Load spectrum processing method, device, equipment and storage medium

Abstract

The application provides a load spectrum processing method, device, equipment and storage medium, the method comprises the following steps: collecting the load spectrum of an automobile part, and performing cycle statistics, grade counting and other processing on the time domain load in the load spectrum to generate a preliminary equivalent load block spectrum; then, the pseudo damage values of the load spectrum and the preliminary equivalent load block spectrum are calculated respectively, and the preliminary equivalent load block spectrum is corrected according to the pseudo damage values to obtain an equivalent load block spectrum. When the random load spectrum is converted into the equivalent load block spectrum, the technical scheme of the application considers the influence of the load average value and the maximum value, and the phase relationship between multiple loads, improves the equivalence of the equivalent load of the automobile part durability test loading, and improves the accuracy of the durability test result at the same time; the fatigue durability test process of the automobile part is simplified, and the time cost is saved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of automobile durability test, and in particular to a load spectrum processing method, device, equipment and storage medium. BACKGROUND

[0002] In order to verify the fatigue performance of automobile structural parts, it is necessary to carry out part fatigue durability test in the development process, and it is also necessary to assemble the parts on a sample vehicle for test field road test. In the process of part fatigue durability test, the accuracy of input load directly affects the effectiveness of the test. Therefore, it is necessary to convert the random load spectrum into a block spectrum composed of several sinusoidal wave load spectrums for loading, because the block spectrum has the characteristics of simple loading and short test time; this process of converting random spectrum into block spectrum by some method is called load equivalence.

[0003] However, in the conversion process of converting random load spectrum into block spectrum in the above-mentioned prior art, there is a problem of not considering the influence of the average value, thereby ignoring the influence of the maximum load, but the damage caused by the maximum load is the largest; or in the case of processing multiple loadings at the same time, the phase relationship of multiple loads is not considered, thereby affecting the equivalence of the equivalent load input in the durability test, and reducing the accuracy of the durability test result. SUMMARY

[0004] Therefore, the purpose of the present application is to overcome the deficiencies in the prior art, and to provide a load spectrum processing method, device, equipment and storage medium.

[0005] In a first aspect, the present application provides a load spectrum processing method, which comprises:

[0006] Collecting the load spectrum of the parts in the automobile, wherein the load spectrum contains multiple groups of time domain loads;

[0007] Using the four-point method to perform cycle statistics on the time domain loads to obtain the load range amplitude and the cycle number;

[0008] Performing grade counting on the time domain loads to obtain the average value of the equivalent load corresponding to the time domain loads, and determining a preliminary equivalent load block spectrum according to the load range amplitude, the cycle number and the average value;

[0009] Correcting the preliminary equivalent load block spectrum to obtain an equivalent load block spectrum.

[0010] In an embodiment, the load spectrum includes a single direction load spectrum and a multi-direction load spectrum.

[0011] In an embodiment, before the four-point method is used to perform cycle statistics on the time domain loads to obtain the load range amplitude and the cycle number, it further comprises:

[0012] obtaining a first load value of the time-domain load at a time point, and a second load value and a third load value corresponding to a previous time point and a subsequent time point of the time point;

[0013] if an increasing or decreasing relationship is formed between the first load value, the second load value and the third load value, deleting the first load value.

[0014] In an embodiment, when the load spectrum is a single-direction load spectrum, the cyclic statistics of the time-domain load by the four-point method to obtain the load range amplitude and the cycle number comprises:

[0015] determining the cyclic composition of each group of the time-domain load by the four-point method, wherein each cycle in the cyclic composition contains two load data points in the time-domain load;

[0016] calculating the difference between the load values of the load data points constituting each cycle in the cyclic composition, and taking the difference as the load range amplitude of each group of the time-domain load;

[0017] accumulatively counting the cyclic composition according to the load range amplitude to obtain the cycle number.

[0018] In an embodiment, the modification of the preliminary equivalent load block spectrum to obtain the equivalent load block spectrum comprises:

[0019] calculating a first pseudo-damage value of the load spectrum and a second pseudo-damage value of the preliminary equivalent load block spectrum by a preset pseudo-damage calculation formula;

[0020] comparing the first pseudo-damage value and the second pseudo-damage value to obtain a comparison result;

[0021] adjusting the equivalent load block spectrum according to the comparison result to obtain the equivalent load block spectrum.

[0022] In an embodiment, when the load spectrum is a multi-direction load spectrum, the cyclic statistics of the time-domain load by the four-point method to obtain the load range amplitude and the cycle number comprises:

[0023] calculating a synthesis coefficient of each time-domain load in the multi-direction load spectrum according to a preset synthesis coefficient calculation formula;

[0024] calculating a first synthesis load corresponding to each group of the time-domain load according to the synthesis coefficient;

[0025] determining the cyclic composition of each group of the first synthesis load by the four-point method;

[0026] According to the cycle composition, a load range amplitude of an equivalent load corresponding to the time-domain load of each direction in the multi-direction load spectrum and a cycle number are calculated.

[0027] In an embodiment, the modifying the preliminary equivalent load block spectrum to obtain an equivalent load block spectrum comprises:

[0028] adjusting a phase relationship between the equivalent loads corresponding to the time-domain loads of each direction, and calculating a second synthetic load corresponding to the equivalent loads according to the phase relationship and the synthesis coefficient;

[0029] According to the pseudo-damage calculation formula, a third pseudo-damage value of the first synthetic load and a fourth pseudo-damage value of the second synthetic load are calculated;

[0030] According to the phase relationship, the third pseudo-damage value and the fourth pseudo-damage value, the preliminary equivalent load block spectrum is adjusted to generate an equivalent load block spectrum with a phase relationship.

