Wind tunnel test aerodynamic force and displacement signal phase difference correction method and system based on self-excited vibration characteristics and storage medium

Abstract

The invention discloses a wind tunnel test aerodynamic force and displacement signal phase difference correction method based on self-excited vibration characteristics. The method comprises the following steps: independently collecting structure surface wind pressure and vibration displacement signals; integrating the wind pressure signal to obtain a self-excitation aerodynamic force time history; identifying the vibration frequency and the total damping ratio of the system from the displacement signal; filtering the aerodynamic force time history to extract a fundamental frequency component; based on a structural dynamic balance principle, establishing an analytic relational expression between an aerodynamic force out-of-phase component coefficient and total damping of the system; and carrying out iterative time translation on the aerodynamic force time history by taking the displacement signal as a reference until the out-of-phase component of the aerodynamic force time history meets the analytic relationship, so as to determine and correct the system delay. The invention further discloses a wind tunnel test aerodynamic force and displacement signal phase difference correction system based on the self-excited vibration characteristic and a storage medium. According to the method, electric triggering and physical transmission delay can be compensated with high precision without additional hardware, and the pneumatic parameter identification reliability is effectively improved.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of aerodynamic wind tunnel test and structural health monitoring, and in particular to a wind tunnel test aerodynamic force and displacement signal phase difference correction method, system and storage medium based on self-excited vibration characteristics, which is particularly suitable for vortex-induced vibration and flutter mechanism research of large-span bridges and high-rise structure sections. BACKGROUND

[0002] In the field of structural wind engineering, the use of wind tunnel tests to study the self-excited vibration (such as vortex vibration and flutter) characteristics of large-span bridges and high-rise structures is a key link to ensure engineering safety. In order to reveal the fluid-structure interaction mechanism, test personnel not only need to observe the macroscopic vibration response of the structure through laser displacement meters or acceleration sensors, but also need to accurately obtain the unsteady aerodynamic force distribution acting on the structure surface through electronic scanning valves and other pressure measurement systems, and analyze the work characteristics and aerodynamic derivatives of the aerodynamic force.

[0003] However, in the existing test technology system, the accurate synchronization of aerodynamic force and displacement signals still faces many difficulties. First, the vibration measurement system and the pressure measurement system are usually produced by different manufacturers, each with independent clock sources, sampling frequencies and triggering mechanisms. In the absence of a unified high-precision external triggering device, the data collected by the two systems will inevitably have a random starting deviation in the time axis, making the data unable to be directly aligned. Second, even if the synchronization triggering of electrical signals is achieved, the pressure signal from the pressure measurement hole on the model surface to the scanning valve sensor still needs to go through a corresponding delay. This physical delay fluctuates with the changes in pipe length, pipe diameter and airflow frequency, and cannot be easily eliminated through simple hardware connection.

[0004] This signal phase difference caused by hardware independence and physical transmission has a fatal impact on the identification of self-excited force parameters. In the classic Scanlan self-excited force model, the phase difference between the aerodynamic force and the displacement determines the nature of the aerodynamic derivative: the in-phase component corresponds to the aerodynamic stiffness, affecting the vibration frequency; while the out-of-phase component corresponds to the aerodynamic damping, directly determining the energy input and dissipation of the system. If there is an error in the phase difference, it will directly lead to incorrect identification of the aerodynamic derivative, and even the sign will be reversed, which will misjudge the energy absorption effect as an energy dissipation effect, and thus draw completely opposite conclusions on stability. The commonly used cross-correlation analysis method has limited accuracy when dealing with wind tunnel signals containing complex non-stationary turbulent noise, and it is difficult to effectively distinguish between physical delay and system delay. Therefore, there is an urgent need for a high-precision synchronization method that does not rely on additional hardware, is based on the physical nature, and can simultaneously correct system errors and physical transmission delays, to meet the needs of refined wind tunnel tests. SUMMARY

[0005] Therefore, the present application aims to provide a wind tunnel test aerodynamic force and displacement signal phase difference correction method, system and storage medium based on self-excited vibration characteristics, to solve the problem of aerodynamic force and displacement signal asynchronization caused by independent acquisition of pressure measurement and vibration measurement system in wind tunnel test, to realize high-precision signal synchronization without additional hardware by establishing the analytical relationship between aerodynamic force out-of-phase component and system total damping and iteratively optimizing time delay, and to improve the identification accuracy of key parameters such as aerodynamic derivatives.

