Method and device for determining fatigue life characteristic curve, equipment and medium

Abstract

The embodiment of the invention provides a method, a device, equipment and a medium for determining a fatigue life characteristic curve, strain gauges are respectively arranged on the inner and outer sides of a first reference position and a second reference position of a lamination, and the first reference position and the second reference position are located in an area, which is not shielded by other components, on the lamination. Based on the stress values collected by the strain gauges, the stress level at the target test position when the test load is applied to the shaft body of the coupler can be calculated, and the corresponding relation between the test load and the stress level at the target test position is established. Based on the corresponding relationship and the fatigue cycle times measured when a test load is applied to the shaft body of the coupler for a fatigue test, the fatigue cycle times corresponding to the laminations under the action of different stress levels can be obtained, so that the fatigue life characteristic curve of the laminations is determined. According to the embodiment of the invention, the problem that the fatigue characteristic curve is difficult to accurately obtain under the condition that the strain gauges are difficult to arrange at the stress concentration positions on the laminations is solved.

Description

Technical Field

[0001] This application relates to the field of material fatigue performance testing technology, and in particular to methods, apparatus, equipment and media for determining fatigue life characteristic curves. Background Technology

[0002] Permanent magnet direct-drive couplings, as crucial components connecting the motor and wheels in high-power permanent magnet direct-drive locomotives, function to transmit motor torque and adapt to the relative displacement of the wheelset to the motor. During locomotive operation, vibration excitation from the track and changes in track curvature cause frequent relative movements between the motor and wheels. The laminations in the coupling, as important elastic elements, bear all the displacements of the wheels relative to the motor. Therefore, under frequent elastic deformation conditions, the fatigue resistance of the laminations is particularly important. In practice, the fatigue resistance of the components is generally characterized by SN curves (Stress-Number of Cycles curves) or PSN curves (Probability-Stress-Number of Cycles curves).

[0003] Given that crack initiation in materials often occurs at stress concentration points, strain gauges are typically placed at these stress concentration points to collect stress levels and measure the number of fatigue cycles under different stress levels, thus obtaining the SN or PSN curves of a device. However, due to the structural limitations of couplings, it is often difficult to place strain gauges at stress concentration points on the coupling laminations, making it challenging to accurately obtain the SN or PSN curves of the laminations to assess their fatigue resistance. Summary of the Invention

[0004] The purpose of this application is to provide a method and related equipment for determining the fatigue life characteristic curve of coupling laminations, in order to solve the problem of difficulty in accurately obtaining the fatigue characteristic curve of the laminations when the coupling structure makes it difficult to place strain gauges at stress concentration locations on the laminations. The specific technical solution is as follows: In a first aspect, embodiments of this application provide a method for determining the fatigue life characteristic curve of coupling laminations, including: A test load is applied to the shaft of the coupling to conduct a fatigue test on the laminated plates in the coupling. The test load corresponds to a specific stress level at a target test location on the laminated plates, and the number of fatigue cycles of the laminated plates under that specific stress level is obtained. The target test location is the stress concentration location of the laminated plates during operation. The specific stress level corresponding to this test load is determined through the following steps one and two: Step one: Obtain the stress values ​​collected by each strain gauge in the strain gauge group on the laminated plates during the application of the test load to the shaft. The strain gauge group includes: a first strain gauge and a second strain gauge respectively disposed on the inner and outer surfaces of the laminated plates at a first reference position; and a third strain gauge and a fourth strain gauge respectively disposed on the inner and outer surfaces of the laminated plates at a second reference position. A first reference position and a second reference position are located in areas on the lamination that are not obstructed by other components. The second reference position is located on the side of the first reference position away from the target test position. Step 2: Calculate the estimated stress at the target test position based on the stress values ​​collected by each strain gauge to obtain the stress level at the target position during the application of the test load to the shaft, which is taken as the specific stress level. Based on different test loads corresponding to different stress levels at the target test position, repeat the step of applying test loads to the shaft of the coupling to conduct fatigue tests on the laminations in the coupling, and obtain the number of fatigue cycles corresponding to each lamination under different stress levels. Based on the number of fatigue cycles corresponding to each lamination under different stress levels, determine the fatigue life characteristic curve of the lamination.

[0005] Secondly, embodiments of this application provide an apparatus for determining the fatigue life characteristic curve of coupling laminations, comprising: The test module is used to apply a test load to the shaft of the coupling to conduct a fatigue test on the laminated plates in the coupling. The test load corresponds to a specific stress level at a target test position on the laminated plates, and the number of fatigue cycles of the laminated plates under that specific stress level is obtained. The target test position is the stress concentration location of the laminated plates during operation. The specific stress level corresponding to this test load is determined through the following steps one and two: Step one: Obtain the stress values ​​collected by each strain gauge in the strain gauge group on the laminated plates during the application of the test load to the shaft. The strain gauge group includes: a first strain gauge and a second strain gauge respectively disposed on the inner and outer surfaces of the laminated plates at a first reference position; a third strain gauge and a fourth strain gauge respectively disposed on the inner and outer surfaces of the laminated plates at a second reference position; the first reference position and... The second reference position is located in the area on the lamination that is not obstructed by other components, and the second reference position is located on the side of the first reference position away from the target test position; Step 2: Calculate the estimated stress at the target test position based on the stress values ​​collected by each strain gauge, so as to obtain the stress level at the target position during the application of the test load to the shaft, as a specific stress level; Repeat module, used to instruct the test module to repeatedly execute the step of applying the test load to the shaft of the coupling to perform fatigue testing on the lamination in the coupling based on different test loads corresponding to different stress levels of the target test position, so as to obtain the number of fatigue cycles corresponding to each lamination under different stress levels; Determine module, used to determine the fatigue life characteristic curve of the lamination based on the number of fatigue cycles corresponding to each lamination under different stress levels.

[0006] Thirdly, embodiments of this application provide an electronic device, including a processor, a communication interface, a memory, and a communication bus, wherein the processor, the communication interface, and the memory communicate with each other through the communication bus; the memory is used to store computer programs; and the processor is used to execute the program stored in the memory to implement the above-mentioned method for determining the fatigue life characteristic curve of the coupling laminations.

[0007] Fourthly, embodiments of this application provide a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the method described above for determining the fatigue life characteristic curve of coupling laminations.

[0008] This application also provides a computer program product containing instructions that, when run on a computer, cause the computer to execute the above-described method for determining the fatigue life characteristic curve of coupling laminations.

[0009] Beneficial effects of the embodiments in this application: The method, apparatus, equipment, and medium for determining fatigue life characteristic curves provided in this application's embodiments select a first reference position and a second reference position on the coupling laminations in areas not obstructed by other components. The second reference position is located away from the target test position set at the stress concentration location, and strain gauges are respectively set on the inner and outer surfaces of the laminations at the first reference position and the inner and outer surfaces of the laminations at the second reference position. Based on the stress values ​​collected by each strain gauge at the first and second reference positions on the laminations, the stress level at the target test position when a test load is applied to the coupling shaft can be indirectly calculated, establishing a correspondence between the test load and the stress level at the target test position. Therefore, based on this correspondence, and the number of fatigue cycles measured when the laminations are subjected to fatigue testing by applying a test load to the coupling shaft, the number of fatigue cycles corresponding to each lamination under different stress levels can be obtained, thereby determining the fatigue life characteristic curve of the laminations.