[0031] In a second aspect, the present application provides a load spectrum processing device, the device comprising:

[0032] The acquisition module is configured to acquire a load spectrum of a part in a vehicle, wherein the load spectrum comprises a plurality of groups of time-domain loads.

[0033] The statistical module is configured to perform cycle statistics on the time-domain loads by using a four-point method to obtain a load range amplitude and a cycle number.

[0034] The determination module is configured to perform grade-by-grade counting on the time-domain loads to obtain an average value of equivalent loads corresponding to the time-domain loads, and determine a preliminary equivalent load block spectrum according to the load range amplitude, the cycle number and the average value.

[0035] The modification module is configured to modify the preliminary equivalent load block spectrum to obtain an equivalent load block spectrum.

[0036] In a third aspect, the present application provides a load spectrum processing device, which comprises a memory and at least one processor, the memory stores a computer program, and the processor is configured to execute the computer program to implement the load spectrum processing method described above.

[0037] In a fourth aspect, the present application provides a computer readable storage medium, which stores a computer program, and the computer program is executed to implement the load spectrum processing method described above.

[0038] Embodiments of the present application have the following advantages:

[0039] The technical scheme of the present application generates a preliminary equivalent load block spectrum through cyclic statistics and grade-counting of the time-domain load in the load spectrum, and then calculates the pseudo-damage values of the load spectrum and the preliminary equivalent load block spectrum respectively, and corrects the preliminary equivalent load block spectrum to obtain the equivalent load block spectrum; and for the multi-directional load, the technical scheme of the present application further determines the phase relationship of the equivalent load in each direction by comparing the pseudo-damage distribution of the combined load of the time-domain load and the combined load of the equivalent load, so as to convert the random load spectrum into the equivalent load block spectrum, improve the equivalence of the equivalent load in the durability test loading of the automobile parts, and improve the accuracy of the durability test result; simplify the process of the fatigue durability test of the automobile parts, and save the time cost.

[0040] In order to make the above object, features and advantages of the present application more obvious and easy to understand, the following preferred embodiments are described in detail below, and the accompanying drawings are described as follows. BRIEF DESCRIPTION OF DRAWINGS

[0041] In order to more clearly illustrate the technical scheme of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments, and it should be understood that the following drawings only show some embodiments of the present application, and therefore should not be regarded as a limitation to the scope, and for those skilled in the art, other related drawings can also be obtained without creative labor on the basis of these drawings.

[0042] Figure 1 A schematic diagram of one embodiment of the load spectrum processing method in the embodiments of the present application;

[0043] Figure 2 A cycle accumulation result diagram of the time-domain load in a single direction in the embodiments of the present application;

[0044] Figure 3 A grade-counting result diagram of the time-domain load in the embodiments of the present application;

[0045] Figure 4 A schematic diagram of another embodiment of the load spectrum processing method in the embodiments of the present application;

[0046] Figure 5 A cycle accumulation result diagram of load 1 in the embodiments of the present application;

[0047] Figure 6 A cycle accumulation result diagram of load 2 in the embodiments of the present application;

[0048] Figure 7 A grade-counting result diagram of load 1 in the embodiments of the present application;

[0049] Figure 8 A grade-counting result diagram of load 2 in the embodiments of the present application;

[0050] Figure 9 Fig. 2 is a schematic diagram of pseudo-damage values of all synthesized loads in the time domain load A in an embodiment of the present application;

[0051] Figure 10 Fig. 3 is a schematic diagram of pseudo-damage values of synthesized loads in each channel when the phase difference of two equivalent loads is 150 degrees in an embodiment of the present application;

[0052] Figure 11 Fig. 4 is a schematic diagram of an embodiment of the load spectrum processing device in the present application. DETAILED DESCRIPTION

[0053] Embodiments of the present application are described in detail below with reference to the attached drawings. The embodiments of the present application described below are examples for explaining the present application and should not be construed as limiting the present application.

[0054] It should be noted that when an element is referred to as being "on" another element, it can be directly on the other element or intervening elements can also be present. In contrast, when an element is referred to as being "directly on" another element, there are no intervening elements present. Like reference numerals refer to like elements throughout the specification.

[0055] In the present application, unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connecting", "fixing" and the like should be understood in a broad sense, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above-mentioned terms in the present application can be understood according to the specific circumstances.

[0056] In addition, the terms "first", "second" are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "multiple" is two or more, unless otherwise explicitly specified and limited.

[0057] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description of the templates herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the present application. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0058] Embodiment 1

[0059] Please refer to Figure 1 The present embodiment proposes a load spectrum processing method, and the equivalent load block spectrum method will be described in detail below.

[0060] 101, collect a plurality of groups of time-domain loads of parts in the automobile;

[0061] In order to verify the fatigue performance of the automobile structure, it is necessary to carry out part fatigue durability test in the development process, and it is also necessary to assemble the parts on the sample vehicle for test field road test. In the process of part fatigue durability test, the accuracy of the input load directly affects the effectiveness of the test. In the initial development stage of the part, the main sources of input load include: experience load, load virtual extraction under standard working condition or virtual road load extraction. After the sample vehicle is assembled, the input load is derived from the test field load spectrum collection. Some simple structure parts can directly obtain accurate load through calibration, and some parts which are not convenient to collect load can also extract the load of the parts through the multi-body dynamics model simulation of the sample vehicle.