[0006] To achieve the above-mentioned purpose, the present application provides the following technical solutions: The present application first proposes a wind tunnel test aerodynamic force and displacement signal phase difference correction method based on self-excited vibration characteristics, comprising the following steps: Step one: in the wind tunnel test, independently acquire the wind pressure time history signal of the surface of the structure model to be tested and the vibration displacement time history signal of the structure model ; Step two: integrate the wind pressure time history signal to obtain the self-excited aerodynamic force time history per unit length, including self-excited lift and self-excited lift moment , and convert it into dimensionless lift coefficient time history and lift moment coefficient time history ; Step three: perform parameter identification on the vibration displacement time history signal to obtain the frequency and system total damping ratio of the structure vibration at the current wind speed ; Step four: perform frequency domain filtering on the lift coefficient time history and lift moment coefficient time history to filter out high-order harmonic and noise components, and extract the fundamental frequency aerodynamic force component with the same frequency as the vibration frequency ; Step five: based on the principle of structural dynamics balance, establish an analytical balance relationship formula representing the out-of-phase component coefficient of the phase relationship between aerodynamic force and displacement; the analytical balance relationship formula is derived from the structural dynamics equation, which relates the out-of-phase component coefficient of aerodynamic force to the system total damping ratio and vibration frequency identified through displacement signal ; Step six: take the vibration displacement time history signal , until the calculated out-of-phase component coefficient satisfies the analytical balance relationship described in step five; the corresponding The system acquisition delay is determined, and the original aerodynamic force data is time-shifted and corrected according to the system acquisition delay, so as to realize the phase synchronization of the aerodynamic force and the displacement signal.

[0007] Further, in the step one, the surface wind pressure time history signal is obtained through a pressure measurement system; and the structural vibration displacement time history signal is collected through a laser displacement meter or an acceleration sensor.

[0008] Further, in the step two, the specific formula of the integral processing and dimensionless is as follows: Unit length self-excited lift: ; Unit length self-excited lift moment: ; Lift coefficient: ; Lift moment coefficient: ; Wherein: is the self-excited lift time history; is the self-excited lift moment time history; is the zero mean fluctuating pressure of the i-th pressure measurement point at the t-th moment; and are the representative length of the i-th pressure measurement point along the cross-sectional circumference direction and the distance from the cross-sectional center, respectively; is the air density; is the wind speed; is the cross-sectional width. Further, in the step three, the method for parameter identification of the vibration displacement time history signal is as follows: The Hilbert transform is performed on

[0009] to obtain the analytical signal thereof: The time-varying amplitude and the time-varying phase are represented as: The time-varying vibration frequency and the time-varying damping ratio are represented as: Wherein:​​​ is the analytical signal obtained by performing Hilbert transform on the vibration displacement time history signal ; is the imaginary part of the displacement in Laplace domain; is the vibration displacement time history signal; is the integral kernel, representing an all-pass filter; is time; is the integral variable, representing time delay; is the vibration displacement time history signal at the time point represented by the integral variable ; is the Hilbert transform operator; is the fitted amplitude envelope.

[0010] Further, in the step four, the specific method of extracting the fundamental frequency aerodynamic force component is: using the integral method based on the orthogonality of trigonometric functions to extract the coefficients of the component containing only the fundamental frequency from the measured aerodynamic force coefficients containing high-order harmonic components.

[0011] Further, for the lift coefficient, the fundamental frequency component is represented as: its in-phase coefficient and out-of-phase coefficient are obtained by the following integral: For the lift moment coefficient, the fundamental frequency component is represented as: its in-phase coefficient and out-of-phase coefficient are obtained by the following integral: wherein: and are the vertical and torsional vibration amplitudes, respectively; and are the measured aerodynamic force coefficients containing high-order harmonic components; and are the phase angles of the lift coefficient and the lift moment coefficient with respect to the displacement signal, respectively; is the vibration frequency; ; ​​​is the vibration period; is the number of periods; is the time.

