A fan blade vibration stress calculation method, device, electronic device and storage medium

Abstract

The present application discloses a method, device, electronic device, and storage medium for calculating vibration stress of fan blades. The method comprises the following steps: S1. Determine, through finite element analysis, the point at which the circumferential vibration displacement of the blade tip under each order mode of the blade that can be excited by the excitation source is greater than a preset value within the operating speed range, and determine the final blade tip amplitude measurement point; S2. Calculate the vibration stress of each order mode of the fan blade under each working condition based on the displacement of the blade tip amplitude measurement point under each order mode, the position of the blade measured by the final blade tip amplitude measurement point under static conditions, the relationship between the displacement of each measurement point under each order mode and the vibration stress under the corresponding order mode. The present application can select fewer final blade tip amplitude measurement points to achieve blade tip amplitude measurement, thereby significantly reducing the number and cycle of tests; at the same time, the deformation of the blade under static load is taken into account, avoiding the change in measurement point displacement caused by blade deformation, so that the error of the converted fan blade vibration stress of each order mode under each working condition is smaller and more accurate.

Description

Technical Field

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

[0002] Figure 1 The fan blades of turbofan engines operate in harsh environments, and their vibration needs to be monitored during component and complete machine testing. Non-contact rotor blade vibration measurement enables real-time monitoring of blade tip vibration displacement. The selection of measurement points affects the reliability of the blade tip vibration displacement measurement results. The conversion of the measured blade tip vibration displacement to blade vibration stress is a key factor in determining whether blade vibration is excessive.

[0003] Turbofan engine fan blades have large aspect ratios, high stress levels, and harsh operating conditions. The centrifugal force generated by high-speed rotation and the aerodynamic forces caused by airflow impact easily cause the blades to vibrate. This vibration generates significant vibration stress, which can easily lead to blade fatigue failure and is a major factor in fan blade failure. To verify and optimize the vibration characteristics of fan blades, it is necessary to monitor their vibration during component and complete engine testing. Non-contact vibration measurement based on the blade tip timing principle can measure the blade tip amplitude in real time and then derive the blade vibration stress through a specific algorithm.

[0004] The principle of non-contact rotor blade vibration measurement system is as follows Figure 2 As shown in the figure, a new data acquisition is triggered by a standard speed pulse every time the rotor rotates. The optical fiber or eddy current probe installed on the casing measures the arrival time of the reflected pulse from the blade tip of the specified number in turn. When the blade vibrates, the blade tip will deviate forward or backward in the circumferential direction (such as Figure 3 As shown in the figure), the change of the pulse arrival time is caused. Combined with the synchronization signal provided by the speed synchronization sensor and the circumferential diameter of the blade tip, the blade's tangential direction (such as Figure 3 The vibration displacement amplitude and frequency are shown in Figure 2.

[0005] The more commonly used blade vibration monitoring methods include non-contact rotor blade vibration measurement. Existing non-contact rotor blade vibration measurement usually only measures a limited number of modes, that is, it only measures the vibration of a certain modal order for the possible resonance of the blade, and it is difficult to measure the vibration of all modal orders of the blade. At the same time, the subsequent direct use of the measured blade tip vibration displacement to convert the vibration stress does not take into account the displacement change of the measuring point caused by blade deformation, resulting in a large deviation between the final 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 fan blades, which is used to solve the technical problem that the stress value converted during the existing non-contact rotor blade vibration measurement has a large deviation from the actual value.

[0007] This application is implemented through the following scheme:

[0008] A method for calculating vibration stress of a fan blade comprises the following steps:

[0009] S1. Determine through finite element analysis the point within the operating speed range where the blade tip circumferential vibration displacement under each mode of the blade that can be excited by the excitation source is greater than the preset value, and determine the final blade tip amplitude measurement point;

[0010] S2. Calculate the vibration stress of the fan blade in each mode under each operating condition based on the displacement of the blade tip amplitude measurement point under each 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 under each mode and the vibration stress under the corresponding mode.

[0011] Furthermore, the step S1 specifically includes the steps of:

[0012] S11. Determine, based on finite element analysis, the point at which the blade tip circumferential vibration displacement under multiple modes of the blade that can be excited by the excitation source is greater than a preset value within the operating speed range, determine the potential blade tip amplitude measurement point under each mode order, and calculate the relationship between the displacement of each potential blade tip amplitude measurement point and the maximum modal stress of the corresponding order;

[0013] S12. Selecting the minimum 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.

