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

Abstract

This invention discloses a method for correcting the phase difference between aerodynamic and displacement signals in wind tunnel tests based on self-excited vibration characteristics. The method includes: independently acquiring wind pressure and vibration displacement signals from the structural surface; integrating the wind pressure signal to obtain the self-excited aerodynamic time history; identifying the vibration frequency and the total system damping ratio from the displacement signal; filtering the aerodynamic time history to extract the fundamental frequency component; establishing an analytical relationship between the aerodynamic out-of-phase component coefficient and the total system damping based on the structural dynamic equilibrium principle; and iteratively shifting the aerodynamic time history using the displacement signal as a reference until the out-of-phase components satisfy the analytical relationship, thereby determining and correcting the system delay. This invention also discloses a system and storage medium for correcting the phase difference between aerodynamic and displacement signals in wind tunnel tests based on self-excited vibration characteristics. This invention requires no additional hardware and can accurately compensate for electrical triggering and physical transmission delays, effectively improving the reliability of aerodynamic parameter identification.

Description

Technical Field

[0001] This invention belongs to the field of aerodynamic wind tunnel testing and structural health monitoring technology. Specifically, it is a method, system and storage medium for correcting the phase difference between aerodynamic and displacement signals in wind tunnel tests based on self-excited vibration characteristics. It is particularly suitable for the study of vortex-induced vibration and flutter mechanisms in the cross-sections of long-span bridges and tall structures. Background Technology

[0002] In the field of structural wind engineering, wind tunnel testing is a crucial step in ensuring engineering safety by studying the self-excited vibration characteristics (such as vortex-induced vibration and flutter) of long-span bridges and tall structures. To deeply reveal the fluid-structure interaction mechanism, researchers not only need to observe the macroscopic vibration response of the structure using laser displacement gauges or accelerometers, but also need to accurately obtain the distribution of unsteady aerodynamic forces acting on the structural surface using pressure measurement systems such as electronic scanning valves, and use this information to analyze the work characteristics and aerodynamic derivatives of the aerodynamic forces.

[0003] However, achieving precise synchronization of aerodynamic and displacement signals remains challenging within existing testing technologies. First, vibration and pressure measurement systems are typically manufactured by different companies, each with its own independent clock source, sampling frequency, and triggering mechanism. Without a unified, high-precision external triggering device, the data collected by the two systems will inevitably exhibit random initial deviations on the time axis, preventing direct data alignment. Second, even with synchronized triggering at the electrical signal level, the pressure signal still experiences a delay as it travels from the pressure measurement hole on the model surface through the conduit to the scanning valve sensor. This physical delay fluctuates with variations in pipe length, diameter, and airflow frequency, making it difficult to eliminate through simple hardware connections.

[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 aerodynamic force and displacement determines the nature of the aerodynamic derivative: the in-phase component corresponds to aerodynamic stiffness, affecting the vibration frequency; while the out-of-phase component corresponds to aerodynamic damping, directly determining the system's energy input and dissipation. If there is an error in the phase difference, it will directly lead to incorrect identification of the aerodynamic derivative, or even sign reversal, misjudging the energy absorption effect as an energy dissipation effect, thus leading to diametrically opposed stability conclusions. Currently used cross-correlation analysis methods have limited accuracy when processing 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 physical properties, and can simultaneously correct system errors and physical transmission delays to meet the needs of refined wind tunnel testing. Summary of the Invention

[0005] In view of this, the purpose of this invention is to provide a method, system and storage medium for correcting the phase difference between aerodynamic and displacement signals in wind tunnel tests based on self-excited vibration characteristics, so as to solve the problem of asynchronous aerodynamic and displacement signals caused by independent acquisition by pressure measurement and vibration measurement systems in wind tunnel tests. By establishing the analytical relationship between the aerodynamic phase components and the total system damping, and iteratively optimizing the time delay, high-precision signal synchronization without additional hardware is achieved, thereby improving the accuracy of identification of key parameters such as aerodynamic derivatives.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] This invention first proposes a method for correcting the phase difference between aerodynamic forces and displacement signals in wind tunnel tests based on self-excited vibration characteristics, comprising the following steps:

[0008] 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 ;

[0009] 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 ;

[0010] Step 3: Analyze the vibration displacement time history signal. Perform parameter identification to obtain the frequency of structural vibration at the current wind speed. and the total damping ratio of the system ;

[0011] Step 4: Time history of the lift coefficient and lift moment coefficient time history Frequency domain filtering is performed to remove higher harmonics and noise components, and the vibration frequency is extracted. The fundamental frequency aerodynamic component of the same frequency;

[0012] 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;

[0013] 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.