[0012] Further, in step five, for the torsional degree of freedom, the analytical balance relation is established by the following procedure: torsional displacement and velocity history are defined as: where: is the torsional amplitude; is the vibration frequency; is the time; The equation of motion for the torsional degree of freedom of the structure is: where: is the unit length moment of inertia; is the torsional structural damping; is the torsional circular frequency of the structure; is the torsional acceleration; is the torsional velocity; is the torsional displacement; The torsional displacement and velocity history are substituted into the left side of the equation of motion for the torsional degree of freedom, and the lift moment coefficient is substituted into the right side of the equation of motion for the torsional degree of freedom, and the coefficients of terms on both sides of the equation are equated, and the coefficients of terms on both sides of the equation are equated, and the definition of the total system torsional damping ratio which includes the aerodynamic damping, is combined, and the analytical balance relation for the out-of-phase component is obtained as: where: is the torsional vibration amplitude; is the phase angle of the lift moment coefficient with respect to the torsional displacement; is the dimensionless frequency; is the half-chord length; is the chord length; is the wind speed; is the air density.

[0013] Further, in step five, for the vertical degree of freedom, the analytical balance relation is established by the following procedure: vertical displacement and velocity history are defined as: in: Vertical amplitude; The equations of motion for the vertical degrees of freedom of the structure are: in: Mass per unit length; For vertical structural damping; The vertical circular frequency of the structure; This is the vertical displacement acceleration; This represents the vertical displacement velocity; This is a vertical displacement; air density; Wind speed; The width of the cross section; Time history of lift coefficient; For time; Vertical displacement and speed time history Substituting the left side of the equations for the vertical degrees of freedom of the structure, and changing the lift coefficient... Substituting the equation for the vertical degrees of freedom of the structure into the right side, let both sides of the equation... Equal coefficients of terms and cos on both sides of the equation The coefficients are equal, and combined with the total vertical damping ratio of the system including aerodynamic damping. By defining the equations, we obtain the analytical equilibrium relations for the heterogeneous components as follows: in: This represents the vertical vibration amplitude. and The total vertical damping ratio and vibration frequency of the system after being affected by the self-excited force; This represents the phase difference between vertical and torsional motions. The phase angle of the lift coefficient relative to the vertical displacement; It is a dimensionless frequency; , is the width of half the cross section.

[0014] This invention also proposes a wind tunnel test aerodynamic force and displacement signal phase difference correction system based on self-excited vibration characteristics, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the wind tunnel test aerodynamic force and displacement signal phase difference correction method based on self-excited vibration characteristics as described above.

[0015] The application further provides a storage medium, which has a computer program stored thereon, and the computer program is executed by a processor to implement the method for correcting the phase difference between the wind tunnel test aerodynamic force and the displacement signal based on the self-excited vibration characteristics.

[0016] The application has the following beneficial effects: The method for correcting the phase difference between the wind tunnel test aerodynamic force and the displacement signal based on the self-excited vibration characteristics has the following technical effects: (1) High-precision software synchronization is achieved, and hardware dependence is broken: the application creatively uses the structural dynamics balance equation as a physical criterion, accurately back-projects and compensates the system delay through an iterative algorithm, and achieves signal alignment precision comparable to or even higher than hardware synchronization without relying on expensive hardware synchronization devices; (2) The accuracy of aerodynamic parameter identification is significantly improved: by accurately correcting the phase difference, the sign misjudgment of aerodynamic derivatives (such as misjudging the aerodynamic negative damping as positive damping) caused by asynchronous signals is fundamentally avoided, ensuring the reliability of key stability conclusions such as vortex vibration and flutter, and providing a more accurate data basis for structural safety evaluation; (3) Strong anti-interference and adaptive ability: the orthogonal filtering step built in the application method can effectively filter out wideband turbulent noise and aerodynamic force high-order harmonics, and extract pure fundamental frequency components; the calibration mechanism based on the physical equation of the application has good robustness to environmental noise and signal non-stationarity, and is suitable for actual test conditions under complex wind fields; (4) A general technical solution is formed: the analytical balance relationship established by the application has strong universality and can be applied to various vibration modes such as vertical and torsional vibrations, and the electrical trigger delay and physical pipeline transmission delay are uniformly corrected, providing a general software solution for multi-system data synchronization in wind tunnel tests, and reducing test complexity and cost.

