Method for analyzing time domain correlation atlas of bending moments of different cross sections of helicopter rotor shaft

Abstract

The invention belongs to the field of helicopter strength design, and relates to a time domain correlation atlas analysis method for bending moments of different cross sections of a helicopter rotor shaft. The method comprises the following steps: extracting actual measurement data of rotor shaft bending moment measurement strain gauges on all cross sections under a specific working condition, and constructing a bending moment data matrix Mm of each cross section according to geometric arrangement of the rotor shaft bending moment measurement strain gauges; wherein each cross section has actually measured data with two orthogonal channels; forming a measuring point horizontal coordinate and a measuring point vertical coordinate of a Cartesian coordinate system by the data at the same moment in the two groups of measured data of the channels in the same direction of the different cross sections, or forming the measuring point horizontal coordinate and the measuring point vertical coordinate of the Cartesian coordinate system by the data at the same moment in the two groups of measured data of the channels in the different directions of the different cross sections; drawing positions of all measuring points on the time domain to obtain a time domain correlation graph; obtaining a helicopter rotor shaft bending moment correct measurement data time domain correlation graph normal form with the same working condition and the same number of rotor support arms; and comparing the time domain correlation graph with the time domain correlation graph normal form.

Description

Technical Field

[0001] The invention belongs to the field of helicopter strength design and relates to a time domain correlation spectrum analysis method for bending moments of different cross sections of a helicopter rotor shaft. Background Art

[0002] The rotor system is the core mechanical system for helicopters to perform various motion functions. The rotor shaft is the main path for the static and dynamic loads of the blades to be transmitted to the fuselage structure. The bending moment load borne by its structure is the manifestation of the load at the center of the hub. It is the input and optimization object of its static strength, fatigue and vibration control design, and the main basis for evaluating the static and dynamic strength, service life, reliability and structural design of the rotor shaft. They can also be used for real-time monitoring, analysis and evaluation of the static and dynamic load levels and structural health status of the blades and hubs. At the same time, by using the reverse derivation of the bending moment, four vibration loads at the center of the hub can be obtained, which can be used for the prediction and verification of the vibration response of the fuselage structure, the active / passive vibration control design, and the mechanism analysis of the problem of excessive vibration of the fuselage structure; the vibration loads obtained by this technical route are directly derived from the actual flight test data, which is more accurate and more practical than the results obtained through the rotor / fuselage aerodynamic simulation calculation.

[0003] At the same time, the rotor shaft bending moment is also the most important transmission link of the aerodynamic load of the blade under different flight conditions and the most direct reflection of its characteristics. This provides a new perspective and scenario for understanding, recognizing, and analyzing the complexity of the aerodynamic load of the helicopter rotor system (especially conditions such as deceleration and descent).

[0004] The measurement and application of rotor shaft bending moment has received more and more attention and importance from the helicopter industry. In recent years, a variety of data verification and analysis methods have been proposed to provide technical support for the model application of main shaft bending moment. How to ensure the authenticity and validity of rotor shaft bending moment measurement data and to study and discover some more efficient and accurate data analysis methods have become a new direction and new hotspot in rotor shaft bending moment research. Summary of the invention

[0005] Purpose of the invention: To provide a new method for verifying the authenticity and validity of the bending moment measurement data of different cross-sections of the rotor shaft, which is intuitive, vivid and quick; at the same time, it provides a new perspective and scenario for understanding, recognizing, understanding and analyzing the complexity of the aerodynamic loads of the helicopter rotor system (especially working conditions such as deceleration and descent).

[0006] Technical solution:

[0007] A method for time domain correlation spectrum analysis of bending moments of different cross sections of a helicopter rotor shaft is provided, comprising:

[0008] The measured data of the rotor shaft bending moment measurement strain gauges on all cross sections under specific working conditions are extracted, and the bending moment data matrix M of each cross section is constructed according to the geometric arrangement of the rotor shaft bending moment measurement strain gauges. m; Each cross section has two channels of orthogonal measured data;

[0009] The data at the same time in two sets of measured data of the same direction channels of different sections are used to form the horizontal coordinates and vertical coordinates of the measuring points in the Cartesian coordinate system, or the data at the same time in two sets of measured data of the different direction channels of different cross sections are used to form the horizontal coordinates and vertical coordinates of the measuring points in the Cartesian coordinate system;

[0010] Plot the positions of all measurement points in the time domain in the Cartesian coordinate system to obtain the time domain correlation graph;

[0011] Obtain the time domain correlation graphical paradigm for the correct measurement data of the rotor shaft bending moment of helicopters with the same working condition and the same number of rotor arms;

[0012] Compare the time domain correlation graph with the above time domain correlation graph paradigm to determine whether there is a fault in the measured data.

