Multi-axial fatigue life prediction method and electronic equipment

Abstract

The invention relates to a multi-axial fatigue life prediction method and electronic equipment, and the method comprises the steps: obtaining multi-axial fatigue experiment data of a to-be-predicted material, including material performance data and a load spectrum; decomposing the load spectrum to obtain a plurality of half cycles of reaction material loading conditions; calculating normal stress and shear stress on each slope based on the load spectrum data, and calculating fatigue life and damage corresponding to each semi-cycle based on an equivalent stress model; on the basis of an equivalent damage theory, carrying out weighting processing on an inclined plane included angle corresponding to a maximum shear stress surface, calculating a critical plane where fatigue damage occurs, calculating equivalent stress of each semi-cycle, and carrying out fatigue life prediction on the critical plane based on the equivalent stress. Compared with the prior art, the method has the advantages that the accuracy of calculating the critical surface and predicting the fatigue life is improved, the operation is simple, and the implementation cost is low.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of aerospace technology, and in particular to a multi-axial fatigue life prediction method and electronic equipment. BACKGROUND

[0002] In the actual work of aerospace, because the engineering structure material often bears complex multi-axial load, multi-axial fatigue failure is one of the main failure modes, therefore, the research on multi-axial fatigue failure and life prediction method has important practical significance. In the process of predicting multi-axial fatigue life, equivalent stress method and critical plane method are widely used to improve the prediction accuracy. However, the existing methods have the following limitations:

[0003] For the equivalent stress method, many models are only for equivalent calculation of high cycle fatigue or low cycle fatigue, and it is difficult to accurately describe the influence of complex load conditions, resulting in insufficient prediction accuracy.

[0004] For the critical plane method, the traditional model usually determines the critical plane by the maximum shear stress when predicting the critical plane. Under the condition of non-proportional loading, the principal stress direction changes constantly, and the maximum shear stress plane also changes constantly, so it is difficult to determine the position of the critical plane under variable amplitude loading.

[0005] Through retrieval, Chinese invention patent application publication No. CN111624116A discloses a multi-axial fatigue life prediction method based on weight average maximum shear stress plane. The application obtains the load history of the notched part through the strain gauge arranged on the notched part, determines all load reversals in the load history by using Wang-Brown multi-axial cycle counting algorithm; for each load reversal, a weight function is established by using the change range of shear stress, and the phase angle of the weighted average maximum shear stress range plane of each load reversal is determined to determine the critical plane of the entire load history, and then the cumulative fatigue damage is calculated. Wang et al. take the shear stress change range of the maximum shear stress plane as the weight, and propose a weight function critical plane determination method by the maximum average shear stress plane, and then predict the fatigue life of the material. The existing patent and method have the problem of determining the critical plane only by establishing a weight function model of shear stress change.

[0006] How to comprehensively consider the influence of shear stress and normal stress on the orientation of the critical plane and damage, and improve the prediction accuracy of multi-axial fatigue life, becomes a technical problem to be solved. SUMMARY

[0007] The purpose of the present application is to overcome the defects of the prior art and provide a multi-axial fatigue life prediction method and electronic equipment.

[0008] The purpose of the present application can be achieved by the following technical solutions:

[0009] According to one aspect of the present application, a multi-axial fatigue life prediction method is provided, the method comprising the steps of:

[0010] Step 1, obtaining multi-axial fatigue test data of a material to be predicted, including material performance data and load spectrum;

[0011] Step 2, decomposing the load spectrum to obtain a plurality of half cycles reflecting loading conditions of the material;

[0012] Step 3, calculating normal stress and shear stress on each inclined plane based on the load spectrum data, and calculating fatigue life and fatigue damage corresponding to each half cycle based on an equivalent stress model;

[0013] Step 4, based on the calculation results of Step 3, performing weighted processing on the angle of the inclined plane corresponding to the maximum shear stress plane based on equivalent damage theory, and calculating a critical plane where fatigue failure occurs;

[0014] Step 5, calculating equivalent stress on the critical plane of each half cycle through the equivalent stress model, and predicting fatigue life based on the equivalent stress on the critical plane.

