Fan blade vibration stress calculation method and device, electronic equipment and storage medium

Abstract

The invention discloses a fan blade vibration stress calculation method and device, electronic equipment and a storage medium, and the method comprises the steps: S1, determining a point where the blade tip circumferential vibration displacement, which can be excited by an excitation source, of a blade in each-order mode is determined to be greater than a preset value within a working rotation speed range through finite element analysis, and determining a final blade tip amplitude measurement point; and S2, calculating the vibration stress of the fan blade in each order mode under each working condition according to the displacement of the blade tip amplitude measuring point in each order mode, the position of the blade measured by the final blade tip amplitude measuring point in a static state, and the relationship between the displacement of each measuring point in each order mode and the vibration stress in the corresponding order mode. According to the invention, fewer final blade tip amplitude measurement points can be selected to realize blade tip amplitude measurement, so that the test frequency and period are greatly reduced; meanwhile, the deformation of the blade under the static load is considered, and the displacement change of the measuring point caused by the deformation of the blade is avoided, so that the error of the vibration stress of the fan blade in each modal under each working condition obtained by conversion is smaller and more accurate.

Description

Technical Field

[0001] The present invention relates to the technical field of aeroengines, and in particular, to a method, device, equipment, and storage medium for calculating the vibration stress of fan blades. Background Art

[0002] Figure 1 It is a fan blade of a turbofan engine. The working environment is harsh. During component and whole-machine tests, it is necessary to monitor its vibration. Non-contact vibration measurement of rotor blades can realize real-time monitoring of the vibration displacement at the blade tip. The selection of measurement points affects the reliability of the measurement result of the vibration displacement at the blade tip. How to convert the measured vibration displacement at the blade tip into the vibration stress of the blade is a key factor in judging whether the blade vibration is excessive.

[0003] The fan blades of turbofan engines have a large aspect ratio, a high stress level, and a harsh working condition. The centrifugal force generated by high-speed rotation and the aerodynamic force caused by air flow impact easily cause the blades to vibrate. The vibration generates a large vibration stress, which is likely to cause fatigue failure of the blades and is an important factor leading to fan blade failures. To verify, design, optimize, and improve the vibration characteristics of fan blades, it is necessary to monitor their vibration during component and whole-machine tests. Non-contact vibration measurement based on the tip-timing principle can measure the amplitude at the blade tip in real time, and then deduce the vibration stress of the blade through a certain algorithm.

[0004] The principle of the non-contact vibration measurement system for rotor blades is as Figure 2 shown. A standard speed pulse is used to trigger a new data acquisition every time the rotor rotates one circle. The optical fiber or eddy current probe installed on the casing measures the arrival time of the reflected pulses at the blade tips of the specified numbers in sequence. When the blade vibrates, the blade tip will deviate forward or backward in the circumferential direction (as Figure 3 shown), causing a change in the pulse arrival time. Combining the synchronization signal provided by the speed synchronization sensor and the diameter of the circumference where the blade tip of the measured blade is located, the vibration displacement amplitude and frequency of the blade in the circumferential tangential direction (as Figure 3 shown) can be calculated.

[0005] Relatively common blade vibration monitoring methods include non-contact vibration measurement of rotor blades. Existing non-contact vibration measurement of rotor blades usually only measures a limited number of modal orders, that is, only measures the resonance that may exist in the blade, measures the vibration of a certain modal order, and it is difficult to measure the vibration conditions of all modal orders of the blade. At the same time, for the subsequent conversion of the measured vibration displacement at the blade tip into the vibration stress, the stress conversion does not consider the displacement change of the measurement point caused by the blade deformation, resulting in a large deviation between the finally converted stress value and the actual value. Summary of the Invention

[0006] On the one hand, the present application provides a method for calculating the vibration stress of a fan blade, which is used to solve the technical problem that the stress value obtained by conversion has a large deviation from the actual value during the non-contact vibration measurement of a rotor blade.