[0010] As can be seen from the above, the method for determining the fatigue life characteristic curve of coupling laminations provided in this application embodiment does not require directly arranging strain gauges at the stress concentration locations of the laminations, yet it can effectively calculate the stress level at the stress concentration locations on the laminations when a test load is applied to the shaft of the coupling. This solves the problem of difficulty in directly measuring the stress level at stress concentration locations, leading to inaccurate fatigue characteristic curves of the laminations, in scenarios where the coupling structure makes it difficult to place strain gauges at these locations.

[0011] Of course, implementing any product or method of this application does not necessarily require achieving all of the advantages described above at the same time. Attached Figure Description

[0012] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other embodiments can be obtained based on these drawings.

[0013] Figure 1 This is a schematic diagram of a direct-drive coupling structure in related technologies; Figure 2 Provided for the embodiments of this application Figure 1 A schematic diagram showing the target test position, the first reference position, and the second reference position set on the structure. Figure 3 Provided for the embodiments of this application Figure 1 A schematic diagram of strain gauges installed on the structure. Figure 4A flowchart illustrating a method for determining the fatigue life characteristic curve of coupling laminations as provided in an embodiment of this application; Figure 5 A flowchart illustrating the process of predicting the fatigue life of laminates provided in this application embodiment; Figure 6 A schematic diagram illustrating a complete process for predicting the fatigue life of coupling laminations, provided for embodiments of this application; Figure 7 A schematic diagram of the structure of the device for determining the fatigue life characteristic curve of coupling laminations provided in the embodiments of this application; Figure 8 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application. Detailed Implementation

[0014] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art based on this application are within the scope of protection of this application.

[0015] As mentioned in the background section above, due to the limitations of the coupling device structure, it is often difficult to place strain gauges at the stress concentration locations on the laminations in the coupling, making it difficult to accurately obtain the SN curve or PSN curve of the laminations to evaluate their fatigue resistance.

[0016] To facilitate understanding, an example of a possible device structure for a coupling will be provided. Figure 1 The device structure of a permanent magnet direct drive coupling is shown; see [link / reference]. Figure 1 The permanent magnet direct drive coupling includes a hollow shaft 1, on both sides of which are respectively provided a transmission disc 2, a transmission pin 3, a lamination pressure plate 4, and laminations 5. The specific functions of each component can be found in relevant technical documents. In practical applications, one end of the permanent magnet direct drive coupling is connected to the wheel, and the other end is connected to the motor output end to transmit the torque from the motor output end to the wheel and adapt to the wheel's displacement relative to the motor.

[0017] for Figure 1 Regarding the device structure shown, the stress concentration point of the stack 5 is located on the stack 5 at the edge of the stack pressure plate 4. See also Figure 2 and Figure 3 , Figure 2 It shows Figure 1 Detailed diagram of part a of the middle structure. Figure 3 This shows Figure 3 A schematic diagram of part b of the middle structure from the perspective of direction d1 in the illustration. See also... Figure 2Position A on the laminate 5, located at the edge of the lamination plate 4, is a stress concentration point (any point on the laminate 5 located at the edge of the lamination plate 4 can be considered a stress concentration point). To directly measure the stress level at position A, which is the stress concentration point, it is necessary to refer to... Figure 3 As illustrated, strain gauges are placed on both the inner and outer surfaces of laminate 5 at position A (i.e., the S1 and S2 surfaces of laminate 5 as shown in the diagram) to test the stress level at section AA of laminate 5 at position A. However, combined with... Figures 1-3 It can be seen that, due to the obstruction of the stacked plate 4, it is difficult to set strain gauges on both sides of position A on the stacked plate 5 in practical applications, thus making it difficult to accurately obtain the SN curve or PSN curve of the stacked plate 5.

[0018] To facilitate accurate determination of the SN or PSN curves of the laminations in a coupling, embodiments of this application provide a method for determining the fatigue life characteristic curves of coupling laminations. See [link to relevant documentation]. Figure 4 The method includes the following steps: Step S101: Apply a test load to the shaft of the coupling to conduct a fatigue test on the laminations in the coupling. The test load corresponds to a specific stress level at the target test position on the laminations, and obtain the number of fatigue cycles of the laminations under the specific stress level. The target test position is the stress concentration position of the laminations during operation. The specific stress level corresponding to the test load is determined by the following steps one to two: Step one: Obtain the stress values ​​collected by each strain gauge in the strain gauge group on the laminations during the application of the test load to the shaft. The strain gauge group includes: a first strain gauge and a second strain gauge respectively disposed on the inner and outer surfaces of the laminations at the first reference position, and a third strain gauge and a fourth strain gauge respectively disposed on the inner and outer surfaces of the laminations at the second reference position. The first reference position and the second reference position are located in the area of ​​the laminations that is not obstructed by other components, and the second reference position is located on the side of the first reference position away from the target test position. Step two: Calculate the estimated stress at the target test position based on the stress values ​​collected by each strain gauge, so as to obtain the stress level borne at the target position during the application of the test load to the shaft, which is taken as the specific stress level.

[0019] To facilitate understanding, let's first explain the concept of the fatigue life characteristic curve: The fatigue life characteristic curve of a laminate is used to characterize the relationship between the stress level borne by the laminate and the number of fatigue cycles (the number of fatigue cycles of a laminate under a stress level refers to the number of cycles the laminate undergoes under that stress level until fatigue failure occurs; the number of fatigue cycles is also often referred to as fatigue life). In practical applications, the fatigue life characteristic curve can be either an SN curve or a PSN curve.

[0020] In this embodiment, a test load needs to be applied to the shaft of the coupling so that the stress concentration points of the laminations bear a specific stress level. This allows for fatigue testing of the laminations to determine the number of fatigue cycles at the target test locations under different stress levels, thereby deriving the fatigue life characteristic curve of the laminations. However, as mentioned earlier, due to the limitations of the coupling's structure, it is often difficult to install strain gauges at the stress concentration points on the laminations, making it difficult to measure the stress level at these locations when a specific test load is applied to the shaft of the coupling.

[0021] In view of this, in the embodiments of this application, a target test position is specifically set at the stress concentration location of the laminations during the operation of the coupling, and a first reference position and a second reference position are set in an area on the laminations that is not obstructed by other components. The second reference position is located on the side of the first reference position away from the target test position. Since the first and second reference positions are not obstructed by other components, in practical applications, it is relatively easy to set the first and second strain gauges on the inner and outer surfaces of the laminations at the first reference position, and to set the third and fourth strain gauges on the inner and outer surfaces of the laminations at the second reference position. In one example, the target test position, the first reference position, and the second reference position can be set to be collinear in the plane direction of the laminations, and the first and second reference positions can be selected near the target test position.

[0022] By utilizing the fundamental principles of plane stress in elasticity, the estimated stress at the target test location on the laminate can be indirectly calculated based on the stress values ​​collected by the first to fourth strain gauges. Therefore, as described in steps one through three above, when a specific test load is applied to the shaft of the coupling, the estimated stress at the target test location can be calculated based on the stress values ​​collected by the first to fourth strain gauges, thus determining the stress level at the target test location under that test load and confirming the correspondence between the specific test load and the stress level. Consequently, during the fatigue test, by cyclically applying this test load to the shaft of the coupling to perform a fatigue test on the laminate, the number of fatigue cycles of the laminate under the corresponding stress level can be determined.

[0023] In practical applications, the stress level can be represented by parameters such as the stress amplitude or stress variation range of the estimated stress at the target test location during the application of the test load to the shaft. Therefore, in specific implementations, the estimated stress at the target test location during the application of the test load to the shaft can be calculated based on the stress values ​​collected by each strain gauge in the strain gauge group at different time points during the application of the test load to the shaft. This allows us to determine the stress level at the target test location under the test load.