[0015] Preferably, in Step 3, the calculation of fatigue life and damage corresponding to each half cycle based on the equivalent stress model comprises:

[0016] calculating equivalent stress σ eq.i on each half cycle based on the equivalent stress model

[0017]

[0018] wherein σ max is the maximum normal stress on the inclined plane, τ a is the shear stress amplitude on the inclined plane, σ a is the normal stress amplitude on the inclined plane, τ -1 is the material torsional fatigue limit when the stress ratio is -1, σ -1 is the material tensile fatigue limit when the stress ratio is -1, and σ0 is the tensile fatigue limit when the stress ratio is 0.

[0019] Based on the equivalent stress of each half cycle and the material performance data, the fatigue life N i and the damage D i of each half cycle are obtained through an S-N curve.

[0020] Preferably, Step 4 comprises:

[0021] Step 41, based on the equivalent damage theory, equivalent damage of the equivalent stress in all half cycles to the half cycle where the maximum equivalent stress is located;

[0022] Step 42, calculate the weight factor of each half-cycle slope angle;

[0023] Step 43, based on the weight factor, weighted average of all half-cycle slope angle, calculated critical surface of fatigue failure occurs.

[0024] More preferably, in step 41, the damage equivalent of all half-cycle equivalent stress is equivalent to the half-cycle where the maximum equivalent stress is located, and the equivalent process is:

[0025]

[0026] Where, n i , N i and D i are the loading cycle number, fatigue life and fatigue damage corresponding to the ith half-cycle, respectively, N max is the fatigue life corresponding to the half-cycle where the maximum equivalent stress is located in all half-cycles, is the equivalent damage, is the loading cycle number corresponding to the ith half-cycle after equivalent to the half-cycle where the maximum equivalent stress is located in all half-cycles.

[0027] More preferably, in step 42, the weight factor of each half-cycle slope angle includes:

[0028] If the cycle number of each half-cycle before using the equivalent damage method is equal to 1, then the weight factor is established for each slope angle by using the equivalent cycle number:

[0029]

[0030] Where, W i is the weight factor, ranging from (0, 1];

[0031] If the cycle number of each half-cycle before using the equivalent damage method is not equal to 1, directly use the equivalent cycle number As the weight factor, it cannot reflect the difference in weight, so the maximum cycle number is used to normalize each equivalent cycle number :

[0032]

[0033] Where, n max is the maximum cycle number, that is, the cycle number corresponding to the half-cycle where the maximum equivalent stress is located in all half-cycles, and the range after normalization is (0, 1];

[0034] After normalization, the weight factor is established for each slope angle using the following formula:

[0035]

[0036] wherein W i is a weight factor, ranging from (0, 1].

[0037] More preferably, in the step 43, the critical interface included angle is obtained by weighted average of the included angles of all the slopes based on the weight factor, and the slope corresponding to the critical interface included angle is the critical interface where fatigue failure occurs.

[0038] More preferably, the calculation formula of the critical interface included angle is:

[0039]

[0040] wherein m is the total number of half cycles; θ c is the included angle between the critical interface where fatigue failure occurs and the axial direction of the sample, i.e. the critical interface included angle; W i and θ i are the weight factor and the slope included angle of the i-th slope, respectively.

[0041] Preferably, the equivalent stress on the critical interface of each half cycle is specifically calculated as:

[0042]

[0043] wherein σ max is the maximum normal stress on the critical interface, τ a is the shear stress amplitude on the critical interface, σ a is the normal stress amplitude on the critical interface, σ eq.i is the equivalent stress on the critical interface of each half cycle.

[0044] More preferably, the fatigue life prediction on the critical interface based on the equivalent stress includes:

[0045] Based on the equivalent stress on the critical interface of each half cycle calculated, the corresponding fatigue life N i and fatigue damage D i are obtained according to the S-N curve.

[0046] The fatigue life prediction on the critical interface includes:

[0047]

[0048] wherein N f is the fatigue life prediction value, D i is the fatigue damage caused by the i-th half cycle, and m is the total number of half cycles.

[0049] According to another aspect of the present application, there is provided an electronic device comprising a memory having a computer program stored thereon and a processor which implements the method when executing the program.

[0050] Compared with the prior art, the present application has the following beneficial effects:

[0051] 1、The equivalent stress model is constructed to calculate the fatigue life and damage corresponding to each half cycle; the critical surface where fatigue failure occurs is obtained by weighting the included angle of the inclined surface corresponding to the maximum shear stress surface based on the equivalent damage method, and the equivalent stress on the critical surface in each half cycle is calculated through the equivalent stress model, so as to predict the fatigue life on the critical surface, the accuracy of predicting the critical surface and the equivalent stress is improved, and thus the accuracy of predicting the fatigue life is improved.