[0014] Furthermore, 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.

[0015] Furthermore, in step two, the specific formulas for the integration process and dimensionless transformation are as follows:

[0016] Self-excited lift per unit length: ;

[0017] Self-excited lift torque per unit length: ;

[0018] Lift coefficient: ;

[0019] Lift moment coefficient: ;

[0020] 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.

[0021] Furthermore, in step three, the vibration displacement time history signal... The method for parameter identification is as follows:

[0022] right The analytic signal is obtained by performing a Hilbert transform:

[0023]

[0024]

[0025] Time-varying amplitude and time-varying phase Represented as:

[0026]

[0027]

[0028] Time-varying vibration frequency and time-varying damping ratio Represented as:

[0029]

[0030]

[0031] 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.

[0032] Furthermore, 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.

[0033] Furthermore, the fundamental frequency component of the lift coefficient is expressed as:

[0034]

[0035] Its in-phase coefficient and heterogeneous coefficient Earned through the following points:

[0036]

[0037]

[0038] The fundamental frequency component of the lift moment coefficient is expressed as:

[0039]

[0040] Its in-phase coefficient and heterogeneous coefficient Earned through the following points:

[0041]

[0042]

[0043] 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.

[0044] Furthermore, in step five, the analytical equilibrium equation for the torsional degree of freedom is established through the following process:

[0045] Torsional displacement and speed time history Defined as:

[0046]

[0047]

[0048] in: To torsional amplitude; The vibration frequency; For time;

[0049] The equations of motion for the torsional degrees of freedom of the structure are:

[0050]

[0051] in: The moment of inertia per unit length; For torsional structural damping; The torsional circular frequency of the structure; Torsional acceleration; Torsional speed; For torsional displacement;

[0052] 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:

[0053]

[0054] 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.

[0055] Furthermore, in step five, the analytical equilibrium relationship for the vertical degree of freedom is established through the following process:

[0056] Vertical displacement and speed time history Defined as:

[0057]

[0058]

[0059] in: Vertical amplitude;

[0060] The equations of motion for the vertical degrees of freedom of the structure are:

[0061]

[0062] 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;

[0063] 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:

[0064]

[0065] 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.

[0066] 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.

[0067] The present invention also proposes a storage medium storing a computer program, which, when executed by a processor, implements the phase difference correction method for wind tunnel test aerodynamic and displacement signals based on self-excited vibration characteristics as described above.

[0068] The beneficial effects of this invention are as follows:

[0069] This invention relates to a method for correcting the phase difference between aerodynamic and displacement signals in wind tunnel tests based on self-excited vibration characteristics. By deeply exploring the physical essence of energy balance in the self-excited vibration process, the following technical effects have been achieved:

[0070] (1) Achieving high-precision software synchronization and breaking through hardware dependence: This invention creatively uses the structural dynamics equilibrium equation as a physical criterion, and accurately back-calculates and compensates for system delay through iterative algorithms. Without relying on expensive hardware synchronization devices, it achieves signal alignment accuracy comparable to or even higher than hardware synchronization.

[0071] (2) Significantly improve the accuracy of aerodynamic parameter identification: By accurately correcting the phase difference, the misjudgment of aerodynamic derivative sign caused by signal asynchrony (such as misjudging aerodynamic negative damping as positive damping) 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 assessment.

[0072] (3) Strong anti-interference and adaptive capabilities: The orthogonal filtering step built into the method of this invention can effectively filter out broadband turbulent noise and aerodynamic high-order harmonics, and extract pure fundamental frequency components; The calibration mechanism based on physical equations of this invention has good robustness to environmental noise and signal non-stationarity, and is adaptable to actual test conditions under complex wind fields.

[0073] (4) Forming a universal technical solution: The analytical equilibrium relationship established by this invention has strong universality and can be applied to various vibration modes such as vertical and torsional vibrations. It also uniformly corrects the electrical triggering delay and physical pipeline transmission delay, providing a universal software solution for multi-system data synchronization in wind tunnel tests, reducing the complexity and cost of the test.

[0074] In summary, the method of this invention combines the rigor of the theoretical model with the flexibility of the algorithm implementation, effectively overcoming the long-standing problem of signal synchronization in fine wind tunnel tests, and is of great value in promoting the research of fluid-structure interaction mechanism and engineering wind-resistant design. Attached Figure Description

[0075] To make the objectives, technical solutions, and beneficial effects of this invention clearer, the following figures are provided for illustration:

[0076] Figure 1 This is a schematic diagram of the bridge's cross-sectional structure.