[0013] Furthermore, the method further comprises:

[0014] If the time domain correlation graph is the same as the above time domain correlation graph paradigm, the measured data of the corresponding two channels are valid;

[0015] If the time domain correlation graph is different from the above time domain correlation graph paradigm, the measured data of the corresponding two channels are invalid and a fault exists.

[0016] Further, after obtaining the time domain correlation graphical paradigm of the correct measurement data of the rotor shaft bending moment of helicopters under the same working condition and with the same number of rotor arms, the method further includes:

[0017] Calculate the correlation coefficient of two groups of measured data of the same direction channels with different cross sections, or calculate the correlation coefficient of two groups of measured data of the different direction channels with different cross sections;

[0018] Compare the time domain correlation graph with the above time domain correlation graph paradigm, and compare the correlation coefficient of the measured data with the corresponding correct measured data time domain correlation coefficient paradigm to determine whether the measured data has a fault;

[0019] If the time domain correlation graph is the same as the above time domain correlation graph paradigm, and the correlation coefficient of the measured data meets the requirements of the correct measurement data time domain correlation coefficient paradigm, then the measured data of the corresponding two channels are valid;

[0020] If the time domain correlation graph is different from the above time domain correlation graph paradigm, and the correlation coefficient of the measured data does not meet the requirements of the correct measurement data time domain correlation coefficient paradigm, the measured data of the corresponding two channels are invalid and a fault exists.

[0021] Furthermore, for the same cross-section, the time domain correlation diagram paradigm of the bending moment of the orthogonal channels of the hub main shaft with the same cross-section and typical arm geometry configuration includes the time domain correlation diagram paradigm of the correct measurement data of the bending moment of the helicopter rotor shaft with different numbers of rotor arms under different special working conditions.

[0022] Furthermore, the time domain correlation spectra of different channels are shown in Table 1:

[0023] Table 1

[0024]

[0025] Furthermore, for different cross sections, the time domain correlation diagram paradigms of the bending moment of the orthogonal channel of the hub main axis with the same cross section of the typical arm geometry configuration include:

[0026] The correlation coefficient of two sets of measured data of the same direction channel is greater than or equal to 0.999, and\or, the time domain correlation graph of the two sets of measured data of the same direction channel is a 45° oblique line;

[0027] The correlation coefficient of the two groups of measured data of the channels in different directions is less than 0.1, and\or, the time domain correlation graphs of the two groups of measured data of the channels in different directions conform to the time domain correlation graph paradigm of the bending moment of the orthogonal channel of the hub main shaft with the same cross-section of the typical arm geometric configuration under the same cross-section.

[0028] Furthermore, the method further comprises:

[0029] If the correlation coefficient of two sets of measured data of the same channel on cross sections in different directions is less than 0.1, and\or, the time domain correlation graph conforms to the time domain correlation graph paradigm of the bending moment of the orthogonal channel of the hub main axis with the same cross section under the typical arm geometry configuration under the same cross section, then the channel identification cross channel is determined;

[0030] If the time domain correlation graphs of two groups of measured data of channels in different directions on different cross sections do not conform to any of the time domain correlation graph paradigms in the time domain correlation graph paradigms of the bending moments of orthogonal channels of the same cross section of the hub main shaft in a typical arm geometry configuration, it is determined that the channel is in crosstalk with the bending moment measurement channels of other structural parts.

[0031] Furthermore, the method further comprises:

[0032] According to the characteristics of the helicopter rotor shaft bending moment, the time domain correlation spectrum paradigm of the correct test data of the helicopter rotor shaft bending moment is determined.

[0033] Beneficial effects:

[0034] 1) Graphical representation of digital information is intuitive, vivid and quick, making it easy to recognize;

[0035] 2) It can be used to verify the authenticity and validity of the bending moment measurement data of different cross sections of the rotor shaft;

[0036] 3) It can be used for fault diagnosis and processing of rotor shaft bending moment measurement;

[0037] 4) It can be used to understand and analyze the complexity and characteristics of blade loads in different flight conditions;

[0038] 5) It can be used to analyze and understand the problem of excessive vibration of helicopter body in conditions such as transition speed forward flight, deceleration descent, deceleration forward flight, and high speed forward flight. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 Schematic diagram of the main shaft structure and its bending moment measurement strain gauge layout and channel identification.