[0007] The present application is implemented through the following solutions: A method for calculating the vibration stress of a fan blade, comprising the steps of: S1. Determine, through finite element analysis, the points where the circumferential vibration displacement of the blade tip in each order of mode excited by the excitation source within the working speed range is greater than a preset value, and determine the final blade tip amplitude measurement points. S2. Calculate the vibration stress of the fan blade in each order of mode under each working condition according to the displacement of the blade tip amplitude measurement points in each order of mode, the position of the blade measured at the final blade tip amplitude measurement point under static conditions, and the relationship between the displacements of each measurement point and the vibration stress in the corresponding order of mode.

[0008] Further, the step S1 specifically includes the steps of: S11. Determine, through finite element analysis, the points where the circumferential vibration displacement of the blade tip in multiple orders of mode excited by the excitation source within the working speed range is greater than a preset value, determine the potential blade tip amplitude measurement points in each order of mode, and calculate the relationship between the displacement of each potential blade tip amplitude measurement point and the maximum modal stress in the corresponding order. S12. Select the minimum number of blade tip amplitude measurement points that meet the set conditions from the potential blade tip amplitude measurement points to determine the final blade tip amplitude measurement points.

[0009] Further, the step S11 specifically includes the steps of: S111. First, through finite element analysis, calculate the axial displacement of the blade tip of the fan blade under typical working conditions to obtain the axial displacement of each node at the blade tip of the fan blade. S112. Determine the optional range of the blade tip amplitude measurement points according to the selected sensor size specification and the maximum axial displacement of each node at the blade tip of the blade. S113. Through finite element analysis, determine that the maximum modal order excited by the excitation source within the working speed range is n, take n as the modal order to be measured, and calculate the modal vibration shape and modal stress distribution of each order of mode under each working condition. S114. For each order of mode to be measured, read out the maximum modal circumferential displacement and the corresponding node number within the optional area of the blade tip amplitude measurement points, take this node as the potential blade tip amplitude measurement point of this order of mode, and calculate the relationship between the displacement of each potential blade tip amplitude measurement point and the maximum modal stress in the corresponding order.

[0010] Further, the typical working conditions include ground idle condition, in-air idle condition, cruise condition, takeoff condition, and maximum steady state condition.

[0011] Further, step S12 specifically includes the following steps: S121. Set the maximum modal stress of each order to 30 MPa, and calculate the axial displacement A of each potential tip amplitude measurement point in each order of mode according to the relationship between the displacement of each potential tip amplitude measurement point and the maximum modal stress of the corresponding order, ij to obtain an n×n matrix; S122. Select, from the potential tip amplitude measurement points, the fewest measurement points that make at least one axial A ij > 0.1 mm in each column as the final tip amplitude measurement points.

[0012] Further, step S122 specifically includes the following steps: S1221. Select the potential tip amplitude measurement points of the first-order mode. When the selected potential tip amplitude measurement points of the first-order mode make at least one axial displacement A ij > 0.1 m in each column of the matrix, then only select the potential tip amplitude measurement points of the first-order mode as the final tip amplitude measurement points; S1222. When the selected potential tip amplitude measurement points of the first-order mode cannot make at least one axial displacement A ij > 0.1 m in each column of the matrix, then continue to select the potential tip amplitude measurement points of the second-order mode. When the selected potential tip amplitude measurement points of the second-order mode and the potential tip amplitude measurement points of the first-order mode make at least one axial displacement A ij > 0.1 m in each column of the matrix, then take the potential tip amplitude measurement points of the first-order mode and the selected potential tip amplitude measurement points of the second-order mode together as the final tip amplitude measurement points; S1223. And so on, until at least one axial displacement A ij > 0.1 m in each column of the matrix for all the selected potential tip amplitude measurement points, and the final tip amplitude measurement points are obtained.

[0013] Further, step S2 specifically includes the following steps: S21. Fix the final tip amplitude measurement points on the fan casing. Under the action of centrifugal, aerodynamic and temperature loads in each working condition, make the tip of the fan blade generate axial displacement. According to the position of the blade measured by the final tip amplitude measurement points under static conditions and the axial displacement of each node of the fan blade tip under typical working conditions, determine the actual position of the final tip amplitude measurement points relative to the fan blade in each working condition; S22. According to the modal vibration modes of each order in each working condition, read out the circumferential displacement and the corresponding maximum modal stress of the actual position of the blade measured by each measurement point of each order in each working condition; S23. Calculate the ratio relationship between the maximum modal stress and the measured circumferential displacement to obtain the ratio relationship between the maximum modal stress of each order of mode and the measured circumferential displacement in each working condition; S24. Calculate the maximum modal stress of each order of the fan blade under each working condition according to the circumferential displacement, ratio relationship and blade vibration frequency under each order of modal vibration of the blade, so as to obtain the vibration stress of the fan blade of each order of modal under each working condition.

