those skilled in the art will appreciate that the logic and / or steps represented in the flowchart or otherwise described herein, for example, may be considered as an ordered list of executable instructions for implementing logical functions, and may be specifically implemented in any computer device readable medium for use by an instruction execution system, apparatus or device (such as a computer device-based system, a system including a processor, or other system that can fetch instructions from an instruction execution system, apparatus or device and execute instructions), or in conjunction with such instruction execution systems, apparatuses or devices. For purposes of this specification, "computer device readable medium" may be any device that can contain, store, communicate, propagate or transmit a program for use by an instruction execution system, apparatus or device, or in conjunction with such instruction execution systems, apparatuses or devices.

[0163] More specific examples of computer device readable media (a non-exhaustive list) include the following: an electrical connection with one or more wirings (electronic device), a portable computer device disk case (magnetic device), a random access memory (RAM), a read-only memory (ROM), an erasable and editable read-only memory (EPROM or flash memory), an optical fiber device, and a portable compact disk read-only memory (CDROM). In addition, the computer device readable medium may even be a paper or other suitable medium on which the program is printed, since the program may be obtained electronically, for example, by optically scanning the paper or other medium, followed by editing, deciphering or processing in another suitable manner as necessary, and then stored in a computer device memory.

[0164] It should be understood that the various parts of the present invention can be implemented by hardware, software, firmware or a combination thereof. In the above-mentioned embodiments, a plurality of steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, it can be implemented by any one of the following technologies known in the art or a combination thereof: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0165] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0166] The above-mentioned embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application shall be subject to the attached claims.

Claims

1. A method for compiling a load spectrum, applied to a stabilizer bar of a vehicle to be tested, characterized in that: The method for compiling the load spectrum includes: Obtaining stress cloud diagrams of the finite element model of the stabilizer bar under various working conditions, and determining the position of the strain measuring point of the stabilizer bar according to the hot spot position in the stress cloud diagram and the position information of the stabilizer bar when failure occurs in the road test; Performing component bench calibration on the stabilizer bar to obtain a corresponding calibration curve, and performing linearity verification on the calibration curve; If the linearity verification of the calibration curve passes, the stabilizer bar and the wheel center acceleration sensor are installed on the vehicle to be tested to perform a road test, and the first strain load spectrum of the strain measuring point position and the wheel center acceleration load spectrum of the vehicle to be tested are collected according to the road test specification of the road test; Performing a multi-body dynamics analysis on the vehicle to be tested to obtain a hard point load spectrum of the stabilizer bar, and obtaining a second strain load spectrum at the strain measuring point position according to a virtual test of the stabilizer bar; evaluating the damage strength of the stabilizer bar according to the first strain load spectrum and the wheel center acceleration load spectrum and the hard point load spectrum and the second strain load spectrum, respectively, and determining whether the damage strength evaluated by the first strain load spectrum and the wheel center acceleration load spectrum is consistent with the damage strength evaluated by the hard point load spectrum and the second strain load spectrum; If the damage intensity evaluated by the first strain load spectrum and the wheel center acceleration load spectrum is consistent with the damage intensity evaluated by the hard point load spectrum and the second strain load spectrum, the first strain load spectrum, the wheel center acceleration load spectrum, the hard point load spectrum and the second strain load spectrum are edited and processed, and the multi-level program load spectrum of the stabilizer bar is compiled in combination with the calibration curve.

2. The method for compiling a load spectrum according to claim 1, characterized in that: Before the step of performing component bench calibration on the stabilizer bar, the method further comprises: Determining the type of strain gauge at the position of the strain measuring point according to the type of load on the stabilizer bar; Install corresponding strain gauges at the strain measuring point according to the strain gauge type.

3. The method for compiling a load spectrum according to claim 2, characterized in that: The step of performing component bench calibration on the stabilizer bar to obtain a corresponding calibration curve comprises: Fixing a stabilizing rod equipped with a strain gauge on a test bench, applying a load to the stabilizing rod equipped with the strain gauge by using an actuator cylinder at a preset time, and collecting a displacement signal of the actuator cylinder and a strain signal on the stabilizing rod equipped with the strain gauge at a preset number of times; The collected multiple displacement signals and strain signals are linearly fitted to obtain a corresponding calibration curve.

