Blade dynamic strain measuring point determination method and device, equipment, storage medium and product

Abstract

The invention discloses a blade dynamic strain measuring point determination method, device and equipment, a storage medium and a product, and the method comprises the steps: S1, calculating a blade modal through finite element software, calculating the dynamic strain sensitivity of different nodes of the blade in different directions according to the information of all finite element nodes under each order derived from a finite element calculation result; s2, screening and searching the maximum value of the dynamic strain sensitivity from the dynamic strain sensitivities of different nodes and different directions to obtain the blade dynamic strain optimal measurement point position and measurement direction of the strain gauge and the minimum sensitivity of the modal group; and S3, similarly calculating the group sensitivity, the optimal measurement point position and the group optimal measurement direction of all modal groups to obtain the blade dynamic strain optimal measurement point position and measurement direction of all strain gauges and the minimum sensitivity of the modal groups. The method avoids omission of the optimal measuring point, has the characteristics of economy, rapidness and high test sensitivity, and can determine more reasonable dynamic strain measuring points and measuring directions.

Description

Technical Field

[0001] The present invention relates to the technical field of dynamic strain measurement of turbine machine blades, and in particular, to a method, device, equipment, storage medium and product for determining dynamic strain measurement points of blades. Background Art

[0002] Turbine equipment is widely used in industries such as electric power, chemical industry, aviation, and aerospace, and is a key equipment for national defense and industrial production. Blades are the core components of turbine equipment. Multi-modal dynamic strain monitoring of turbine machine blades plays a key role in the safe operation and life assessment of equipment. Since blades are prone to induce multi-order modal vibrations under complex aerodynamic-thermal coupling loads, monitoring only a single mode is likely to overlook potential high-order resonance risks, leading to structural failures such as fatigue cracks. Therefore, when using strain gauges (strain meters) to achieve multi-modal vibration monitoring of blades, it is necessary to capture dynamic strain vibration signals of multiple modes more accurately and comprehensively.

[0003] The current main implementation path for strain monitoring of rotating turbine blades is as follows: Strain gauges are pasted on the blades, and the strain gauges are connected to slip rings through leads. The slip rings are used to transmit the dynamic strain signals of the rotating blades to a data collector, and finally the dynamic strain acquisition of the rotating blades is realized. Due to factors such as the limited surface space of the blades, the cost of strain gauges, and the limited number of slip ring channels, the number of strain gauge measurement point positions is restricted. Only a very limited number of measurement points can be taken in each test, while multiple blade numbers and multiple (even dozens of) modal numbers need to be monitored. Therefore, in actual tests, the following problems are faced: It is necessary to monitor multi-order modes of multiple blades with fewer strain measurement points and ensure that the sensitivity of the dynamic strain values of each mode to be monitored (including key modes or dangerous modes) meets a certain standard value.

[0004] Traditional methods for determining dynamic strain measurement points cannot select the best measurement point positions from all "finite element nodes" on the blade surface, but only select the best points from limited alternative points, which will miss the best measurement points and thus reduce the sensitivity of the measured strain. Summary of the Invention

[0005] One aspect of the present application provides a method for determining dynamic strain measurement points of blades, which is used to solve the technical problem that the existing traditional method for determining dynamic strain measurement points will miss the best measurement points, thereby reducing the sensitivity of the measured strain.

[0006] The present application is implemented through the following solutions: A method for determining dynamic strain measurement points of blades includes the steps of: S1. Calculate the blade modes through finite element software, and calculate the dynamic strain sensitivities of different nodes and different directions of the blade according to the information of all finite element nodes at each order derived from the finite element calculation results; S2. Screen and search for the maximum dynamic strain sensitivity from the dynamic strain sensitivities in different directions at different nodes, and then obtain the best measuring point positions, measuring directions, and the minimum sensitivity of the modal group for the corresponding strain gauges. S3. Calculate the group sensitivities, best measuring point positions, and group best measuring directions for all modal groups, that is, obtain the best measuring point positions, measuring directions, and the minimum sensitivity of the modal group for all strain gauges.

[0007] Further, the step S1 specifically includes the following steps: S11. Use finite element software to calculate the blade modes, and export the first and third principal strains, equivalent strain, and strain tensor of all finite element nodes at each order from the finite element calculation results, obtain the strain tensor of the nodes on the pasteable surface, and the maximum first principal strain in the blade node results.

