Helicopter flexible beam actual measurement load substitution analysis method

Abstract

The invention discloses a helicopter flexible beam actually-measured load substitution analysis method, which comprises the following steps: considering that actually-measured load data at the root part of a flexible beam is effective in the initial stage of test flight, and utilizing an effective time period corresponding to effective test flight data of the actually-measured load at the root part of the flexible beam; performing spectral analysis on the measured load of the root section of the flexible beam and the measured load of the section of the airfoil section on the same tail rotor blade within the effective time period of the effective test flight data at a preset interval time, so as to obtain the amplitudes of the measured load of the root section of the flexible beam and the measured load of the section of the airfoil section corresponding to the rotating speed frequency of the tail rotor; the amplitudes of all the time points in the effective time period are combined to form two groups of data columns; scatter diagrams of two groups of data columns can be drawn, a plurality of correlation formulas of the two groups of data columns are obtained through linear fitting, and the correlation formula with the optimal correlation between the airfoil section section actual measurement load and the flexible beam root section actual measurement load on the same tail rotor blade is selected as the basis of calculation of the flexible beam root section actual measurement load. And the actual measurement load of the root section of the flexible beam in the whole flight process can be obtained based on the actual measurement load of the tail rotor blade airfoil section section.

Description

Technical Field

[0001] The present invention relates to the field of but not limited to the technical field of helicopter structural strength design, and in particular to a helicopter flexible beam measured load substitution analysis method. Background Art

[0002] The bearingless tail rotor of a helicopter is currently a commonly used configuration for helicopter tail rotors. It has a simple structure and good maintainability. Its main features are: a flexible beam is used to replace the flapping hinge, swing hinge, and variable pitch hinge of the previous configuration, and the flapping, swing, and variable pitch functions of the tail rotor are achieved through the deformation of the flexible beam.

[0003] The strength design of the flexible beam is a key factor in the safe flight of the tail rotor. Since its load is extremely complex, it is difficult to obtain a reliable load through calculation. It is particularly important to measure the load of the flexible beam through actual measurement. In order to achieve the flapping, oscillation and pitch change of the tail rotor blades during the flight of the helicopter, the flexible beam will produce a large deformation, resulting in frequent damage to the load strain gauge at the root of the flexible beam, making it difficult to meet the monitoring and testing requirements of the test flight. Summary of the invention

[0004] The purpose of the present invention is: in order to solve the above-mentioned problem, an embodiment of the present invention provides a helicopter flexible beam measured load replacement analysis method to solve the existing strength design method of the flexible beam in the bearingless configuration tail rotor. In order to realize the flapping, swinging and pitch changing movement of the tail rotor blades, the flexible beam is required to produce a large deformation, which leads to frequent damage of the load strain gauge at the root of the flexible beam, making it difficult to ensure the monitoring and testing requirements of the test flight.

[0005] The technical solution of the present invention is as follows: In a first aspect, an embodiment of the present invention provides a helicopter flexible beam measured load replacement analysis method, comprising:

[0006] Step 1, obtaining the effective test flight data of the measured load of the root section of the flexible beam and the corresponding effective time period;

[0007] Step 2, performing frequency spectrum analysis on the measured load of the root section of the flexible beam and the measured load of the airfoil section on the tested tail rotor blade at preset intervals within the effective time period of the effective test flight data of the measured load of the root section of the flexible beam, and obtaining the amplitudes of the measured load of the root section of the flexible beam and the measured load of the airfoil section corresponding to the tail rotor speed frequency respectively;

[0008] Step 3, combining the amplitudes within the effective time period to form two sets of data columns, obtaining the correlation formulas of the two sets of data columns through linear fitting, and obtaining multiple sets of correlation formulas of the measured loads of the flexible beam root section and the measured loads of the airfoil section section;

[0009] Step 4, select the correlation formula with the best correlation between the measured load of the tail rotor blade upper airfoil section and the measured load of the flexible beam root section, and use it to calculate the measured load of the flexible beam root section.

[0010] Optionally, in the helicopter flexible beam measured load substitution analysis method as described above, step 1 comprises:

[0011] The flight states are divided according to the flight speed and flight altitude in the performance parameters of the helicopter test flight data, and the time periods corresponding to the test flight data in which the actual measured load at the root of the flexible beam and the actual measured load at the airfoil section are both valid in each flight state are recorded.