[0014] On the other hand, the present application also provides a device for calculating the vibration stress of a fan blade, including: A tip amplitude measurement point determination module, configured to determine, through finite element analysis, points where the circumferential vibration displacement of the blade tip under each order of modal excited by a definite excitation source within the working speed range is greater than a preset value, and determine the final tip amplitude measurement points; A fan blade vibration stress calculation module, configured to calculate the vibration stress of the fan blade of each order of modal under each working condition according to the displacement of the tip amplitude measurement points under each order of modal, the position of the blade measured at the final tip amplitude measurement point under static conditions, and the relationship between the displacements of each measurement point under each order of modal and the vibration stress under the corresponding order of modal.

[0015] On the other hand, the present application also provides an electronic device, including a memory, a processor, and a computer program stored on the memory and executable on the processor. When the processor executes the computer program, the steps of the method for calculating the vibration stress of the fan blade are implemented.

[0016] On the other hand, the present application also provides a storage medium. The storage medium includes a stored program. When the program runs, it controls the device where the storage medium is located to execute the steps of the method for calculating the vibration stress of the fan blade.

[0017] Compared with the prior art, the present application has the following beneficial effects: The present invention provides a method for calculating the vibration stress of a fan blade. The method for calculating the vibration stress of the fan blade fully considers the maximum modal order that can be excited by a definite excitation source within the working speed range, comprehensively analyzes the sensitivity of potential measurement points of the tip amplitude of each order of modal, and can select fewer final tip amplitude measurement points to measure the tip amplitude of all possible excited modes within the working speed range, thereby greatly reducing the number of tests and the test period. At the same time, when selecting the tip amplitude measurement points and converting the vibration stress, the deformation of the blade under static load is considered, avoiding the change in the displacement of the measurement points caused by the deformation of the blade, and making the vibration stress of the fan blade of each order of modal under each working condition obtained by conversion have a smaller deviation from the actual value and be more accurate.

[0018] In addition to the purposes, features and advantages described above, the present application has other purposes, features and advantages. The following will refer to the drawings to further describe the present application in detail. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The accompanying drawings, which form a part of this application, are used to provide a further understanding of this application. The schematic embodiments and descriptions thereof of this application are used to explain this application and do not constitute an improper limitation of this application: Figure 1 It is a schematic diagram of the fan blade structure of a turbofan engine; Figure 2 It is a schematic diagram of the principle of a non-contact rotor blade vibration measurement system; Figure 3 It is a schematic diagram of the vibration displacement amplitude and frequency of the blade along the circumferential tangential direction during the measurement of the tip amplitude of the fan blade; Figure 4 It is a schematic diagram of the flow of the fan blade vibration stress calculation method according to the preferred embodiment of this application; Figure 5 It is a schematic diagram of the optional area of the tip amplitude measurement point of the fan blade; Figure 6 It is a schematic diagram of the point with the maximum circumferential displacement of the tip mode of the fan blade; Figure 7 It is a schematic diagram of the point with the maximum modal stress of the tip mode of the fan blade; Figure 8 It is a schematic diagram of the tip amplitude measurement of the fan blade; Figure 9 It is a schematic diagram of the relationship between the maximum modal stress of each order and the ratio of the measured displacement of the measurement point; Figure 10 It is a schematic diagram of the tip amplitude measurement result of the fan blade; Figure 11 It is a schematic diagram of the module of the fan blade vibration stress calculation device according to the preferred embodiment of this application; Figure 12 It is a schematic block diagram of the entity of the electronic device according to the preferred embodiment of this application; Figure 13 It is the internal structure diagram of the computer device according to the preferred embodiment of this application. Detailed Description of the Preferred Embodiment

[0020] The embodiments of this application will be described in detail below with reference to the accompanying drawings. However, this application can be implemented in many different ways defined and covered by the following.