[0040] Figure 2(1) shows the arrangement of the moment strain gauges for the main axis cross section 1 Figure 1 .

[0041] FIG2(2) is a schematic diagram 2 showing the arrangement of the bending moment strain gauges for the main axis cross section 1.

[0042] Figure 3 This is a time domain curve diagram of typical data of main shaft bending moment.

[0043] Figure 4 It is a time domain correlation graph of two channel data in the same orthogonal direction at different cross sections of the main axis of the five-arm hub.

[0044] Figure 5(1) is a time domain correlation diagram of two channel data in different orthogonal directions of the ground driving cross section of the five-arm hub main shaft.

[0045] Figure 5(2) is a time domain correlation diagram of two channel data in different orthogonal directions of the near-ground acceleration cross section of the five-arm hub main axis.

[0046] Figure 5(3) is a time domain correlation diagram of two channel data in different orthogonal directions of the uniform climbing cross section of the five-arm hub main shaft.

[0047] Figure 5(4) is a time domain correlation diagram of two channel data in different orthogonal directions of the cross section of the five-arm hub main shaft in low-speed forward flight.

[0048] Figure 5 (5) is a time domain correlation diagram of two channel data in different orthogonal directions in the forward speed cross section of the five-arm hub main shaft.

[0049] Figure 5(6) is a time domain correlation diagram of two channel data in different orthogonal directions of the five-arm hub main axis accelerated forward flight cross section.

[0050] Figure 5(7) is a time domain correlation diagram of two channel data in different orthogonal directions of the cross section of the five-arm hub main shaft deceleration forward flight.

[0051] Figure 5(8) is a time domain correlation diagram of two channel data in different orthogonal directions of the cross section of the five-arm hub main shaft in high-speed forward flight.

[0052] Figure 5(9) is a time domain correlation diagram of the two channel data in different orthogonal directions of the cross section of the five-arm propeller hub main shaft deceleration descent. DETAILED DESCRIPTION

[0053] The layout and geometric relationship of the helicopter rotor shaft bending moment test channel (test station) are shown in Figure 1 , Figure 2(1) and Figure 2(2). In fact, after many processes such as sensor calibration, installation, calibration, acquisition, and DSP processing, the bending moment data of each test channel is a set of digital signals synchronously sampled and arranged in time sequence, forming a one-dimensional digital array. The number of elements n of the array is determined by the sampling frequency f s and the length of the analyzed data period t c The typical time domain data of the bending moment of the four channels of the two cross sections of the rotor shaft are shown in the attached Figure 3 .

[0054] The technical idea of ​​the present invention is: first, taking the geometric arrangement of the rotor shaft bending moment measurement strain gauge and the measured data as the object, construct the bending moment data matrix M m ; Secondly, the data of the main shaft bending moment channels in different directions at the same time construct a two-variable first-order equation with unknown coefficients. Based on the secondary equation, the data of any period in the time domain is constructed to form a two-variable first-order matrix equation; Thirdly, the positions of all measurement points in the time domain of the above two channel data are plotted in the Cartesian coordinate system using computer software graphics tools (such as VC++, VB or MATLAB, etc.) to obtain their time domain correlation graphs. Finally, the time domain correlation graph paradigm of the helicopter rotor shaft bending moment is established.

[0055] The layout and geometric relationship of the helicopter rotor shaft bending moment test channel (test station) are shown in Figure 1 , Figure 2(1) and Figure 2(2). In fact, after many processes such as sensor calibration, installation, calibration, acquisition, and DSP processing, the bending moment data of each test channel is a set of digital signals synchronously sampled and arranged in time sequence, forming a one-dimensional digital array. The number of elements n of the array is determined by the sampling frequency f s and the length of the analyzed data period t c The typical time domain data of the bending moment of the four channels of the two cross sections of the rotor shaft are shown in the attached Figure 3 .