[0008] Further, the step S2 specifically includes the following steps: S21. For the modal group G k , calculate the maximum sensitivity of all nodes on the pasteable surface at each order in the modal group G k . The set of maximum sensitivity values is A, and the elements in A are: the maximum sensitivity of the i-th node at the j-th order calculated. S22. Screen the nodes on the pasteable surface in step S21. The nodes meet the condition: their sensitivities at each order are greater than or equal to a%, where the value of a% is set according to the actual situation. The remaining nodes are represented by the set B. S23. Calculate the point sensitivity and point best measuring direction of all nodes in the set B according to the normal strains at each order of each node in the set B in different angular directions. S24. Take the maximum value from the point sensitivities of all nodes as the group sensitivity of the modal group G k . The position of the point corresponding to the maximum value is the best measuring point position, and the corresponding point best measuring direction is the group best measuring direction of the modal group G k . Thus, obtain the best measuring point position, the minimum sensitivity of the modal group, and the best measuring direction of the strain gauge SG k .

[0009] Further, the step S23 specifically includes the following steps: S231. For a certain node in the set B, traverse and calculate the normal strains of this node at each order in different angular directions, and calculate the minimum sensitivity at all modes at each angle as the sensitivity at the angle, and obtain the sensitivities at all angles. S232. Search for the maximum value among the sensitivities at all angles of a certain node in the set B as the point sensitivity of this node, and the angle corresponding to the point sensitivity is the point best measuring direction of this node. S233. Calculate the point sensitivity and the optimal point measurement direction of all nodes in set B according to steps S231 to S232.

[0010] Further, in step S21, the method for calculating the maximum sensitivity of the i -th node at the j -th order is as follows: ; Where: is the coordinate position of the measurement point, is the test direction of the strain gauge patch, is the sensitivity of the strain gauge at the -th order mode; is the strain value monitored in the coordinate position in the direction, obtained through finite element calculation; is the maximum modal strain value at the -th order mode. Here, the maximum modal strain value is taken as the maximum value among the first principal strain, the third principal strain (absolute value), or the equivalent strain of all nodes on the blade surface.

[0011] Further, in step S22, the value of a% is 30%.

[0012] On the other hand, the present application also provides a device for determining the dynamic strain measurement points of a blade, including: A finite element calculation module, configured to calculate the blade mode through finite element software, and calculate the dynamic strain sensitivity of different nodes and different directions of the blade according to the information of all finite element nodes at each order derived from the finite element calculation results; A screening and searching module, configured to screen and search for the maximum dynamic strain sensitivity from the dynamic strain sensitivities of different nodes and different directions, and then obtain the optimal measurement point position, the measurement direction, and the minimum sensitivity of the modal group of the blade dynamic strain; A loop calculation module, configured to calculate the group sensitivity, the optimal measurement point position, and the group optimal measurement direction of all modal groups, that is, obtain the optimal measurement point position, the measurement direction, and the minimum sensitivity of the modal group of all strain gauges.

[0013] 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 determining the dynamic strain measurement points of the blade are implemented.

[0014] 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 determining the dynamic strain measurement points of the blade.

[0015] On the other hand, the present application also provides a computer program product, including a computer program or computer-executable instructions. When the computer program or computer-executable instructions are executed by a processor, the steps of the method for determining the dynamic strain measurement points of the blade are implemented.

[0016] Compared with the prior art, the present application has the following beneficial effects: The present application provides a method for determining the dynamic strain measurement points of a blade. This method calculates the dynamic strain sensitivities in different directions of different nodes from information such as the strain tensors of finite element nodes, and obtains the optimal blade dynamic strain measurement point positions and measurement directions after screening and searching for the maximum points of the dynamic strain sensitivities. Compared with traditional methods, the present application can be automatically executed by a program. After calculating the required information file in a finite element software, the best measurement point positions of strain gauges, the minimum sensitivity of the modal group, and the best measurement directions can be directly calculated by the compiled computer program, which is fast and convenient. In addition, since the present application uses all finite element nodes as alternative points for calculation, it avoids missing the best measurement points, maximizes the minimum value of the dynamic strain sensitivity in all measured modes, and thus improves the sensitivity of the strain gauge. The method for determining the dynamic strain measurement points of the blade in the present application has the characteristics of economy, speed, and high test sensitivity, and can be applied to the dynamic strain measurement test design of turbine blades, so as to determine more reasonable dynamic strain measurement points and measurement directions.