[0012] Optionally, in the helicopter flexible beam measured load substitution analysis method as described above, step 2 comprises:

[0013] Step 21, in the effective time period when the load is effective in each flight state, the measured load of the root section of the flexible beam on the tested tail rotor blade and the measured load of the airfoil section are respectively subjected to spectrum analysis at preset intervals, so as to obtain the measured load of the root section of the flexible beam and the airfoil section on the tested tail rotor blade at each influencing frequency in each flight state, and the tail rotor speed frequency is the dominant spectrum in the influencing frequency;

[0014] Step 22, for each effective time period, respectively extract the amplitude of the tail rotor speed frequency corresponding to the measured load of the flexible beam root section and the measured load of the airfoil section section at the corresponding flight state at the same time.

[0015] Optionally, in the helicopter flexible beam measured load substitution analysis method as described above, step 3 comprises:

[0016] Step 31, combining the amplitudes of the tail rotor speed frequency corresponding to the measured load of the root section of the flexible beam and the measured load of the airfoil section at the same time extracted from the flight state corresponding to each effective time period to form two sets of data columns, and drawing scatter plots of the two sets of data columns, and obtaining the correlation formula of the two sets of data columns by linear fitting;

[0017] Step 32, for each section position on the same tail blade, obtain the correlation formula corresponding to the measured section load of the flexible beam root and the measured section load of the airfoil section at each section position, thereby obtaining multiple correlation formulas corresponding to multiple section positions in the same tail blade.

[0018] Optionally, in the helicopter flexible beam measured load substitution analysis method as described above, step 4 comprises:

[0019] Step 41, on the same tail blade, select the correlation formula with the best correlation between the measured load of the airfoil section section and the measured load of the flexible beam root section.

[0020] Optionally, the helicopter flexible beam measured load substitution analysis method as described above further includes:

[0021] Step 42, selecting an optimal correlation formula for calculating the measured load of the root section of the flexible beam from among the optimal correlation formulas selected for the plurality of tail rotor blades.

[0022] Optionally, in the above-mentioned helicopter flexible beam measured load substitution analysis method, the method of selecting the optimal correlation formula in step 4 is:

[0023] Through linear fitting, the correlation formula of the two sets of data columns is obtained. According to the fitting variance of the correlation formula, the optimal correlation formula is selected. The closer the fitting variance value is to 1, the better the linear fit is.

[0024] Optionally, the helicopter flexible beam measured load substitution analysis method as described above further includes:

[0025] Step 5, using the optimal correlation formula selected in step 4, the measured load of the flexible beam root section during the entire flight process is obtained according to the measured load of the airfoil section section.

[0026] In a second aspect, an embodiment of the present invention further provides a computer-readable storage medium, including: a memory and a processor;

[0027] The memory is configured to store executable instructions;

[0028] The processor is configured to implement any of the above-mentioned helicopter flexible beam measured load replacement analysis methods when executing the executable instructions stored in the memory.

[0029] The beneficial effects of the present invention are as follows: an embodiment of the present invention provides a helicopter flexible beam measured load replacement analysis method, the overall scheme is to obtain the flexible beam root section measured load according to the tail rotor blade airfoil section measured load; generally in the early stage of the test flight, the flexible beam root measured load data is valid, and the flexible beam root measured load and the airfoil section measured load on the same tail rotor blade are subjected to spectrum analysis at preset intervals within the effective time period of the effective test flight data by using the effective time period corresponding to the effective test flight data of the flexible beam root measured load. The amplitudes of the measured loads on the root section of the flexible beam and the measured loads on the airfoil section corresponding to the tail rotor speed frequency are calculated; the amplitudes at each time point in the effective time period are combined to form two groups of data columns; a scatter plot of the two groups of data columns can be drawn, and multiple correlation formulas of the two groups of data columns can be obtained through linear fitting, and the correlation formula with the best correlation between the measured loads on the airfoil section on the same tail rotor blade and the measured loads on the root section of the flexible beam is selected as the basis for calculating the measured loads on the root section of the flexible beam, so that the measured loads on the root section of the flexible beam during the entire flight process can be obtained based on the measured loads on the airfoil section of the tail rotor blade.

[0030] Relevant application examples show that the measured load replacement analysis method for helicopter flexible beams provided in the embodiment of the present invention can obtain the actual measured load of the root section of the flexible beam, ensuring the measured load flight test and safety monitoring requirements of the flexible beam, providing accurate and reliable measured load data for the strength design of the flexible beam, and being able to carry out the strength design of the flexible beam more accurately, which has high universality and engineering application value. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The accompanying drawings are used to provide a further understanding of the technical solution of the present invention and constitute a part of the specification. Together with the embodiments of the present application, they are used to explain the technical solution of the present invention and do not constitute a limitation on the technical solution of the present invention.