[0056] The technical idea of ​​the present invention is: first, taking the geometric arrangement of the rotor shaft bending moment measurement strain gauge and the measured data as the object, construct the bending moment data matrix M m; Secondly, the data of the main shaft bending moment channels in different directions at the same time construct a two-variable first-order equation with unknown coefficients. Based on the secondary equation, the data of any period in the time domain is constructed to form a two-variable first-order matrix equation; Thirdly, the positions of all measurement points in the time domain of the above two channel data are plotted in the Cartesian coordinate system using computer software graphics tools (such as VC++, VB or MATLAB, etc.) to obtain their time domain correlation graphs. Finally, the time domain correlation graph paradigm of the helicopter rotor shaft bending moment is established.

[0057] The present invention can be subdivided into the following 11 steps, which are specifically as follows.

[0058] The first step is to determine the geometric position relationship of the two cross sections of the rotor shaft and the identification of the two mutually orthogonal moment channels in each cross section according to the rotor shaft structure and the geometric arrangement of the moment test strain gauges, see Figure 1 , Figure 2(1) and Figure 2(2): The two channels of cross section 1 are BB1 ​​NRL and BB1 PRL, and the two channels of cross section 2 are BB2 NRL and BB2 PRL.

[0059] In the second step, the original measured data of the main shaft bending moment is a discrete digital signal collected synchronously and sequentially at equal time intervals. The data of each channel is arranged in order according to time to form a data sequence M. bpn is a data series of the spindle bending moment channel with n elements, where b represents the spindle bending moment; for the convenience of expression, p takes a natural number 1, 2, 3, 4, where "1" represents "BB1NRL", "2" represents "BB1PRL", "3" represents "BB2NRL", and "4" represents "BB2PRL"; n is a natural number, which is determined by the sampling frequency f s and the length of the analyzed data period t c Sure.

[0060] The third step is to construct a time series digital signal main shaft bending moment matrix M based on the measured data of the four channels of main shaft bending moment in different cross sections under a typical flight condition. m , see formula (1).

[0061]

[0062] In the fourth step, a two-variable linear equation is constructed using the data of two channels (BB1 NRL and BB2 NRL) with different cross sections and the same orthogonal direction of the main axis bending moment at the same time, as shown in formula (2).

[0063] y=k×x (2)

[0064] The fifth step is to construct a two-variable linear matrix equation for the data of any period in the time domain, see equation (3). The data signal series collected from the two main shaft bending moment channels with different cross sections, a single data is q=1, 2, 3, …, n.

[0065]

[0066] Step 6: Calculate the arithmetic mean of n sample signals of two channels and See equations (4) and (5).

[0067]

[0068] Step 7: Use the Pearson product-moment correlation coefficient method to calculate the correlation coefficient R of the two bending moment channel data in the time domain. ij , see formula (6).

[0069]

[0070] In the eighth step, computer software graphics tools (such as VC++, VB or MATLAB, etc.) are used to plot the positions of all measurement points in the time domain of the above two channel data in a Cartesian coordinate system to obtain their time domain correlation graphs.

[0071] Step 9. Repeat steps 1 to 8 to obtain the time-domain correlation graphs of the channel bending moments in the same orthogonal direction of different sections of the hub main axis with a support arm geometric configuration under various typical flight conditions.

[0072] In the tenth step, repeat the first step to the ninth step to obtain the time-domain correlation maps of the bending moments of the channels in the same orthogonal direction of the hub main shaft with different cross-sections of four typical arm geometric configurations, and establish the time-domain correlation map paradigm of the bending moments of the channels in the same orthogonal direction of different cross-sections of the helicopter rotor shaft, see Table 1.

[0073] In the eleventh step, the data of two channels (BB1 NRL and BB2 PRL) with different orthogonal directions of the main shaft bending moment at the same time with different cross-sections are used to construct a two-variable linear equation. Steps 4 to 10 are repeated to obtain the time-domain correlation maps of the channels with the same orthogonal directions of the main shaft of four typical arm geometric configurations. The time-domain correlation map paradigm of the channels with different orthogonal directions of the main shaft of the helicopter rotor shaft with different cross-sections is established, see Table 2.