[0017] In summary, the method of the application combines the rigor of the theoretical model with the flexibility of the algorithm implementation, effectively solving the signal synchronization problem that has long plagued fine wind tunnel tests, and has important value for promoting fluid-structure coupling mechanism research and engineering wind resistance design. BRIEF DESCRIPTION OF DRAWINGS

[0018] In order to make the purpose, technical scheme and beneficial effects of the application clearer, the application provides the following drawings for illustration: Figure 1 It is a schematic diagram of a bridge cross-section structure; Figure 2 It is a flowchart of the method for correcting the phase difference between the wind tunnel test aerodynamic force and the displacement signal based on the self-excited vibration characteristics of the application; Figure 3The time history signals of vibration displacement of the bridge structure measured in wind tunnel tests are shown in Figure 1; (a) represents vertical displacement; (b) represents torsional displacement. Figure 4 Time history diagrams of aerodynamic coefficients for bridge structures; (a) time history of lift coefficient; (b) time history of lift moment coefficient; Figure 5 The structural damping is obtained by performing Hilbert transform on the displacement data; (a) is the vertical amplitude envelope; (b) is the torsional amplitude envelope; (c) is the total damping ratio; (d) is the vibration frequency. Figure 6 (a) is the amplitude spectrum of aerodynamic lift and lift moment coefficient; (b) is the amplitude spectrum of lift coefficient; Figure 7 The diagram shows the aerodynamic coefficients and displacement data after phase difference correction; (a) shows the time history of lift moment and torsional displacement; (b) shows the time history of lift and vertical displacement. Detailed Implementation

[0019] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, so that those skilled in the art can better understand and implement the present invention. However, the embodiments described are not intended to limit the present invention.

[0020] In this embodiment, a proposed method for correcting the phase difference between aerodynamic and displacement signals in wind tunnel tests based on self-excited vibration characteristics is applied. This method corrects the phase difference between the measured aerodynamic and displacement signals based on the surface wind pressure time history signal and the structural vibration displacement time history signal measured during wind tunnel tests of the bridge structure. Specifically, the model cross-section used is as follows: Figure 1 As shown, the bridge model is a single box girder structure with a cross-sectional width of 569 mm, a height of 49.5 mm, and a length of 2 m. Multiple pressure gauge holes are arranged along the cross-section for obtaining wind pressure time history.

[0021] like Figure 2 As shown in the figure, the wind tunnel test aerodynamic force and displacement signal phase difference correction method based on self-excited vibration characteristics in this embodiment includes the following steps.

[0022] Step 1: In the wind tunnel test, independently acquire the wind pressure time history signal on the surface of the structural model under test. Vibration displacement time history signal of structural model .

[0023] In this embodiment, regarding the angle of attack... 0°, wind speed The surface wind pressure time history signal and structural vibration displacement time history signal of the bridge cross-section at 4.57 m / s were acquired. The surface wind pressure time history signal was acquired through a pressure measurement system, with a pressure measuring valve pre-embedded inside the model for measuring the surface wind pressure time history signal. The structural vibration displacement time history signal was acquired through a laser displacement meter or accelerometer. Specifically, in this embodiment, a laser displacement meter was used outside the model to acquire vertical and torsional displacement data. Figure 3 This refers to the measured time history signal of the vibration displacement of the bridge cross-section structure.

[0024] Step 2: Analyze the wind pressure time history signal. By performing integration, the time history of the self-excited aerodynamic forces per unit length is obtained, including the self-excited lift. and self-excited lift torque And convert it into a dimensionless lift coefficient time history. and lift moment coefficient time history .

[0025] In this embodiment, the wind pressure time history signal on the bridge structure surface measured by the pressure measuring valve in the wind tunnel test is integrated to obtain the aerodynamic time history of self-excited lift and lift moment. The specific method is as follows.

[0026] Self-excited lift per unit length and self-excited lift torque for: in: For the first Zero-mean pulsating pressure at each pressure measurement point; and For the first The representative length of each pressure measuring point along the perimeter of the cross section and its distance from the center of the cross section.

[0027] Lift and lift moment are respectively expressed using the lift coefficient. and lift moment coefficient Expressed as: in: air density; Wind speed; This refers to the cross-sectional width.

[0028] like Figure 4 As shown, the bridge structure lift coefficient is obtained by integrating the wind pressure time history signal. and lift moment coefficient .

[0029] Step three: parameter identification is performed on the vibration displacement time history signal to obtain the frequency of the structure vibration at the current wind speed and the total damping ratio of the system .