[0017] 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 for a further detailed description of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The drawings constituting a part of the present application are used to provide a further understanding of the present application. The schematic embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation to the present application: Figure 1 It is a schematic flowchart of the method for determining the dynamic strain measurement points of the blade in the preferred embodiment of the present application; Figure 2 It shows a schematic diagram of the sensitivity curve of a certain node in a certain modal group within the angular range of -90 degrees to +90 degrees in the embodiment; Figure 3 It shows a schematic diagram of the relationship between the blade surface and the surface where the strain gauge can be pasted; Figure 4 It is a schematic diagram of the module of the device for determining the dynamic strain measurement points of the blade in the preferred embodiment of the present application; Figure 5 It is a schematic block diagram of the entity of the electronic device in the preferred embodiment of the present application; Figure 6 It is an internal structure diagram of the computer device in the preferred embodiment of the present application. Detailed implementation manners

[0019] The embodiments of the present application will be described in detail below with reference to the accompanying drawings. However, the present application can be implemented in many different ways defined and covered by the following.

[0020] A concept is involved in the method for determining the strain gauge pasting position: "strain gauge attachable surface". Since there are relatively flat surfaces on the blade surface at the blade basin and the blade back, that is, the surfaces with relatively small surface curvatures; there are also surfaces with relatively large curvatures at the blade top and the edge. Generally, the strain gauge is preferably pasted on the relatively flat surface to ensure that the strain gauge does not become loose during high-speed rotation and to ensure the signal quality. Therefore, the "relatively flat surface" on which the strain gauge can be pasted is defined as the strain gauge attachable surface (hereinafter referred to as the "attachable surface").

[0021] When performing finite element calculations, the directly calculated values are the strain tensors (and stress tensors) of the nodes on the blade, while the values usually obtained through strain gauge monitoring experiments are the normal strains in a certain direction at a point on the blade surface. Before conducting the experiment, it is necessary to obtain the maximum normal strain point and the normal strain direction on the blade surface through finite element calculations; correlating the dynamic strain (dynamic stress) of the blade obtained from the finite element calculations with the strain measured by the strain gauge is an important link in the strain monitoring experiment. The following gives a method for calculating and determining the normal strain direction at a point on the blade surface by the finite element method.

[0022] The engineering strain array of a point on the blade can be calculated by the finite element calculation program , which is expressed as: ; In the formula: , , are respectively the engineering linear strains; , , are respectively the engineering shear strains. And the Cauchy strain tensor at a point on the blade is: ; In the formula: , , are respectively the normal strain components; , , etc. are respectively the shear strain components. The Cauchy strain tensor is obtained from the strain array: ; The Cauchy strain tensor is a symmetric tensor and can completely represent the stress state of a point. Calculate the maximum principal strain , that is, to find the maximum value among the eigenvalues of the determinant of the strain tensor. For any direction vector , the linear strain in this direction is expressed as: ; For the maximum principal strain , its direction cosine is denoted as , and according to the relationship between the strain tensor and the principal strain, there is the following formula: ; According to the relationship between the strain tensor and the principal strain, the direction cosine of the maximum principal strain can be obtained. This direction cosine determines the direction of the maximum principal strain at a point on the blade in a certain mode. According to this direction, the dangerous state of the blade can be determined, providing a basis for calculating the fatigue life of the blade. At the same time, it can also determine the best pasting direction of the strain gauge when using the strain gauge to monitor the dynamic strain of the blade. At a point on the blade surface, the maximum principal strain direction should be tangent to the blade surface.

[0023] Before calculation, the known conditions should include: the number of strain gauge patches on each blade P , all modal orders H (H = 1, 2, 3,..., m ), the number of finite element nodes on the blade surface n b , the number of finite element nodes on the attachable surface of the blade n g . The group numbers of modal grouping are denoted as G1, G2, G3,..., G k ,..., and the corresponding measured point strain gauges are denoted as SG1, SG2, SG3,..., SG k ,....