[0074] Table 1 Time domain correlation spectrum of channel bending moment in the same orthogonal direction in different sections of the hub main axis of typical arm geometry

[0075]

[0076]

[0077] Table 2 Time domain correlation diagram of channel bending moment in different orthogonal directions in different sections of the hub main axis of typical arm geometry

[0078] Condition Name Three arms Four arms Five arms Six arms Ground driving Ring Ring Ring Ring Near ground acceleration Equilateral triangle ring Nearly square ring Regular pentagonal ring Hexagonal ring Fly forward at low speed Near triangle ring Four-corner ring Pentagonal Ring Hexagonal ring Medium speed forward flight Triangular cloud Nearly square ring Pentagonal Ring Hexagonal wreath Flying forward at high speed Equilateral triangle ring Square ring Pentagram ring Hexagonal ring Accelerate forward flight Equilateral triangle cloud Four-corner ring Pentagonal Ring Slow down and fly forward Near triangle ring Five-pointed cloud Slow down Triangular cloud Four-cornered cloud Five-pointed cloud Hexagonal Cloud

[0079] Now take the time domain correlation spectrum analysis of the main rotor shaft bending moment of the five-arm ball flexible hub as an example, as follows:

[0080] The first step is to determine the geometric position relationship of the two cross sections of the rotor shaft and the identification of the two mutually orthogonal moment channels in each cross section according to the rotor shaft structure and the geometric arrangement of the moment test strain gauges, see Figure 1 , Figure 2(1) and Figure 2(2): The two channels of cross section 1 are BB1 ​​NRL and BB1 PRL, and the two channels of cross section 2 are BB2 NRL and BB2 PRL.

[0081] In the second step, the original measured data of the main shaft bending moment is a discrete digital signal collected synchronously and sequentially at equal time intervals. The data of each channel is arranged in order according to time to form a data sequence M. bpn is a data series of the spindle bending moment channel with n elements, where b represents the spindle bending moment; for the convenience of expression, p takes a natural number 1, 2, 3, 4, where "1" represents "BB1NRL", "2" represents "BB1PRL", "3" represents "BB2NRL", and "4" represents "BB2PRL"; n is a natural number, which is determined by the sampling frequency f s and the length of the analyzed data period t c Sure.

[0082] The third step is to construct a time series digital signal main shaft bending moment matrix M based on the measured data of the four channels of main shaft bending moment in different cross sections under a typical flight condition. m , see formula (1).

[0083] In the fourth step, a two-variable linear equation is constructed using the data of two channels (BB1 NRL and BB2 NRL) with different cross sections and the same orthogonal direction of the main axis bending moment at the same time, as shown in formula (2).

[0084] The fifth step is to construct a two-variable linear matrix equation for the data of any period in the time domain, see equation (3). The data signal series collected from the two main shaft bending moment channels with different cross sections, a single data is q=1, 2, 3, …, n.

[0085] Step 6: Calculate the arithmetic mean of n sample signals of two channels and See equations (4) and (5).

[0086] Step 7: Use the Pearson product-moment correlation coefficient method to calculate the correlation coefficient R of the two bending moment channel data in the time domain. ij , see formula (6).

[0087] Step 8: Use computer software graphics tools (such as VC++, VB or MATLAB, etc.) to plot the positions of all measurement points in the time domain of the above two channel data in the Cartesian coordinate system to obtain their time domain correlation graphs, see the attached figure. Figure 4 .

[0088] Step 9: Repeat Steps 1 to 8 to obtain the time domain correlation graphs of the channel bending moments in the same orthogonal direction of the hub main axis in different sections of a support arm geometry for multiple typical flight conditions, see Figure 5(1)-Figure 5(9) .

[0089] In the tenth step, repeat the first step to the ninth step to obtain the time-domain correlation maps of the bending moments of the channels in the same orthogonal direction of the hub main shaft with different cross-sections of four typical arm geometric configurations, and establish the time-domain correlation map paradigm of the bending moments of the channels in the same orthogonal direction of different cross-sections of the helicopter rotor shaft, see Table 1.

[0090] In the eleventh step, the data of two channels (BB1 NRL and BB2 PRL) with different orthogonal directions of the main shaft bending moment at the same time with different cross-sections are used to construct a two-variable linear equation. Steps 4 to 10 are repeated to obtain the time-domain correlation maps of the channels with the same orthogonal directions of the main shaft of four typical arm geometric configurations. The time-domain correlation map paradigm of the channels with different orthogonal directions of the main shaft of the helicopter rotor shaft with different cross-sections is established, see Table 2.