4. The method for compiling a load spectrum according to claim 1, characterized in that: The step of respectively evaluating the damage strength of the stabilizer bar according to the first strain load spectrum and the wheel center acceleration load spectrum and the hard point load spectrum and the second strain load spectrum comprises: Preprocessing the first strain load spectrum and the wheel center acceleration load spectrum to remove invalid signals in the first strain load spectrum and the wheel center acceleration load spectrum; The preprocessed first strain load spectrum and wheel center acceleration load spectrum are simplified into a number of load cycles consisting of load amplitudes and load means; The first strain load spectrum and the wheel center acceleration load spectrum are calculated by using the load cycle to evaluate the damage strength of the stabilizer bar.

5. The method for compiling a load spectrum according to claim 1, characterized in that: The steps of editing the first strain load spectrum, the wheel center acceleration load spectrum, the hard point load spectrum and the second strain load spectrum, and compiling a multi-level program load spectrum of the stabilizer bar in combination with the calibration curve include: Stepwise performing load spectrum mathematical statistics and load spectrum extrapolation on the first strain load spectrum, the wheel center acceleration load spectrum, the hard point load spectrum and the second strain load spectrum; After the load spectrum extrapolation is completed, the corresponding two-dimensional damage matrix is ​​established according to the load spectrum damage statistics; Establishing a corresponding one-dimensional damage matrix using a load stress function, the first strain load spectrum, the wheel center acceleration load spectrum, the hard point load spectrum, and the second strain load spectrum; A multi-level programmed load spectrum of the stabilizer bar is compiled according to the two-dimensional damage matrix, the one-dimensional damage matrix and the calibration curve.

6. A load spectrum compilation system, applied to the stabilizer bar of a vehicle to be tested, characterized in that: The load spectrum compilation system comprises: a first processing module, for obtaining stress cloud diagrams of the finite element model of the stabilizer bar under various working conditions, and determining the position of the strain measuring point of the stabilizer bar according to the hot spot position in the stress cloud diagram and the position information of the stabilizer bar when failure occurs in the road test; A bench calibration module, used for performing a component bench calibration on the stabilizer bar to obtain a corresponding calibration curve, and performing a linear verification on the calibration curve; a second processing module, configured to install the stabilizer bar and the wheel center acceleration sensor on the vehicle to be tested to perform a road test if the linear verification of the calibration curve passes, and collect a first strain load spectrum of the strain measuring point position and a wheel center acceleration load spectrum of the vehicle to be tested according to a road test specification of the road test; An analysis module, used for performing a multi-body dynamics analysis on the vehicle to be tested to obtain a hard point load spectrum of the stabilizer bar, and obtaining a second strain load spectrum at the strain measuring point position according to a virtual test of the stabilizer bar; an evaluation module, configured to evaluate the damage strength of the stabilizer bar according to the first strain load spectrum and the wheel center acceleration load spectrum and the hard point load spectrum and the second strain load spectrum, respectively, and determine whether the damage strength evaluated by the first strain load spectrum and the wheel center acceleration load spectrum is consistent with the damage strength evaluated by the hard point load spectrum and the second strain load spectrum; A compilation module is used to edit the first strain load spectrum, the wheel center acceleration load spectrum, the hard point load spectrum and the second strain load spectrum if the damage intensity evaluated by the first strain load spectrum and the wheel center acceleration load spectrum is consistent with the damage intensity evaluated by the hard point load spectrum and the second strain load spectrum, and compile a multi-level program load spectrum of the stabilizer bar in combination with the calibration curve.

7. The load spectrum compilation system according to claim 6, characterized in that: The system further comprises: A determination module, used to determine the type of strain gauge at the position of the strain measurement point according to the type of load on the stabilizer bar; The third processing module is used to install the corresponding strain gauge at the strain measuring point according to the strain gauge type.

8. The load spectrum compilation system according to claim 7, characterized in that: The bench calibration module comprises: A processing unit, used for fixing a stabilizing bar equipped with a strain gauge on a test bench, applying a load to the stabilizing bar equipped with the strain gauge by using an actuator at a preset time, and collecting a displacement signal of the actuator and a strain signal on the stabilizing bar equipped with the strain gauge at a preset number of times; The fitting unit is used to perform linear fitting on the collected multiple displacement signals and the strain signals to obtain a corresponding calibration curve.

9. A readable storage medium having a computer device program stored thereon, characterized in that: When the program is executed by a processor, the method for compiling a load spectrum as described in any one of claims 1 to 5 is implemented.

10. A computer device comprising a memory, a processor, and a computer device program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer device program, the load spectrum compilation method according to any one of claims 1 to 5 is implemented.

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