[0032] Figure 1 A schematic flow chart of a helicopter flexible beam measured load replacement analysis method provided by an embodiment of the present invention;

[0033] Figure 2 A schematic diagram of the positions of the flexible beam root section and the tail rotor blade airfoil section section in the helicopter flexible beam measured load substitution analysis method provided by an embodiment of the present invention;

[0034] Figure 3 It is a schematic diagram of a time domain curve of the measured load on the root section of the flexible beam on the tail rotor blade at a typical moment in an embodiment of the present invention;

[0035] Figure 4 It is a schematic diagram of a frequency domain curve of the measured load on the root section of the flexible beam on the tail rotor blade at a typical moment in an embodiment of the present invention;

[0036] Figure 5 Schematic diagram of a frequency domain curve of the measured load on the flexible airfoil section of the tail rotor blade at a typical moment in an embodiment of the present invention;

[0037] Figure 6 Schematic diagram of the correlation between the measured load of the root section of the flexible beam and the measured load of the tail rotor blade airfoil section section in an embodiment of the present invention;

[0038] Figure 7 The figure is a schematic diagram of the results of the measured load on the root section of the flexible beam during a typical flight, obtained by using the method provided by the embodiment of the present invention. DETAILED DESCRIPTION

[0039] The accompanying drawings are used to provide a further understanding of the technical solution of the present invention and constitute a part of the specification. Together with the embodiments of the present application, they are used to explain the technical solution of the present invention and do not constitute a limitation on the technical solution of the present invention.

[0040] As explained in the above background technology, the helicopter bearingless tail rotor is a commonly used configuration for helicopter tail rotors, and the strength design of the flexible beam is a key factor in ensuring the safe flight of the tail rotor. According to the existing strength design method of the flexible beam in the bearingless tail rotor, in order to realize the flapping, shimmying and pitch-changing motion of the tail rotor blades, the flexible beam is required to produce a large deformation, which leads to frequent damage of the load strain gauge at the root of the flexible beam, making it difficult to ensure the monitoring and testing requirements of the test flight.

[0041] In response to the above problems, the strength design method for the flexible beam of previous models is: through actual measurement of the tail rotor shaft load, the cross-sectional load at the root of the flexible beam is deduced from the tail rotor shaft cross-sectional load. Since the correlation coefficient between the tail rotor shaft load and the flexible beam load changes with the flight state, there is a large difference between the root load of the flexible beam derived by this method and the actual load. It is very necessary to obtain the load of the flexible beam in a more reliable way.

[0042] In response to the testing requirements of flexible beam loads, an embodiment of the present invention provides a helicopter flexible beam actual measured load alternative analysis method, which takes the force transmission of the tail rotor load as a theoretical basis, combined with the characteristics of the flexible beam root load and the tail rotor blade airfoil section load, and proposes to derive the flexible beam root load based on the tail rotor blade airfoil section load, thereby forming a helicopter flexible beam actual measured load alternative analysis method.

[0043] The design idea of ​​the helicopter flexible beam measured load replacement analysis method provided by the embodiment of the present invention is:

[0044] On the one hand, considering that the direct source of the load at the root of the flexible beam is the aerodynamic load and inertial load of the tail rotor blade airfoil section, theoretically, there is a certain proportional relationship between the load at the root of the flexible beam and the cross-sectional load of the same tail rotor blade airfoil section;

[0045] On the other hand, the frequency component of the load at the root of the flexible beam is relatively single, and the frequency component of the tail rotor speed is absolutely dominant in the load. Therefore, the method of deriving the cross-sectional load at the root of the flexible beam using the cross-sectional load of the tail rotor blade airfoil is feasible and reliable.

[0046] The present invention provides the following specific embodiments which can be combined with each other. The same or similar concepts or processes may not be described in detail in some embodiments.

[0047] Figure 1 A schematic diagram of a flow chart of a helicopter flexible beam measured load replacement analysis method provided by an embodiment of the present invention. Figure 1 As shown, the helicopter flexible beam measured load replacement analysis method provided by the embodiment of the present invention includes the following steps:

[0048] Step 1: Obtain effective test flight data of the actual load at the root of the flexible beam and the corresponding effective time period.