[0024] As Figure 1 shown, the preferred embodiment of the present application provides a method for determining the measuring points of the dynamic strain of a blade, including the steps: S1. Calculate the blade modes through finite element software, and calculate the dynamic strain sensitivities of different nodes and different directions of the blade according to the information of all finite element nodes at each order derived from the finite element calculation results. When calculating the blade modes by finite element software, derive the first and third principal strains, equivalent strain, strain tensor, obtain the strain tensor of the attachable surface nodes, and the maximum first principal strain in the blade node results from the finite element calculation results at each order; S2. Screen and search for the maximum value of the dynamic strain sensitivity from the dynamic strain sensitivities of different nodes and different directions, and then obtain the best measuring point position, measuring direction of the blade dynamic strain and the minimum sensitivity of the modal group corresponding to the strain gauge; S3. Calculate the group sensitivity, the best measuring point positions, and the group's best measuring directions for all modal groups, that is, obtain the best measuring point positions and measuring directions of the blade dynamic strain for all strain gauges and the minimum sensitivity of the modal group.

[0025] This application provides a method for determining the measuring points of blade dynamic strain. This method calculates the dynamic strain sensitivities of different nodes in different directions from information such as the strain tensors of finite element nodes, and obtains the optimal blade dynamic strain measuring point positions and measuring directions after screening and searching for the maximum points of the dynamic strain sensitivities. Compared with traditional methods, this application can be automatically executed by a program. After calculating the required information files in finite element software, the best measuring point positions, the minimum sensitivity of the modal group, and the best measuring directions of the strain gauges can be directly calculated by the compiled computer program, which is fast and convenient. In addition, since this application uses all finite element nodes as alternative points for calculation, it avoids missing the best measuring points, maximizes the minimum value of the dynamic strain sensitivities in all measured modes, and thus improves the sensitivity of the strain gauges. The method for determining the measuring points of blade dynamic strain in this application has the characteristics of economy, speed, and high test sensitivity, and can be applied to the experimental design of dynamic strain measurement of turbine blades, thereby determining more reasonable dynamic strain measuring points and measuring directions.

[0026] Preferably, the step S2 specifically includes the steps: S21. For the modal group G k , calculate the maximum sensitivities of all nodes on the pasteable surfaces at each order in the modal group G k . The set of maximum sensitivity values is A, and the elements in A are: the maximum sensitivity of the i-th node at the j-th order calculated. S22. Screen the nodes on the pasteable surfaces in step S21. The nodes meet the condition: their sensitivities at each order are greater than or equal to a%, where the value of a% is set according to the actual situation. The remaining nodes are represented by the set B. S23. Calculate the point sensitivities and point best measuring directions of all nodes in the set B based on the normal strains at each order of these nodes in different angular directions. S24. Take the maximum value from the point sensitivities of all nodes as the group sensitivity of the modal group G k . The position of the point corresponding to the maximum value is the best measuring point position, and the corresponding point best measuring direction is the group best measuring direction of the modal group G k . Thus, obtain the best measuring point position, the minimum sensitivity of the modal group, and the best measuring direction of the strain gauge SG k .

[0027] Preferably, the step S23 specifically includes the steps: S231. For a certain node in set B, traverse and calculate the normal strains of each order in different angular directions of this node, calculate the minimum sensitivity in all modes at each angle as the sensitivity at that angle, and obtain the sensitivities at all angles; S232. Search for the maximum value of the sensitivities at all angles of a certain node in set B as the point sensitivity of this node, and the angle corresponding to the point sensitivity is the point optimal measurement direction of this node; S233. According to steps S231 to S232, calculate the point sensitivities and point optimal measurement directions of all nodes in set B.

[0028] Preferably, in step S21, the method for calculating the maximum sensitivity of the i th node in the j th order is as follows: ; Where: is the coordinate position of the measurement point, is the test direction of the strain gauge patch, is the sensitivity of the strain gauge in the th mode; is the strain value monitored in the coordinate position in the direction, obtained by finite element calculation; is the maximum modal strain value in the th mode. Here, the maximum modal strain value is taken as the maximum value among the first principal strain, the third principal strain (absolute value), or the equivalent strain of all nodes on the blade surface.