[0062] After obtaining the load spectrum at the loading point of the part on the automobile, the load spectrum can be processed and converted into a sinusoidal waveform load. In general, the load spectrum collected or extracted in the automobile durability test contains a plurality of groups of time-domain load data, and each group of load needs to be loaded a certain number of times during the test. Each group of time-domain load is composed of a series of (multi-channel) time interval value points representing load size. Each channel represents the load in different directions or the load at different loading points. After obtaining the load spectrum at the loading point of the part on the automobile, the load spectrum can be processed and converted into a sinusoidal waveform load.

[0063] The parts in the automobile can be subjected to single direction load or multi-direction load, that is, the collected load spectrum of the parts in the automobile includes single direction load spectrum and multi-direction load spectrum. The following will take the single direction load spectrum as an example to describe the technical scheme.

[0064] 102, using four-point method to cyclically count the time-domain load, to obtain the load range amplitude and the cycle number;

[0065] Before the four-point method is used to cyclically count the time-domain load, a first load value at a time point of the time-domain load, and second and third load values at time points adjacent to the time point need to be obtained; and whether the first load value, the second load value and the third load value form an increasing or decreasing relationship is judged; if the first load value, the second load value and the third load value form an increasing or decreasing relationship, the first load value is deleted. That is, the data points other than the inflection points in each group of time-domain loads are removed, and only the inflection points are retained. If the load value of the time-domain load at a time point is greater than or less than the load values at the time points before and after the time point, the load value at the time point is an inflection point and needs to be retained.

[0066] The time-domain load from which the non-inflection points are removed is divided into two sections from the point of the maximum absolute value, and then the first section is connected to the end of the second section. This processing ignores the time sequence of the time-domain load, but is used as equivalent processing and can simplify the cycle recognition program. Then the four-point method is used to cyclically count the time-domain load, that is, to recognize the load cycle, and the recognition method is as follows:

[0067] (1) Four load data points in the time-domain load are determined in turn, for example, S i , S i+1 , S i+2 and S i+3 . If min(S i , S i+3 )≤min(S i+1 , S i+2 ) and max(S i , S i+3 )≥max(S i+1 , S i+2 ), it is considered that S i+1 to S i+2 form a cycle, the cycle is recorded, and S i+1 and S i+2 are removed from the sequence of the time-domain load.

[0068] (2) After the data points S i+1 and S i+2 are removed, whether there is a data point before S i is judged. If there is only one data point S k , the data point S k is recombined with S i , S i+3 and S i+4 to form four points, and the method in (1) is used for recognition. After the data points S i+1 and S i+2 are removed, if S iIf there is more than one data point remaining, then the one closest to S will be selected. i Two data points S m S k With S i S i+3 Reassemble the four points and identify them using the method from the previous step.

[0069] (3) If S i S i+1 S i+2 and S i+3 If the conditions in (1) above are not met, then S will be... i+1 S i+2 S i+3 and S i+4 Combine them into four points and perform cyclic recognition.

[0070] After performing cyclic identification of time-domain loads using the four-point method, the cyclic composition of each group of time-domain loads can be determined, wherein each cycle in the cyclic composition contains two load data points in the time-domain load.

[0071] Furthermore, after obtaining the cyclic composition of the time-domain load, the equivalent load corresponding to the time-domain load can be calculated based on the cyclic composition. The difference between the two load data points constituting each cycle is taken as the amplitude of the first load range, where the amplitude of the first load range is the first load range. Each group of time-domain loads is processed sequentially, and then the cyclic compositions identified from each group of time-domain loads are cumulatively counted from largest to smallest according to the first load range. At the same time, the number of times each group of time-domain loads is loaded is considered (each group of time-domain loads must be loaded repeatedly a certain number of times, where the number of loading times can be preset) to obtain the cumulative number of cycles. This cumulative number of cycles is taken as the first number of cycles, resulting in a curve of load range - cumulative number of cycles (cyclic cumulative result graph).

[0072] The load range versus cumulative cycle count curve is divided into several segments based on the cumulative cycle count, and the average value of the cyclic load range for each segment is estimated. This average value is taken as the load range of the equivalent load for the corresponding load segment, and the cumulative cycle count for each segment is taken as the cycle count of the equivalent load. The equivalent load range is taken as the second load range amplitude or the second load range, and the cycle count of the equivalent load is taken as the second cycle count.

[0073] like Figure 2 (The graph shows the cumulative results of cyclic loading in a single direction.) Based on the load range in the graph, the curve is divided into several segments. Here, we take five segments (only the first four segments are calculated) as an example, that is, the curve is segmented at the cumulative cycle counts of 100, 1000, 10000, and 100000 respectively. Then, based on the load range of each segment, the average load range is roughly determined. For example... Figure 2The load range corresponding to the horizontal straight line approximating the curve of the first four paragraphs represents the average load range of the paragraph, thereby determining the range of the equivalent load block spectrum and its corresponding cycle number, i.e., taking the average load range of each paragraph as the equivalent load range of the equivalent load block spectrum, and taking the cumulative cycle number corresponding to the average load range as the cycle number of the equivalent load, as shown in Table 1.