[0030] In this embodiment, the vertical displacement data and the torsional displacement data measured by the wind tunnel test are subjected to Hilbert transform respectively, and the total damping ratio and the vibration frequency of the vertical and torsional vibration can be obtained. The total damping and the vibration frequency of the bridge structure obtained by fitting the vertical displacement data and the torsional displacement data are shown in FIG. 3. Figure 5 The specific method is as follows.

[0031] The definition of Hilbert transform is as follows: Wherein: is the imaginary part of the displacement in the Laplace domain; is the vibration displacement time history signal; is the integral kernel, representing an all-pass filter; is the time; is the integral variable, representing the time delay; is the vibration displacement time history signal at the time point represented by the integral variable ; is the Hilbert transform operator.

[0032] After obtaining the imaginary part of the displacement in the Laplace domain , the displacement time history in the Laplace domain is obtained : Wherein: is the analytic signal obtained by Hilbert transform on the displacement signal ; and are the time-varying amplitude and the time-varying phase of the displacement signal respectively.

[0033] The time-varying vibration frequency and the time-varying damping ratio are represented as: Wherein: is the signal envelope obtained by Hilbert transform, representing the time-varying amplitude.

[0034] Step four: time history of the lift coefficient and the moment coefficient Frequency domain filtering is performed to filter out the high harmonic and noise components, and to extract the fundamental frequency aerodynamic force component with the same frequency as the vibration frequency.

[0035] In this embodiment, the specific method for extracting the fundamental frequency aerodynamic force component is: using the integral method based on the orthogonality of trigonometric functions to extract the coefficient of the component containing only the fundamental frequency from the measured aerodynamic force coefficient and containing high harmonics. Specifically, directly performing Fourier transform on the self-excited aerodynamic time history obtained in step two can obtain the frequency spectrum of the aerodynamic force, as shown in , the relative size of the components at other frequencies and the components at the natural frequency can be more intuitively observed, and the torsional vibration amplitude Figure 6 5.075×10 -3 , the vertical and torsional vibration amplitudes 5.164×10 -2 , and the vibration frequency 1.583 H. It can be seen that the measured self-excited lift and moment contain multiple frequency components of the motion frequency and its high harmonics, making the time history of the self-excited aerodynamic force exhibit a sawtooth-like fluctuation as shown by the blue line in , the original signal superimposed with high-frequency noise exhibits obvious sawtooth-like fluctuations. The high harmonic components of the aerodynamic force do no work in one vibration period and have no effect on the system frequency and damping. Therefore, in the following analysis, the high harmonic components of the aerodynamic force should be filtered out first, and only the components with the same frequency as the motion should be retained to obtain the aerodynamic force time history containing only the components with the same frequency as the motion. Figure 4 For the lift coefficient, the fundamental frequency component is represented as:

[0036] Its in-phase coefficient and out-of-phase coefficient are obtained by the following integrals: For the moment coefficient, the fundamental frequency component is represented as: Its in-phase coefficient and out-of-phase coefficient are obtained by the following integrals: wherein: and​​ These are the vertical and torsional vibration amplitudes, respectively. and These are aerodynamic coefficients based on measured data, which include higher harmonic components; and These are the phase angles of the lift coefficient and lift moment coefficient relative to the displacement signal, respectively. The vibration frequency; = ; = , is the oscillation period; The number of cycles; For time.

[0037] By filtering out the higher harmonic components of the aerodynamic forces using this method, and retaining only the components with the same frequency as the motion, the time history of the aerodynamic forces after filtering is as follows: Figure 4 As shown by the red line, the time history signal curve of the aerodynamic force becomes smooth and continuous after retaining only the component with the same frequency as the motion. The filtered signal suppresses sawtooth fluctuations and clearly reflects the low-frequency response characteristics of the structure.

[0038] Step 5: Based on the principle of structural dynamics equilibrium, establish an analytical equilibrium relationship for the out-of-phase component coefficients characterizing the relationship between aerodynamic forces and displacement phase. This analytical equilibrium relationship is derived from the structural dynamics equations and combines the out-of-phase component coefficients of the aerodynamic forces with the total system damping ratio obtained through displacement signal identification. and vibration frequency Related.

