A method for analyzing launch vehicle flight loads based on flight measurement data

Abstract

The present application discloses a method for analyzing the flight load of a launch vehicle based on flight measurement data, which relates to the field of aerospace technology and includes: measuring the flight load during the rocket flight to obtain actual flight strain data and actual flight trajectory data; calculating the total load of the rocket body at each station on the rocket body based on the actual flight strain data and a pre-established load-strain correspondence; calculating the static load of the rocket body at each station during the actual flight using the actual flight trajectory data; subtracting the corresponding static load of the rocket body from the total load of the rocket body at each station to obtain the dynamic load of the rocket body at each station; optimizing the theoretical calculation method for the flight load and dynamic load using the static load of the rocket body at each station and the dynamic load of the rocket body at each station to obtain an optimized flight load calculation method. The present application can obtain the rocket body structural load during the actual flight by measuring the load during the flight process, thereby inferring the actual static load and dynamic load of the actual flight.

Description

Technical Field

[0001] The present application relates to the field of aerospace technology, and in particular to a method for analyzing the flight load of a launch vehicle based on flight measurement data. Background Art

[0002] During flight, launch vehicles are subject to external forces such as engine thrust, aerodynamic forces, inertial forces, and control forces. Based on load characteristics, flight loads can be divided into quasi-static and dynamic loads. For example, rated engine thrust and steady winds cause longitudinal and lateral static loads; engine ignition, shutdown, and separation cause axial dynamic loads; and transonic pressure fluctuations and gusts during flight cause lateral dynamic loads. Due to the influence of rocket body elasticity and the accuracy of external load input, the analysis and assessment of dynamic loads during flight is more difficult than that of static loads. With the development of larger launch vehicles, the elastic frequency of rocket bodies has decreased, and the proportion of dynamic loads during flight has increased, potentially accounting for 50% or more of the design loads. Flight loads directly influence rocket body structural design. Designed flight loads that are too low directly impact flight safety, while excessive flight loads increase structural deadweight, thereby impacting launch vehicle performance.

[0003] Previous flight load analysis relied primarily on theoretical calculations and engineering analysis methods, which are inherently conservative. To accurately understand the rocket loads during flight, it is necessary to analyze the loads experienced by the rocket during actual flight using actual flight measurement parameters. This can then optimize flight load design methods, reduce the conservatism of flight loads, and ultimately enhance the launch vehicle's carrying capacity.

[0004] The traditional flight load analysis method based on theoretical calculation has a high accuracy in static load calculation, but has a large deviation in dynamic load calculation, which is mainly restricted by:

[0005] (1) During the design process, external load inputs such as transonic pulsating pressure and gusts during flight are obtained through simulation calculations, wind tunnel tests, or engineering experience. The accuracy of the obtained external loads is limited, which in turn affects the accuracy of flight load calculations.

[0006] (2) The external loads (especially dynamic loads) and the elasticity of the rocket body during flight are both time-varying data. When calculating the actual loads, it is necessary to select characteristic points for envelopment. The calculation method of the structural response under random loads is also conservative to a certain extent.

[0007] Analyzing launch vehicle flight loads based on measured flight data can more accurately assess rocket body flight loads and optimize flight load design methods. For example, patent application publication number CN116108558A, titled "A Method for Calibrating Launch Vehicle Flight Static Loads," describes a method for static load assessment focused on deviations from overall parameters, but does not address analysis methods related to dynamic loads.

[0008] Therefore, it is necessary to propose a new launch vehicle flight load analysis method based on flight measurement data to solve the above problems. Summary of the Invention

[0009] The purpose of this application is to provide a method for analyzing the flight load of a launch vehicle based on flight measurement data, to reversely infer the flight load using the measured data during the flight, and to optimize the design method of the flight load by distinguishing between dynamic loads and static loads, thereby improving the accuracy of the flight load and contributing to the structural optimization of the launch vehicle and the improvement of its carrying capacity.