[0074] Table 1 Equivalent load range and cycle number

[0075] Serial number Equivalent load range (N) Cycle number (times) 1 23800 100 2 17500 900 3 9200 9000 4 5000 90000

[0076] 103, the step counting of the time domain load is performed, the average value of the equivalent load corresponding to the time domain load is obtained, and the preliminary equivalent load block spectrum is determined according to the load range amplitude, the cycle number and the average value;

[0077] After removing the load values of non-inflexion points, the step counting of the time domain load is performed. Based on the full range of load value distribution, the load value distribution is divided into a certain number of intervals, for example, the load value distribution is between-16000N and +13000N, and-16000N to +13000N is divided into an interval every 100N. When the load value of the time domain load rises from one interval to another, the cumulative count in the corresponding interval is increased by one, and only the number of times the time domain load passes through the interval during the increase of the load value is recorded. After counting each group of time domain loads required for loading in the durability test, the step counting results are combined and summarized, and the statistical results are shown in Figure 3 (step counting results of the time domain load).

[0078] According to the number of segments in the load range-cumulative cycle number curve, the step counting is segmented, and the average value of the load value of each segment of the time domain load is estimated, which is taken as the average value of the equivalent load of the segment. As shown in Figure 3 , the step counting results are segmented at 100 times, 1000 times, 10000 times and 100000 times, and the average value of each segment of the load is estimated, and the results are shown in Table 2.

[0079] Table 2 Equivalent load range, average value and cycle number

[0080] Serial number Equivalent load range (N) Average value (N) Cycle number (times) 1 23800 -1500 100 2 17500 0 900 3 9200 -1000 9000 4 5000 -1200 90000

[0081] The preliminary equivalent load block spectrum can be generated according to the second load range, the second cycle number and the average value of the equivalent load.

[0082] 104, the preliminary equivalent load block spectrum is corrected to obtain the equivalent load block spectrum;

[0083] The four-point method is used to cyclically identify the time-domain load, and the cyclic composition of the time-domain load can be obtained. According to a preset pseudo-damage value calculation formula, i.e., a fatigue damage linear accumulation hypothesis rule (Miner rule), a preliminary equivalent load block spectrum and a pseudo-damage value of the time-domain load spectrum (load spectrum) can be calculated, wherein the pseudo-damage value of the time-domain load spectrum is taken as a first pseudo-damage value, and the pseudo-damage value of the preliminary equivalent load block spectrum is taken as a second pseudo-damage value.

[0084] The pseudo-damage value calculation formula without considering the average value correction is as follows:

[0085] D i = n i × S i m / 10 7

[0086] wherein D i is the pseudo-damage of the load cycle i; n i is the cycle number of the load cycle i; S i is the amplitude of the load cycle i, and the value is equal to half of the load range amplitude (load range) of the load cycle i; and m is a parameter related to material properties, sample forms, stress ratios and loading methods, and for general metal parts in automobiles, m is recommended to be 3-7.

[0087] According to the pseudo-damage value calculation method, the pseudo-damage value calculation results of the equivalent load in Table 2 are shown in Table 3 (in the pseudo-damage value calculation process of Table 3, it is assumed that m is 5), i.e., the second pseudo-damage value is calculated according to the second load range and the second cycle number:

[0088] Table 3 Pseudo-damage value of equivalent load

[0089]

[0090] According to the pseudo-damage value calculation method, the pseudo-damage value of the load cycle of the time-domain load can also be calculated, i.e., the first pseudo-damage value is calculated according to the first cycle number and the first load range, and the cumulative cycle results of the time-domain load are shown in Table 4. Figure 2

[0091] Table 4 Pseudo-damage value of time-domain load

[0092]

[0093] ​The first pseudo-damage value of the time-domain load spectrum and the second pseudo-damage value of the preliminary equivalent load block spectrum are compared. If there is a large difference between the first pseudo-damage value and the second pseudo-damage value, that is, the difference between the first pseudo-damage value and the second pseudo-damage value is greater than a preset threshold value, the preliminary equivalent load block spectrum is corrected according to the first pseudo-damage value and the second pseudo-damage value to obtain an equivalent load block spectrum. The preset threshold value can be set according to actual conditions and is not limited here.

[0094] Further, when there is a large difference between the first pseudo-damage value and the second pseudo-damage value, the value of the equivalent load range of the equivalent load is continuously adjusted, that is, the value of the second load range is adjusted to obtain a third load range. According to the third load range and the second cycle number, a fifth pseudo-damage value of the preliminary equivalent load block spectrum is calculated. When the difference between the fifth pseudo-damage value and the first pseudo-damage value is less than the threshold value, the equivalent load block spectrum can be generated according to the third load range, the second cycle number, and the average value of the equivalent load.

[0095] According to the pseudo-damage value calculation results of the time-domain load (see Table 4) and the pseudo-damage value calculation results of the equivalent load (see Table 3), the equivalent load range with a larger pseudo-damage value difference is corrected. The corrected equivalent load block spectrum is shown in Table 5.

[0096] Table 5 Corrected equivalent load block spectrum

[0097]

[0098] As an optional embodiment, please refer to Figure 4 , which is described below taking a multi-directional load spectrum as an example.

[0099] Some parts in a vehicle can be subjected to loads in multiple directions, for example, a front control arm is mainly subjected to loads in X and Y directions at the ball joint position, and a steering knuckle is mainly subjected to loads in X, Y, and Z directions at the tire contact point. When processing the loads of these parts, the phase relationship between the loads needs to be considered.

