Suspension bridge three-dimensional flutter critical wind speed prediction method and system based on segment model parameter correction

Abstract

The invention discloses a suspension bridge three-dimensional flutter critical wind speed prediction method and system based on segment model parameter correction, and relates to the technical field of bridge engineering. The method comprises the following steps: firstly, carrying out a segment model flutter test of the suspension bridge according to a base-order vibration mode to obtain a flutter critical wind speed and a flutter frequency of the suspension bridge; according to the flutter critical wind speed, a flutter derivative is obtained through interpolation calculation; and based on the principle that the two-dimensional segment model flutter system damping is equal to the three-dimensional full-bridge aeroelastic model flutter system damping, a segment model system mass correction factor is obtained, and then the segment model system mass is corrected. And repeating the steps until the value of the mass correction factor of the segment model system does not change, and taking the flutter critical wind speed obtained by the flutter test of the segment model in the current state as the predicted value of the three-dimensional flutter critical wind speed of the suspension bridge. Compared with a traditional segment model test method, the accuracy of the three-dimensional flutter critical wind speed prediction result of the suspension bridge is remarkably improved, the test operation is simple, and the efficiency is high.

Description

Technical Field

[0001] The present invention relates to the technical field of bridge engineering, and more particularly to a method and system for predicting critical wind speed of three-dimensional flutter of a suspension bridge based on segment model parameter correction. Background Art

[0002] The wind-resistant design code for bridges points out that it is necessary to conduct traditional segmental model flutter tests based on the base-order vertical bending and torsion modes of suspension bridges in order to preliminarily evaluate the flutter stability of suspension bridges or optimize the aerodynamic shape of the main beam section. Due to the influence of the multi-modal coupling effect in the three-dimensional aeroelastic effect, the flutter critical wind speed predicted by the traditional two-dimensional segmental model test is sometimes significantly higher than and seriously deviates from the prediction results of the three-dimensional full-bridge aeroelastic model test, which is contrary to the expectations of researchers and bridge design engineers. Therefore, it is necessary to propose a segmental model test method that can more accurately predict the three-dimensional flutter critical wind speed of suspension bridges.

[0003] Prior art 1 is based on the analysis of the two-degree-of-freedom coupled flutter mechanism of bridge structures, and calculates the improved design parameters of the segment model flutter test according to the least squares method. Prior art 2 proposes an equivalent mass simulation method for the segment model flutter test considering the incomplete similarity of vibration modes and multi-modal coupling effects. It is worth pointing out that although both prior art 1 and 2 can accurately predict the three-dimensional flutter critical wind speed of the suspension bridge through the segment model test, they either have more modified test parameters or the test parameter determination process is more complicated, so they have not yet been widely used in the design and research of actual projects.

[0004] In summary, in the methods for predicting the critical flutter wind speed of suspension bridges based on the existing technology, there is an obvious gap between the critical flutter wind speed of suspension bridges predicted by the traditional segment model flutter test and the prediction result of the full-bridge aeroelastic model test, and the prediction result of the segment model may significantly overestimate the flutter stability of the suspension bridge. Therefore, it is a technical problem that needs to be urgently solved in this field to propose a convenient and highly accurate segment model test method for predicting the three-dimensional critical flutter wind speed of suspension bridges. Summary of the invention

[0005] In view of this, the present invention starts from the bridge flutter theory, based on the principle of equal system damping of the two-dimensional segment model and the three-dimensional full-bridge aeroelastic model, derives the calculation expression of the segment model system mass correction factor, and accordingly proposes a three-dimensional flutter critical wind speed prediction method and system for suspension bridges based on segment model system mass correction.