[0077] Figure 2 This is a flowchart of the wind tunnel test aerodynamic force and displacement signal phase difference correction method based on self-excited vibration characteristics according to the present invention.

[0078] Figure 3 The 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.

[0079] Figure 4 Time history diagrams of aerodynamic coefficients for bridge structures; (a) time history of lift coefficient; (b) time history of lift moment coefficient;

[0080] 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.

[0081] Figure 6 (a) is the amplitude spectrum of aerodynamic lift and lift moment coefficient; (b) is the amplitude spectrum of lift coefficient;

[0082] 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

[0083] 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.

[0084] 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.

[0085] 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.

[0086] 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 .

[0087] 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.

[0088] 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 .

[0089] 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.

[0090] Self-excited lift per unit length and self-excited lift torque for:

[0091]

[0092]

[0093] 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.

[0094] Lift and lift moment are respectively expressed using the lift coefficient. and lift moment coefficient Expressed as:

[0095]

[0096]

[0097] in: air density; Wind speed; This refers to the cross-sectional width.

[0098] like Figure 4 As shown, the bridge structure lift coefficient is obtained by integrating the wind pressure time history signal. and lift moment coefficient .

[0099] Step 3: Analyze the vibration displacement time history signal. Perform parameter identification to obtain the frequency of structural vibration at the current wind speed. and the total damping ratio of the system .

[0100] In this embodiment, Hilbert transforms are performed on the vertical displacement and torsional displacement data measured in the wind tunnel test, respectively, to obtain the total damping ratio and vibration frequency of the vertical and torsional vibrations. The total damping and vibration frequency of the bridge structure obtained by fitting the vertical displacement and torsional displacement data are as follows: Figure 5 As shown. The specific method is as follows.

[0101] The Hilbert transform is defined as follows:

[0102]

[0103] in: 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; This is the Hilbert transform operator.

[0104] Obtain the imaginary part of the displacement within the Lagrange domain. Then, the displacement time history within the Lagrange domain is obtained. :

[0105]

[0106]

[0107]

[0108] in: For displacement signal The analytic signal obtained by performing the Hilbert transform; and Displacement signals The time-varying amplitude and time-varying phase.

[0109] Time-varying vibration frequency and time-varying damping ratio Represented as:

[0110]

[0111]

[0112] in: Let be the signal envelope obtained through Hilbert transform, and let represent the time-varying amplitude.

[0113] Step 4: Time history of the lift coefficient and lift moment coefficient time history Frequency domain filtering is performed to remove higher harmonics and noise components, and the vibration frequency is extracted. The fundamental frequency aerodynamic component with the same frequency.

[0114] In this embodiment, 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. Specifically, by directly performing a Fourier transform on the self-excited aerodynamic time history obtained in step two, the spectrum of the aerodynamic force can be obtained, such as... Figure 6 As shown, the relative magnitudes of the aerodynamic components at other frequencies and the components at the natural frequency can be observed more intuitively, and the torsional vibration amplitude can be obtained. 5.075×10 -3 Vertical and torsional vibration amplitude 5.164×10 -2 Vibration frequency 1.583 H. It can be seen that the measured self-excited lift and lift torque contain multiple frequency components, including the motion frequency and its higher harmonics, causing the time history of the self-excited aerodynamic force to exhibit the following characteristics: Figure 4 As shown by the blue line, the original signal superimposed with high-frequency noise exhibits obvious sawtooth-like fluctuations. The higher harmonic components of the aerodynamic force do no work within one oscillation cycle and have no effect on the system frequency and damping. Therefore, in the following analysis, the higher harmonic components of the aerodynamic force should first be filtered out, retaining only the components with the same frequency as the motion, to obtain the aerodynamic time history containing only the components with the same frequency as the motion.

[0115] The fundamental frequency component of the lift coefficient is expressed as:

[0116]

[0117] Its in-phase coefficient and heterogeneous coefficient Earned through the following points:

[0118]

[0119]

[0120] The fundamental frequency component of the lift moment coefficient is expressed as:

[0121]

[0122] Its in-phase coefficient and heterogeneous coefficient Earned through the following points:

[0123]

[0124]

[0125] 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.

[0126] By filtering out the higher harmonic components of 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 only retaining 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.

[0127] 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.

[0128] (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.