[0029] Preferably, in step S22, the value of a% is 30%. Its advantages and purposes are: to ensure that the vibration stress at the patch position has a sufficient magnitude (the maximum stress of the blade in many orders is not high), to have a sufficient signal-to-noise ratio, to ensure that the strain gauge can effectively identify the actual vibration stress at the patch position, and to ensure a small measurement error.

[0030] The following further illustrates the application through another embodiment.

[0031] First, introduce the applicable application scenarios of this embodiment. This embodiment can be applied to the experimental design of turbine blades. Before measuring the dynamic strain of the turbine blade, more reasonable dynamic strain measurement points and measurement directions can be determined according to this method. Figure 2 shows the sensitivity curve of a certain node in the embodiment within the angular range of -90 degrees to +90 degrees under a certain modal grouping; Figure 3 shows the relationship between the blade surface and the surface where the strain gauge can be pasted.

[0032] A method for determining the dynamic strain measurement points of a blade, comprising the steps: Step S101: Calculate the blade modes by finite element method, obtain the first and third principal strains, equivalent strain, strain tensor of all finite element nodes at each order, obtain the strain tensor of the nodes on the pasteable surface, and the maximum first principal strain in the blade node results.

[0033] Given the mode grouping G k In this embodiment, one mode grouping is G1, which specifically includes: mode 5, mode 6, mode 7, mode 8, mode 9, mode 12, mode 14, mode 15; another mode grouping is G2, which specifically includes mode 1, mode 2, mode 3, mode 4, mode 10, mode 11, mode 13, mode 16, a total of 2 groups of mode groupings, that is, it is expected to implement two measurement points (for each blade). It should be noted that the two measurement points in this embodiment are implemented at different positions on the same blade. In other embodiments, two strain measurement points can also be implemented on two blades respectively.

[0034] Step S102: Calculate the maximum sensitivity of all nodes on the pasteable surface at each order in mode grouping G1 to obtain the set of maximum sensitivity values as A, and the elements in A are: the maximum sensitivity of the calculated i th node at j order is denoted as .

[0035] Step S103: Screen the nodes on the pasteable surface to meet the condition that their sensitivities at each order are greater than or equal to a%. In this embodiment, a% is taken as 40%. The remaining nodes are represented by set B.

[0036] Step S104: For a certain node (finite element node number 6711) in set B, traverse and calculate the normal strain of this node at different angular directions at each order; obtain the sensitivity at all angles of this node. As Figure 2 shown, it shows the sensitivity curve of a certain node in the angular range of -90 degrees to +90 degrees under mode grouping G k . For a certain angle on the abscissa, calculate the minimum sensitivity corresponding to all modes at this angle, which is the sensitivity at the angle.

[0037] Step S105: Search for the maximum value of the sensitivity of this node (finite element node number 6711) at all angles; the angles corresponding to this maximum value and the second maximum value are the point sensitivity and the point best measurement direction. For node number 6711, the point sensitivity and the point best measurement direction are shown graphically. The point sensitivity is 19.2%, and the point best measurement direction is (0.2100, 0.1770, 0.9615).

[0038] Step S106: Perform the calculations of Step S104 and Step S105 for all the nodes in set B; obtain the point sensitivities and the point optimal measurement directions of all the nodes.

[0039] Step S107: Search for the maximum value among the point sensitivities of all the nodes; the maximum value in the point sensitivities is the minimum sensitivity of the mode group, the position of the corresponding point is the optimal measurement point position of strain gauge SG1, and the point optimal measurement direction corresponding to the point sensitivity of this point is the optimal measurement direction of strain gauge SG1. Then, obtain that the optimal measurement point position of strain gauge SG1 is the position of node numbered 6711, the minimum sensitivity of the mode group is 19.2%, and the optimal measurement direction is (0.2100, 0.1770, 0.9615).

[0040] Step S108: Perform the calculations of Steps S102 - S107 for all the mode groups; that is, obtain the optimal measurement point positions, the minimum sensitivities of the mode groups, and the optimal measurement directions of all the strain gauges (see Table 1).

[0041] Table 1: Results Table of Strain Gauge Measurement Points

[0042] The above is how to obtain the optimal measurement point position, the minimum sensitivity of the mode group, and the optimal measurement direction of the strain gauge from the finite element calculation information; this minimum sensitivity of the mode group refers to the maximum sensitivity that can be obtained as the minimum value among the dynamic strain sensitivities of each order corresponding to the mode group tested by this strain gauge.