[0021] As Figure 4 shown, the preferred embodiment of this application provides a method for calculating the vibration stress of a fan blade, including the steps of: S1. Determine, through finite element analysis, the points where the circumferential vibration displacement of the blade tip in each order of mode excited by the clear excitation source within the operating speed range is greater than the preset value, and determine the final tip amplitude measurement points; S2. Calculate the vibration stress of the fan blade in each working condition and each order of mode according to the displacement of the tip amplitude measurement point in each order of mode, the position of the blade measured by the final tip amplitude measurement point under static conditions, and the relationship between the displacement of each measurement point and the vibration stress in the corresponding order of mode.

[0022] This embodiment provides a method for calculating the vibration stress of a fan blade. This method for calculating the vibration stress of a fan blade first determines, through finite element analysis, the points where the circumferential vibration displacement of the blade tip in each order of mode excited by a definite excitation source within the working speed range is greater than a preset value, and determines the final tip amplitude measurement points. Then, according to the displacement of the tip amplitude measurement point in each order of mode, the position of the blade measured by the final tip amplitude measurement point under static conditions, and the relationship between the displacement of each measurement point and the vibration stress in the corresponding order of mode, the vibration stress of the fan blade in each order of mode under each working condition is calculated considering multiple aspects. This embodiment fully considers the maximum order of mode that a definite excitation source can excite the blade within the working speed range, comprehensively analyzes the sensitivity of the potential measurement points of the tip amplitude of each order of mode, and can select fewer final tip amplitude measurement points to measure the tip amplitude of all possible excited modes within the working speed range, thereby greatly reducing the number of tests and the test period. At the same time, when selecting the tip amplitude measurement points and converting the vibration stress, the deformation of the blade under static load is considered, avoiding the change in the displacement of the measurement point caused by the deformation of the blade, making the vibration stress of the fan blade in each order of mode under each working condition obtained by conversion have a smaller deviation from the actual value and be more accurate.

[0023] Preferably, step S1 specifically includes the following steps: S11. According to finite element analysis, determine the points where the circumferential vibration displacement of the blade tip in multiple orders of mode excited by a definite excitation source within the working speed range is greater than a preset value, determine the potential tip amplitude measurement points in each order of mode, and calculate the relationship between the displacement of each potential tip amplitude measurement point and the maximum modal stress in the corresponding order. S12. Select the least number of tip amplitude measurement points that meet the set conditions from the potential tip amplitude measurement points to determine the final tip amplitude measurement points.

[0024] In this embodiment, by first determining the potential tip amplitude measurement points in each order of mode and calculating the relationship between the displacement of each potential tip amplitude measurement point and the maximum modal stress in the corresponding order, and then selecting the least number of tip amplitude measurement points that meet the set conditions from the potential tip amplitude measurement points to determine the final tip amplitude measurement points, the tip amplitude of all possible excited modes within the working speed range is measured by selecting fewer final tip amplitude measurement points, thereby greatly reducing the number of tests and the test period.

[0025] Preferably, step S11 specifically includes the following steps: S111. First, through finite element analysis, calculate the axial displacement of the fan blade tip under typical operating conditions to obtain the axial displacements of each node at the fan blade tip, where the maximum axial displacement is a (mm). The typical operating conditions include ground idle condition, in-air idle condition, cruise condition, takeoff condition, and maximum steady-state condition. Here, the axial displacement refers to the displacement along the blade rotation axis. Explanation of nodes: In finite element calculation, the blade is first discretized into many elements. The shape of these elements is determined by the nodes, and the degrees of freedom of the nodes determine the degrees of freedom of the blade. Here, the nodes can be understood as the position points distributed regularly at the blade tip part; S112. According to the selected sensor size specification, combined with the maximum axial displacement of each node at the blade tip, determine the optional range of the tip amplitude measurement points, such as Figure 5 shown. In the figure, a is the maximum axial displacement of each node of the blade obtained by calculation, and (a + 1)m is to consider the sensor size and installation error, to avoid the sensor measurement position falling outside the blade due to the axial displacement of the blade and thus unable to measure the circumferential displacement of the blade. Therefore, the sensor is moved inward by 1mm; S113. Through finite element analysis, clarify that the maximum modal order that the excitation source can excite the blade within the operating speed range is n. Determine n as the modal order to be measured, and calculate the modal vibration shapes and modal stress distributions of each order under each operating condition, such as Figure 6 and Figure 7 shown; S114. For each order of the mode to be measured, read out the maximum modal circumferential displacement and the corresponding node number within the optional area of the tip amplitude measurement point, take this node as the potential tip amplitude measurement point of this order of the mode, and calculate the relationship between the displacements of each potential tip amplitude measurement point and the maximum modal stress of the corresponding order. To determine the measurement position and ensure that the measurement position does not exceed the blade chord length, the tip amplitude measurement measures the circumferential displacement of the blade.