[0006] In order to achieve the above object, the present invention provides the following technical solutions:

[0007] A method for predicting critical wind speed of three-dimensional flutter of a suspension bridge based on segment model parameter correction includes the following steps:

[0008] Step 1: Perform a segment model flutter test of the suspension bridge according to the fundamental vibration mode to obtain the flutter critical wind speed and flutter frequency of the suspension bridge;

[0009] Step 2: According to the flutter critical wind speed, obtain the flutter derivative by interpolation calculation

[0010] Step 3: According to the flutter frequency and the flutter derivative Based on the principle that the damping of the flutter system of the two-dimensional segment model is equal to that of the flutter system of the three-dimensional full-bridge aeroelastic model, the mass correction factor η of the segment model system is obtained;

[0011] Step 4: Use the mass correction factor to correct the mass of the segment model system, and re-perform the segment model flutter test of the suspension bridge;

[0012] Step 5, repeating steps 1 to 4 until the value of the segment model system mass correction factor η no longer changes, and taking the flutter critical wind speed obtained from the current state segment model flutter test as the predicted value of the three-dimensional flutter critical wind speed of the suspension bridge.

[0013] Furthermore, in step 1, the fundamental vibration mode includes a fundamental symmetrical torsional mode and a two-order symmetrical vertical bending mode;

[0014] For a single-span simply supported suspension bridge, its flutter vertical bending participating modes are the fundamental and second-order symmetrical vertical bending modes; for a multi-span continuously supported suspension bridge, its flutter vertical bending participating modes are the fundamental and third-order symmetrical vertical bending modes.

[0015] Furthermore, in step 2, the flutter derivative is obtained by interpolation calculation The process is:

[0016] Step 2.1, respectively record the vertical free vibration attenuation time history of the segment model under the condition of no wind and the condition of flutter critical wind speed, and obtain the instantaneous amplitude u0(t) of the vertical free vibration attenuation time history under the condition of no wind and the instantaneous amplitude u1(t) of the vertical free vibration attenuation time history under the condition of flutter critical wind speed;

[0017] Step 2.2: Calculate the time-varying system damping ζ of the segment model under windless conditions according to the instantaneous amplitudes u0(t) and u1(t). v0 (t) and the time-varying system damping ζ of the segment model under the flutter critical wind speed condition v1 (t);

[0018] Step 2.3: According to the time-varying system damping ζ of the segment model under windless conditions v0 (t) and the time-varying system damping ζ of the segment model under the flutter critical wind speed condition v1 (t), the flutter derivative is calculated

[0019] Furthermore, in step 2.1, the instantaneous amplitudes u0(t) and u1(t) are obtained by:

[0020] The vertical free vibration attenuation time history of the segment model under no wind conditions and flutter critical wind speed conditions is subjected to Hilbert transform HT to obtain the instantaneous amplitude envelope of the vertical free vibration attenuation time history. The instantaneous amplitude envelope is fitted with an exponential function to obtain the instantaneous amplitude u i The fitting expression of (t) is:

[0021]

[0022] In the formula, u i (t) is the instantaneous amplitude of the vertical free vibration decay history, t is the time, and u0, λ1, λ2, κ1 and κ2 are the fitting coefficients.

[0023] Furthermore, in step 2.2, the time-varying system damping ζ vi The calculation formula of (t) is:

[0024]

[0025] In the formula, ζ vi (t) is the time-varying system damping of the segment model; f vi is the vibration frequency of the vertical free vibration decay history, f v0 represents the vibration frequency of the vertical free vibration attenuation time under windless conditions, f v1 It represents the vibration frequency of the vertical free vibration attenuation time under the critical flutter wind speed condition.

[0026] Furthermore, in step 2.3, the flutter derivative The calculation formula is:

[0027]

[0028] Where ρ is the air density; B is the width of the main beam of the suspension bridge; and m is the equivalent mass of the vertical bending mode.

[0029] Furthermore, in step 3, the calculation formula of the segment model system quality correction factor η is:

[0030]

[0031]

[0032]

[0033] Where ρ is the air density; B is the width of the main beam of the suspension bridge; m is the equivalent mass of the vertical bending mode; ω v1 Represents the first-order natural circular frequency of the vertical bending mode, ω v2 represents the second-order natural circular frequency of the vertical bending mode; ω is the flutter circular frequency; D v1,α and D v2,α is the modal similarity factor between the vertical bending mode and the fundamental torsional mode; L g is the length of the main girder of the suspension bridge; φ vj (s g ) is the vertical bending mode shape of the main beam of the suspension bridge; φ t (s g ) is the torsional mode shape of the main beam of the suspension bridge; s g are the local coordinates of the main girder of the suspension bridge.