[0052] 2、The equivalent stress is calculated through the equivalent stress model constructed in the present application, the equivalent stress is more accurate, and thus the calculation accuracy of the critical surface and the fatigue life is improved, because the model combines the relationship between the normal stress and shear stress of each inclined surface and the material constant, and considers the influence of the multi-axial fatigue limit of the material on each inclined surface.

[0053] 3、The weight factor of each inclined surface is calculated through the equivalent cycle number, the weight factor is more accurate, and thus the calculation accuracy of the fatigue life is improved, because the weight factor is calculated by the equivalent damage method, the damage of all half cycles is equivalent to a fixed half cycle, the influence caused by different half cycles is controlled, the influence is specifically reflected in the fatigue damage, and then the weight is calculated through the relationship between the fatigue damage and the critical surface.

[0054] 4、The critical surface is obtained through the weight method, and the fatigue life is predicted, the steps of predicting the multi-axial fatigue life by using the method are relatively simple, the operation method is relatively easy, and the implementation cost is relatively low. BRIEF DESCRIPTION OF DRAWINGS

[0055] Figure 1 It is a flowchart of the multi-axial fatigue life prediction method in the present application;

[0056] Figure 2 It is a schematic diagram of the process of calculating the weight factor by using the equivalent damage method in the present application;

[0057] Figure 3 It is an error effect diagram of predicting the multi-axial fatigue life in the present application. DETAILED DESCRIPTION

[0058] With reference to the drawings of the embodiments of the present application, the technical solutions in the embodiments of the present application will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those of ordinary skill in the art without creative work should fall within the protection scope of the present application.

[0059] Embodiment 1

[0060] The present embodiment relates to a multi-axial fatigue life prediction method, which combines Wang-Brown cycle counting method, equivalent damage method, equivalent stress method and critical plane method, and considers the influence of each half cycle on the critical plane of the material through weight. The critical plane predicted by the weight is used to predict the slope of the material where fatigue failure occurs, and the fatigue life of the critical plane is predicted, thereby improving the accuracy and safety of life prediction.

[0061] A multi-axial fatigue life prediction method, such as Figure 1 , comprises the following steps:

[0062] S1: Obtain multi-axial fatigue test data of the material to be predicted, including material performance data and load spectrum.

[0063] Preprocess the fatigue test data: the load spectrum of the multi-axial fatigue test contains normal stress and shear stress, and Wang-Brown cycle counting method is used for counting processing. In the counting processing, the load spectrum is decomposed to obtain a plurality of half cycles reflecting the loading condition of the material. The material performance data includes: S-N curve (stress-life curve) of the material to be predicted, tensile fatigue limit (maximum stress amplitude of the material under tensile load corresponding to infinite life) and torsional fatigue limit (maximum shear stress amplitude of the material under torsional load corresponding to infinite life).

[0064] S2: Process the load spectrum data of the multi-axial fatigue test, and calculate the normal stress and shear stress on each slope, which are used as input features of the multi-axial fatigue life prediction model.

[0065] Based on the normal stress σ and shear stress τ in the multi-axial fatigue test, the normal stress and shear stress on each slope are calculated respectively:

[0066]

[0067] Wherein, σ θ and τ θ are the normal stress and shear stress on the slope, σ x and σ y are the test normal stresses, τ xy is the test shear stress, and θ is the angle between the slope and the axial direction of the sample.

[0068] For each half cycle, the angle between the maximum shear stress amplitude corresponding to the inclined plane and the axial direction of the specimen (hereinafter referred to as the inclined plane angle) is θ i and (θ i + 90°), where θ i ∈ (0°, 90°). According to the maximum normal stress σ θ corresponding to the inclined plane obtained, the shear stress τ θ is calculated, and the inclined plane angle θ i is calculated. The maximum normal stress of the two inclined planes of (θ i + 90°) is greater, and the equivalent stress of the inclined plane is taken as the equivalent stress corresponding to the half cycle.

[0069] By considering the relationship between the normal stress and shear stress on the inclined plane and the material constant, an equivalent stress model is established to calculate the equivalent stress σ eq.i on each half cycle:

[0070]

[0071] where σ max is the maximum normal stress on the inclined plane, τ a is the shear stress amplitude on the inclined plane, σ a is the normal stress amplitude on the inclined plane, τ -1 is the material torsional fatigue limit when the stress ratio is -1, σ -1 is the material tensile fatigue limit when the stress ratio is -1, and σ0 is the tensile fatigue limit when the stress ratio is 0.