[0010] To achieve the above-mentioned purpose, the present application provides a method for analyzing the flight load of a carrier rocket based on flight measurement data, comprising the following steps: measuring the flight load during the rocket flight to obtain actual flight strain data and actual flight trajectory data; calculating the total rocket load at each position on the rocket body according to the actual flight strain data and a pre-established load-strain correspondence, wherein the total rocket body load is the load corresponding to the actual flight strain data in the pre-established load-strain correspondence; the total rocket body load includes at least axial force, shear force, and bending moment; calculating the rocket body static load at each position during the actual flight using the actual flight trajectory data, wherein the rocket body static load includes at least axial force, shear force, and bending moment; subtracting the corresponding rocket body static load from the total rocket body load at each position to obtain the rocket body dynamic load at each position; optimizing the flight load and dynamic load theoretical calculation method using the rocket body static load and the rocket body dynamic load at each position to obtain an optimized flight load calculation method.

[0011] As described above, optimizing the theoretical calculation method of the flight load dynamic load using the static load of the rocket body at each station and the dynamic load of the rocket body at each station includes at least: correcting the rocket body elasticity according to the frequency domain characteristics of the measurement data; and correcting the excitation force function of the flight process according to the dynamic load magnitude and the distribution of the dynamic load along the rocket body.

[0012] As described above, the specific method for correcting the elasticity of the rocket body according to the frequency domain characteristics of the measurement data is as follows: by performing frequency domain analysis on the dynamic load of the rocket body at each station, the flight spectrum characteristics of the dynamic load of the rocket body at each station are obtained, and the theoretically calculated elastic characteristics of the rocket body are corrected according to the flight spectrum characteristics of the dynamic load of the rocket body at each station.

[0013] As above, the flight spectrum characteristics of the rocket body dynamic load at each station corresponding to different frequency bands are obtained by fast Fourier transform.

[0014] As mentioned above, the specific method for correcting the excitation force function of the flight process according to the magnitude of the dynamic load and the distribution of the dynamic load along the rocket body is as follows: by comparing the magnitude of the dynamic load of the rocket body at each station in different frequency domains with the magnitude of the dynamic load obtained by the original input, the external force function is adjusted as a whole or the external force function of different rocket body positions is adjusted according to the distribution of the dynamic load along the rocket body, so that the theoretically calculated dynamic load is close to the dynamic load of the rocket body at each position; the dynamic load of the rocket body at each station obtained by multiple flights is accumulated to obtain the dynamic load envelope during the rocket flight, thereby optimizing the design load of the rocket body and guiding the optimization of the rocket body structure.

[0015] As described above, the static load of the arrow body at each station during the actual flight process is calculated using actual flight trajectory data through theoretical methods or finite element models.

[0016] As above, the theoretical method is the existing D'Alembert principle.

[0017] As mentioned above, typical positions of the rocket structure are used as strain measurement positions, and strain gauges are attached to the strain measurement positions to obtain actual flight strain data of the rocket body structure during flight, wherein the actual flight strain data at least includes: axial strain data of the rocket body.

[0018] As mentioned above, the axial strain data of the rocket body includes at least: axial strain data of the fairing position, axial strain data of the instrument cabin position, axial strain data of the interstage position and axial strain data of the tail section position.

[0019] As above, where the shear force Q in the static load of the rocket body at the kth station is 1k The calculation formula is: in: is the aerodynamic normal force coefficient acting on the pressure center of the rocket body corresponding to the i-th station; i∈[1,k], k is a natural number, indicating the number of stations; m 1i is the mass of the substation at the ith station; N1 is the derivative of the aerodynamic normal acceleration coefficient; N2 is the derivative of the aerodynamic normal rotation angular acceleration coefficient; x z is the center of mass of the arrow body; x i is the line length corresponding to the i-th station; q represents the flight pressure; Sa represents the aerodynamic reference area, that is, the area of ​​the i-th station.

[0020] The beneficial effects achieved by this application are as follows:

[0021] (1) The present invention relates to a method for analyzing the flight load of a launch vehicle based on flight measurement data. By measuring the load during flight, the load on the rocket body structure during the actual flight is obtained, and the static load and dynamic load of the actual flight are obtained by reverse calculation.

[0022] (2) The launch vehicle flight load analysis method based on flight measurement data of the present application optimizes the flight load design method through the static load and dynamic load of actual flight. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments recorded in this application. For ordinary technicians in this field, other drawings can also be obtained based on these drawings.