[0024] Combination Figures 1-3 The structure in the example is illustrated below. See [link to example]. Figure 2 As illustrated, position A in the diagram can be taken as the target test point, position B as the first reference position, and position C as the second reference position. It can be seen that positions B and C are not obstructed by other components. In practical applications, the strain gauges 6 installed on the laminate 5 include: a first strain gauge 61 and a second strain gauge 62 respectively installed on the inner and outer surfaces of the laminate 5 at position B; and a third strain gauge 63 and a fourth strain gauge 64 respectively installed on the inner and outer surfaces of the laminate 5 at position C. Therefore, the estimated stress at section AA of the laminate 5 at position A can be indirectly calculated from the stress values ​​collected by each of the first strain gauge 61 to the fourth strain gauge 64.

[0025] For example, if in the direction of Figures 1-3 During the process of applying a load of amplitude α to the hollow shaft 1 of the coupling shown, based on the stress values ​​collected by the first strain gauge 61 to the fourth strain gauge 64, the stress level β borne by position A on the laminate 5 under the action of a load of amplitude α can be indirectly obtained. Therefore, the load of amplitude α can be used as the test load corresponding to stress level β. Thus, by cyclically applying a test load of amplitude α to the hollow shaft 1 of the coupling to conduct a fatigue test on the laminate 5, the number of fatigue cycles of the laminate 5 under stress level β can be determined.

[0026] Step S102: Based on different test loads corresponding to different stress levels at the target test location, repeat step S101 to obtain the number of fatigue cycles corresponding to each of the laminates under different stress levels.

[0027] Specifically, following the steps one and two described above, multiple different test loads corresponding to different stress levels at the target test location can be determined. Then, for each of these stress levels, a fatigue test can be conducted on the laminate by applying a test load corresponding to that stress level to the shaft of the coupling, thereby determining the number of fatigue cycles of the laminate under that stress level.

[0028] Step S103: Determine the fatigue life characteristic curve of the laminate based on the number of fatigue cycles corresponding to each of the laminates under different stress levels.

[0029] As mentioned above, based on steps S101-S102, the number of fatigue cycles corresponding to the laminations under different stress levels can be obtained. Therefore, the fatigue life characteristic curve used to characterize the relationship between the stress level borne by the laminations and the number of fatigue cycles of the laminations can be determined based on these data.

[0030] The method for determining the fatigue life characteristic curve of a coupling lamination provided in this application involves selecting a first reference position and a second reference position on the coupling lamination in areas not obscured by other components. The second reference position is located away from the target test position set at the stress concentration point, just away from the first reference position. Strain gauges are respectively installed on the inner and outer surfaces of the lamination at the first reference position and on the inner and outer surfaces of the lamination at the second reference position. Based on the stress values ​​collected by the strain gauges at the first and second reference positions on the lamination, the stress level at the target test position when a test load is applied to the coupling shaft can be indirectly calculated, establishing a correspondence between the test load and the stress level at the target test position. Based on this correspondence, and the number of fatigue cycles measured when the lamination is subjected to a fatigue test by applying a test load to the coupling shaft, the number of fatigue cycles corresponding to the lamination under different stress levels can be obtained, thereby determining the fatigue life characteristic curve of the lamination.

[0031] As can be seen from the above, the method for determining the fatigue life characteristic curve of coupling laminations provided in this application embodiment does not require directly arranging strain gauges at the stress concentration locations of the laminations, yet it can effectively calculate the stress level at the stress concentration locations on the laminations when a test load is applied to the shaft of the coupling. This solves the problem of difficulty in directly measuring the stress level at stress concentration locations, leading to inaccurate fatigue characteristic curves of the laminations, in scenarios where the coupling structure makes it difficult to place strain gauges at these locations.

[0032] In one embodiment of this application, the process of calculating the estimated stress at the target test location based on the stress values ​​collected by each strain gauge in the strain gauge group in step one above can be specifically implemented through the following steps a1-a5: Step a1: Based on the stress values ​​collected by the first strain gauge and the second strain gauge respectively, calculate the first membrane stress component and the first bending stress component at the first reference position.

[0033] It should be understood that, by using the basic principle of plane stress in elasticity, the first membrane stress component and the first bending stress component at the first reference position on the laminate can be calculated based on the stress values ​​collected by the strain gauges on the inner and outer surfaces of the laminate at the first reference position.

[0034] In one example, the calculation of the first membrane stress component can be based on the following equation (1): (1) in, Characterizing the first membrane stress component, The stress value acquired by the first strain gauge is characterized. The first strain gauge is set on the first side surface of the stack of strain gauges. The stress value acquired by the second strain gauge is characterized. The second strain gauge is set on the second side surface of the stack. The calculation of the first bending stress component can be achieved based on the following equation (2): (2) in, Characterizes the first bending stress component.

[0035] In practical applications, either the inner or outer surface of the laminate can be used as the first surface, and the other surface can be used as the second surface, depending on the actual situation.

[0036] Combination Figures 1-3 The structure is illustrated by way of example. Position A can be used as the target test position, position B as the first reference position, and position C as the third reference position. The first strain gauge 61 is disposed on the S1 side surface of the stack 5 at position A, the second strain gauge 62 is disposed on the S2 side surface of the stack 5 at position A, the third strain gauge 63 is disposed on the S1 side surface of the stack 5 at position B, and the fourth strain gauge 64 is disposed on the S2 side surface of the stack 5 at position B. In this case, the first membrane stress component and the first bending stress component at the cross section BB of the stack 5 at position B can be calculated based on the stress values ​​collected by the first strain gauge 61 and the second strain gauge 62 respectively, according to the above equations (1) and (2).

[0037] Step a2: Based on the stress values ​​collected by the third and fourth strain gauges, calculate the second membrane stress component and the second bending stress component at the second reference position.

[0038] Step a2 differs from the aforementioned step a1 only in that the calculated membrane stress component and bending stress component are applied to the positions on the laminate.

[0039] In one example, the calculation of the second membrane stress component can be based on the following equation (3): (3) in, Characterizes the second membrane stress component; The calculation of the second bending stress component can be achieved based on the following equation (4): (4) in, Characterizes the second bending stress component.

[0040] In step a1, combine Figures 1-3The exemplary description of the structure shows that the second membrane stress component and the second bending stress component at the cross section CC of the stack 5 at position C can be calculated based on the stress values ​​collected by the third strain gauge 63 and the fourth strain gauge 64 respectively, according to the above formulas (3) and (4).

[0041] Step a3: Determine the first or second membrane stress component as the third membrane stress component at the target test location.

[0042] According to the basic principle of plane stress in elasticity, the membrane stress component at the target test position on the stack is equal to the membrane stress components at the first reference position and the second reference position on the stack. Therefore, the first membrane stress component or the second membrane stress component can be used as the third membrane stress component at the target test position.

[0043] In step a2, combine Figures 1-3 An exemplary illustration of the structure, in one example, shows the second membrane stress component at the cross-section CC of the stack 5 at position C. The third membrane stress component at the target test location (That is, the membrane stress component at section AA at position A of the stacked sheet 5), such that: .

[0044] Step a4: Calculate the third bending stress component at the target test location based on the first bending stress component and the second bending stress component.

[0045] Using the basic principle of plane stress in elasticity, the third bending stress component of the target test point on the stack that is collinear with the first and second reference positions can be calculated based on the first bending stress component at the first reference position on the stack and the second bending stress component at the second reference position on the stack.

[0046] In one example, the calculation of the third bending stress component can be based on the following equation (5): (5) in, Characterizing the third bending stress component, Characterizes the distance between the second reference position and the target test position. This represents the distance between the second reference position and the first reference position, where the second reference position is farther from the target test position compared to the first reference position. Specifically, the distance between the two positions on the stack refers to the straight-line distance between them on the plane of the stack.