[0100] For this type of parts, the step of converting the load spectrum into an equivalent load block spectrum in the form of a sine wave can be summarized as follows:

[0101] 401, collecting multiple groups of time-domain loads of parts in a vehicle;

[0102] 402, calculating the synthesis coefficients of each time-domain load in the multi-directional load spectrum according to a preset synthesis coefficient calculation formula;

[0103] 403, calculating a first synthesized load corresponding to each group of time-domain loads according to the synthesis coefficients;

[0104] The multi-directional load spectrum of the parts in the automobile is collected or extracted, wherein the load spectrum contains a plurality of groups of time-domain load data, and each group of load needs to be repeatedly loaded for a certain number of times during the test. Each group of time-domain load is composed of a series of (multi-channel) equal time interval numerical points representing load size. Each channel represents the load in different directions or the load of different loading points.

[0105] According to a preset synthesis coefficient calculation formula, the synthesis load of each group of time-domain load in the multi-directional load spectrum is calculated. For two-directional (two-channel) time-domain load, the synthesis coefficients are shown in Table 6:

[0106] Table 6 Synthesis coefficients of two-directional (two-channel) load

[0107]

[0108]

[0109] Wherein:

[0110] Synthesis load 1 = 1 × load 1 + 0 × load 2;

[0111] Synthesis load 2 = 0.97 × load 1 + 0.26 × load 2;

[0112] All synthesis loads are calculated one by one according to the load synthesis coefficients in the above table.

[0113] For three-directional (three-channel) load, the synthesis coefficients are shown in Table 7:

[0114] Table 7 Synthesis coefficients of three-directional (three-channel) load

[0115]

[0116]

[0117] Wherein:

[0118] Synthesis load 1 = 1 × load 1 + 0 × load 2 + 0 × load 3;

[0119] Synthesis load 2 = 0 × load 1 + 1 × load 2 + 0 × load 3;

[0120] All synthesis loads are calculated one by one according to the load synthesis coefficients in the above table.

[0121] In summary, when calculating the synthesis load of the time-domain load, the synthesis coefficients can be other combinations, but all conform to the following formula:

[0122] (load 1 synthesis coefficient) 2 +(load 2 synthesis coefficient) 2+... + (Load I synthesis coefficient) 2 = 1, where I is the number of directional values (channel number) of the time domain load;

[0123] In addition, the synthesis load obtained in this process is taken as the first synthesis load in this embodiment.

[0124] 404, the first synthesis load is cyclically counted by using the four-point method to obtain the cyclic composition of each group of the first synthesis load;

[0125] Before the first synthesis load is counted by using the four-point method, the data points other than the inflection points are removed from the first synthesis load of each channel, and only the inflection points are retained. This process is the same as the process of removing the data points other than the inflection points from each group of the time domain load in the processing of the single-direction load spectrum, and thus is not described herein.

[0126] After the data points other than the inflection points are removed from the first synthesis load of each channel, the first synthesis load is counted by using the four-point method to obtain the cyclic composition of each group of the first synthesis load. This process is the same as the process of counting the time domain load in the processing of the single-direction load spectrum, and thus is not described herein.

[0127] In this process, the cyclic composition of each group of the first synthesis load calculated includes the cyclic composition of the load of each direction in the multi-direction time domain load. For example, if the time domain load includes the load of two directions (Load 1 and Load 2), in this step, when the cyclic composition of all the first synthesis loads of the time domain load is calculated, the first synthesis load with the synthesis coefficient of (1, 0) and the first synthesis load with the synthesis coefficient of (0, 1) are included in all the first synthesis loads calculated, that is, the first synthesis load 1 and the first synthesis load 7 in Table 6, and thus the cyclic composition of the first synthesis load 1 and the first synthesis load 7 is the cyclic composition of the load of two directions (Load 1 and Load 2) in the time domain load. In addition, if the time domain load includes the load of three directions (Load 1, Load 2 and Load 3), in this step, when the cyclic composition of all the first synthesis loads of the time domain load is calculated, the first synthesis load with the synthesis coefficient of (1, 0, 0), the first synthesis load with the synthesis coefficient of (0, 1, 0) and the first synthesis load with the synthesis coefficient of (0, 0, 1) are included in all the first synthesis loads calculated, that is, the first synthesis load 1, the first synthesis load 2 and the first synthesis load 3 in Table 7, and thus the cyclic composition of the first synthesis load 1, the first synthesis load 2 and the first synthesis load 7 is the cyclic composition of the load of three directions (Load 1, Load 2 and Load 3) in the time domain load.

[0128] 405, the load range amplitude and the cycle number of the equivalent load corresponding to the load of each direction in the multi-direction time domain load are calculated;

[0129] In the process, for each direction (two directions or three directions) of the time domain load, the cyclic composition of each direction of the time domain load is searched from the cyclic composition of all the first composite loads of the multi-direction time domain load, a load range-accumulative cycle number curve (cycle accumulation result graph) is generated according to the cyclic composition of each direction of the time domain load, and the load range amplitude and cycle number of the equivalent load corresponding to each direction of the multi-direction time domain load are estimated according to the cycle accumulation result graph. In the process, the processing method of generating the cycle accumulation result graph according to the cyclic composition is the same as the processing method of generating the cycle accumulation result graph according to the cyclic composition of the single direction load, and will not be repeated here. For example, the time domain load A contains two direction loads (load 1 and load 2), and the cycle accumulation result graph of load 1 (equal to the composite load 1 in Table 6) (as shown in Figure 5 ) and the cycle accumulation result graph of load 2 (equal to the composite load 7 in Table 6) (as shown in Figure 6 ) can be generated.