[0026] Preferably, step S12 specifically includes the steps: S121. Set the maximum modal stress of each order to 30 MPa. According to the relationship between the displacements of each potential tip amplitude measurement point and the maximum modal stress of the corresponding order, calculate the axial displacement A ij of each potential tip amplitude measurement point under each order of the mode to obtain an n×n matrix, as shown in Table 1.

[0027] Table 1 Displacements of each potential measurement point under each order of the mode

[0028] S122. Select the least number of measurement points from the potential tip amplitude measurement points such that at least one axial A ij > 0.1 mm in each column as the final tip amplitude measurement points.

[0029] In this embodiment, by selecting as few potential measurement points as possible as the final measurement points, at least one Aij > 0.1 mm is ensured in each column of numbers, and the result of the measurement point selection is as Figure 8 shown. By selecting fewer final tip amplitude measurement points, the tip amplitude measurement of all possible excited modes within the operating speed range is achieved, thereby significantly reducing the number of tests and the test period.

[0030] Preferably, the step S122 specifically includes the steps of: S1221. Select the potential tip amplitude measurement points of the first-order mode. When at least one axial displacement A in each column of the matrix is greater than 0.1 m with the selected potential tip amplitude measurement points of the first-order mode, only the potential tip amplitude measurement points of the first-order mode are selected as the final tip amplitude measurement points; ij > 0.1 m, then only select the potential tip amplitude measurement points of the first-order mode as the final tip amplitude measurement points; S1222. When the selected potential tip amplitude measurement points of the first-order mode cannot ensure that at least one axial displacement A in each column of the matrix is greater than 0.1 m, then continue to select the potential tip amplitude measurement points of the second-order mode. When the selected potential tip amplitude measurement points of the second-order mode and the potential tip amplitude measurement points of the first-order mode ensure that at least one axial displacement A in each column of the matrix is greater than 0.1 m, then the potential tip amplitude measurement points of the first-order mode and the selected potential tip amplitude measurement points of the second-order mode are jointly used as the final tip amplitude measurement points; ij > 0.1 m, then continue to select the potential tip amplitude measurement points of the second-order mode. When the selected potential tip amplitude measurement points of the second-order mode and the potential tip amplitude measurement points of the first-order mode ensure that at least one axial displacement A in each column of the matrix is greater than 0.1 m, then the potential tip amplitude measurement points of the first-order mode and the selected potential tip amplitude measurement points of the second-order mode are jointly used as the final tip amplitude measurement points; ij > 0.1 m, then the potential tip amplitude measurement points of the first-order mode and the selected potential tip amplitude measurement points of the second-order mode are jointly used as the final tip amplitude measurement points; S1223. And so on, until at least one axial displacement A in each column of the matrix is greater than 0.1 m with all the selected potential tip amplitude measurement points, and the final tip amplitude measurement points are obtained. ij > 0.1 m, then the final tip amplitude measurement points are obtained.

[0031] This embodiment gives a strategy for selecting the final tip amplitude measurement points. If the potential measurement points of the first-order mode can ensure that at least one A in each column is ij > 0.1 m, then just selecting the potential measurement points of the first-order mode is okay, that is, one measurement point can meet the measurement requirements; if one measurement point cannot ensure that at least one A in each column is ij > 0.1 m, the number of measurement points needs to be increased to ensure that at least one A in each column is ij > 0.1 m. The reason for requiring A ij > 0.1 m is that if the measured displacement is less than 0.1 mm, the converted vibration stress error will be relatively large. In this embodiment, by restricting the axial displacement A ij , the converted vibration stress error is reduced.