[0047] In step a3, combine Figures 1-3 For an exemplary description of the structure, see [link to documentation]. Figure 3The diagram shows the distance between the target test location A and the second reference location C, which is the distance between section AA and section CC in the diagram. And the distance between the first reference position B and the second reference position C, which is the distance between the BB section and the CC section shown in the figure. It can be based on , Based on the calculation results of the aforementioned equations (2) and (4), the third bending stress component at section AA of the laminate 5 at position A is calculated using the aforementioned equation (5).

[0048] Step a5: Based on the third membrane stress component and the third bending stress component, calculate the structural stress at the target test location to obtain the estimated stress.

[0049] Specifically, the structural stress at the target test location is obtained by adding the absolute values ​​of the third membrane stress component and the third bending stress component at the target test location. This can be expressed as equation (6) below: (6) in, Characterizing structural stress, Characterizing the third membrane stress component, Represents absolute value.

[0050] In step a4, combine Figures 1-3 An exemplary illustration of the structure, in conjunction with equation (6), describes the membrane stress components at section AA of the laminate 5 at position A. And the third bending stress component at section AA of laminate 5 at position A. The structural stress at section AA at position A of laminate 5 can then be obtained. .

[0051] In one example, combining equation (6), as well as equations (3) and (5), the structural stress at the target test location can be expressed by the following equation (7): (7) In practical applications, the fatigue life characteristic curves of the laminated sheets obtained from steps S101-S103 can be used to predict the fatigue life of the laminated sheets in the actual working conditions of the coupling. The following description, in conjunction with specific embodiments, is provided for reference. Figure 5 In one embodiment of this application, to predict the fatigue life of laminated sheets, the method provided in this application, in addition to steps S101-S103 described above, further includes... Figure 5 The following steps are shown: Step S104: Obtain the measured load spectrum during the actual operation of the coupling.

[0052] The measured load spectrum refers to the data on the distribution of loads on the coupling shaft over time, measured during the actual operation of the coupling. In practical applications, this can be measured by installing sensors on the coupling shaft.

[0053] Step S105: Process the load data at each time point in the measured load spectrum using the finite element model of the coupling to determine the expected stress level that the target test position on the lamination will bear during actual operation.

[0054] The finite element model of the coupling is specifically used for stress analysis. Based on the finite element model, the measured load spectrum can be analyzed to calculate the structural stress borne by the target test location during actual operation, thus determining the expected stress level at that location. The stress analysis process based on the finite element model can be implemented using finite element simulation software; details can be found in related technologies. By combining the measured load spectrum with the finite element model to determine the expected stress level borne by the target test location on the laminations during actual operation, it is unnecessary to physically place strain gauges on the laminations to collect stress data during actual operation. This avoids the impact of strain gauge placement on coupling operation and helps ensure the stability of coupling operation.

[0055] Step S106: Based on the fatigue life characteristic curve, determine the predicted number of fatigue cycles of the laminate under the expected stress level.

[0056] Specifically, the fatigue life characteristic curve is used to represent the relationship between the stress level borne by the lamination and the number of fatigue cycles to determine the number of fatigue cycles corresponding to the expected stress level calculated in step S105, and the determined number of fatigue cycles is used as the predicted number of fatigue cycles of the lamination under the expected stress level.

[0057] Step S107: Based on the number of cycles of the expected stress level that the lamination has already withstood, and the predicted number of fatigue cycles of the lamination under the expected stress level, determine the fatigue damage of the lamination. The fatigue damage is used to assess the life of the lamination.

[0058] The number of cycles of the expected stress level that the laminate has endured here specifically refers to the number of cycles of the expected stress level that the laminate endures during the actual operation of the coupling in step S104, which is the actual number of cycles of that expected stress level in the measured load spectrum.

[0059] In one example, the ratio of the number of cycles the laminate has endured at the expected stress level to the predicted number of fatigue cycles the laminate will undergo under the expected stress level can be used as the fatigue damage of the laminate. fatigue damage It can be used to evaluate the lifespan of a wafer stack.

[0060] In practical applications, fatigue damage can be considered as The maximum value shall not exceed 1, fatigue damage The closer the value is to 1, the more prone the laminated sheets are to fatigue failure. Based on this, fatigue damage... This can be used to evaluate the lifespan of laminates. In one possible implementation, fatigue damage can be used... reciprocal To characterize the lifetime of a wafer, its physical meaning is: to predict the maximum resistance the wafer can withstand. The actual working process in step S104.

[0061] In this embodiment, the fatigue life characteristic curve of the laminations obtained in steps S101-S103 is used to predict the fatigue life of the laminations during the actual operation of the coupling. Since the fatigue life characteristic curve itself has high accuracy, high prediction accuracy can also be achieved, which helps to ensure timely maintenance and replacement of the laminations in actual industrial scenarios, thus guaranteeing the continuity of industrial production.

[0062] Furthermore, traditional fatigue analysis methods typically use a finite element model to directly read the maximum stress at a target location, thus deriving the expected stress level at that location. The problem with this approach is that stress concentration points are highly sensitive to mesh height; different mesh sizes result in different stress levels. Therefore, calculating the expected stress level at the target test location on the laminate using this method, and then combining it with fatigue life characteristic curves to predict the laminate's life, may lead to inaccurate predictions. In view of this, in one embodiment of this application, a structural stress method can be used to decompose the stress experienced by the target test location during actual operation into membrane stress components and bending stress components. Then, based on these membrane stress components and bending stress components, the expected stress level of the structural stress at the target test location can be determined to improve the accuracy of the life prediction results. The specific details are as follows: In this embodiment of the application, the aforementioned step S105 specifically includes the following steps b1-b2: Step b1: Process the load data at each time point in the measured load spectrum using the finite element model, and apply the structural stress method to calculate the first expected stress level component of the membrane stress component and the second expected stress level component of the bending stress component at the target test location during actual operation.

[0063] Specifically, for the load data at a single time point in the measured load spectrum, the structural stress method can be applied. Using a finite element model, the membrane stress component and the bending stress component at the target test location at that time point can be calculated based on this load data. Based on this method, the membrane stress components experienced by the target test location at various time points during the actual operation of the coupling can be obtained. The stress amplitude or stress variation range of these membrane stress components can then be used as the first expected stress level component of the membrane stress. Similarly, the bending stress components experienced by the target test location at various time points during the actual operation of the coupling can also be obtained. The stress amplitude or stress variation range of these bending stress components can then be used as the second expected stress level component of the bending stress.

[0064] For details on how to process this load data using a finite element model, and how to calculate the membrane stress components and bending stress components at the target test location using the finite element model, please refer to relevant technologies.

[0065] Step b2: Based on the first expected stress level component and the second expected stress level component, determine the expected stress level of the structural stress that the target test location will bear during actual operation.

[0066] In this step, the sum of the first expected stress level component and the second expected stress level component can be used as the expected stress level of the structural stress that the target test location will experience during actual operation.

[0067] In determining the expected stress level at the target test location, this embodiment of the application decomposes the stress at the target test location into membrane stress components and bending stress components based on the structural stress method. Since the decomposed membrane stress components and bending stress components are only related to and balanced with the external forces, the structural stress at the stress concentration location on the laminate is only related to the nodal forces of the mesh and is independent of the mesh size; that is, the resulting structural stress mesh is insensitive. Based on the insensitive characteristic of the resulting structural stress mesh, this embodiment of the application uses the expected stress level of the structural stress in combination with the fatigue life characteristic curve to predict the life of the laminate. By combining the predicted stress level obtained from finite element simulation with the fatigue life characteristic curve obtained from experiments, the accuracy of the fatigue life prediction results, i.e., the prediction efficiency, can be effectively improved, and the prediction cost of the laminate fatigue life can be reduced.