[0130] 406, the average value of the equivalent load is obtained by counting the grade of the load in each direction of the multi-direction time domain load, and the preliminary equivalent load block spectrum is determined according to the average value of the equivalent load, the load range amplitude and the cycle number of the equivalent load.

[0131] The average value of the equivalent load is obtained by counting the grade of the load in each direction of the multi-direction time domain load. The process is the same as the process of counting the grade of the single direction time domain load, and will not be repeated here.

[0132] For example, for the load A containing two direction loads (two direction loads are load 1 and load 2), the grade counting result is shown in Figure 7 (the grade counting result graph of load 1) and Figure 8 (the grade counting result graph of load 2).

[0133] The preliminary equivalent load block spectrum is generated according to the load range amplitude, cycle number and average value of the equivalent load.

[0134] 407, the first pseudo-damage value of the multi-direction time domain load and the second pseudo-damage value of the preliminary equivalent load block spectrum are calculated by using the pseudo-damage value calculation formula.

[0135] 408, the first pseudo-damage value and the second pseudo-damage value are compared to obtain a comparison result, and the preliminary equivalent load block spectrum is preliminarily adjusted according to the comparison result.

[0136] The processing method for adjusting the preliminary equivalent load block spectrum according to the pseudo damage value of the time domain load and the pseudo damage value of the preliminary equivalent load block spectrum in this process is the same as the processing method for adjusting the preliminary equivalent load block spectrum of the single direction load, and thus is not described herein.

[0137] The equivalent load block spectrum results of the load 1 and the load 2 in the time domain load A with two directions finally obtained are shown in the following table 8 and table 9.

[0138] Table 8: Equivalent load block spectrum of load 1

[0139]

[0140] Table 9: Equivalent load block spectrum of load 2

[0141]

[0142] 409, adjusting the phase relationship between the multiple equivalent loads corresponding to the multi-direction time domain load, and calculating the second synthesis load corresponding to the equivalent load according to the phase relationship and the synthesis coefficient;

[0143] 410, calculating the third pseudo damage value of the first synthesis load and the fourth pseudo damage value of the second synthesis load according to the pseudo damage calculation formula;

[0144] 411, adjusting the preliminary equivalent load block spectrum again according to the phase relationship, the third pseudo damage value and the fourth pseudo damage value, to generate the equivalent load block spectrum with the phase relationship.

[0145] In the above steps, the load cycle composition of each synthesis load of each group of time domain loads has been obtained respectively, and the total pseudo damage value of each synthesis load, i.e. the third pseudo damage value, can be calculated according to the preset pseudo damage value calculation formula, i.e. the fatigue damage linear accumulation hypothesis rule (miner rule). Figure 9 As shown in (schematic diagram of pseudo damage values of all synthesis loads of the time domain load A), a certain group of time domain loads A with two directions obtains the total pseudo damage value of the synthesis load of all channels through calculation.

[0146] According to the above-mentioned synthesis coefficients, the second synthesized load corresponding to the equivalent load can be calculated, and the phase relationship between the multiple equivalent loads corresponding to the multi-direction time-domain load is adjusted, so that the pseudo-damage values of each synthesized load (second synthesized load) synthesized by the equivalent load according to the synthesis coefficients meet the damage distribution rule of each synthesized load (first synthesized load) synthesized by the multi-direction time-domain load according to the synthesis coefficients. Specifically, the four-point method is used to cyclically count each synthesized load synthesized by the equivalent load to obtain the cyclic composition of each synthesized load corresponding to the equivalent load, and the load range amplitude and the cycle number of the synthesized load corresponding to the equivalent load can be calculated according to the cyclic composition; according to the phase relationship, the pseudo-damage calculation formula, the load range amplitude and the cycle number of the synthesized load corresponding to the equivalent load, the fourth pseudo-damage value of each synthesized load synthesized by the equivalent load is calculated, the third pseudo-damage value of the synthesized load of the multi-direction time-domain load and the fourth pseudo-damage value of the synthesized load of the equivalent load are compared, if there is a large difference between the third pseudo-damage value and the fourth pseudo-damage value, that is, the difference between the third pseudo-damage value and the fourth pseudo-damage value is greater than the preset threshold value, the phase between the equivalent loads is adjusted, and the pseudo-damage value of the synthesized load of the adjusted equivalent load is calculated again; when the difference between the third pseudo-damage value and the fourth pseudo-damage value is within the preset difference range, the phase relationship is set as the phase relationship of the equivalent load, and finally the equivalent load block spectrum with the phase relationship is generated.

[0147] For example, the phase relationship between the equivalent load of load 1 and the equivalent load of load 2 in Tables 8 and 9 is adjusted, so that the fourth pseudo-damage value of each synthesized load synthesized by the two equivalent loads according to the synthesis coefficients of the two direction loads meets the damage (third pseudo-damage value) distribution rule of each synthesized load shown in Figure 9 , that is, the fourth pseudo-damage value of each synthesized load synthesized by the two equivalent loads is very close to Figure 9 , and the damage error of each channel is small. Therefore, the equivalent load of load 1 and the equivalent load of load 2 can be used to replace the original time-domain load, and the phase of the two equivalent loads is set to 150 degrees, so as to generate the equivalent load block spectrum. Figure 10 (Analogous diagram of pseudo-damage values of synthesized loads of each channel when the phase difference between the two equivalent loads is 150 degrees) and Figure 9 , the pseudo-damage values of each synthesized load in

[0148] The embodiment of the present application generates a preliminary equivalent load block spectrum by performing cycle statistics, grade counting and other processing on the time domain load in the load spectrum, and then calculates the pseudo damage value of the load spectrum and the preliminary equivalent load block spectrum respectively, modifies the preliminary equivalent load block spectrum, and obtains the equivalent load block spectrum; thus, the random load spectrum is converted into the equivalent load block spectrum, the process of the fatigue durability test of the automobile parts is simplified, the time cost is saved, the mutual influence between multiple loads is considered, the phase relationship between the equivalent loads is set, and the simplified equivalent load retains the characteristics of the original load as much as possible, so as to excite the same fatigue failure mode and life.