[0032] Preferably, the step S2 specifically includes the steps of: S21. Fix the final tip amplitude measurement point on the fan casing. Under the action of centrifugal, aerodynamic, and temperature loads in each working condition, cause the fan blade tip to generate axial displacement. Based on the position of the blade measured by the final tip amplitude measurement point under static conditions and the axial displacement of each node of the fan blade tip under typical working conditions, determine the actual position of the final tip amplitude measurement point relative to the fan blade under each working condition; S22. According to the modal shapes of each order of mode in each working condition, read out the circumferential displacement of the actual position of the blade measured by each measurement point and the corresponding maximum modal stress (which can be equivalent stress or von Mises stress, the first principal stress, the third principal stress) in each order and each measurement point under each working condition; S23. Calculate the ratio relationship between the maximum modal stress and the measured circumferential displacement, and obtain the ratio relationship between the maximum modal stress and the measured circumferential displacement of each order of mode under each working condition (as Figure 9 shown); S24. According to the circumferential displacement, ratio relationship, and blade vibration frequency of each order of mode vibration of the blade, calculate the maximum modal stress of each order of mode under each working condition to obtain the vibration stress of the fan blade of each order of mode under each working condition.

[0033] After obtaining the vibration stress of the fan blade of each order of mode under each working condition, high-cycle fatigue assessment can be carried out to determine whether the blade amplitude is too large.

[0034] The present invention has been applied in the vibration measurement test of the fan blade of a certain type of engine and achieved the expected results. Figure 10 For the test results obtained from the measurement points determined according to the present invention, the circumferential displacement change curve of different measurement points of the fan blade with the engine speed can be obtained, and the displacement at different speeds of each measurement point can be read out. Then, the vibration stress of the blade can be obtained by conversion according to the method described in this article.

[0035] As Figure 11 shown, another preferred embodiment of the present application also provides a fan blade vibration stress calculation device, including: A tip amplitude measurement point determination module, configured to determine the points where the circumferential vibration displacement of the blade tip in each order of mode excited by the excitation source within the working speed range is greater than a preset value through finite element analysis, and determine the final tip amplitude measurement point; A fan blade vibration stress calculation module, configured to calculate the vibration stress of the fan blade of each order of mode under each working condition according to the displacement of the tip amplitude measurement point under each order of mode, the position of the blade measured by the final tip amplitude measurement point under static conditions, and the relationship between the displacement of each measurement point and the vibration stress under the corresponding order of mode.

[0036] As Figure 12As shown in the figure, a preferred embodiment of the present application further provides an electronic device, including a memory, a processor, and a computer program stored on the memory and executable on the processor. When the processor executes the computer program, the steps of the fan blade vibration stress calculation method in the above embodiment are implemented.

[0037] As Figure 13 shown in the figure, a preferred embodiment of the present application further provides a computer device, which may be a terminal or a living body detection server, and its internal structure diagram may be as Figure 13 shown in the figure. The computer device includes a processor, a memory, and a network interface connected through a system bus. Among them, the processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a computer program. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The network interface of the computer device is used to communicate with other external computer devices through a network connection. When the computer program is executed by the processor, the steps of the above fan blade vibration stress calculation method are implemented.

[0038] Those skilled in the art can understand that Figure 13 the structure shown in the figure is only a block diagram of some structures related to the solution of the present application, and does not constitute a limitation on the computer device to which the solution of the present application is applied. The specific computer device may include more or fewer components than those shown in the figure, or combine some components, or have different component arrangements.

[0039] A preferred embodiment of the present application further provides a storage medium, and the storage medium includes a stored program. When the program runs, the device where the storage medium is located is controlled to execute the steps of the fan blade vibration stress calculation method in the above embodiment.

[0040] It should be noted that the steps shown in the flowchart of the accompanying drawings can be executed in a computer system such as a set of computer executable instructions. And although the logical order is shown in the flowchart, in some cases, the steps shown or described can be executed in a different order than here.