[0034] A three-dimensional flutter critical wind speed prediction system for suspension bridges based on segment model parameter correction, comprising:

[0035] The flutter test module is used to perform a segment model flutter test of a suspension bridge according to the fundamental vibration mode to obtain the critical flutter wind speed and flutter frequency of the suspension bridge;

[0036] A flutter derivative calculation module is used to obtain the flutter derivative by interpolation calculation according to the flutter critical wind speed.

[0037] A mass correction factor calculation module, used to obtain a mass correction factor η of a segment model system according to the flutter frequency and the flutter derivative H*1, based on the principle that the damping of a two-dimensional segment model flutter system is equal to the damping of a three-dimensional full-bridge aeroelastic model flutter system;

[0038] The system mass correction module is used to correct the mass of the segment model system using the mass correction factor and re-perform the segment model flutter test of the suspension bridge;

[0039] The loop module is used to repeat the system mass correction and flutter test until the value of the segment model system mass correction factor η no longer changes, and the flutter critical wind speed obtained from the current state segment model flutter test is used as the predicted value of the three-dimensional flutter critical wind speed of the suspension bridge.

[0040] It can be seen from the above technical solutions that the present invention provides a method and system for predicting critical wind speed of three-dimensional flutter of a suspension bridge based on segment model parameter correction, which has the following beneficial effects compared with the prior art:

[0041] (1) Improving prediction accuracy: Based on the principle that the damping of the two-dimensional segment model flutter system is equal to the damping of the three-dimensional full-bridge aeroelastic model flutter system, the present invention creatively proposes a calculation expression for the segment model system mass correction factor. By iteratively correcting the system mass of the segment model, the gap between the prediction results of the segment model flutter test and the full-bridge aeroelastic model test is reduced, thereby significantly improving the accuracy of the prediction of the critical wind speed of suspension bridge flutter.

[0042] (2) Reducing test parameter correction: The solution of the present invention does not require complex corrections to multiple test parameters, but only corrects the quality of the segment model through the segment model system quality correction factor, which simplifies the test process and reduces the difficulty of the test.

[0043] In summary, the scheme of the present invention has the beneficial effects of accurate prediction, simple operation, high test efficiency, etc. According to the scheme of the present invention, engineering and technical personnel can conveniently and accurately grasp the flutter performance of the suspension bridge, and significantly improve the quality and work efficiency of the wind-resistant design of the suspension bridge. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0045] Figure 1 It is a flow chart of a method for predicting critical wind speed of three-dimensional flutter of a suspension bridge based on segment model parameter correction of the present invention;

[0046] Figure 2 is the flutter derivative provided by the specific embodiment of the present invention Schematic diagram;

[0047] Figure 3 It is a schematic diagram of the change of three-dimensional flutter characteristics provided by a specific embodiment of the present invention. DETAILED DESCRIPTION

[0048] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0049] The embodiment of the present invention discloses a method for predicting critical wind speed of three-dimensional flutter of a suspension bridge based on segment model parameter correction, see Figure 1, including the following steps:

[0050] Step 1: Perform a segment model flutter test of the suspension bridge according to the fundamental vibration mode to obtain the flutter critical wind speed and flutter frequency of the suspension bridge.

[0051] The fundamental vibration modes mainly include the fundamental symmetrical torsional mode and the two-order symmetrical vertical bending modes. For a single-span simply supported suspension bridge, its flutter vertical bending participating modes are the fundamental and second-order symmetrical vertical bending modes. For a multi-span continuously supported suspension bridge, its flutter vertical bending participating modes are the fundamental and third-order symmetrical vertical bending modes.