[0014] Furthermore, step S11 specifically includes the following steps:

[0015] S111. First, calculate the axial displacement of the fan blade tip under typical working conditions through finite element analysis to obtain the axial displacement of each node of the fan blade tip;

[0016] S112. Determine the optional range of blade tip amplitude measurement points based on the selected sensor size and specifications and the maximum axial displacement of each blade tip node;

[0017] S113. Through finite element analysis, determine the maximum modal order n of the blade that can be excited by the excitation source within the operating speed range, determine n as the modal order to be measured, and calculate the modal vibration shape and modal stress distribution of each mode under each operating condition;

[0018] S114. For each mode that needs 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 point, use the node as the potential blade tip amplitude measurement point for the 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.

[0019] Furthermore, the typical operating conditions include ground slow-speed operating conditions, air slow-speed operating conditions, cruising operating conditions, take-off operating conditions, and maximum steady-state operating conditions.

[0020] Furthermore, step S12 specifically includes the steps of:

[0021] S121. Set the maximum modal stress of each mode to 30 MPa. Calculate the axial displacement A of each potential blade tip amplitude measurement point under each mode according to the relationship between the displacement of each potential blade tip amplitude measurement point and the corresponding maximum modal stress. ij , get an n×n matrix;

[0022] S122. Select from the potential blade tip amplitude measurement points so that there is at least one axial A in each row. ij The minimum measuring point with a value >0.1 mm is used as the final blade tip amplitude measuring point.

[0023] Furthermore, the step S122 specifically includes the following steps:

[0024] S1221. Select the first-order modal potential blade tip amplitude measurement point. When the selected first-order modal potential blade tip amplitude measurement point makes at least one axial displacement A in each column of the matrix ij When the distance is >0.1m, only the first-order mode potential blade tip amplitude measurement point is selected as the final blade tip amplitude measurement point;

[0025] S1222, when the selected first-order modal potential blade tip amplitude measurement point cannot make at least one axial displacement A in each column of the matrix ij If the value is greater than 0.1m, the second-order modal potential blade tip amplitude measurement point is further selected. When the second-order modal potential blade tip amplitude measurement point and the first-order modal potential blade tip amplitude measurement point are selected, there is at least one axial displacement A in each column of the matrix. ij When the angle is greater than 0.1m, the first-order mode potential blade tip amplitude measurement point and the additional second-order mode potential blade tip amplitude measurement point are taken together as the final blade tip amplitude measurement point;

[0026] S1223, and so on, until all potential blade tip amplitude measurement points are selected so that there is at least one axial displacement A in each column of the matrix. ij When the blade tip amplitude is greater than 0.1m, the final blade tip amplitude measurement point is obtained.

[0027] Furthermore, the step S2 specifically includes the steps of:

[0028] S21. Fixing a final blade tip amplitude measurement point on a fan casing, causing the fan blade tip to generate axial displacement under centrifugal, aerodynamic, and temperature loads under various operating conditions, and determining the actual position of the final blade tip amplitude measurement point relative to the fan blade under various operating conditions based on the blade position measured at the final blade tip amplitude measurement point under static conditions and the axial displacement of each node of the fan blade tip under typical operating conditions;

[0029] S22. Based on the modal vibration shapes of each mode order under each operating condition, read out the circumferential displacement of the actual position of the blade measured at each measuring point of each order under each operating condition and the corresponding maximum modal stress;

[0030] S23. Calculate the ratio of the maximum modal stress to the measured circumferential displacement to obtain the ratio of the maximum modal stress to the measured circumferential displacement for each modal order under each working condition;

[0031] S24. Calculate the maximum modal stress of each modal under each operating condition based on the circumferential displacement, ratio relationship, and blade vibration frequency of each modal vibration of the blade to obtain the vibration stress of each modal fan blade under each operating condition.

[0032] On the other hand, the present application also provides a fan blade vibration stress calculation device, comprising:

[0033] The blade tip amplitude measurement point determination module is used to determine the point where the blade tip circumferential vibration displacement under each mode of the blade that can be excited by the excitation source is greater than the preset value within the operating speed range through finite element analysis, and determine the final blade tip amplitude measurement point;

[0034] The fan blade vibration stress calculation module is used to calculate the vibration stress of the fan blade in each mode under each operating condition based on the displacement of the blade tip amplitude measurement point under each 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 under each mode and the vibration stress under the corresponding mode.