[0149] Embodiment 2

[0150] Please refer to Figure 11 The embodiment provides a load spectrum processing device 100, which comprises:

[0151] The acquisition module 110 is configured to acquire a load spectrum of a part in an automobile, wherein the load spectrum comprises a plurality of time domain loads.

[0152] The statistical module 120 is configured to perform cycle statistics on the time domain loads by using a four-point method to obtain a load range amplitude and a cycle number.

[0153] The determination module 130 is configured to perform grade counting on the time domain loads to obtain an average value of equivalent loads corresponding to the time domain loads, and determine a preliminary equivalent load block spectrum according to the load range amplitude, the cycle number and the average value.

[0154] The correction module 140 is configured to correct the preliminary equivalent load block spectrum to obtain an equivalent load block spectrum.

[0155] The load spectrum processing device described above corresponds to the load spectrum processing method of embodiment 1. Any optional item in embodiment 1 is also applicable to this embodiment, and will not be described in detail here.

[0156] The embodiment of the present application also provides a load spectrum processing device, which comprises a memory and at least one processor, the memory stores a computer program, and the processor is configured to execute the computer program to implement the load spectrum processing method of the above-mentioned embodiments.

[0157] The memory can include a program storage area and a data storage area, wherein the program storage area can store an operating system and at least one application required by a function; the data storage area can store data (such as pseudo damage values, equivalent load block spectrums, etc.) created according to the use of the load spectrum processing device, etc. In addition, the memory can include a high-speed random access memory, and can also include a non-volatile memory, for example, at least one magnetic disk storage device, a flash memory device, or other volatile solid-state memory device.

[0158] The embodiment of the present application further provides a computer readable storage medium, which stores machine executable instructions, and when the machine executable instructions are invoked and executed by a processor, the machine executable instructions cause the processor to execute the steps of the load spectrum processing method in the above embodiment.

[0159] In several embodiments provided by the present application, it should be understood that the disclosed apparatus and method can also be implemented by other manners. The apparatus embodiments described above are merely illustrative, for example, the flowcharts and structural diagrams in the drawings show the possible implementation architecture, functions and operations of the apparatus, method and computer program product according to the embodiments of the present application. In this regard, each block in the flowchart or structural diagram can represent a module, a program segment or a part of code, which contains one or more executable instructions for implementing the specified logic function. It should also be noted that in alternative implementation manners, the functions annotated in the blocks can also occur in different order from that annotated in the drawings. For example, two consecutive blocks can actually be executed substantially in parallel, and sometimes they can also be executed in reverse order, depending on the functions involved. It should also be noted that each block in the structural diagram and / or flowchart, and the combination of blocks in the structural diagram and / or flowchart, can be implemented by a dedicated hardware-based system for executing the specified functions or actions, or can be implemented by a combination of dedicated hardware and computer instructions.

[0160] In addition, each functional module or unit in the embodiments of the present application can be integrated together to form an independent part, or each module can exist independently, or two or more modules can be integrated to form an independent part.

[0161] If the functions are implemented in the form of software function modules and sold or used as independent products, they can be stored in a computer readable storage medium. Based on this understanding, the technical solutions of the present application can be embodied in the form of a software product, and the computer software product is stored in a storage medium, and includes several instructions for causing a computer device (which can be a smart phone, a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in the embodiments of the present application. The aforementioned storage medium includes: a U disk, a mobile hard disk, a read-only memory (ROM, Read-Only Memory), a random access memory (RAM, Random Access Memory), a magnetic disk or an optical disk, and various media that can store program codes.

[0162] In all of the examples shown and described herein, any specific values should be interpreted as merely exemplary and not limiting, and thus other examples of the example embodiments can have different values.

[0163] It should be noted that like reference numerals and letters refer to like items throughout the several views, and once an item is defined in one view, it is not necessary to further define and explain it in the subsequent views.

[0164] The above-described embodiments are merely illustrative of several embodiments of the present application, and the description is relatively specific and detailed, but it should not be understood as limiting the scope of the present application. It should be noted that for those skilled in the art, several modifications 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.