[0024] Figure 1 A flow chart of an embodiment of a method for analyzing flight loads of a launch vehicle based on flight measurement data;

[0025] Figure 2 A schematic diagram of an embodiment of a pre-built load-strain correspondence;

[0026] Figure 3 A schematic diagram of an embodiment of the process of deriving shear force caused by aerodynamic forces. DETAILED DESCRIPTION

[0027] The following is a clear and complete description of the technical solutions in the embodiments of the present invention, in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0028] like Figure 1-3 As shown, the present application provides a method for analyzing the flight load of a launch vehicle based on flight measurement data, comprising the following steps:

[0029] S1: Measure the flight load during the rocket flight and obtain actual flight strain data and actual flight trajectory data.

[0030] Specifically, typical locations on the rocket structure are used as strain measurement locations. Strain gauges are attached to these locations to obtain actual flight strain data of the rocket body structure during flight. The actual flight strain data includes at least axial strain data of the rocket body. The axial strain data of the rocket body includes at least axial strain data of the fairing, instrument cabin, interstage, and tail stage.

[0031] Furthermore, selecting the middle of the rocket (i.e., where lateral bending dynamic loads are greater) and / or the bottom of the rocket (i.e., where axial loads are greater) as strain measurement locations and placing strain gauges in relatively simple structural areas of the middle and / or bottom of the rocket can more accurately correlate the measured strain data with load. Furthermore, since rocket loads primarily cause axial strain, if measurement access is limited, only axial strain data can be measured.

[0032] During the flight, the actual flight trajectory data of each flight is obtained through telemetry. The actual flight trajectory data includes at least: altitude, speed, engine thrust, aerodynamic force, angle of attack and control force.

[0033] S2: Calculate the total rocket body load at each station on the rocket body based on the actual flight strain data and a pre-established load-strain correspondence relationship, where the total rocket body load is the load corresponding to the actual flight strain data in the pre-established load-strain correspondence relationship; the total rocket body load includes at least: axial force, shear force, and bending moment.

[0034] Specifically, through finite element simulation and ground testing, strain data at typical locations on the rocket structure under different loads is obtained. Based on this strain data, a load-strain relationship for the typical structure is established, and this load-strain relationship is used as the pre-established load-strain relationship. Since the rocket structure remains in the elastic range during flight, the load-strain relationship is linear.

[0035] Among them, such as Figure 2 As shown in Figure 2, the pre-built load-strain correspondence is compared with the actual flight strain data (i.e.: Figure 1 The load corresponding to the microstrain in Figure 1 The load in / KN) is taken as the total load of the rocket body.

[0036] Wherein, each station is a different position on the arrow body. For an embodiment of each station, see Figure 3 , for example: Q1, Q2, Q 4-1 and Q4 are all positions, but positions are not limited to Q1, Q2, Q 4-1 and Q4.

[0037] S3: Calculate the static load of the rocket body at each station during the actual flight process using the actual flight trajectory data, wherein the static load of the rocket body includes at least: axial force, shear force and bending moment.

[0038] Furthermore, the static load of the rocket body at each position during the actual flight process is calculated using theoretical methods or finite element models using actual flight trajectory data.

[0039] Specifically, the static load of the cross section corresponding to each position of the rocket during flight is calculated using theoretical methods or finite element models based on the rocket's mass characteristics, engine thrust, aerodynamic force, control force and other external loads.

[0040] Furthermore, the theoretical method is the existing D'Alembert principle, but is not limited to the D'Alembert principle. The present application preferably uses the D'Alembert principle to calculate the static load of the rocket during flight.

[0041] Taking the transverse shear force as an example, the calculation method of the static load of the rocket body is as follows:

[0042] like Figure 3 As shown, the top of the arrow body is taken as the origin, the length direction of the arrow body from the top of the arrow body to the tail of the arrow body is taken as the X-axis, and the direction perpendicular to the X-axis is taken as the Y-axis, and the Y-axis is located to the right of the origin.

[0043] During free flight, the shear force Q in the static load of the rocket body at the kth station is 1k The calculation formula is:

[0044]

[0045] in: is the aerodynamic normal force coefficient acting on the pressure center of the rocket body corresponding to the i-th station; i∈[1,k], k is a natural number, indicating the number of stations; m 1i is the mass of the substation at the ith station; N1 is the derivative of the aerodynamic normal acceleration coefficient; N2 is the derivative of the aerodynamic normal rotation angular acceleration coefficient; x z is the center of mass of the arrow body; x i is the line length corresponding to the i-th station; q represents the flight pressure; Sa represents the aerodynamic reference area, that is, the area of ​​the i-th station.