[0068] Furthermore, in actual industrial scenarios, the measured load spectrum of the coupling during actual operation may not have a fixed amplitude and frequency, resulting in a highly chaotic measured load spectrum. This is not conducive to accurately assessing the expected stress level borne by the laminations. Therefore, in one embodiment of this application, the measured load spectrum can be decomposed using the rainflow counting method, and then fatigue prediction of the laminations can be performed based on the decomposed measured load spectrum to ensure the accuracy of the fatigue prediction results. The specific details are as follows: In this embodiment of the application, the aforementioned step b1 is preceded by the following step b0: Step b0: The measured load spectrum is processed by the rainflow counting method to decompose the measured load spectrum into equal amplitude loads of different levels.

[0069] For guidance on how to apply the rainflow counting method to decompose the measured load spectrum into different levels of equal-amplitude loads, please refer to relevant techniques.

[0070] After decomposing the measured load spectrum into different levels of equal amplitude loads, the number of cycles of the equal amplitude load at each level in the measured load spectrum can be recorded.

[0071] For ease of subsequent explanation, if the measured load spectrum is decomposed into a common... The first level of constant amplitude load, then specifically the first Levels ( From 1 to The actual number of cycles of a constant amplitude load (a natural number between 0 and 1) in the measured load spectrum is denoted as . .

[0072] Accordingly, step b1 mentioned above specifically includes: For each level of constant amplitude load, the load data in the constant amplitude load of that level is processed by the finite element model, and the structural stress method is applied to calculate the first expected stress level component of the membrane stress and the second expected stress level component of the bending stress at the target test location under the constant amplitude load of that level.

[0073] Similar to the explanation of step b1 above, for load data at a single time point within a uniform amplitude load of a certain level, the membrane stress and bending stress components borne by the target test location at that time point under the uniform amplitude load of that level can be calculated using a finite element model based on this load data. Based on this method, the membrane stress components borne by the target test location at different time points under the uniform amplitude load of that level can be obtained. Therefore, parameters such as the stress amplitude or stress variation range of the membrane stress components during this process can be used as the first expected stress level component of the membrane stress borne by the target test location under the uniform amplitude load of that level. Similarly, the bending stress components borne by the target test location at different time points within the uniform amplitude load of that level can also be obtained. Therefore, parameters such as the stress amplitude or stress variation range of the bending stress components during this process can be used as the second expected stress level component of the bending stress borne by the target test location under the uniform amplitude load of that level.

[0074] As an example, for the first The constant amplitude load of the [number] level can be obtained by measuring the target test position on the stack at that [number]. The range of variation of membrane stress components under constant amplitude loads at each level The target test position is characterized in the first place. The first expected stress level component under constant amplitude load of each level; and can be measured by the target test position on the stack at this first level. The range of bending stress components under constant amplitude loads of various levels The target test position is characterized in the first place. The second expected stress level component under constant amplitude load of each level.

[0075] Accordingly, step b2 mentioned above specifically includes: For each level of constant amplitude load, based on the first expected stress level component of the membrane stress and the second expected stress level component of the bending stress borne by the target test location under the constant amplitude load of that level, the expected stress level of the structural stress borne by the target test location under the constant amplitude load of that level is determined.

[0076] Specifically, for a level of constant amplitude load, the first expected stress level component of the membrane stress borne by the target test location under the constant amplitude load of that level can be added to the second expected stress level component of the bending stress borne by the target test location under the constant amplitude load of that level to obtain the expected stress level of the structural stress borne by the target test location under the constant amplitude load of that level.

[0077] Following the previous example, the target test position is at the [number]th position. The expected stress level of the structure under constant amplitude load of level 1 can be determined by the target test location at the 1st level. The range of structural stress variation under constant amplitude loads at various levels Characterization, specifically .

[0078] Accordingly, the aforementioned step S106 specifically includes: For each level of constant amplitude load, based on the fatigue life characteristic curve, the predicted number of fatigue cycles of the laminate under the expected stress level corresponding to the constant amplitude load of that level is determined.

[0079] The expected stress level corresponding to a certain level of constant amplitude load refers to the expected stress level of the structure at the target test location under a certain level of constant amplitude load. Specifically, for the first... The expected stress level corresponding to each level of constant amplitude load can be determined using the correspondence represented by the fatigue life characteristic curve. The number of fatigue cycles corresponding to this stress level can then be used as the number of fatigue cycles for the lamination in the [number of]th [period]. The predicted number of fatigue cycles under the expected stress level corresponding to each level of constant amplitude load. For ease of subsequent explanation, the number of cycles will be... The predicted number of fatigue cycles under the expected stress level corresponding to each level of constant amplitude load is abbreviated as: .

[0080] Accordingly, the aforementioned step S107 specifically includes the following steps c1-c2: Step c1: For each level of constant amplitude load, based on the number of cycles of constant amplitude load that the lamination has already borne and the predicted number of fatigue cycles of the lamination under the expected stress level corresponding to the constant amplitude load of that level, determine the single-level fatigue damage corresponding to the constant amplitude load of that level.

[0081] Regarding the first The first level of constant amplitude load can specifically refer to the load already borne by the laminate. The number of cycles for the constant amplitude load at each level, that is, the number of cycles for the first level of constant amplitude load. The actual number of cycles of a constant amplitude load at each level in the random load spectrum , and the stacked pieces in the first Predicted fatigue cycle number under expected stress levels corresponding to each level of constant amplitude load. The ratio, as the first The single-level fatigue damage corresponding to the constant amplitude load of each level. The single-level fatigue damage corresponding to each level of constant amplitude load is denoted as . ,but .

[0082] Step c2: Accumulate the single-level fatigue damage corresponding to each level of constant amplitude load to obtain the fatigue damage of the laminate.

[0083] In other words, fatigue damage of laminated sheets , which is all the components decomposed from the random load spectrum The cumulative value of single-level fatigue damage corresponding to each level of constant amplitude load, i.e. .

[0084] In one embodiment of this application, the PSN curve can be selected as the fatigue life characteristic curve. In this case, for a test load corresponding to a specific stress level, the aforementioned step S101, "applying a test load to the shaft of the coupling to perform a fatigue test on the laminations in the coupling, and obtaining the number of fatigue cycles of the laminations under a specific stress level," specifically includes: Based on a preset number of tests, a test load corresponding to the specific stress level is applied to the shaft of the coupling to conduct multiple fatigue tests on the laminations in the coupling, thereby obtaining a set of fatigue cycle numbers of the laminations under a specific stress level.

[0085] As can be easily understood from the preceding explanation, the solution of this application requires determining multiple different test loads corresponding to multiple different stress levels at the target test location. In the embodiments of this application, for each test load, it is necessary to apply that test load to the shaft of the coupling to conduct multiple fatigue tests on the laminate based on that test load, and obtain a set of fatigue cycle numbers of the laminate under the stress level corresponding to that test load.

[0086] In short, if a total of [number] locations relative to the target test location are determined... The different stress levels correspond to The first different test load, the indivual( From 1 to (Natural numbers between) test load and target test position The stress level corresponds to the [number]th stress level. Then, based on the [number]th [level]... A total of test loads were applied to the stack. The fatigue test can determine the stacked sheets in the first fatigue test. Under stress levels of all levels The number of fatigue cycles is denoted as follows: , , ..., ,this The fatigue cycle count, i.e., the number of stacking cycles in the [number]th fatigue cycle, is [number] times. A set of fatigue cycles under stress levels of various grades.