[0072] Based on the equivalent stress of each half cycle, the fatigue life N i and damage D i corresponding to each half cycle are obtained through the S-N curve.

[0073] S3: Based on the equivalent damage theory, the maximum shear stress plane is weighted by integrating the weight function and the equivalent stress method, and a multi-axial fatigue life prediction model is established.

[0074] S31, based on the equivalent damage theory, the damage of the equivalent stress in all half cycles is equivalent to the half cycle where the maximum equivalent stress is located, and the equivalent process is:

[0075]

[0076] where n i , N i and D i are the loading cycle number, fatigue life and fatigue damage corresponding to the ith half cycle, N max is the fatigue life corresponding to the half cycle where the maximum equivalent stress is located in all half cycles, and D is the equivalent damage. is the number of loading cycles corresponding to the maximum equivalent stress in the i-th half cycle.

[0077] S32, calculate the weight factor of each slope θ i ∈(0°, 90°)

[0078] If the number of cycles of each half cycle before using the equivalent damage method (i.e., the equivalent pre-cycle number of Figure 1 ) is equal to 1, then the equivalent cycle number is used for each slope angle θ i Establish the weight factor:

[0079]

[0080] where W i is the weight factor, ranging from (0, 1];

[0081] If the number of cycles of each half cycle before using the equivalent damage method (i.e., the equivalent pre-cycle number of Figure 1 ) is not equal to 1, the equivalent cycle number As the weight factor cannot reflect the difference in weight, the maximum cycle number is used to normalize each equivalent cycle number :

[0082]

[0083] where n max is the maximum cycle number, i.e., the cycle number corresponding to the half cycle where the maximum equivalent stress is located, and the normalized processing range is (0, 1];

[0084] After normalization, the weight factor is established for each slope angle θ i :

[0085]

[0086] where W i is the weight factor, ranging from (0, 1].

[0087] S33, calculate the critical surface where fatigue failure occurs

[0088] Based on the slope angle θ i where the maximum shear stress amplitude in each half cycle is located, and the weight factor W i of each half cycle, all half cycles are weighted respectively, and a new slope is calculated, which is defined as the critical surface where fatigue failure occurs:

[0089]

[0090] Where m is the total number of half cycles, θ c ∈(0°,90°) is the angle between the critical plane where fatigue failure occurs and the axial direction of the specimen (referred to as the critical plane angle).

[0091] S34, calculate the equivalent stress for each half cycle

[0092] According to the predicted critical surface of material fatigue failure, the relationship between the normal stress and shear stress on the predicted critical surface and the material constant is considered, and the critical surface θ of each half cycle is calculated by the established equivalent stress model. c and (θ c The equivalent stress σ on the inclined plane with the larger maximum normal stress among the two inclined planes (+90°) eq.i :

[0093]

[0094] Among them, σ max is the maximum normal stress on the critical surface, τ a is the shear stress amplitude on the critical surface, σ a is the normal stress amplitude on the critical surface, σ eq.i is the equivalent stress on the critical surface for each half cycle.

[0095] S35, Fatigue life prediction on critical surfaces based on equivalent stress

[0096] Based on the calculated equivalent stress σ eq.i , according to the SN curve, calculate the corresponding fatigue life N i and fatigue damage D i , and finally at the critical surface θ of the aviation material c Fatigue life prediction is performed on:

[0097]

[0098] Among them, N f is the fatigue life prediction value, is the sum of fatigue damage caused by all half cycles.

[0099] Example 2

[0100] This embodiment also relates to a multi-axial fatigue life prediction method, which performs multi-axial fatigue life prediction on GH4169 alloy. The prediction process is the same as that of embodiment 1. Figure 1 As shown, it will not be repeated here.

[0101] like Figure 2 As shown in the figure, the process includes: the horizontal axis is the number of cycles corresponding to the half cycle, the vertical axis is the damage caused by the half cycle, and the equivalent stress σ involved in the figure eq.iCalculate the fatigue life N corresponding to the i-th half cycle through the S-N curve i Take the 1st half cycle and the i-th half cycle as an example, calculate the fatigue life corresponding to each half cycle through the S-N curve, and assume that the damage caused by the 1st half cycle is: Then there must be a damage D i equal to the damage D1 in the i-th half cycle. That is, the damage caused by cycling n1 times in the 1st half cycle is equal to the damage caused by cycling n1 times in the i-th half cycle.