[0046] in, is the derivative of the normal force coefficient corresponding to the i-th station.

[0047] Assuming that the rocket body is divided into S+1 stations, the overall aerodynamic normal force coefficient derivative of the rocket body is: Where S is a natural number, i∈[1,S+1]. The derivative of the aerodynamic normal force coefficient acts on the pressure center of the rocket body, and the derivative of the aerodynamic normal force coefficient is divided by the mass m1 of the rocket body (where And m 1i is the substation quality at the i-th station), we can get It is called the derivative of the aerodynamic normal acceleration coefficient. The normal acceleration of the rocket body caused by the aerodynamic normal force is: Arrow body center of mass The center of pressure of the arrow body The moment of inertia of the rocket body J=(x z -x i ) 2 ·m 1i , thus obtaining the aerodynamic normal rotation angular acceleration coefficient derivative The angular acceleration of the rocket body caused by the aerodynamic normal force is ).

[0048] S4: Subtract the corresponding static load of the arrow body from the total load of the arrow body at each station to obtain the dynamic load of the arrow body at each station.

[0049] Specifically, the dynamic load of the rocket body at each station obtained by subtracting the corresponding static load of the rocket body from the total load of the rocket body at each station is the dynamic load of the rocket body during actual flight.

[0050] S5: Optimize the theoretical calculation method of flight load and dynamic load using the static load of the rocket body at each station and the dynamic load of the rocket body at each station to obtain an optimized flight load calculation method.

[0051] Specifically, the flight load and dynamic load theoretical calculation method includes: a static load calculation method and a dynamic load calculation method.

[0052] Among them, the static load calculation method is: through the rocket mass characteristics, engine thrust, aerodynamic force and control force and other external loads, use theoretical methods or finite element models to calculate the static load of the cross section corresponding to each position of the rocket during flight.

[0053] The dynamic load calculation method is: based on the dynamic characteristics of the rocket, transonic pulsating pressure, gust external load, the dynamic load of the cross section corresponding to each position of the rocket during flight is calculated by theoretical methods or finite element models. The dynamic load calculation principle is:

[0054] For an elastic beam with infinite degrees of freedom, the dynamic load calculation method is discretized into the elastic vibration equation of a multi-degree-of-freedom system, which is expressed as follows:

[0055]

[0056] in, is the generalized acceleration corresponding to the j-th vibration mode; is the generalized velocity corresponding to the j-th vibration mode; q j is the generalized displacement corresponding to the j-th vibration mode; ξ j is the j-th order elastic vibration modal damping of the beam; ω j is the j-th order elastic vibration circular frequency; M j is the generalized mass corresponding to the j-th vibration mode, φ j is the j-th order elastic vibration mode of the beam, x represents the cross section at any station; l is the length of the arrow body; represents the jth-order generalized mass of the entire rocket beam calculated by integration; m(x) represents the mass characteristic of the rocket body; dx represents the integral along the length of the rocket; N j (t) represents the external generalized force corresponding to the j-th vibration mode; t represents time.

[0057] The solution of the elastic vibration equation depends on the exciting force f(x,t). j When determined, the elastic displacement of the beam is obtained Among them, q j (x) represents the jth-order generalized coordinate corresponding to the x-coordinate of the rocket body. The shear force and bending moment values ​​at the section x at any position of the rocket are calculated using the following formula. The expression of the shear force Q(x) at the section x at any position of the rocket is:

[0058]

[0059] Where EI is the bending stiffness of the rocket body, which is set as a constant; is the symbol of partial differential in mathematics; y represents the deflection of the beam; φ j (x) is the j-th elastic vibration mode of the beam, x represents the cross section at any station; q j represents the generalized displacement corresponding to the j-th vibration mode; Q j ′ represents the vibration mode φ j The corresponding modal shear force.

[0060] The expression of the bending moment M(x) at the section x at any position of the rocket is:

[0061]

[0062] Where EI is the bending stiffness of the rocket body, which is set as a constant; M j ′ is related to the vibration mode φ j The corresponding modal bending moment.

[0063] Specifically, when the bending stiffness EI of the rocket body is not constant, the i-th order elastic vibration circular frequency ω is obtained from the finite element calculation of the rocket body transverse vibration: j 、Vibration shape φ j , and vibration mode φ jThe corresponding modal shear force Q j ′ and vibration mode φ j The corresponding modal bending moment M j ′ data.