[0087] Accordingly, the aforementioned step S103 specifically includes: Based on a set of fatigue cycle numbers corresponding to each of the laminates at different stress levels, the coefficients in the mathematical expression of the probabilistic form of the stress-life curve (i.e., the mathematical expression of the PSN curve) are solved to obtain the stress-life curve of the laminate at a specified survival probability (i.e., the PSN curve at a specified survival probability), which serves as the fatigue life characteristic curve.

[0088] In other words, by fitting the mathematical expression of the PSN curve to the set of fatigue cycle numbers corresponding to each stress level of the laminate and solving for the coefficients, the fatigue life characteristic curve of the laminate can be obtained. The survival probability can be set according to actual needs.

[0089] To facilitate understanding, the following is a possible implementation method for solving the PSN curve of the stacked wafers using a fitting approach: The mathematical expression for the PSN curve is usually represented by a logarithm to characterize the stress level and the number of fatigue cycles, as shown in equation (8) below: (8) in, Representing the logarithm, Characterizes the stress level experienced at the target test location on the laminate. Characterizing the number of fatigue cycles, and For coefficients, Specifies the survival probability.

[0090] To solve and This allows for the calculation of the mean and variance of a set of logarithmic fatigue cycles for each stress level of the laminate. The laminate is in the [stress level]... The average number of fatigue cycles under a set of stress levels See equation (9) below for variance. See equation (10) below: (9) (10) Since the logarithmic fatigue cycle count of the laminated sheets under a stress level follows a normal distribution, a given survival probability... Below, the stacked pieces are in the first... Logarithmic fatigue cycle count under stress levels of various levels It satisfies the following equation (11): (11) in, For parameter items, Indicates the stacked pieces at the 1st The standard deviation of a set of fatigue cycles under stress levels can be determined based on the following equation (12): (12) Equation (12) specifically illustrates the specified survival probability. by An expression for variables, where, Pi This is the natural base. In practical applications, the survival probability can be set according to actual needs. The value of is obtained based on equation (12). The value of .

[0091] Based on the above equations (9)-(12), the coefficients in equation (8) can be solved by the following equations (13) and (14): (13) in, Characterizes the specified survival probability Below, the stacked pieces are all The mean of the logarithmic fatigue cycle count under each stress level. Characterizing the first Each level of stress, Representing all The mean of the logarithms of each stress level.

[0092] (14)

[0093] In one embodiment of this application, a complete process for predicting the fatigue life of coupling laminations is provided. See also Figure 6 The process includes a first branch for determining the PSN curve of the laminations, comprising steps S11-S13; a second branch for calculating the stress level experienced by the laminations during the actual operation of the coupling, comprising steps S21-S23; and a final step S3. Step S11: Calculate the mean and variance of the logarithm of the number of fatigue cycles of the laminate under each structural stress level using fatigue test data.

[0094] For the acquisition of fatigue test data, please refer to the explanation of steps S101-S102 above. For the calculation of the mean and variance of the logarithm of the number of fatigue cycles, please refer to the explanation of equations (9)-(10) above.

[0095] Step S12: Calculate the probabilistic fatigue cycle number of the stack under a given survival probability based on the mean and variance of the logarithm of the fatigue cycle number.

[0096] See the explanation of equation (11) above.

[0097] Step S13: Fit the PSN curve of the coupling laminations using the least squares method.

[0098] See the explanation of equations (8) to (14) above.

[0099] Step S21: The measured load spectrum is processed using the rainflow counting method and decomposed into several levels of equal amplitude loads.

[0100] See the previous explanation of step b0.

[0101] Step S22: Establish the finite element model of the coupling.

[0102] Step S23: Calculate the range of structural stress variation of the laminate under each level of constant amplitude load.

[0103] See the previous explanation of steps b1-b2.

[0104] Step S3: Predict the fatigue life of the coupling laminations.

[0105] See the previous description of steps S106-S107.

[0106] Based on the same inventive concept, this application also provides an apparatus for determining the fatigue life characteristic curve of coupling laminations, see [link to relevant documentation]. Figure 8 The device includes: Test module 801 is used to apply a test load to the shaft of the coupling to conduct a fatigue test on the laminations in the coupling. The test load corresponds to a specific stress level at a target test location on the laminations, and the number of fatigue cycles of the laminations under the specific stress level is obtained. The target test location is the stress concentration location of the laminations, and the specific stress level corresponding to the test load is determined through the following steps one and two: Step one: Obtain the stress values ​​collected by each strain gauge in the strain gauge group on the laminations during the application of the test load to the shaft. The strain gauge group includes: strain gauges respectively disposed on the laminations... The first and second strain gauges on the inner and outer surfaces of the sheet at the first reference position, and the third and fourth strain gauges on the inner and outer surfaces of the sheet at the second reference position, respectively; the first and second reference positions are located in areas on the sheet that are not obstructed by other components, and the second reference position is located on the side of the first reference position away from the target test position; Step 2: Calculate the estimated stress at the target test position based on the stress values ​​collected by each strain gauge, so as to obtain the stress level at the target position during the application of the test load to the shaft, which is taken as the specific stress level; The repeat module 802 is used to instruct the test module 801 to repeatedly perform the step of applying the test load to the shaft of the coupling to perform fatigue testing on the laminations in the coupling based on different test loads corresponding to different stress levels at the target test location, so as to obtain the number of fatigue cycles corresponding to the laminations under different stress levels. The determination module 801 is used to determine the fatigue life characteristic curve of the laminate based on the number of fatigue cycles corresponding to the laminate under different stress levels.

[0107] For more information on the apparatus for determining the fatigue life characteristic curve of coupling laminations and its beneficial effects, please refer to the content of the method embodiment for determining the fatigue life characteristic curve of coupling laminations mentioned above.

[0108] In one embodiment of this application, the step of calculating the estimated stress at the target test location based on the stress values ​​collected by each strain gauge includes: Based on the stress values ​​collected by the first strain gauge and the second strain gauge respectively, the first membrane stress component and the first bending stress component at the first reference position are calculated. Based on the stress values ​​collected by the third strain gauge and the fourth strain gauge respectively, the second membrane stress component and the second bending stress component at the second reference position are calculated. The first membrane stress component or the second membrane stress component is determined as the third membrane stress component at the target test location; Based on the first bending stress component and the second bending stress component, the third bending stress component at the target test location is calculated; Based on the third membrane stress component and the third bending stress component, the structural stress at the target test location is calculated as the estimated stress.

[0109] In one embodiment of this application, the first membrane stress component at the first reference location is calculated based on the following formula:

[0110] in, Characterizing the first membrane stress component, The stress value acquired by the first strain gauge is characterized, and the first strain gauge is disposed on the first side surface of the stack of strain gauges. The stress value acquired by the second strain gauge is characterized, and the second strain gauge is disposed on the second side surface of the stack; The first bending stress component at the first reference location is calculated based on the following formula:

[0111] in, Characterizing the first bending stress component; The second membrane stress component at the second reference position is calculated based on the following formula:

[0112] in, Characterizing the second membrane stress component, The stress value acquired by the third strain gauge is characterized, and the third strain gauge is disposed on the first side surface of the stack. The stress value acquired by the fourth strain gauge is characterized, and the fourth strain gauge is disposed on the second side surface of the stack; The second bending stress component at the second reference location is calculated based on the following formula:

[0113] in, Characterizing the second bending stress component; The third bending stress component at the target test location is calculated based on the following formula:

[0114] in, Characterizing the third bending stress component, This represents the distance between the second reference position and the target test position. The distance between the second reference position and the first reference position is represented, wherein the second reference position is farther away from the target test position compared to the first reference position; The structural stress at the target test location is calculated based on the following formula:

[0115] in, Characterizing the stress of the structure, Characterizing the third membrane stress component, Represents absolute value.