Claims

1. A load spectrum processing method characterized by, The method comprises the following steps: Collecting a load spectrum of parts in a vehicle, wherein the load spectrum comprises a plurality of groups of time-domain loads; Using a four-point method to perform cycle statistics on the time-domain loads to obtain a load range amplitude and a cycle number; Performing step counting on the time-domain loads to obtain an average value of equivalent loads corresponding to the time-domain loads, and determining a preliminary equivalent load block spectrum according to the load range amplitude, the cycle number, and the average value; Correcting the preliminary equivalent load block spectrum to obtain an equivalent load block spectrum, including: using a preset pseudo-damage calculation formula to calculate a first pseudo-damage value of the load spectrum and a second pseudo-damage value of the preliminary equivalent load block spectrum; comparing the first pseudo-damage value and the second pseudo-damage value, if the difference between the first pseudo-damage value and the second pseudo-damage value is greater than a preset threshold, then continuously adjusting the value of the equivalent load range of the equivalent load to obtain a third load range, and calculating a fifth pseudo-damage value of the preliminary equivalent load block spectrum according to the third load range and the cycle number of the equivalent load, when the difference between the fifth pseudo-damage value and the first pseudo-damage value is less than the threshold, generating an equivalent load block spectrum according to the third load range, the cycle number of the equivalent load, and the average value of the equivalent load; wherein the pseudo damage calculation formula is D i = n i × S i m / 10 7 ; in the formula, D i is the pseudo damage of the load cycle i; n i is the cycle number of the load cycle i; S i is the amplitude of the load cycle i; and m is a parameter related to material properties, sample form, stress ratio, and loading mode.

2. The load spectrum processing method of claim 1, wherein The load spectrum includes a single-direction load spectrum and a multi-direction load spectrum.

3. The load spectrum processing method of claim 2, wherein, Before the step of using a four-point method to perform cycle statistics on the time-domain loads to obtain a load range amplitude and a cycle number, the method further comprises the following steps: Obtaining a first load value at a time point, and a second load value and a third load value at a previous time point and a subsequent time point corresponding to the time point; If the first load value, the second load value, and the third load value form an increasing or decreasing relationship, then deleting the first load value.

4. The load spectrum processing method of claim 3, wherein, When the load spectrum is a single-direction load spectrum, the step of using a four-point method to perform cycle statistics on the time-domain loads to obtain a load range amplitude and a cycle number comprises the following steps: Using a four-point method to determine a cycle composition of each group of the time-domain loads, wherein each cycle in the cycle composition comprises two load data points in the time-domain loads; Calculating a difference between the load values of the load data points constituting each cycle in the cycle composition, and taking the difference as a load range amplitude of each group of the time-domain loads; Accumulatively counting the cycle composition according to the load range amplitude to obtain a cycle number.

5. The load spectrum processing method of claim 2, wherein, When the load spectrum is a multi-direction load spectrum, the step of using a four-point method to perform cycle statistics on the time-domain loads to obtain a load range amplitude and a cycle number comprises the following steps: Calculating a synthesis coefficient of each time-domain load in the multi-direction load spectrum according to a preset synthesis coefficient calculation formula; Calculating a first synthesis load corresponding to each group of the time-domain loads according to the synthesis coefficient; Using a four-point method to perform cycle statistics on the first synthesis load to obtain a cycle composition of each group of the first synthesis load; Calculating a load range amplitude and a cycle number of equivalent loads corresponding to the time-domain loads in each direction of the multi-direction load spectrum according to the cycle composition.

6. The load spectrum processing method of claim 5, wherein, The modifying the preliminary equivalent load block spectrum to obtain an equivalent load block spectrum comprises: adjusting a phase relationship between the equivalent loads corresponding to the time-domain loads in each direction, and calculating a second synthesized load corresponding to the equivalent loads according to the phase relationship and the synthesis coefficients; calculating a third pseudo-damage value of the first synthesized load and a fourth pseudo-damage value of the second synthesized load according to the pseudo-damage calculation formula; adjusting the preliminary equivalent load block spectrum according to the phase relationship, the third pseudo-damage value and the fourth pseudo-damage value to generate an equivalent load block spectrum with a phase relationship.

7. A load spectrum processing apparatus characterized by comprising: comprise: The acquisition module is configured to acquire a load spectrum of a part in a vehicle, wherein the load spectrum comprises a plurality of groups of time-domain loads; The statistical module is configured to perform cycle statistics on the time-domain loads by using a four-point method to obtain a load range amplitude and a cycle number; The determination module is configured to perform step counting on the time-domain loads to obtain an average value of equivalent loads corresponding to the time-domain loads, and determine a preliminary equivalent load block spectrum according to the load range amplitude, the cycle number and the average value; The modification module is configured to modify the preliminary equivalent load block spectrum to obtain an equivalent load block spectrum, comprising: calculating a first pseudo-damage value of the load spectrum and a second pseudo-damage value of the preliminary equivalent load block spectrum by using a preset pseudo-damage calculation formula; comparing the first pseudo-damage value and the second pseudo-damage value, if a difference between the first pseudo-damage value and the second pseudo-damage value is greater than a preset threshold, continuously adjusting a value of an equivalent load range of the equivalent load to obtain a third load range, and calculating a fifth pseudo-damage value of the preliminary equivalent load block spectrum according to the third load range and a cycle number of the equivalent load, when a difference between the fifth pseudo-damage value and the first pseudo-damage value is less than the threshold, generating an equivalent load block spectrum according to the third load range, the cycle number of the equivalent load and the average value of the equivalent load; wherein the pseudo damage calculation formula is D i = n i × S i m / 10 7 ; in the formula, D i is the pseudo damage of the load cycle i; n i is the cycle number of the load cycle i; S i is the amplitude of the load cycle i; and m is a parameter related to material properties, sample form, stress ratio, and loading mode.

8. A load spectrum processing apparatus characterized by comprising: The load spectrum processing device comprises a memory and at least one processor, the memory stores a computer program, and the processor is configured to execute the computer program to implement the load spectrum processing method in any one of claims 1-6.

9. A computer storage medium, characterized in that The computer program is executed to implement the load spectrum processing method in any one of claims 1-6.

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