[0064] If the excitation force function f(x,t) = F(x)ξ(t), where F(x) represents the external force function that varies at different positions along the rocket body; ξ(t) is a random function of time. It can be shown that the displacement mean square response for:

[0065]

[0066] Where, represents the integral calculation; f(ω) is the input power spectral density; z(ω) is the rocket body transfer function.

[0067] in:

[0068]

[0069] Where f(ω) is the input power spectrum density; l is the length of the rocket body; φ j (x) is the j-th order elastic vibration mode of the beam, x represents the cross section at any station; M j is the generalized mass corresponding to the j-th vibration mode; ω j is the j-th order elastic vibration circular frequency; ω represents the circular frequency.

[0070] Among them, the j-th order generalized displacement mean square response for:

[0071]

[0072] Where, ξ j represents the j-th order elastic vibration modal damping of the beam; f(ω j ) represents the input power spectral density; π is pi.

[0073] Furthermore, the theoretical calculation method of the flight load dynamic load is optimized using the static load of the rocket body at each station and the dynamic load of the rocket body at each station (i.e., load optimization), which at least includes: correcting the rocket body elasticity according to the frequency domain characteristics of the measurement data; and correcting the excitation force function of the flight process according to the dynamic load magnitude and the distribution of the dynamic load along the rocket body.

[0074] Furthermore, the specific method for correcting the elasticity of the rocket body according to the frequency domain characteristics of the measurement data is as follows: by performing frequency domain analysis on the dynamic load of the rocket body at each station, the flight spectrum characteristics of the dynamic load of the rocket body at each station are obtained, and the theoretically calculated elastic characteristics of the rocket body are corrected according to the flight spectrum characteristics of the dynamic load of the rocket body at each station.

[0075] Specifically, by performing frequency domain analysis on the dynamic loads on the rocket body at each position, the distribution characteristics of the dynamic loads on the rocket body at different frequencies can be obtained. The distribution is larger at the first three natural frequencies of the rocket body. Therefore, the theoretically calculated elastic characteristics of the rocket body are corrected according to the flight frequency spectrum characteristics of the dynamic loads on the rocket body at each position.

[0076] Furthermore, the flight spectrum characteristics of the rocket body dynamic load at each station corresponding to different frequency bands are obtained through FFT transformation (Fast Fourier Transform) for use in subsequent optimization.

[0077] Furthermore, according to the magnitude of the dynamic load and the distribution of the dynamic load along the rocket body, the specific method for correcting the excitation force function of the flight process is as follows: by comparing the magnitude of the dynamic load of the rocket body at each station in different frequency domains with the magnitude of the dynamic load obtained by the original input, the external force function is adjusted as a whole or the external force function of different stations of the rocket body is adjusted according to the distribution of the dynamic load along the rocket body, so that the theoretically calculated dynamic load is close to the dynamic load of the rocket body at each station; the dynamic load of the rocket body at each station obtained through multiple flights is accumulated to obtain the dynamic load envelope during the rocket flight process, thereby optimizing the design load of the rocket body and guiding the optimization of the rocket body structure.

[0078] Specifically, this application mainly optimizes the dynamic load, and the optimized flight load calculation method is more accurate.

[0079] The beneficial effects achieved by this application are as follows:

[0080] (1) The present invention relates to a method for analyzing the flight load of a launch vehicle based on flight measurement data. By measuring the load during flight, the load on the rocket body structure during the actual flight is obtained, and the static load and dynamic load of the actual flight are obtained by reverse calculation.

[0081] (2) The launch vehicle flight load analysis method based on flight measurement data of the present application optimizes the flight load design method through the static load and dynamic load of actual flight.

[0082] Although preferred embodiments of the present application have been described, those skilled in the art may make additional changes and modifications to these embodiments once they become aware of the underlying inventive concepts. Therefore, the scope of protection of this application is intended to include the preferred embodiments and all changes and modifications that fall within the scope of this application. Obviously, those skilled in the art may make various changes and modifications to this application without departing from the spirit and scope of this application. Thus, if such changes and modifications of this application fall within the scope of protection of this application and its equivalents, then this application is intended to include such changes and modifications.