[0039] (1) The problem of asynchronous sampling of displacement and wind pressure is solved by using the torsional displacement time history and the lift moment time history.

[0040] Specifically, for the torsional degree of freedom, the analytical equilibrium equation is established through the following process: Torsional displacement and speed time history Defined as: in: To torsional amplitude; The vibration frequency; For time.

[0041] The equations of motion for the torsional degrees of freedom of the structure are: in: Moment of inertia per unit length; For torsional structural damping; The torsional circular frequency of the structure; torsional acceleration; torsional velocity; torsional displacement.

[0042] torsional displacement and velocity history into the left side of the equation of motion in torsional degree of freedom, the lift moment coefficient into the right side of the equation of motion in torsional degree of freedom, we get: the term on the right side of the equation represents the aerodynamic stiffness generated by aerodynamic force; the term represents the aerodynamic damping generated by aerodynamic force; in order to make the equation hold, the coefficients on both sides of the equation must be equal, the coefficients of the terms must also be equal.

[0043] define the system total torsional damping ratio move the aerodynamic force term to the left side of the equation of motion, the equation of motion can be written as: where: is the torsional vibration amplitude; is the phase angle of the lift moment coefficient relative to the torsional displacement; is the torsional aerodynamic damping; is the vibration frequency after adding aerodynamic force; is the stiffness term after the structure is affected by aerodynamic force. The system total torsional damping ratio and the vibration frequency after adding aerodynamic force is obtained by Hilbert transform on the torsional displacement data in step three, as shown in Figure 4

[0044] from the coefficients of the terms containing the system total torsional damping ratio and can be obtained: Let be the dimensionless frequency, and the analytical balance relationship of the out-of-phase component is: where: is the half cross-sectional width; is the cross-sectional width; is the wind speed; is the air density.

[0045] ​​(2) The same method is used to correct the phase by vertical displacement and lift.

[0046] For the vertical degree of freedom, the analytical equilibrium equation is established by the following process: Vertical displacement and velocity history is defined as: wherein: is the vertical amplitude.

[0047] The equation of motion for the vertical degree of freedom of the structure is: wherein: is the mass per unit length; is the vertical structural damping; is the vertical circular frequency of the structure; is the vertical displacement acceleration; is the vertical displacement velocity; is the vertical displacement; is the air density; is the wind speed; is the cross-sectional width; is the lift coefficient history; is time.

[0048] The vertical displacement and velocity history are brought into the left side of the equation of motion for the vertical degree of freedom of the structure, the lift coefficient is brought into the right side of the equation of motion for the vertical degree of freedom of the structure, the coefficients of terms on both sides of the equation are made equal, and the coefficients of cos terms on both sides of the equation are made equal, and the definition of the total vertical damping ratio of the system including the aerodynamic damping is combined, to obtain the analytical equilibrium equation for the out-of-phase component as: wherein: is the vertical vibration amplitude; and are the total vertical damping ratio and vibration frequency of the system after being affected by the self-excitation force; is the phase difference between the vertical and torsional motions, in the present embodiment, the phase difference between the vertical and torsional displacement data measured in the wind tunnel test 21.1°; is the phase angle of the lift coefficient relative to the vertical displacement; is the dimensionless frequency; is the half cross-sectional width.

[0049] Step six: a time shift amount is applied to the original self-excited aerodynamic force time history as a time reference, based on the vibration displacement time history signal , the aerodynamic force data after time shift is repeatedly executed step four, the calculation of the aerodynamic force after time shift out of phase component coefficient; Iterative adjustment of the time shift amount , until the calculated out of phase component coefficient satisfies the analytical balance relationship of step five; This time corresponding determined as the system acquisition delay, and accordingly to the original aerodynamic force data time shift correction, output complete phase synchronization correction of aerodynamic force and displacement data set, realize the phase synchronization of aerodynamic force and displacement signal.

[0050] Specifically, using the torsional displacement time history and lift moment time history, the problem of displacement and wind pressure sampling out of synchronization is solved, the initial time of the measured data of the aerodynamic lift moment coefficient is constantly adjusted, and the new is obtained by step four reintegration. Until the equation in step five is established, thereby realizing the phase difference correction of wind pressure and displacement sampling out of synchronization, as shown in Figure 7 (a) is the comparison of the corrected lift moment time history and torsional displacement time history.