[0116] In one embodiment of this application, the apparatus for determining the fatigue life characteristic curve of the coupling laminations further includes: The acquisition module is used to acquire the measured load spectrum during the actual operation of the coupling. The processing module is used to process the load data at each time point in the measured load spectrum through the finite element model of the coupling, so as to determine the expected stress level that the target test position on the lamination will bear during the actual working process; The cycle number determination module is used to determine the predicted fatigue cycle number of the laminate under the expected stress level based on the fatigue life characteristic curve. A prediction module is used to determine fatigue damage of the laminate based on the number of cycles the laminate has already endured at the expected stress level and the predicted number of fatigue cycles the laminate has undergone under the expected stress level. This fatigue damage is used to assess the lifespan of the laminate. In one embodiment of this application, the processing module includes: The processing unit is used to process the load data at each time point in the measured load spectrum through the finite element model, and to calculate the first expected stress level component of the membrane stress component and the second expected stress level component of the bending stress component at the target test location during the actual working process by applying the structural stress method. The determining unit is configured to determine, based on the first expected stress level component and the second expected stress level component, the expected stress level of the structural stress that the target test location experiences during the actual working process.

[0117] In one embodiment of this application, the apparatus for determining the fatigue life characteristic curve of the coupling laminations further includes: The decomposition module is used to process the measured load spectrum using the rainflow counting method to decompose the measured load spectrum into equal-amplitude loads of different levels. The processing unit is specifically used to process the load data of the constant amplitude load at each level through the finite element model, and to calculate the first expected stress level component of the membrane stress and the second expected stress level component of the bending stress at the target test location under the constant amplitude load at that level by applying the structural stress method. The determining unit is specifically used to determine the expected stress level of the structural stress borne by the target test location under the constant amplitude load at each level, based on the first expected stress level component of the membrane stress borne by the target test location under the constant amplitude load at that level, and the second expected stress level component of the bending stress. The cycle count determination module is specifically used to determine the single-level fatigue damage corresponding to the constant amplitude load for each level, based on the number of cycles of the constant amplitude load that the laminate has already borne at that level, and the predicted fatigue cycle count of the laminate under the expected stress level corresponding to the constant amplitude load at that level; and to accumulate the single-level fatigue damage corresponding to each level of constant amplitude load to obtain the fatigue damage of the laminate.

[0118] In one embodiment of this application, for the test load corresponding to the specific stress level, the test module 801 is specifically used to apply the test load corresponding to the specific stress level to the shaft of the coupling based on a preset number of test cycles to conduct multiple fatigue tests on the laminations in the coupling, and obtain a set of fatigue cycle numbers of the laminations under the specific stress level. The determination module 803 is specifically used to solve the coefficients in the mathematical expression of the probabilistic form of the stress-life curve based on a set of fatigue cycle numbers corresponding to the stack at different stress levels, and obtain the stress-life curve of the stack at a specified survival probability, which is used as the fatigue life characteristic curve.

[0119] This application also provides an electronic device, such as... Figure 8 As shown, it includes a processor 801, a communication interface 802, a memory 803, and a communication bus 804. The processor 801, communication interface 802, and memory 803 communicate with each other via the communication bus 804. Memory 803 is used to store computer programs; The processor 801, when executing the program stored in the memory 803, implements the method for determining the fatigue life characteristic curve of the coupling laminations provided in any of the above embodiments.

[0120] The communication bus mentioned in the above electronic devices can be a Peripheral Component Interconnect (PCI) bus or an Extended Industry Standard Architecture (EISA) bus, etc. This communication bus can be divided into address bus, data bus, control bus, etc. For ease of illustration, only one thick line is used to represent it in the diagram, but this does not mean that there is only one bus or one type of bus.

[0121] The communication interface is used for communication between the aforementioned electronic devices and other devices.

[0122] The memory may include random access memory (RAM) or non-volatile memory (NVM), such as at least one disk storage device. Optionally, the memory may also be at least one storage device located remotely from the aforementioned processor.

[0123] The processors mentioned above can be general-purpose processors, including central processing units (CPUs), network processors (NPs), etc.; they can also be digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components.

[0124] In another embodiment provided in this application, a computer-readable storage medium is also provided, which stores a computer program that, when executed by a processor, implements the steps of any of the methods described above for determining the fatigue life characteristic curve of coupling laminations.

[0125] In another embodiment provided in this application, a computer program product containing instructions is also provided, which, when run on a computer, causes the computer to execute any of the methods described above for determining the fatigue life characteristic curve of coupling laminations.

[0126] In the above embodiments, implementation can be achieved entirely or partially through software, hardware, firmware, or any combination thereof. When implemented using software, it can be implemented entirely or partially as a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, all or part of the processes or functions described in the embodiments of this application are generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wired (e.g., coaxial cable, fiber optic, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium can be any available medium that a computer can access or a data storage device such as a server or data center that integrates one or more available media. The available medium can be a magnetic medium (e.g., floppy disk, hard disk, magnetic tape), an optical medium (e.g., DVD), or a semiconductor medium (e.g., solid state disk (SSD)).

[0127] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0128] The various embodiments in this specification are described in a related manner. Similar or identical parts between embodiments can be referred to interchangeably. Each embodiment focuses on its differences from other embodiments. In particular, the apparatus, electronic equipment, and readable storage medium for determining the fatigue life characteristic curve of coupling laminations are basically similar to the method embodiments, and therefore the description is relatively simple; relevant parts can be referred to the descriptions in the method embodiments.

[0129] The above description is merely a preferred embodiment of this application and is not intended to limit the scope of protection of this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application are included within the scope of protection of this application.

Claims

1. A method for determining the fatigue life characteristic curve of coupling laminations, characterized in that, include: A test load is applied to the shaft of the coupling to conduct a fatigue test on the laminations in the coupling. The test load corresponds to a specific stress level at a target test location on the laminations, and the number of fatigue cycles of the laminations under the specific stress level is obtained. The target test location is the stress concentration location of the laminations, and the specific stress level corresponding to the test load is determined through the following steps one and two: Step 1: Obtain the stress values ​​collected by each strain gauge in the strain gauge group on the stack during the application of the test load to the shaft; the strain gauge group includes: a first strain gauge and a second strain gauge respectively disposed on the inner and outer surfaces of the stack at the first reference position, and a third strain gauge and a fourth strain gauge respectively disposed on the inner and outer surfaces of the stack at the second reference position; the first reference position and the second reference position are located in the area of ​​the stack that is not obstructed by other components, and the second reference position is located on the side of the first reference position away from the target test position; Step 2: Calculate the estimated stress at the target test location based on the stress values ​​collected by each strain gauge, so as to obtain the stress level at the target location during the application of the test load to the shaft, which is taken as the specific stress level; Based on different test loads corresponding to different stress levels at the target test location, the step of applying test loads to the shaft of the coupling to perform fatigue tests on the laminations in the coupling is repeated to obtain the number of fatigue cycles corresponding to each lamination under different stress levels. The fatigue life characteristic curve of the stack is determined based on the number of fatigue cycles corresponding to different stress levels.