Claims

1. A time domain correlation spectrum analysis method for bending moments of different cross sections of a helicopter rotor shaft, characterized in that: include: The measured data of the rotor shaft bending moment measurement strain gauges on all cross sections under specific working conditions are extracted, and the bending moment data matrix M of each cross section is constructed according to the geometric arrangement of the rotor shaft bending moment measurement strain gauges. m ; Wherein, each cross section has two channels of orthogonal measured data; The data at the same time in two sets of measured data of the same direction channels with different cross sections are used to form the horizontal coordinates and vertical coordinates of the measuring point in the Cartesian coordinate system, or the data at the same time in two sets of measured data of the different direction channels with different cross sections are used to form the horizontal coordinates and vertical coordinates of the measuring point in the Cartesian coordinate system; Plot the positions of all measurement points in the time domain in the Cartesian coordinate system to obtain the time domain correlation graph; Obtain the time domain correlation graphical paradigm for the correct measurement data of the rotor shaft bending moment of helicopters with the same working condition and the same number of rotor arms; Compare the time domain correlation graph with the above time domain correlation graph paradigm to determine whether there is a fault in the measured data.

2. The method according to claim 1, characterized in that The method further comprises: If the time domain correlation graph is the same as the above time domain correlation graph paradigm, the measured data of the corresponding two channels are valid; If the time domain correlation graph is different from the above time domain correlation graph paradigm, the measured data of the corresponding two channels are invalid and a fault exists.

3. The method according to claim 2, characterized in that After obtaining the time domain correlation graphical paradigm of the correct measurement data of the rotor shaft bending moment of helicopters under the same working condition and with the same number of rotor arms, the method further includes: Calculating the correlation coefficient of two sets of measured data of the same-direction channels with different cross sections, or calculating the correlation coefficient of two sets of measured data of the different-direction channels with different cross sections; Compare the time domain correlation graph with the above time domain correlation graph paradigm, and compare the correlation coefficient of the measured data with the corresponding correct measured data time domain correlation coefficient paradigm to determine whether the measured data has a fault; If the time domain correlation graph is the same as the above time domain correlation graph paradigm, and the correlation coefficient of the measured data meets the requirements of the correct measurement data time domain correlation coefficient paradigm, then the measured data of the corresponding two channels are valid; If the time domain correlation graph is different from the above time domain correlation graph paradigm, and the correlation coefficient of the measured data does not meet the requirements of the correct measurement data time domain correlation coefficient paradigm, the measured data of the corresponding two channels are invalid and a fault exists.

4. The method according to claim 3, characterized in that For the same cross-section, the typical arm geometry configuration of the hub main shaft with the same cross-section orthogonal channel bending moment time domain correlation diagram paradigm includes the helicopter rotor shaft bending moment correct measurement data time domain correlation diagram paradigm for different numbers of rotor arms under different special working conditions.

5. The method according to claim 4, characterized in that The time domain correlation spectrum paradigm of different channels is shown in Table 1: Table 1 。 6. The method according to claim 5, characterized in that For different cross-sections, the time domain correlation diagram paradigms of the bending moment in the orthogonal channels of the hub main axis of the same cross-section of the typical arm geometry configuration include: The correlation coefficient of two sets of measured data of the same direction channel is greater than or equal to 0.999, and\or, the time domain correlation graph of the two sets of measured data of the same direction channel is a 45° oblique line; The correlation coefficient of the two groups of measured data of the channels in different directions is less than 0.1, and\or, the time domain correlation graphs of the two groups of measured data of the channels in different directions conform to the time domain correlation graph paradigm of the bending moment of the orthogonal channel of the hub main shaft with the same cross-section of the typical arm geometric configuration under the same cross-section.

7. The method according to claim 1, characterized in that The method further comprises: If the correlation coefficient of two sets of measured data of the same direction channels on different cross sections is less than 0.1, and\or, the time domain correlation graph conforms to the time domain correlation graph paradigm of the bending moment of the orthogonal channel of the hub main axis with the same cross section under the typical support arm geometry configuration under the same cross section, then the channel identification cross-channel is determined; If the time domain correlation graphs of two groups of measured data of channels in different directions on different cross sections do not conform to any of the time domain correlation graph paradigms in the time domain correlation graph paradigms of the bending moments of orthogonal channels of the same cross section of the hub main shaft in a typical arm geometry configuration, it is determined that the channel is in crosstalk with the bending moment measurement channels of other structural parts.

8. The method according to claim 1, characterized in that The method further comprises: According to the characteristics of the helicopter rotor shaft bending moment, the time domain correlation spectrum paradigm of the correct test data of the helicopter rotor shaft bending moment is determined.

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