[0129] Specifically, for the torsional degree of freedom, the analytical equilibrium relationship is established through the following process:

[0130] Torsional displacement and speed time history Defined as:

[0131]

[0132]

[0133] in: To torsional amplitude; The vibration frequency; For time.

[0134] The equations of motion for the torsional degrees of freedom of the structure are:

[0135]

[0136] in: The moment of inertia per unit length; For torsional structural damping; The torsional circular frequency of the structure; Torsional acceleration; Torsional speed; This is a torsional displacement.

[0137] 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 into the right side of the equation of motion for the torsional degree of freedom, we get:

[0138]

[0139] The right side of the equation The term represents the aerodynamic stiffness generated by aerodynamic forces; The term represents the aerodynamic damping generated by the aerodynamic force; for the equation to hold true, both sides of the equation... The coefficients must be equal. The coefficients must also be equal.

[0140] Define the total torsional damping ratio of the system By moving the aerodynamic term to the left side of the equation of motion, the dynamic equation can be written as:

[0141]

[0142]

[0143] in: This refers to the amplitude of torsional vibration. This is the phase angle of the lift moment coefficient relative to the torsional displacement; For torsional aerodynamic damping; The vibration frequency after the aerodynamic force is applied; This represents the stiffness term of the structure after being affected by aerodynamic forces. The total torsional damping ratio of the system. and vibration frequency after adding aerodynamic force This is obtained by performing a Hilbert transform on the torsional displacement data in step three, such as... Figure 4 As shown.

[0144] The total torsional damping ratio of the system and Equal coefficients of the terms yield the following:

[0145]

[0146]

[0147] make For the dimensionless frequency, the analytical equilibrium equation for the out-of-phase components can be obtained as follows:

[0148]

[0149] in: , is the width of half the cross-section; The width of the cross section; Wind speed; This refers to air density.

[0150] (2) The same method is used to correct the phase through vertical displacement and lift.

[0151] For the vertical degree of freedom, the analytical equilibrium equation is established through the following process:

[0152] Vertical displacement and speed time history Defined as:

[0153]

[0154]

[0155] in: This represents the vertical amplitude.

[0156] The equations of motion for the vertical degrees of freedom of the structure are:

[0157]

[0158] 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.

[0159] 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:

[0160]

[0161] 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; In this embodiment, the phase difference between vertical and torsional motions refers to the phase difference between the vertical and torsional displacement data measured in the wind tunnel test. 21.1°; 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.

[0162] 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 system acquisition delay was identified, and the original aerodynamic data was time-shifted accordingly. The aerodynamic and displacement datasets with phase synchronization correction were output, thus achieving phase synchronization of the aerodynamic and displacement signals.

[0163] Specifically, when addressing the issue of asynchronous displacement and wind pressure sampling by utilizing torsional displacement time history and lift moment time history, the aerodynamic lift moment coefficient of the measured data is continuously adjusted. The initial time is obtained by re-integrating in step four to get the new time. Until the equation in step five holds true, phase difference correction for asynchronous wind pressure and displacement acquisition is achieved, such as... Figure 7 (a) shows a comparison of the corrected lift moment time history and torsional displacement time history.

[0164] Similarly, the vertical displacement time history and lift time history can be used to address the issue of asynchronous displacement and wind pressure sampling by continuously adjusting the aerodynamic lift coefficient of the measured data. The initial time is obtained by re-integrating in step four to get the new time. Until the equation in step five holds true, phase difference correction for asynchronous wind pressure and displacement acquisition is achieved, such as... Figure 7 (b) shows a comparison of the corrected lift time history and vertical displacement time history.

[0165] The above-described embodiments are merely preferred embodiments provided to fully illustrate the present invention, and the scope of protection of the present invention is not limited thereto. Equivalent substitutions or modifications made by those skilled in the art based on the present invention are all within the scope of protection of the present invention. The scope of protection of the present invention is defined by 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 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 ; 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 3: Analyze the vibration displacement time history signal. Perform parameter identification to obtain the frequency of structural vibration at the current wind speed. and the total damping ratio of the system ; Step 4: Time history of the lift coefficient and lift moment coefficient time history Frequency domain filtering is performed to remove higher harmonics and noise components, and the vibration frequency is extracted. The fundamental frequency aerodynamic component of the same frequency; 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; 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 and displacement signals in wind tunnel tests based on self-excited vibration characteristics according to claim 5, characterized in that: The fundamental frequency component of the lift coefficient 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; This refers to the cross-sectional width; 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; This refers to the cross-sectional width; 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 force 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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