2. The method according to claim 1, characterized in that, The calculation of the estimated stress at the target test location based on the stress values ​​collected by each strain gauge includes: Based on the stress values ​​collected by the first strain gauge and the second strain gauge respectively, the first membrane stress component and the first bending stress component at the first reference position are calculated. Based on the stress values ​​collected by the third strain gauge and the fourth strain gauge respectively, the second membrane stress component and the second bending stress component at the second reference position are calculated. The first membrane stress component or the second membrane stress component is determined as the third membrane stress component at the target test location; Based on the first bending stress component and the second bending stress component, the third bending stress component at the target test location is calculated; Based on the third membrane stress component and the third bending stress component, the structural stress at the target test location is calculated as the estimated stress.

3. The method according to claim 2, characterized in that, The first membrane stress component at the first reference position is calculated based on the following formula: in, Characterizing the first membrane stress component, The stress value acquired by the first strain gauge is characterized, and the first strain gauge is disposed on the first side surface of the stack of strain gauges. The stress value acquired by the second strain gauge is characterized, and the second strain gauge is disposed on the second side surface of the stack; The first bending stress component at the first reference location is calculated based on the following formula: in, Characterizing the first bending stress component; The second membrane stress component at the second reference position is calculated based on the following formula: in, Characterizing the second membrane stress component, The stress value acquired by the third strain gauge is characterized, and the third strain gauge is disposed on the first side surface of the stack. The stress value acquired by the fourth strain gauge is characterized, and the fourth strain gauge is disposed on the second side surface of the stack; The second bending stress component at the second reference location is calculated based on the following formula: in, Characterizing the second bending stress component; The third bending stress component at the target test location is calculated based on the following formula: in, Characterizing the third bending stress component, This represents the distance between the second reference position and the target test position. The distance between the second reference position and the first reference position is represented, wherein the second reference position is farther away from the target test position compared to the first reference position; The structural stress at the target test location is calculated based on the following formula: in, Characterizing the stress of the structure, Characterizing the third membrane stress component, Represents absolute value.

4. The method according to claim 1, characterized in that, The method further includes: Obtain the measured load spectrum during the actual operation of the coupling; The load data at each time point in the measured load spectrum are processed by the finite element model of the coupling to determine the expected stress level that the target test position on the lamination will bear during the actual working process. Based on the fatigue life characteristic curve, the predicted number of fatigue cycles of the laminate under the expected stress level is determined; The fatigue damage of the lamination is determined based on the number of cycles the lamination has endured at the expected stress level and the predicted number of fatigue cycles the lamination will undergo under the expected stress level. This fatigue damage is used to assess the life of the lamination.

5. The method according to claim 4, characterized in that, The process of processing the load data at various time points in the measured load spectrum using a finite element model of the coupling to determine the expected stress level experienced by the target test position on the lamination during actual operation includes: The load data at each time point in the measured load spectrum are processed by the finite element model, and the structural stress method is applied to calculate the first expected stress level component of the membrane stress component and the second expected stress level component of the bending stress component at the target test location during the actual working process. Based on the first expected stress level component and the second expected stress level component, the expected stress level of the structural stress that the target test location will experience during the actual working process is determined.

6. The method according to claim 5, characterized in that, Before processing the load data at each time point in the measured load spectrum using the finite element model of the coupling, the method further includes: The measured load spectrum is processed by rainflow counting method to decompose the measured load spectrum into equal amplitude loads of different levels; The process involves processing the load data at various time points in the measured load spectrum using the finite element model, and applying the structural stress method to calculate the first expected stress level component of the membrane stress and the second expected stress level component of the bending stress at the target test location during the actual working process. This includes: For each level of constant amplitude load, the load data in the constant amplitude load of that level is processed by the finite element model, and the structural stress method is applied to calculate the first expected stress level component of the membrane stress and the second expected stress level component of the bending stress at the target test location under the constant amplitude load of that level. Determining the expected stress level of the structural stress experienced by the target test location during the actual working process based on the first stress level component and the second stress level component includes: For each level of constant amplitude load, based on the first expected stress level component of the membrane stress borne by the target test location under the constant amplitude load of that level, and the second expected stress level component of the bending stress, the expected stress level of the structural stress borne by the target test location under the constant amplitude load of that level is determined. The step of determining the predicted number of fatigue cycles of the laminate under the expected stress level based on the fatigue life characteristic curve includes: For each level of constant amplitude load, based on the fatigue life characteristic curve, the predicted number of fatigue cycles of the laminate under the expected stress level corresponding to the constant amplitude load of that level is determined; The determination of the cumulative fatigue damage of the laminate based on the number of cycles subjected to the expected stress level and the predicted number of fatigue cycles of the laminate under the corresponding expected stress level includes: For each level of constant amplitude load, based on the number of cycles of the constant amplitude load that the laminate has already borne, and the predicted number of fatigue cycles of the laminate under the expected stress level corresponding to the constant amplitude load of that level, the single-level fatigue damage corresponding to the constant amplitude load of that level is determined. The fatigue damage of the laminate is obtained by accumulating the single-level fatigue damage corresponding to each level of constant amplitude load.

7. The method according to claim 1, characterized in that, For a test load corresponding to the specific stress level, applying a test load to the shaft of the coupling to perform a fatigue test on the laminates in the coupling, and obtaining the number of fatigue cycles of the laminates under the specific stress level, includes: Based on a preset number of tests, a test load corresponding to the specific stress level is applied to the shaft of the coupling to conduct multiple fatigue tests on the laminations in the coupling, thereby obtaining a set of fatigue cycle numbers of the laminations under the specific stress level. The determination of the fatigue life characteristic curve of the laminate based on the number of fatigue cycles corresponding to different stress levels includes: Based on a set of fatigue cycle counts corresponding to the stack at different stress levels, the coefficients in the mathematical expression of the probabilistic form of the stress-life curve are solved to obtain the stress-life curve of the stack at a specified survival probability, which is used as the fatigue life characteristic curve.

8. An apparatus for determining the fatigue life characteristic curve of coupling laminations, characterized in that, include: The testing module is used to apply a test load to the shaft of the coupling to conduct a fatigue test on the laminates in the coupling. The test load corresponds to a specific stress level at a target test location on the laminate, and the number of fatigue cycles of the laminate under the specific stress level is obtained. The target test location is the stress concentration location of the laminate, and the specific stress level corresponding to the test load is determined through the following steps one and two: Step one: Obtain the stress values ​​collected by each strain gauge in the strain gauge group on the laminate during the application of the test load to the shaft. The strain gauge group includes strain gauges respectively disposed on the laminate. The first and second strain gauges on the inner and outer surfaces of the first reference position are respectively disposed on the third and fourth strain gauges on the inner and outer surfaces of the stack at the second reference position; the first reference position and the second reference position are located in the area of ​​the stack that is not obstructed by other components, and the second reference position is located on the side of the first reference position away from the target test position; Step 2: Calculate the estimated stress at the target test position based on the stress values ​​collected by each strain gauge, so as to obtain the stress level borne at the target position during the application of the test load to the shaft, as the specific stress level; The repeat module is used to instruct the test module to repeatedly perform the step of applying the test load to the shaft of the coupling to conduct a fatigue test on the laminations in the coupling based on different test loads corresponding to different stress levels at the target test location, so as to obtain the number of fatigue cycles corresponding to each lamination under different stress levels. The determination module is used to determine the fatigue life characteristic curve of the laminate based on the number of fatigue cycles corresponding to the laminate under different stress levels.

9. An electronic device, characterized in that, It includes a processor, a communication interface, a memory, and a communication bus, wherein the processor, the communication interface, and the memory communicate with each other through the communication bus; Memory, used to store computer programs; A processor, when executing a program stored in memory, implements the steps of the method described in any one of claims 1-7.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that, when executed by a processor, implements the steps of the method described in any one of claims 1-7.

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