[0102] The prediction results are shown in Figure 3 The abscissa is the material serial number, and the ordinate is the fatigue life prediction error. The red part represents the multi-axial fatigue life predicted by using the equivalent stress model established by the present application and the method for predicting the critical interface of the present application, and by comparing with the fatigue life obtained by the test, the fatigue life prediction error is calculated using the following formula:

[0103]

[0104] Where T is the total number of material samples, N t.i is the fatigue life of sample i obtained by multi-axial fatigue test, N f.i is the fatigue life of sample i predicted by the present application, and total error is the average value of the prediction errors of all samples.

[0105] From the error results, it can be seen that the method of the present application has good prediction effect on fatigue life.

[0106] Example 3

[0107] The electronic device of the present application includes a central processing unit (CPU) which can perform various appropriate actions and processes according to computer program instructions stored in a read-only memory (ROM) or computer program instructions loaded from a storage unit into a random access memory (RAM). In the RAM, various programs and data required for device operation can also be stored. The CPU, ROM, and RAM are connected to each other through a bus. An input / output (I / O) interface is also connected to the bus.

[0108] A plurality of components in the device are connected to the I / O interface, including: an input unit such as a keyboard, a mouse, etc.; an output unit such as various types of displays, a loudspeaker, etc.; a storage unit such as a magnetic disk, an optical disk, etc.; and a communication unit such as a network card, a modem, a wireless communication transceiver, etc. The communication unit allows the device to exchange information / data with other devices through a computer network such as the Internet and / or various telecommunication networks.

[0109] ​The processing units perform the various methods and processes described above. For example, in some embodiments, the methods can be implemented as a computer software program tangibly embodied in a machine readable medium, such as a storage unit. In some embodiments, portions of the computer program, or all of the computer program, can be loaded onto the device via, for example, the ROM and / or the communications unit. When the computer program is loaded onto the RAM and executed by the CPU, one or more of the steps of the methods described above can be performed. Alternatively, in other embodiments, the CPU can be configured to perform the methods by way of other means (e.g., via firmware).

[0110] The functionality described herein above can be performed, at least in part, by one or more hardware logic components. For example, and without limitation, illustrative types of hardware logic components that can be used include Field-programmable Gate Arrays (FPGAs), Application-specific Integrated Circuits (ASICs), Application-specific Standard Products (ASSPs), System-on-a-chip systems (SOCs), Complex Programmable Logic Devices (CPLDs), etc.

[0111] Program code for carrying out methods of the present application can be written in any combination of one or more programming languages. This program code can be provided to a processor or controller of a general purpose computer, special purpose computer, or other programmable data processing apparatus to produce a machine, such that the program code, when executed by the processor or controller, produces a means for implementing the functions / acts specified in the flowcharts and / or block diagrams. The program code can be retrieved from a machine-readable medium or device, a storage medium, a memory medium, a tangible medium, or a non-transitory medium. The program code can be executed by a machine, such as a computer, which can be a special purpose computer or a general purpose computer. The program code can be executed by a controller or a processor, which can be a special purpose controller or a general purpose controller.

[0112] In the context of the present application, a machine-readable medium can be any tangible medium that can contain, or store a program for use by or in connection with an instruction execution system, apparatus, or device. The machine-readable medium can be a machine-readable signal medium or a machine-readable storage medium. A machine-readable medium can include, but is not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. More specific examples of the machine-readable storage medium will include one or more lines of a computer program code, a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

[0113] The above merely illustrates the specific embodiments of the present application, but the protection scope of the present application is not limited thereto, and any skilled person in the art can easily think of various equivalent modifications or replacements within the technical range disclosed by the present application, and these modifications or replacements shall be covered within the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. A method for predicting multi-axial fatigue life, the method comprising the steps of: Step 1, obtaining multi-axial fatigue test data of a material to be predicted, including material property data and a load spectrum; Step 2, decomposing the load spectrum to obtain a plurality of half cycles that reflect loading conditions of the material; Step 3, calculating normal stress and shear stress on each plane based on the load spectrum data, and calculating fatigue life and fatigue damage corresponding to each half cycle based on an equivalent stress model; Step 4, based on the calculation results of Step 3, weighting the plane angle corresponding to the plane of maximum shear stress based on the equivalent damage theory, and calculating a critical plane where fatigue failure occurs; Step 5, calculating equivalent stress on the critical plane of each half cycle through the equivalent stress model, and predicting fatigue life based on the equivalent stress on the critical plane. In Step 3, the calculation of fatigue life and damage corresponding to each half cycle based on the equivalent stress model comprises: Step 4 comprises: Step 41, based on the equivalent damage theory, equivalent damage of the equivalent stress in all half cycles to the half cycle where the maximum equivalent stress is located; Step 42, calculating a weight factor of the plane angle of each half cycle; Step 43, based on the weight factor, weighting and averaging the plane angle of all half cycles to obtain the critical plane where fatigue failure occurs.