[0035] On the other hand, the present application also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of the fan blade vibration stress calculation method when executing the computer program.

[0036] On the other hand, the present application further provides a storage medium, which includes a stored program, and when the program is run, controls the device where the storage medium is located to execute the steps of the fan blade vibration stress calculation method.

[0037] Compared with the existing technology, this application has the following beneficial effects:

[0038] The present invention provides a method for calculating the vibration stress of a fan blade. The method fully considers the maximum modal order of the blade that can be excited by a clear excitation source within the operating speed range, comprehensively analyzes the sensitivity of potential measuring points of the blade tip amplitude of each modal order, and can select fewer final blade tip amplitude measuring points to achieve blade tip amplitude measurement of all possible excited modes within the operating speed range, thereby greatly reducing the number and cycle of tests; at the same time, when selecting the blade tip amplitude measuring points and converting the vibration stress, the deformation of the blade under static load is taken into account, avoiding the displacement change of the measuring point caused by the blade deformation, so that the converted vibration stress of the fan blade of each modal order under each working condition has a smaller deviation from the actual one and is more accurate.

[0039] In addition to the above-described purposes, features and advantages, the present application also has other purposes, features and advantages. The present application will be further described in detail below with reference to the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] The accompanying drawings, which constitute a part of this application, are used to provide a further understanding of the application. The exemplary embodiments of the application and their descriptions are used to explain the application and do not constitute an improper limitation of the application.

[0041] Figure 1 It is a schematic diagram of the structure of the fan blade of a turbofan engine;

[0042] Figure 2 This is a schematic diagram of the principle of a non-contact rotor blade vibration measurement system;

[0043] Figure 3 This is a schematic diagram of the vibration displacement amplitude and frequency of the blade along the circumferential tangent when measuring the tip amplitude of the fan blade;

[0044] Figure 4 This is a flow chart of a fan blade vibration stress calculation method according to a preferred embodiment of the present application;

[0045] Figure 5 This is a schematic diagram of the optional area for measuring the fan blade tip amplitude;

[0046] Figure 6 It is a schematic diagram of the maximum circumferential displacement point of the fan blade tip modal;

[0047] Figure 7 It is a schematic diagram of the maximum modal stress point of the fan blade tip;

[0048] Figure 8 This is a schematic diagram of fan blade tip amplitude measurement;

[0049] Figure 9 It is a schematic diagram of the relationship between the maximum modal stress of each mode and the displacement ratio measured at the measuring point;

[0050] Figure 10 This is a schematic diagram of the fan blade tip amplitude measurement results;

[0051] Figure 11 This is a schematic diagram of a module of a fan blade vibration stress calculation device according to a preferred embodiment of the present application;

[0052] Figure 12 This is a schematic block diagram of an electronic device according to a preferred embodiment of the present application;

[0053] Figure 13 It is a diagram of the internal structure of a computer device according to a preferred embodiment of the present application. DETAILED DESCRIPTION

[0054] The embodiments of the present application are described in detail below with reference to the accompanying drawings, but the present application can be implemented in a variety of different ways defined and covered below.

[0055] like Figure 4 As shown, a preferred embodiment of the present application provides a method for calculating vibration stress of a fan blade, comprising the steps of:

[0056] S1. Determine through finite element analysis the point within the operating speed range where the blade tip circumferential vibration displacement under each mode of the blade that can be excited by the excitation source is greater than the preset value, and determine the final blade tip amplitude measurement point;

[0057] S2. Calculate the vibration stress of the fan blade in each mode under each operating condition based on the displacement of the blade tip amplitude measurement point under each 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 under each mode and the vibration stress under the corresponding mode.