[0051] Similarly, the vertical displacement time history and lift time history can be used to solve the problem of displacement and wind pressure sampling out of synchronization, the initial time of the measured data of the aerodynamic lift coefficient is constantly adjusted, and the new is obtained by step four reintegration. Until the equation in step five is established, thereby realizing the phase difference correction of wind pressure and displacement sampling out of synchronization, as shown in Figure 7 (b) is the comparison of the corrected lift time history and vertical displacement time history.

[0052] The above-described embodiments are only preferred embodiments for fully illustrating the present application, and the protection scope of the present application is not limited thereto. The equivalent substitutions or transformations made by the person skilled in the art on the basis of the present application are within the protection scope of the present application. The protection scope of the present application is subject to the claims.

Claims

1. A method for correcting the phase difference between aerodynamic and displacement signals in wind tunnel tests based on self-excited vibration characteristics, characterized in that: Includes the following steps: Step one: in the wind tunnel test, independently collect the wind pressure time history signal of the surface of the structure model to be tested and the vibration displacement time history signal of the structure model ; Step 2: Analyze the wind pressure time history signal. By performing integration, the time history of the self-excited aerodynamic forces per unit length is obtained, including the self-excited lift. and self-excited lift torque And convert it into a dimensionless lift coefficient time history. and lift moment coefficient time history ; Step three: performing parameter identification on the vibration displacement time history signal to obtain the frequency of the structure vibration at the current wind speed and the total damping ratio of the system ; Step four: time history of the lift coefficient and the moment coefficient Frequency domain filtering is performed to filter out high-order harmonic and noise components, and to extract the fundamental frequency aerodynamic force component with the same frequency as the vibration frequency ​ Step five: based on the structural dynamics equilibrium principle, an analytical equilibrium relationship of the out-of-phase component coefficient representing the phase relationship between the aerodynamic force and the displacement is established; the analytical equilibrium relationship is derived from the structural dynamics equation, which associates the out-of-phase component coefficient of the aerodynamic force with the total damping ratio of the system identified through the displacement signal and the vibration frequency ; Step Six: Using the vibration displacement time history signal Using this as the time reference, a time shift is applied to the original self-excited aerodynamic time history. Repeat step four on the translated aerodynamic data to calculate the aerodynamic phase component coefficients; iteratively adjust the time translation amount. Continue until the calculated heterogeneous component coefficients satisfy the analytical equilibrium relationship described in step five; then, the corresponding... The delay was identified as a system acquisition delay, and the original aerodynamic data was time-shifted accordingly to achieve phase synchronization between the aerodynamic and displacement signals.

2. The method for correcting the phase difference between aerodynamic and displacement signals in wind tunnel tests based on self-excited vibration characteristics according to claim 1, characterized in that: In step one, the surface wind pressure time history signal is acquired through a pressure measurement system; the structural vibration displacement time history signal is acquired through a laser displacement meter or an accelerometer.

3. The method for correcting the phase difference between aerodynamic and displacement signals in wind tunnel tests based on self-excited vibration characteristics according to claim 1, characterized in that: In step two, the specific formulas for integration and dimensionless transformation are as follows: Self-excited lift per unit length: ; Self-excited lift torque per unit length: ; Lift coefficient: ; Lift moment coefficient: ; in: For the self-excited lift time history; The time history of the self-excited lift torque; For the first Each pressure measurement point is located at Zero-mean pulsating pressure at time t; and The first The representative length of each pressure measurement point along the perimeter of the cross section and its distance from the center of the cross section; air density; Wind speed; This refers to the cross-sectional width.

4. The method for correcting the phase difference between aerodynamic and displacement signals in wind tunnel tests based on self-excited vibration characteristics according to claim 1, characterized in that: In step three, the vibration displacement time history signal The method for parameter identification is as follows: right The analytic signal is obtained by performing a Hilbert transform: Time-varying amplitude and time-varying phase Represented as: Time-varying vibration frequency and time-varying damping ratio Represented as: in: For vibration displacement time history signal The analytic signal obtained by performing the Hilbert transform; This represents the imaginary part of the displacement within the Lagrange domain; This is the vibration displacement time history signal; The integral kernel represents an all-pass filter; For time; Let be the integral variable, representing the time delay; Vibration displacement time history signal In the integral variable The value at the point in time it represents; For Hilbert transform operators; This is the amplitude envelope obtained from the fitting.