[0049] Step 2, perform spectrum analysis on the measured load of the root section of the flexible beam and the measured load of the airfoil section on the tested tail rotor blade at preset intervals within the effective time period of the effective test flight data, and obtain the amplitudes of the measured load of the root of the flexible beam and the measured load of the airfoil section corresponding to the tail rotor speed frequency.

[0050] like Figure 2 , which is a schematic diagram of the positions of the flexible beam root section and the tail rotor blade airfoil section section in the helicopter flexible beam measured load replacement analysis method provided by an embodiment of the present invention.

[0051] Step 3, combining the amplitudes within the effective time period to form two sets of data columns, obtaining the correlation formulas of the two sets of data columns through linear fitting, and obtaining multiple sets of correlation formulas of the measured loads of the flexible beam root section and the measured loads of the airfoil section section;

[0052] Step 4, select the correlation formula with the best correlation between the measured load of the tail rotor blade upper airfoil section and the measured load of the flexible beam root section, and use it to calculate the measured load of the flexible beam root section.

[0053] In an implementation of the embodiment of the present invention, the implementation of the above step 1 may include, for example:

[0054] During the scientific research test flight of a certain type of aircraft, the flight states are divided according to the flight speed and flight altitude in the performance parameters of the helicopter test flight data, and the effective time period corresponding to the test flight data for each flight state in which the measured loads of the root section of the flexible beam and the measured loads of the wing section are both valid is recorded.

[0055] In one implementation of the embodiment of the present invention, the implementation process of the above step 2 may include:

[0056] Step 21, in the effective time period when the load is effective in each flight state, the measured load of the root section of the flexible beam on the tested tail rotor blade and the measured load of the airfoil section are respectively subjected to spectrum analysis at preset intervals, so as to obtain the measured load of the root section of the flexible beam and the airfoil section on the tested tail rotor blade at each influencing frequency in each flight state, and the tail rotor speed frequency is the dominant spectrum in the influencing frequency;

[0057] Step 22, for each effective time period, respectively extract the amplitude of the tail rotor speed frequency corresponding to the measured load of the flexible beam root section and the measured load of the airfoil section section at the corresponding flight state at the same time.

[0058] After comparative analysis, it is found that the frequency component of the cross-section load at the root of the flexible beam is relatively single, and the frequency component of the tail rotor speed (1Ωt) is absolutely dominant in the load.

[0059] In an implementation of the embodiment of the present invention, the implementation of the above step 3 may include, for example:

[0060] Step 31, combine the amplitudes of the tail rotor speed frequency corresponding to the measured load of the root section of the flexible beam and the measured load of the airfoil section at the same time extracted from the flight state corresponding to each effective time period to form two sets of data columns, draw scatter plots of the two sets of data columns, and obtain the correlation formula of the two sets of data columns through linear fitting.

[0061] In this step, the load amplitude corresponding to the tail rotor speed frequency (1Ωt) in each flight state forms two sets of data series, that is, the measured load of the flexible beam root section and the measured load of the tail rotor blade airfoil section section are used to draw a scatter plot of the two series of data.

[0062] Step 32, for each section position on the same tail blade, obtain the correlation formula corresponding to the measured section load of the flexible beam root and the measured section load of the airfoil section at each section position, thereby obtaining multiple correlation formulas corresponding to multiple section positions in the same tail blade.

[0063] In an implementation of the embodiment of the present invention, the implementation of the above step 4 may include, for example:

[0064] On the one hand, on the same tail blade, the correlation formula with the best correlation between the measured load of the airfoil section profile and the measured load of the flexible beam root profile is selected.

[0065] On the other hand, among the optimal correlation formulas selected for the multiple tail rotor blades, an optimal correlation formula is selected for estimating the measured load of the root section of the flexible beam.

[0066] In one implementation of the embodiment of the present invention, the method of selecting the optimal correlation formula in the above step 4 is:

[0067] Through linear fitting, the correlation formula of the two sets of data columns is obtained. According to the fitting variance of the correlation formula, the optimal correlation formula is selected. The closer the fitting variance value is to 1, the better the linear fit is.

[0068] Furthermore, the helicopter flexible beam measured load replacement analysis method provided by the embodiment of the present invention may also include:

[0069] Step 5, using the optimal correlation formula selected in step 4, the measured load of the flexible beam root section during the entire flight process is obtained according to the measured load of the airfoil section section.