[0058] This embodiment provides a method for calculating the vibration stress of a fan blade. The method first determines, through finite element analysis, the point at which the circumferential vibration displacement of the blade tip under each mode of the blade that can be excited by the excitation source within the operating speed range is greater than a preset value, and determines the final blade tip amplitude measurement point. Then, based on the displacement of the blade tip amplitude measurement point under each mode, the position of the blade measured by the final blade tip amplitude measurement point under static conditions, the displacement of each measurement point under each mode, and the vibration stress under the corresponding mode, the vibration stress of the fan blade of each mode under each operating condition is calculated taking into account multiple aspects. This embodiment fully considers the maximum modal order of the blade that can be excited by the specific excitation source within the operating speed range, comprehensively analyzes the sensitivity of the potential measuring points of the blade tip amplitude of each mode, and can select fewer final blade tip amplitude measuring points to achieve the blade tip amplitude measurement of all possible excited modes within the operating speed range, thereby greatly reducing the number and cycle of tests; at the same time, when selecting the blade tip amplitude measuring points and converting the vibration stress, the deformation of the blade under static load is taken into account, avoiding the displacement change of the measuring point caused by the blade deformation, so that the converted vibration stress of the fan blade of each mode under each working condition has a smaller deviation from the actual one and is more accurate.

[0059] Preferably, the step S1 specifically includes the steps of:

[0060] S11. Determine, based on finite element analysis, the point at which the blade tip circumferential vibration displacement under multiple modes of the blade that can be excited by the excitation source is greater than a preset value within the operating speed range, determine the potential blade tip amplitude measurement point under each mode order, and calculate the relationship between the displacement of each potential blade tip amplitude measurement point and the maximum modal stress of the corresponding order;

[0061] S12. Selecting the minimum 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.

[0062] This embodiment first determines the potential blade tip amplitude measurement points under each order mode and calculates the relationship between the displacement of each potential blade tip amplitude measurement point and the maximum modal stress of the corresponding order. Then, the minimum blade tip amplitude measurement points that meet the set conditions are selected from the potential blade tip amplitude measurement points to determine the final blade tip amplitude measurement points. By selecting a small number of final blade tip amplitude measurement points, the blade tip amplitude of all possible excited modes within the operating speed range can be measured, thereby significantly reducing the number and cycle of tests.

[0063] Preferably, step S11 specifically includes the steps of:

[0064] S111. First, through finite element analysis, calculate the axial displacement of the fan blade tip under typical operating conditions, and obtain the axial displacement of each node at the fan blade tip, where the maximum axial displacement is a (mm). The typical operating conditions include ground slow-speed operating conditions, air slow-speed operating conditions, cruise operating conditions, takeoff operating conditions, and maximum steady-state operating conditions. The axial displacement here refers to the displacement along the blade's axis of rotation. Regarding nodes: Finite element calculations first discretize the blade into many units. The shape of these units is determined by the nodes. The number of degrees of freedom of the nodes determines the number of degrees of freedom of the blade. The nodes here can be understood as position points distributed according to a certain pattern on the blade tip.

[0065] S112. Based on the selected sensor size and specifications and the maximum axial displacement of each blade tip node, determine the optional range of blade tip amplitude measurement points, such as Figure 5 As shown in the figure, a is the calculated maximum axial displacement of each node of the blade, and (a+1)m is considered to take into account the sensor size and installation error. In order to avoid the sensor measurement position falling outside the blade due to the axial displacement of the blade and failing to measure the circumferential displacement of the blade, the sensor is moved inward by 1mm.

[0066] S113. Through finite element analysis, the maximum modal order of the blade that can be excited by the excitation source is determined to be n within the operating speed range. n is determined as the modal order to be measured, and the modal vibration shape and modal stress distribution of each order mode under each working condition are calculated, such as Figure 6 and Figure 7 As shown;

[0067] S114. For each mode to be measured, read the maximum modal circumferential displacement and corresponding node number within the selectable area for the blade tip amplitude measurement point. This node is used as a potential blade tip amplitude measurement point for that mode. The relationship between the displacement of each potential blade tip amplitude measurement point and the corresponding maximum modal stress is calculated. To determine the measurement position and ensure it does not exceed the blade chord length, blade tip amplitude measurement measures the blade's circumferential displacement.

[0068] Preferably, step S12 specifically includes the steps of:

[0069] S121. Set the maximum modal stress of each mode to 30 MPa. Calculate the axial displacement A of each potential blade tip amplitude measurement point under each mode according to the relationship between the displacement of each potential blade tip amplitude measurement point and the corresponding maximum modal stress. ij , and obtain an n×n matrix, as shown in Table 1.

[0070] Table 1 Displacement of each potential measuring point under each mode

[0071]

[0072] S122. Select from the potential blade tip amplitude measurement points so that there is at least one axial A in each row. ij The minimum measuring point with a value >0.1 mm is used as the final blade tip amplitude measuring point.