[0052] Step 2: According to the flutter critical wind speed, obtain the flutter derivative by interpolation calculation The specific process is:

[0053] Step 2.1, respectively record the vertical free vibration attenuation time history of the segment model under the condition of no wind and the condition of flutter critical wind speed, perform Hilbert transform HT on the vertical free vibration attenuation time history of the segment model under the condition of no wind and the condition of flutter critical wind speed, obtain the instantaneous amplitude envelope of the vertical free vibration attenuation time history, perform exponential function fitting on the instantaneous amplitude envelope, and obtain the instantaneous amplitude u0(t) of the vertical free vibration attenuation time history under the condition of no wind and the instantaneous amplitude u1(t) of the vertical free vibration attenuation time history under the condition of flutter critical wind speed.

[0054] Among them, the instantaneous amplitude u i The fitting expression of (t) is:

[0055]

[0056] In the formula, u i (t) is the instantaneous amplitude of the vertical free vibration decay history, t is the time, and u0, λ1, λ2, κ1 and κ2 are the fitting coefficients.

[0057] Step 2.2: Calculate the time-varying system damping ζ of the segment model under windless conditions according to the instantaneous amplitudes u0(t) and u1(t). v0 (t) and the time-varying system damping ζ of the segment model under the flutter critical wind speed condition v1 (t).

[0058] Time-varying system damping ζ vi The calculation formula of (t) is:

[0059]

[0060] In the formula, ζvi (t) is the time-varying system damping of the segment model; f vi is the vibration frequency of the vertical free vibration decay history, f v0represents the vibration frequency of the vertical free vibration attenuation time under windless conditions, f v1 It represents the vibration frequency of the vertical free vibration attenuation time under the critical flutter wind speed condition.

[0061] Step 2.3: Subtract the system damping under windy conditions from the system damping under no wind conditions to obtain the aerodynamic damping under the wind speed condition. Basically, it has no amplitude dependence, so the flutter derivative under the flutter critical wind speed condition is for:

[0062]

[0063] Where ρ is the air density; B is the width of the main beam of the suspension bridge; and m is the equivalent mass of the vertical bending mode.

[0064] Step 3: According to the flutter frequency and the flutter derivative Based on the principle that the damping of the flutter system of the two-dimensional segment model is equal to that of the flutter system of the three-dimensional full-bridge aeroelastic model, the mass correction factor η of the segment model system is obtained.

[0065] The calculation formula of the segment model system quality correction factor η is:

[0066]

[0067]

[0068]

[0069] Where ρ is the air density; B is the width of the main beam of the suspension bridge; m is the equivalent mass of the vertical bending mode; ω v1 Represents the first-order natural circular frequency of the vertical bending mode, ω v2 represents the second-order natural circular frequency of the vertical bending mode; ω is the flutter circular frequency; D v1,α and D v2,α is the modal similarity factor between the vertical bending mode and the fundamental torsional mode; L g is the length of the main girder of the suspension bridge; φ vj (s g ) is the vertical bending mode shape of the main beam of the suspension bridge; φ t (s g ) is the torsional mode shape of the main beam of the suspension bridge; s g are the local coordinates of the main girder of the suspension bridge.

[0070] Step 4: Use the mass correction factor to correct the mass of the segment model system, and re-perform the segment model flutter test of the suspension bridge;

[0071] Step 5, repeating steps 1 to 4 until the value of the segment model system mass correction factor η no longer changes and tends to be stable, and taking the flutter critical wind speed obtained from the current state segment model flutter test as the predicted value of the three-dimensional flutter critical wind speed of the suspension bridge.

[0072] The embodiment of the present invention further provides a suspension bridge three-dimensional flutter critical wind speed prediction system based on segment model parameter correction, which is used to implement the above method, including:

[0073] The flutter test module is used to perform a segment model flutter test of a suspension bridge according to the fundamental vibration mode to obtain the critical flutter wind speed and flutter frequency of the suspension bridge;

[0074] A flutter derivative calculation module is used to obtain the flutter derivative by interpolation calculation according to the flutter critical wind speed.