[0070] The helicopter flexible beam measured load replacement analysis method provided by the embodiment of the present invention has an overall solution of obtaining the flexible beam root section measured load according to the tail rotor blade airfoil section measured load; generally, in the early stage of the test flight, the flexible beam root measured load data is valid, and the flexible beam root measured load and the airfoil section measured load on the same tail rotor blade are subjected to spectrum analysis at preset intervals within the valid time period of the valid test flight data by using the valid time period corresponding to the valid test flight data of the flexible beam root measured load. The amplitudes of the measured load and the measured load of the airfoil section section corresponding to the tail rotor speed frequency; the amplitudes at each time point in the effective time period are combined to form two groups of data columns; a scatter plot of the two groups of data columns can be drawn, and multiple correlation formulas of the two groups of data columns can be obtained through linear fitting, and the correlation formula with the best correlation between the measured load of the airfoil section section on the same tail rotor blade and the measured load of the root section of the flexible beam is selected as the basis for calculating the measured load of the root section of the flexible beam, so that the measured load of the root section of the flexible beam during the entire flight process can be obtained based on the measured load of the airfoil section section of the tail rotor blade.

[0071] Relevant application examples show that the measured load replacement analysis method for helicopter flexible beams provided in the embodiment of the present invention can obtain the actual measured load of the root section of the flexible beam, ensuring the measured load flight test and safety monitoring requirements of the flexible beam, providing accurate and reliable measured load data for the strength design of the flexible beam, and being able to carry out the strength design of the flexible beam more accurately, which has high universality and engineering application value.

[0072] The helicopter flexible beam measured load replacement analysis method provided by the embodiment of the present invention is schematically illustrated below through a specific application example.

[0073] Application Examples

[0074] In order to prove the applicability and effectiveness of the helicopter flexible beam measured load substitution analysis method provided by the embodiment of the present invention, the method provided by the present invention is used to analyze the measured data of typical sorties through scientific research test flights to determine the flexible beam load substitution analysis method. The specific implementation method is as follows:

[0075] S1: During the scientific research test flight of a certain type of aircraft, the performance parameters of the flight data are divided into flight states and the corresponding time periods are recorded;

[0076] S2: In the effective time period corresponding to the effective test flight data of the measured load of the root section of the flexible beam, the frequency spectrum analysis is performed on the measured load of the root section of the flexible beam and the measured load of the tail rotor blade airfoil section;

[0077] S3: Through the spectrum analysis in S2, the tail rotor speed frequency (1Ωt) corresponding to the measured load of the flexible beam root section and the tail rotor blade airfoil section section, as well as the load amplitudes of the corresponding flight states of other frequencies 2Ωt, 3Ωt, 4Ωt, and 5Ωt are obtained respectively;

[0078] S4: After comparing and analyzing the measured load amplitudes of the flexible beam root section and the airfoil section section at the corresponding flight states at each frequency, it is concluded that the tail rotor speed frequency (1Ωt) plays an absolutely dominant role in the load; Figure 3 It is a schematic diagram of a time domain curve of the measured load on the root section of the flexible beam on the tail rotor blade at a typical moment in an embodiment of the present invention; Figure 4 It is a schematic diagram of a frequency domain curve of the measured load on the root section of the flexible beam on the tail rotor blade at a typical moment in an embodiment of the present invention; Figure 5 It is a schematic diagram of the frequency domain curve of the measured load on the flexible airfoil section of the tail rotor blade at a typical moment in an embodiment of the present invention.

[0079] S5: Based on the load amplitude corresponding to each flight state, two sets of data series of measured loads of the flexible beam root section and measured loads of the airfoil section section are formed, and scatter plots of the two sets of data series are drawn;

[0080] S6: Through linear fitting, the correlation formula between the two sets of data columns is derived as follows:

[0081] y = 2.6089x - 2.575;

[0082] R 2 =0.9963;

[0083] Where y represents the measured load of the root section of the flexible beam;

[0084] x represents the measured load on the tail rotor blade airfoil section;

[0085] R 2 Represents the fitting variance, which is used to characterize the linear fit, R 2 The correlation formula when =1 is the optimal correlation formula. Figure 6 It is a schematic diagram of the correlation between the measured load of the root section of the flexible beam and the measured load of the tail rotor blade airfoil section section in an embodiment of the present invention.

[0086] S7: According to the optimal correlation formula obtained in S6, the measured load of the flexible beam root section during the entire flight process is obtained based on the measured load of the airfoil section section.

[0087] Figure 7 The figure is a schematic diagram of the results of the measured load on the root section of the flexible beam during a typical flight obtained by using the method provided by the embodiment of the present invention.