[0073] In this embodiment, as few potential measuring points as possible are selected as the final measuring points so that at least one Aij>0.1mm is present in each column. The measuring point selection results are shown in the following table: Figure 8 As shown in the figure, by selecting fewer final blade tip amplitude measurement points, the blade tip amplitude of all possible excited modes within the operating speed range can be measured, thereby greatly reducing the number and cycle of tests.

[0074] Preferably, the step S122 specifically includes the following steps:

[0075] S1221. Select the first-order modal potential blade tip amplitude measurement point. When the selected first-order modal potential blade tip amplitude measurement point makes at least one axial displacement A in each column of the matrix ij When the distance is >0.1m, only the first-order mode potential blade tip amplitude measurement point is selected as the final blade tip amplitude measurement point;

[0076] S1222, when the selected first-order modal potential blade tip amplitude measurement point cannot make at least one axial displacement A in each column of the matrix ijIf the value is greater than 0.1m, the second-order modal potential blade tip amplitude measurement point is further selected. When the second-order modal potential blade tip amplitude measurement point and the first-order modal potential blade tip amplitude measurement point are selected, there is at least one axial displacement A in each column of the matrix. ij When the angle is greater than 0.1m, the first-order mode potential blade tip amplitude measurement point and the additional second-order mode potential blade tip amplitude measurement point are taken together as the final blade tip amplitude measurement point;

[0077] S1223, and so on, until all potential blade tip amplitude measurement points are selected so that there is at least one axial displacement A in each column of the matrix. ij When the blade tip amplitude is greater than 0.1m, the final blade tip amplitude measurement point is obtained.

[0078] This embodiment provides a strategy for selecting the final blade tip amplitude measurement point. If the first-order mode potential measurement point can make at least one A in each column ij >0.1m, then select the first-order mode potential measurement point, that is, one measurement point can meet the measurement requirements; if one measurement point cannot make at least one A in each column ij If the value is >0.1m, the number of measuring points should be increased so that there is at least one A in each column. ij >0.1m, the reason why A is needed ij >0.1m, because if the measured displacement is less than 0.1mm, the error of the converted vibration stress will be large. In this embodiment, the axial displacement A is limited. ij , thereby reducing the error in the converted vibration stress.

[0079] Preferably, the step S2 specifically includes the steps of:

[0080] S21. Fixing a final blade tip amplitude measurement point on a fan casing, causing the fan blade tip to generate axial displacement under centrifugal, aerodynamic, and temperature loads under various operating conditions, and determining the actual position of the final blade tip amplitude measurement point relative to the fan blade under various operating conditions based on the blade position measured at the final blade tip amplitude measurement point under static conditions and the axial displacement of each node of the fan blade tip under typical operating conditions;

[0081] S22. Based on the modal vibration shapes of each mode order under each operating condition, read out the circumferential displacement of the actual position of the blade measured at each measuring point of each order under each operating condition and the corresponding maximum modal stress (which may be equivalent stress or von Mises stress, first principal stress, or third principal stress);

[0082] S23. Calculate the ratio of the maximum modal stress to the measured circumferential displacement, and obtain the ratio of the maximum modal stress of each order mode to the measured circumferential displacement under each working condition (such as Figure 9 shown);

[0083] S24. Calculate the maximum modal stress of each modal under each operating condition based on the circumferential displacement, ratio relationship, and blade vibration frequency of each modal vibration of the blade to obtain the vibration stress of each modal fan blade under each operating condition.

[0084] After obtaining the vibration stress of the fan blades in each mode under each operating condition, a high-cycle fatigue assessment can be performed to determine whether the blade amplitude is too large.

[0085] The present invention has been applied in the vibration measurement test of a certain type of engine fan blade and achieved the expected effect. Figure 10 The test results obtained at the measuring points determined by the present invention can be used to obtain a curve of the circumferential displacement of the fan blade at different measuring points versus engine speed. The displacement of each measuring point at different speeds can be read out, and then the vibration stress of the blade can be converted according to the method described in this article.