[0043] As Figure 4 shown, another embodiment of the present application also provides a device for determining the dynamic strain measurement points of a blade, including: A finite element calculation module, configured to calculate the blade modes through finite element software, and calculate the dynamic strain sensitivities of different nodes and different directions of the blade according to the information of all finite element nodes at each order derived from the finite element calculation results; A screening and searching module, configured to screen and search for the maximum value of the dynamic strain sensitivities from the dynamic strain sensitivities of different nodes and different directions, and then obtain the optimal measurement point position, the measurement direction, and the minimum sensitivity of the mode group of the blade dynamic strain; A loop calculation module, configured to calculate the group sensitivities, the optimal measurement point positions, and the group optimal measurement directions of all the mode groups, that is, obtain the optimal measurement point positions and the measurement directions of all the strain gauges and the minimum sensitivities of the mode groups.

[0044] As Figure 5 shown, a preferred embodiment of 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, and when the processor executes the computer program, it implements the steps of the method for determining the dynamic strain measurement points of the blade in the above - mentioned embodiment.

[0045] As Figure 6 shown, 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 6 shown. 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-mentioned blade dynamic strain measurement point determination method are implemented.

[0046] Those skilled in the art can understand that Figure 6 the structure shown in

[0047] 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.

[0048] The blade dynamic strain measurement point determination method provided by the present application can measure the dynamic strain of all key modes with a smaller number of strain gauge patch numbers by calculating the optimal blade dynamic strain measurement points. The most important effect is that: the minimum value of the dynamic strain sensitivity in all the measured modes reaches the maximum.

[0049] The application purpose of the blade dynamic strain measurement point determination method of the present invention is mainly: for monitoring the multi-modal dynamic strain state of rotating machine blades in a rotating state using the strain gauge method, and the meaning of the multi-modal dynamic strain to be monitored is: there are multiple modes of vibration in the rotating operation process of the blade, and each mode of vibration corresponds to a different dynamic strain state.

[0050] The present application can obtain a preliminary modal order combination (i.e., modal grouping) according to the prior art, or list multiple different modal combinations according to actual experience, and then use the method herein for subsequent calculations.

[0051] 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.

[0052] If 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 that can be read by a computing device. Based on this understanding, the part that contributes to the prior art or the part of this technical solution in the embodiments of this application 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 computing 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 the various embodiments of this application. The foregoing storage media include: USB flash drives, mobile hard disks, read-only memories (ROM, Read-Only Memory), random access memories (RAM, Random Access Memory), magnetic disks, or optical disks, etc., which can store program codes.

[0053] Those skilled in the art should understand that the embodiments of this application can be provided as methods, systems, or computer program products. 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 memories, CD-ROMs, optical memories, etc.) containing 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.

[0054] This application is described with reference to the flowcharts and / or block diagrams of 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 can be implemented by computer program instructions, as well as the combination of flows and / or blocks in the flowchart and / or block diagram. 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 functions specified in Figure 1 one flow or multiple flows and / or blocks Figure 1 one block or multiple blocks.

[0055] These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means that implement the function specified in one or more of the flows Figure 1 and / or boxes Figure 1 specified in one or more of the boxes.

[0056] These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer-implemented process, whereby the instructions executed on the computer or other programmable apparatus provide steps for implementing the function specified in one or more of the flows Figure 1 and / or boxes Figure 1 specified in one or more of the boxes.

[0057] Although the preferred embodiments of the present application have been described, additional changes and modifications can be made by those skilled in the art once they learn of the basic inventive concept. Therefore, the appended claims are intended to be construed to include the preferred embodiments as well as all changes and modifications falling within the scope of the present application.

[0058] 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 determining the measuring points of blade dynamic strain, characterized in that Including the steps: S1. Calculate the blade modes by finite element software, and calculate the dynamic strain sensitivities of different nodes of the blade in different directions according to the information of all finite element nodes at each order derived from the finite element calculation results; S2. Screen and search for the maximum value of the dynamic strain sensitivity from the dynamic strain sensitivities of different nodes in different directions, and then obtain the optimal measuring point positions, measuring directions and minimum sensitivities of the modal groups of the blade dynamic strain corresponding to the strain gauges; S3. Calculate the group sensitivities, optimal measuring point positions and group optimal measuring directions of all modal groups, that is, obtain the optimal measuring point positions, measuring directions and minimum sensitivities of the modal groups of the blade dynamic strain of all strain gauges.