[0088] Although the embodiments disclosed in the present invention are as above, the contents are only embodiments adopted to facilitate understanding of the present invention and are not intended to limit the present invention. Any technician in the field to which the present invention belongs can make any modifications and changes in the form and details of implementation without departing from the spirit and scope disclosed in the present invention, but the patent protection scope of the present invention shall still be subject to the scope defined in the attached claims.

Claims

1. A helicopter flexible beam measured load substitution analysis method, characterized in that: include: Step 1, obtaining the effective test flight data of the measured load of the root section of the flexible beam and the corresponding effective time period; Step 2, performing frequency spectrum analysis on the measured load of the root section of the flexible beam and the measured load of the airfoil section on the tested tail rotor blade at preset intervals within the effective time period of the effective test flight data of the measured load of the root section of the flexible beam, and obtaining the amplitudes of the measured load of the root section of the flexible beam and the measured load of the airfoil section corresponding to the tail rotor speed frequency respectively; Step 3, combining the amplitudes within the effective time period to form two sets of data columns, obtaining the correlation formulas of the two sets of data columns through linear fitting, and obtaining multiple sets of correlation formulas of the measured loads of the flexible beam root section and the measured loads of the airfoil section section; Step 4, select the correlation formula with the best correlation between the measured load of the tail rotor blade upper airfoil section and the measured load of the flexible beam root section, and use it to calculate the measured load of the flexible beam root section.

2. The helicopter flexible beam measured load substitution analysis method according to claim 1 is characterized in that: The step 1 comprises: The flight states are divided according to the flight speed and flight altitude in the performance parameters of the helicopter test flight data, and the time periods corresponding to the test flight data in which the actual measured load at the root of the flexible beam and the actual measured load at the airfoil section are both valid in each flight state are recorded.

3. The helicopter flexible beam measured load substitution analysis method according to claim 2 is characterized in that: The step 2 comprises: Step 21, in the effective time period when the load is effective in each flight state, the measured load of the root section of the flexible beam on the tested tail rotor blade and the measured load of the airfoil section are respectively subjected to spectrum analysis at preset intervals, so as to obtain the measured load of the root section of the flexible beam and the airfoil section on the tested tail rotor blade at each influencing frequency in each flight state, and the tail rotor speed frequency is the dominant spectrum in the influencing frequency; Step 22, for each effective time period, respectively extract the amplitude of the tail rotor speed frequency corresponding to the measured load of the flexible beam root section and the measured load of the airfoil section section at the corresponding flight state at the same time.

4. The helicopter flexible beam measured load substitution analysis method according to claim 3 is characterized in that: The step 3 comprises: Step 31, combining the amplitudes of the tail rotor speed frequency corresponding to the measured load of the root section of the flexible beam and the measured load of the airfoil section at the same time extracted from the flight state corresponding to each effective time period to form two sets of data columns, and drawing scatter plots of the two sets of data columns, and obtaining the correlation formula of the two sets of data columns by linear fitting; Step 32, for each section position on the same tail blade, obtain the correlation formula corresponding to the measured section load of the flexible beam root and the measured section load of the airfoil section at each section position, thereby obtaining multiple correlation formulas corresponding to multiple section positions in the same tail blade.

5. The helicopter flexible beam measured load substitution analysis method according to claim 4 is characterized in that: The step 4 comprises: Step 41, on the same tail blade, select the correlation formula with the best correlation between the measured load of the airfoil section section and the measured load of the flexible beam root section.

6. The helicopter flexible beam measured load substitution analysis method according to claim 5 is characterized in that: Also includes: Step 42, selecting an optimal correlation formula for calculating the measured load of the root section of the flexible beam from among the optimal correlation formulas selected for the plurality of tail rotor blades.

7. The helicopter flexible beam measured load substitution analysis method according to claim 6 is characterized in that: The method of selecting the optimal correlation formula in step 4 is: Through linear fitting, the correlation formula of the two sets of data columns is obtained. According to the fitting variance of the correlation formula, the optimal correlation formula is selected. The closer the fitting variance value is to 1, the better the linear fit is.

8. The helicopter flexible beam measured load substitution analysis method according to any one of claims 1 to 7, characterized in that: Also includes: Step 5, using the optimal correlation formula selected in step 4, the measured load of the flexible beam root section during the entire flight process is obtained according to the measured load of the airfoil section section.

9. A computer-readable storage medium, characterized in that: include: Memory and processor; The memory is configured to store executable instructions; The processor is configured to implement the helicopter flexible beam measured load replacement analysis method according to any one of claims 1 to 8 when executing the executable instructions stored in the memory.

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