[0086] like Figure 11 As shown, another preferred embodiment of the present application further provides a fan blade vibration stress calculation device, comprising:

[0087] The blade tip amplitude measurement point determination module is used to determine the point where the blade tip circumferential vibration displacement under each mode of the blade that can be excited by the excitation source is greater than the preset value within the operating speed range through finite element analysis, and determine the final blade tip amplitude measurement point;

[0088] The fan blade vibration stress calculation module is used to calculate the vibration stress of the fan blade in each mode under each operating condition based on the displacement of the blade tip amplitude measurement point under each 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 under each mode and the vibration stress under the corresponding mode.

[0089] like Figure 12 As shown, a preferred embodiment of the present application also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of the fan blade vibration stress calculation method in the above embodiment when executing the computer program.

[0090] like Figure 13 As shown, the preferred embodiment of the present application further provides a computer device, which can be a terminal or a liveness detection server, and its internal structure diagram can be as shown in FIG. Figure 13As shown. The computer device includes a processor, a memory, and a network interface connected via a system bus. 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 via a network connection. When the computer program is executed by the processor, the steps of the above-mentioned fan blade vibration stress calculation method are implemented.

[0091] Those skilled in the art will understand that Figure 13 The structure shown in the figure is only a block diagram of a part of the structure 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 shown in the figure, or combine certain components, or have a different component arrangement.

[0092] A preferred embodiment of the present application further provides a storage medium, which includes a stored program. When the program is run, 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.

[0093] It should be noted that the steps shown in the flowcharts of the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions, and that, although a logical order is shown in the flowcharts, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0094] If the functions described in the method of this embodiment are implemented in the form of a software functional unit and sold or used as an independent product, they can be stored in a storage medium readable by one or more computing devices. Based on this understanding, the part of the embodiment of this application that contributes to the prior art or the part of the technical solution can be embodied in the form of a software product, which is stored in a storage medium and includes a number of instructions for enabling a computing device (which can be a personal computer, server, mobile computing device or network device, etc.) to execute all or part of the steps of the method described in each embodiment of this application. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk, and other media that can store program code.

[0095] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may take the form of a fully hardware embodiment, a fully software embodiment, or an embodiment combining software and hardware. Furthermore, the present application may take 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.) containing computer-usable program code. The solutions in the embodiments of the present application may be implemented in various computer languages, such as the object-oriented programming language Java and the interpreted scripting language JavaScript.

[0096] The present 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 the present application. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes 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 a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 a process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0097] These computer program instructions may 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 the computer readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 a process or multiple processes and / or boxes Figure 1 The function specified in one or more boxes.

[0098] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing the instructions executed on the computer or other programmable device for implementing the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0099] Although the preferred embodiments of the present application have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present application.

[0100] Obviously, those skilled in the art may make various changes and modifications to this application without departing from the spirit and scope of this application. Thus, if these modifications and variations of this application fall within the scope of the claims of this application and their equivalents, this application is intended to include these modifications and variations.

Claims

1. A method for calculating vibration stress of fan blades, characterized in that: Including steps: S1. Determine through finite element analysis the point within the operating speed range where the blade tip circumferential vibration displacement under each mode of the blade that can be excited by the excitation source is greater than the preset value, and determine the final blade tip amplitude measurement point; S2. Calculate the vibration stress of the fan blade in each mode under each operating condition based on the displacement of the blade tip amplitude measurement point under each 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 under each mode and the vibration stress under the corresponding mode; The step S1 specifically includes the following steps: S11. First, calculate the axial displacement of the fan blade tip under typical working conditions through finite element analysis to obtain the axial displacement of each node of the fan blade tip; S12. Determine the optional range of blade tip amplitude measurement points based on the selected sensor size and specifications and the maximum axial displacement of each blade tip node; S13. Through finite element analysis, determine the maximum modal order n of the blade that can be excited by the excitation source within the operating speed range. Determine n as the modal order to be measured, and calculate the modal vibration shape and modal stress distribution of each mode under each operating condition. S14. For each mode to be measured, read out the maximum modal circumferential displacement and the corresponding node number within the selectable area of the blade tip amplitude measurement point, use the node as the potential blade tip amplitude measurement point for the 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; S15. Selecting the minimum 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.

2. The fan blade vibration stress calculation method according to claim 1, characterized in that: The typical operating conditions include ground slow-speed operating conditions, air slow-speed operating conditions, cruising operating conditions, take-off operating conditions, and maximum steady-state operating conditions.