Claims

1. A method for analyzing the flight load of a launch vehicle based on flight measurement data, characterized in that: The steps include: Measure the flight load during the rocket flight and obtain actual flight strain data and actual flight trajectory data; Calculating the total load on the rocket body at each station on the rocket body based on the actual flight strain data and a pre-established load-strain correspondence, wherein the total load on the rocket body is the load corresponding to the actual flight strain data in the pre-established load-strain correspondence; the total load on the rocket body includes at least: axial force, shear force, and bending moment; Calculating the static load of the rocket body at each station during the actual flight process using actual flight trajectory data, wherein the static load of the rocket body includes at least: axial force, shear force, and bending moment; The dynamic load of the arrow body at each station is obtained by subtracting the corresponding static load of the arrow body from the total load of the arrow body at each station. The flight load and dynamic load theoretical calculation method is optimized using the static load and dynamic load of the rocket body at each station, and the optimized flight load calculation method is obtained. Among them, optimizing the theoretical calculation method of flight load dynamic load using the static load of the rocket body at each station and the dynamic load of the rocket body at each station at least includes: correcting the rocket body elasticity according to the frequency domain characteristics of the measurement data; and correcting the excitation force function of the flight process according to the dynamic load magnitude and the distribution of the dynamic load along the rocket body.

2. The method for analyzing the flight load of a launch vehicle based on flight measurement data according to claim 1, characterized in that: The specific method for correcting the elasticity of the rocket body according to the frequency domain characteristics of the measurement data is: by performing frequency domain analysis on the dynamic load of the rocket body at each station, the flight spectrum characteristics of the dynamic load of the rocket body at each station are obtained, and the theoretically calculated elastic characteristics of the rocket body are corrected according to the flight spectrum characteristics of the dynamic load of the rocket body at each station.

3. The method for analyzing the flight load of a launch vehicle based on flight measurement data according to claim 2, characterized in that: The flight spectrum characteristics of the rocket body dynamic load at each station corresponding to different frequency bands are obtained through fast Fourier transform.

4. The method for analyzing launch vehicle flight loads based on flight measurement data according to claim 1, wherein: The specific method for correcting the excitation force function of the flight process according to the magnitude of the dynamic load and the distribution of the dynamic load along the rocket body is as follows: by comparing the magnitude of the dynamic load of the rocket body at each station in different frequency domains with the magnitude of the dynamic load obtained by the original input, the external force function is adjusted as a whole or the external force function of different rocket body positions is adjusted according to the distribution of the dynamic load along the rocket body, so that the theoretically calculated dynamic load is close to the dynamic load of the rocket body at each station; the dynamic load of the rocket body at each station obtained from multiple flights is accumulated to obtain the dynamic load envelope during the rocket flight, so as to optimize the rocket body design load and guide the optimization of the rocket body structure.

5. The method for analyzing launch vehicle flight loads based on flight measurement data according to claim 1, characterized in that: The static load of the rocket body at each position during the actual flight process is calculated using theoretical methods or finite element models using actual flight trajectory data.

6. The method for analyzing launch vehicle flight loads based on flight measurement data according to claim 5, characterized in that: The theoretical method is the existing D'Alembert principle.

7. The method for analyzing launch vehicle flight loads based on flight measurement data according to claim 1, characterized in that: Typical positions of the rocket structure are used as strain measurement positions. By attaching strain gauges at the strain measurement positions, the actual flight strain data of the rocket body structure during flight is obtained, wherein the actual flight strain data at least includes: axial strain data of the rocket body.

8. The method for analyzing launch vehicle flight loads based on flight measurement data according to claim 7, characterized in that: The axial strain data of the rocket body at least includes: axial strain data at the fairing position, axial strain data at the instrument cabin position, axial strain data at the interstage position and axial strain data at the tail section position.

9. The method for analyzing launch vehicle flight loads based on flight measurement data according to claim 1, characterized in that: Shear force Q in the static load of the rocket body at the kth station 1k The calculation formula is: in: is the aerodynamic normal force coefficient acting on the pressure center of the rocket body corresponding to the i-th station; i∈[1,k], k is a natural number, indicating the number of stations; m 1i is the mass of the substation at the ith station; N1 is the derivative of the aerodynamic normal acceleration coefficient; N2 is the derivative of the aerodynamic normal rotation angular acceleration coefficient; x z is the center of mass of the arrow body; x i is the line length corresponding to the i-th station; q represents the flight pressure; Sa represents the aerodynamic reference area, that is, the area of ​​the i-th station.

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