5. The method for correcting the phase difference between aerodynamic and displacement signals in wind tunnel tests based on self-excited vibration characteristics according to claim 1, characterized in that: In step four, the specific method for extracting the fundamental frequency aerodynamic component is as follows: An integration method based on the orthogonality of trigonometric functions is used to extract the fundamental frequency aerodynamic component from the measured aerodynamic coefficients containing higher harmonics. and Extract only the fundamental frequency The coefficients of the components.

6. The method for correcting the phase difference between aerodynamic forces and displacement signals in wind tunnel tests based on self-excited vibration characteristics according to claim 5, characterized in that: For the lift coefficient, its fundamental frequency component is expressed as: Its in-phase coefficient and heterogeneous coefficient Earned through the following points: The fundamental frequency component of the lift moment coefficient is expressed as: Its in-phase coefficient and heterogeneous coefficient Earned through the following points: in: and These are the vertical and torsional vibration amplitudes, respectively. and These are aerodynamic coefficients based on measured data, which include higher harmonic components; and These are the phase angles of the lift coefficient and lift moment coefficient relative to the displacement signal, respectively. The vibration frequency; = ; = , is the oscillation period; The number of cycles; For time.

7. The method for correcting the phase difference between aerodynamic and displacement signals in wind tunnel tests based on self-excited vibration characteristics according to claim 1, characterized in that: In step five, the analytical equilibrium equation for the torsional degree of freedom is established through the following process: Torsional displacement and speed time history Defined as: in: To torsional amplitude; The vibration frequency; For time; The equations of motion for the torsional degrees of freedom of the structure are: in: Moment of inertia per unit length; For torsional structural damping; The torsional circular frequency of the structure; Torsional acceleration; Torsional speed; For torsional displacement; Torsional displacement and speed time history Substituting the left side of the equation of motion for the torsional degree of freedom, we can change the lift moment coefficient. Substituting the equation for the torsional degree of freedom into the right side, let both sides of the equation... Equal coefficients of terms and both sides of the equation The coefficients are equal, and the total torsional damping ratio of the system, including aerodynamic damping, is combined. By defining the equations, we obtain the analytical equilibrium relations for the heterogeneous components as follows: in: This refers to the amplitude of torsional vibration. This is the phase angle of the lift moment coefficient relative to the torsional displacement; , where is a dimensionless frequency; , is the width of half the cross-section; The width of the cross section; Wind speed; This refers to air density.

8. The method for correcting the phase difference between aerodynamic and displacement signals in wind tunnel tests based on self-excited vibration characteristics according to claim 1, characterized in that: In step five, the analytical equilibrium equation for the vertical degree of freedom is established through the following process: Vertical displacement and speed time history Defined as: in: Vertical amplitude; The equations of motion for the vertical degrees of freedom of the structure are: in: Mass per unit length; For vertical structural damping; The vertical circular frequency of the structure; This is the vertical displacement acceleration; This represents the vertical displacement velocity; This is a vertical displacement; air density; Wind speed; The width of the cross section; Time history of lift coefficient; For time; Vertical displacement and speed time history Substituting the left side of the equations for the vertical degrees of freedom of the structure, and changing the lift coefficient... Substituting the equation for the vertical degrees of freedom of the structure into the right side, let both sides of the equation... Equal coefficients of terms and cos on both sides of the equation The coefficients are equal, and combined with the total vertical damping ratio of the system including aerodynamic damping. By defining the equations, we obtain the analytical equilibrium relations for the heterogeneous components as follows: in: This represents the vertical vibration amplitude. and The total vertical damping ratio and vibration frequency of the system after being affected by the self-excited force; This represents the phase difference between vertical and torsional motions. The phase angle of the lift coefficient relative to the vertical displacement; It is a dimensionless frequency; , is the width of half the cross section.

9. A wind tunnel test aerodynamic and displacement signal phase difference correction system based on self-excited vibration characteristics, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, it implements the wind tunnel test aerodynamic force and displacement signal phase difference correction method based on self-excited vibration characteristics as described in any one of claims 1-8.

10. A storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by the processor, it implements the wind tunnel test aerodynamic force and displacement signal phase difference correction method based on self-excited vibration characteristics as described in any one of claims 1-8.

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