3. The fan blade vibration stress calculation method according to claim 1, characterized in that: Step S12 specifically includes the steps: S121. Set the maximum modal stress of each mode to 30 MPa. Calculate the axial displacement A of each potential blade tip amplitude measurement point under each mode according to the relationship between the displacement of each potential blade tip amplitude measurement point and the corresponding maximum modal stress. ij , get an n×n matrix; S122. Select from the potential blade tip amplitude measurement points so that there is at least one axial A in each row. ij The minimum measuring point with a value >0.1 mm is used as the final blade tip amplitude measuring point.

4. The fan blade vibration stress calculation method according to claim 3, characterized in that: The step S122 specifically includes the following steps: S1221. Select the first-order modal potential blade tip amplitude measurement point. When the selected first-order modal potential blade tip amplitude measurement point makes at least one axial displacement A in each column of the matrix ij When the distance is >0.1m, only the first-order mode potential blade tip amplitude measurement point is selected as the final blade tip amplitude measurement point; S1222, when the selected first-order modal potential blade tip amplitude measurement point cannot make at least one axial displacement A in each column of the matrix ij If the value is greater than 0.1m, the second-order modal potential blade tip amplitude measurement point is further selected. When the second-order modal potential blade tip amplitude measurement point and the first-order modal potential blade tip amplitude measurement point are selected, there is at least one axial displacement A in each column of the matrix. ij When the angle is greater than 0.1m, the first-order mode potential blade tip amplitude measurement point and the additional second-order mode potential blade tip amplitude measurement point are taken together as the final blade tip amplitude measurement point; S1223, and so on, until all potential blade tip amplitude measurement points are selected so that there is at least one axial displacement A in each column of the matrix. ij When the blade tip amplitude is greater than 0.1m, the final blade tip amplitude measurement point is obtained.

5. The fan blade vibration stress calculation method according to claim 1, characterized in that: The step S2 specifically includes the following steps: S21. Fixing a final blade tip amplitude measurement point on a fan casing, causing the fan blade tip to generate axial displacement under centrifugal, aerodynamic, and temperature loads under various operating conditions, and determining the actual position of the final blade tip amplitude measurement point relative to the fan blade under various operating conditions based on the blade position measured at the final blade tip amplitude measurement point under static conditions and the axial displacement of each node of the fan blade tip under typical operating conditions; S22. Based on the modal vibration shapes of each mode order under each operating condition, read out the circumferential displacement of the actual position of the blade measured at each measuring point of each order under each operating condition and the corresponding maximum modal stress; S23. Calculate the ratio of the maximum modal stress to the measured circumferential displacement to obtain the ratio of the maximum modal stress of each modal order to the measured circumferential displacement under each working condition; S24. Calculate the maximum modal stress of each modal under each operating condition based on the circumferential displacement, ratio relationship, and blade vibration frequency of each modal vibration of the blade to obtain the vibration stress of each modal fan blade under each operating condition.

6. A fan blade vibration stress calculation device, characterized in that: include: The blade tip amplitude measurement point determination module is used to determine the point where the blade tip circumferential vibration displacement of each blade mode excited by the excitation source is greater than the preset value within the operating speed range through finite element analysis, and to determine the final blade tip amplitude measurement point. It is specifically used for: First, the axial displacement of the fan blade tip under typical working conditions is calculated through finite element analysis, and the axial displacement of each node of the fan blade tip is obtained; According to the selected sensor size specifications and the maximum axial displacement of each node of the blade tip, determine the optional range of blade tip amplitude measurement points; Through finite element analysis, it is determined that the maximum modal order of the blade that can be excited by the excitation source within the operating speed range is n, n is determined as the modal order required for measurement, and the modal vibration shape and modal stress distribution of each mode under various working conditions are calculated; For each mode that needs to be measured, read out the maximum modal circumferential displacement and the corresponding node number in the optional area of the blade tip amplitude measurement point, take the node as the potential blade tip amplitude measurement point of the mode, and calculate the relationship between the displacement of each potential blade tip amplitude measurement point and the corresponding order maximum modal stress; Select the minimum 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; The fan blade vibration stress calculation module is used to calculate the vibration stress of the fan blade in each mode under each operating condition based on the displacement of the blade tip amplitude measurement point under each 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 under each mode and the vibration stress under the corresponding mode.

7. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: 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 5 are implemented.

8. A storage medium comprising a stored program, which controls a 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 5 when the program is executed.

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