[0041] When the functions described in the method of this embodiment are implemented in the form of software function units and sold or used as independent products, they can be stored in one or more computer-readable storage media. Based on this understanding, the part of this application embodiment that contributes to the prior art or part of this technical solution can be embodied in the form of a software product. This software product is stored in a storage medium and includes several instructions for causing a computer device (which can be a personal computer, a server, a mobile computing device, or a network device, etc.) to execute all or part of the steps of the methods described in various embodiments of this application. The foregoing storage media include: various media that can store program codes such as USB flash drives, mobile hard disks, read-only memories (ROM, Read-Only Memory), random access memories (RAM, Random Access Memory), magnetic disks, or optical discs.

[0042] Those skilled in the art should understand that the embodiments of this application can be provided as a method, a system, or a computer program product. Therefore, this application can adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware aspects. Moreover, this application can adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that contain computer-usable program codes. The solutions in the embodiments of this application can be implemented in various computer languages. For example, object-oriented programming languages such as Java and interpreted scripting languages such as JavaScript.

[0043] This application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of this application. It should be understood that each flow and / or block in the flowchart and / or block diagram, as well as the combination of flows and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing devices to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing devices generate a device for implementing the specified functions in Figure 1 one flow or multiple flows and / or blocks Figure 1 one block or multiple blocks.

[0044] These computer program instructions can also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in this computer-readable memory generate a manufactured article including an instruction device, and this instruction device implements the specified functions in Figure 1 one flow or multiple flows and / or blocks Figure 1The functions specified in one or more boxes.

[0045] These computer program instructions can also be loaded onto a computer or other programmable data processing device, so that a series of operation steps are executed on the computer or other programmable device to generate a computer-implemented process. Thus, the instructions executed on the computer or other programmable device provide for implementing the steps of the functions specified in one Figure 1 process or more processes and / or boxes Figure 1 or more boxes.

[0046] Although the preferred embodiments of the present application have been described, those skilled in the art can make additional changes and modifications to these embodiments once they learn the basic creative concepts. Therefore, the appended claims are intended to be construed as including the preferred embodiments and all changes and modifications that fall within the scope of the present application.

[0047] Obviously, those skilled in the art can make various changes and modifications to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalent technologies, the present application is also intended to include these modifications and variations.

Claims

1. A method for calculating the vibration stress of a fan blade, characterized in that, Including the steps: S1. Determine, through finite element analysis, the points where the circumferential vibration displacement of the blade tip under each order of blade mode excited by the clear excitation source within the working speed range is greater than the preset value, and determine the final blade tip amplitude measurement points; S2. Calculate the vibration stress of the fan blade under each order of mode in each working condition according to the displacement of the blade tip amplitude measurement points under each order of mode, the position of the blade measured by the final blade tip amplitude measurement point under static conditions, and the relationship between the displacement of each measurement point and the vibration stress under the corresponding order of mode.

2. The method for calculating the vibration stress of a fan blade according to claim 1, characterized in that, The specific steps of step S1 include the steps: S11. Determine, through finite element analysis, the points where the circumferential vibration displacement of the blade tip under multiple orders of blade mode excited by the clear excitation source within the working speed range is greater than the preset value, determine the potential blade tip amplitude measurement points under each order of mode, and calculate the relationship between the displacement of each potential blade tip amplitude measurement point and the maximum modal stress of the corresponding order; S12. Select the minimum number of blade tip amplitude measurement points that meet the set conditions from the potential blade tip amplitude measurement points to determine the final blade tip amplitude measurement points.

3. The method for calculating the vibration stress of a fan blade according to claim 2, characterized in that, The specific steps of step S11 include the steps: S111. First, through finite element analysis, calculate the axial displacement of the blade tip of the fan blade under typical working conditions to obtain the axial displacement of each node of the blade tip of the fan blade; S112. Determine the optional range of the blade tip amplitude measurement points according to the selected sensor size specifications and the maximum axial displacement of each node of the blade tip; S113. Through finite element analysis, determine that the maximum modal order of the blade excited by the clear excitation source within the working speed range is n, determine n as the modal order to be measured, and calculate the modal vibration mode and modal stress distribution of each order of mode under each working condition; S114. For each order of mode to be measured, read out the maximum modal circumferential displacement and the corresponding node number within the optional area of the blade tip amplitude measurement points, use this node as the potential blade tip amplitude measurement point of this order of mode, and calculate the relationship between the displacement of each potential blade tip amplitude measurement point and the maximum modal stress of the corresponding order.