2. The method for determining the blade dynamic strain measurement points according to claim 1, wherein The specific steps of step S1 include: S11. Calculate the blade modes by finite element software, derive the first and third principal strains, equivalent strain, strain tensor of all finite element nodes at each order from the finite element calculation results, obtain the strain tensor of the nodes on the pasteable surface, and the maximum first principal strain in the blade node results.

3. The method for determining the blade dynamic strain measurement points according to claim 1, wherein The specific steps of step S2 include: S21. For the modal group G k , calculate the maximum sensitivity of all pasteable surface nodes at each order in the modal group G k . The set of maximum sensitivity values is A, and the elements in A are: the maximum sensitivity of the calculated node i at order j; S22. Screen the nodes on the pasteable surface in step S21. The nodes meet the condition that their sensitivities at each order are greater than or equal to a%, where the value of a% is set according to the actual situation. The remaining nodes are represented by set B; S23. Calculate the point sensitivities and point optimal measuring directions of all nodes in set B according to the normal strains at each order of each node in set B in different angular directions; S24. Take the maximum value from the point sensitivities of all nodes as the modal grouping G k 's group sensitivity. The position of the point corresponding to the maximum value is the optimal measurement point position, and the optimal measurement direction of the corresponding point is the modal grouping G k 's group optimal measurement direction, thereby obtaining the optimal measurement point position, the minimum sensitivity of the modal group, and the optimal measurement direction of the strain gauge SG k .

4. The method for determining the blade dynamic strain measurement points according to claim 3, wherein The specific steps of step S23 include: S231. For a certain node in set B, traverse and calculate the normal strains at each order of this node in different angular directions, and calculate the minimum sensitivity under all modes at each angle as the sensitivity at the angle, and obtain the sensitivities at the angles of all angles; S232. Search for the maximum value of the sensitivities at all angles of a certain node in set B as the point sensitivity of this node, and the angle corresponding to the point sensitivity is the point optimal measuring direction of this node; S233. According to steps S231 to S232, calculate the point sensitivities and point optimal measuring directions of all nodes in set B.

5. The method for determining the dynamic strain measurement points of the blade according to claim 3, wherein In step S21, the method for calculating the maximum sensitivity of the i th node at the j order is as follows: ； Wherein: is the coordinate position of the measurement point, is the test direction of the strain gauge patch, is the sensitivity of the strain gauge in the th order mode; is the strain value monitored in the coordinate position in the direction, obtained by finite element calculation; is the maximum modal strain value in the th order mode. Here, the maximum modal strain value is taken as the maximum value among the first principal strain, the third principal strain, or the equivalent strain of all nodes on the blade surface.

6. The method for determining the dynamic strain measurement points of the blade according to claim 3, characterized in that In step S22, the value of a% is 30%.

7. A device for determining the measuring points of dynamic strain of blades, characterized in that, Including: A finite element calculation module for calculating the blade modes by finite element software, and calculating the dynamic strain sensitivities of different nodes of the blade in different directions according to the information of all finite element nodes at each order derived from the finite element calculation results; A screening and searching module for screening and searching for the maximum value of the dynamic strain sensitivity from the dynamic strain sensitivities of different nodes in different directions, and then obtaining the optimal measuring point positions, measuring directions and minimum sensitivities of the modal groups of the blade dynamic strain; A loop calculation module for calculating the group sensitivities, optimal measuring point positions and group optimal measuring directions of all modal groups, that is, obtaining the optimal measuring point positions, measuring directions and minimum sensitivities of the modal groups of all strain gauges.

8. 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, it implements the steps of the method for determining the measuring points of the blade dynamic strain as described in any one of claims 1 to 6.

9. A storage medium, the storage medium including a stored program, which controls a device where the storage medium is located to execute the steps of the method for determining blade dynamic strain measurement points according to any one of claims 1 to 6 when the program runs.

10. A computer program product, comprising a computer program or computer-executable instructions, characterized in that, When the computer program or computer-executable instructions are executed by a processor, the steps of the method for determining blade dynamic strain measurement points according to any one of claims 1 to 6 are implemented.

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