2. The multi-axial fatigue life prediction method of claim 1, wherein In Step 41, the equivalent damage of the equivalent stress in all half cycles to the half cycle where the maximum equivalent stress is located is as follows: Based on the equivalent stress model, the equivalent stress σ on each half cycle is calculated eq.i : where σ max is the maximum normal stress on the plane, τ a is the shear stress amplitude on the plane, σ a is the normal stress amplitude on the plane, τ -1 is the torsional fatigue limit of the material for a stress ratio of -1, σ -1 is the tensile fatigue limit of the material for a stress ratio of -1, and σ0is the tensile fatigue limit for a stress ratio of 0. Based on the equivalent stress of each half cycle and material property data, the fatigue life N corresponding to each half cycle is solved by S-N curve i With the damage D i .

3. The multi-axial fatigue life prediction method of claim 1, wherein In Step 42, the calculation of the weight factor of the plane angle of each half cycle comprises: If the number of cycles of each half cycle before using the equivalent damage method is equal to 1, then the weight factor is established for each plane angle through the equivalent number of cycles: After normalization, the weight factor is established for each plane angle using the following formula: In Step 43, based on the weight factor, the plane angle of all half cycles is weighted and averaged to obtain the critical plane angle, and the plane corresponding to the critical plane angle is the critical plane where fatigue failure occurs.

4. The multi-axial fatigue life prediction method of claim 3, wherein The formula for calculating the critical plane angle is: wherein n i , N i and D i are the number of loading cycles, fatigue life and fatigue damage corresponding to the ith half cycle, respectively, N max is the fatigue life corresponding to the half cycle in which the maximum equivalent stress occurs among all half cycles, is the equivalent damage, is the number of loading cycles corresponding to the ith half cycle equivalent to the number of loading cycles corresponding to the half cycle in which the maximum equivalent stress occurs among all half cycles.

5. The multi-axial fatigue life prediction method of claim 4, wherein, The calculation of the equivalent stress on the critical plane of each half cycle is as follows: The fatigue life prediction based on the equivalent stress on the critical plane comprises: where W i is a weight factor, ranging from (0, 1]; If the number of cycles per half cycle before using the equivalent damage method is not equal to 1, directly use the equivalent cycle number As the weight factor cannot reflect the difference in weight, the maximum cycle number is used for each equivalent cycle number Normalization processing: wherein n max is the maximum number of cycles, i.e. the number of cycles corresponding to the half cycle in which the maximum equivalent stress of all half cycles is located, the range of the normalized value being (0, 1]; Fatigue life prediction on the critical plane: where W i is a weight factor, ranging from (0, 1].

6. The multi-axial fatigue life prediction method of claim 3, wherein The processor implements the method according to any one of claims 1-9 when executing the program.

7. The multi-axial fatigue life prediction method of claim 6, wherein ​ wherein m is the total number of half cycles; θ c is the angle between the critical plane of fatigue failure and the axial direction of the specimen, i.e., the critical plane angle; W i and θ i are the weight factor and the angle of the i-th facet, respectively.

8. The multi-axial fatigue life prediction method of claim 1, wherein, ​ where σ max is the maximum normal stress on the critical plane, τ a is the shear stress amplitude on the critical plane, σ a is the normal stress amplitude on the critical plane, σ eq.i is the equivalent stress on the critical plane for each half cycle.

9. The multi-axial fatigue life prediction method of claim 8, wherein, ​ Based on the equivalent stress on each half-cycle critical interface, the corresponding fatigue life N is calculated according to the S-N curve i With the fatigue damage D i ; ​ where N f is the fatigue life prediction value, D i is the fatigue damage caused by the ith half cycle, and m is the total number of half cycles.

10. An electronic device comprising a memory and a processor, said memory having stored thereon a computer program, characterized in that, ​

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