4. The method for calculating the vibration stress of a fan blade according to claim 3, characterized in that, The typical working conditions include ground idle condition, in-air idle condition, cruise condition, takeoff condition, and maximum steady state condition.

5. The method for calculating the vibration stress of a fan blade according to claim 3, characterized in that, The specific steps of step S12 include the steps: S121. Set the maximum modal stress of each order of mode to 30 MPa, and calculate the axial displacement A of each potential tip amplitude measurement point under each order of mode according to the relationship between the displacement of each potential tip amplitude measurement point and the maximum modal stress of the corresponding order ij , obtaining an n×n matrix; S122. Select the fewest measurement points that can ensure at least one axial A > 0.1 mm in each column of potential blade tip amplitude measurement points as the final blade tip amplitude measurement points. ij > 0.1 mm as the final blade tip amplitude measurement points.

6. The method for calculating the vibration stress of a fan blade according to claim 5, characterized in that, The specific steps of step S122 include the steps: S1221. Select the potential tip amplitude measurement point of the first-order mode. When the selected potential tip amplitude measurement point of the first-order mode makes at least one axial displacement A in each column of the matrix ij > 0.1 m, only select the potential tip amplitude measurement point of the first-order mode as the final tip amplitude measurement point; S1222. When the selected measurement point of the first-order modal potential tip amplitude cannot make at least one axial displacement A in each column of the matrix ij > 0.1 m, then continue to select the measurement point of the second-order modal potential tip amplitude. When the selected measurement point of the second-order modal potential tip amplitude and the measurement point of the first-order modal potential tip amplitude make at least one axial displacement A in each column of the matrix ij > 0.1 m, then take the measurement point of the first-order modal potential tip amplitude and the selected measurement point of the second-order modal potential tip amplitude together as the final tip amplitude measurement points; S1223, and so on until at least one axial displacement A in each column of the matrix is obtained for all the selected potential tip amplitude measurement points. ij When it is > 0.1 m, the final tip amplitude measurement points are obtained.

7. The method for calculating the vibration stress of a fan blade according to claim 1, characterized in that, The specific steps of step S2 include the steps: S21. Fix the final blade tip amplitude measurement points on the fan casing. Under the action of centrifugal, aerodynamic, and temperature loads in each working condition, cause the blade tip of the fan blade to generate axial displacement. According to the position of the blade measured by the final blade tip amplitude measurement point under static conditions and the axial displacement of each node of the blade tip of the fan blade under typical working conditions, determine the actual position of the final blade tip amplitude measurement point relative to the fan blade in each working condition; S22. According to the modal vibration mode of each order of mode in each working condition, read out the circumferential displacement and the corresponding maximum modal stress of the actual position of the blade measured by each measurement point of each order in each working condition; S23. Calculate the ratio relationship between the maximum modal stress and the measured circumferential displacement to obtain the ratio relationship between the maximum modal stress and the measured circumferential displacement of each order of mode in each working condition; S24. According to the circumferential displacement, ratio relationship, and blade vibration frequency under the vibration of each order of blade mode, calculate the maximum modal stress of each order of mode in each working condition to obtain the vibration stress of the fan blade under each order of mode in each working condition.

8. A device for calculating the vibration stress of a fan blade, characterized in that, Including: The tip amplitude measurement point determination module is used to determine, through finite element analysis, the points where the circumferential vibration displacement of the blade tip in each order of blade mode excited by the excitation source is greater than the preset value within the operating speed range, and determine the final tip amplitude measurement points; The fan blade vibration stress calculation module is used to calculate the vibration stress of the fan blade in each order of mode under each working condition according to the displacement of the tip amplitude measurement point in each order of mode, the position of the blade measured at the final tip amplitude measurement point under static conditions, and the relationship between the displacement of each measurement point and the vibration stress in the corresponding order of mode.

9. An electronic device, comprising a memory, a processor, and a computer program stored on the memory and executable on the processor, characterized in that, When the processor executes the computer program, the steps of the fan blade vibration stress calculation method according to any one of claims 1 to 7 are implemented.

10. A storage medium, the storage medium includes a stored program, and when the program runs, it controls the device where the storage medium is located to execute the steps of the fan blade vibration stress calculation method according to any one of claims 1 to 7.

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