[0075] A mass correction factor calculation module is used to calculate the mass correction factor according to the flutter frequency and the flutter derivative. Based on the principle that the damping of the flutter system of the two-dimensional segment model is equal to that of the flutter system of the three-dimensional full-bridge aeroelastic model, the mass correction factor η of the segment model system is obtained;

[0076] The system mass correction module is used to correct the mass of the segment model system using the mass correction factor and re-perform the segment model flutter test of the suspension bridge;

[0077] The loop module is used to repeat the system mass correction and flutter test until the value of the segment model system mass correction factor η no longer changes, and the flutter critical wind speed obtained from the current state segment model flutter test is used as the predicted value of the three-dimensional flutter critical wind speed of the suspension bridge.

[0078] As for the system module disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the description of the method part.

[0079] The application and effects of the present invention are described in detail below in conjunction with specific embodiments.

[0080] The North Channel Bridge of Zhangjinggao Yangtze River Bridge is selected for example analysis. The North Channel Bridge of Zhangjinggao Yangtze River Bridge is a double-tower single-span steel box girder suspension bridge with a span of 1208m. The width of its steel box main beam is 47.7m, the aspect ratio is 11.9, and it is a flat streamlined box girder section. The main calculation parameters of the North Channel Bridge of Zhangjinggao Yangtze River Bridge are shown in Tables 1 and 2.

[0081] Table 1 Modal parameters of the north channel bridge of Zhangjinggao Yangtze River Bridge

[0082]

[0083] Note: V represents vertical bending mode, S represents symmetric mode, T represents torsional mode, for example, VS-1 represents the first-order symmetric vertical bending mode.

[0084] Table 2 Modal shape similarity factors of the North Channel Bridge of Zhangjinggao Yangtze River Bridge

[0085]

[0086] Flutter derivatives of the main beam of the north channel bridge of Zhangjinggao Yangtze River Bridge under the condition of 0° initial wind attack angle like Figure 2 shown.

[0087] Flutter critical wind speed U of the wind tunnel test of the northern channel bridge segment model of Zhangjinggao Yangtze River Bridge cr , flutter frequency f cr and the mass correction factor η as Figure 3 First, according to the dynamic characteristics and equivalent mass of the fundamental mode, a traditional segment model wind tunnel test (corresponding to the first segment model test) is carried out, and η is calculated accordingly; according to the existing η, the system mass of the segment model is modified, and the following is carried out: Figure 3 The second segment model test is performed as shown, and η is updated; the system quality of the segment model is modified according to the updated η, and the following is performed: Figure 3 The third and fourth segment model tests are shown. When the second segment model flutter test was carried out, the flutter critical wind speed and flutter frequency predicted by the segment model had stabilized and no longer changed.

[0088] The critical flutter wind speed of the full-bridge aeroelastic model of the North Channel Bridge of Zhangjinggao Yangtze River Bridge under the condition of 0° initial wind attack angle, the critical flutter wind speed of the traditional segment model and the critical flutter wind speed predicted by the method of the present invention are shown in Table 3.

[0089] Table 3 Critical flutter wind speed of the north channel bridge of Zhangjinggao Yangtze River Bridge (m·s -1 )

[0090]

[0091] By comparison, it can be found that compared with the prediction results of the traditional segment model, the critical flutter wind speed of the suspension bridge predicted by the method of the present invention is closer to the three-dimensional critical flutter wind speed of the full bridge aeroelastic model. The only test parameter that needs to be modified in the scheme of the present invention is the quality of the segment model system, and the prediction test process is relatively simple, so it has a high application value.

[0092] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0093] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for predicting critical wind speed of three-dimensional flutter of suspension bridge based on segment model parameter correction, characterized in that: The following steps are involved: Step 1: Perform a segment model flutter test of the suspension bridge according to the fundamental vibration mode to obtain the flutter critical wind speed and flutter frequency of the suspension bridge; Step 2: According to the flutter critical wind speed, obtain the flutter derivative by interpolation calculation Step 3: According to the flutter frequency and the flutter derivative Based on the principle that the damping of the flutter system of the two-dimensional segment model is equal to that of the flutter system of the three-dimensional full-bridge aeroelastic model, the mass correction factor η of the segment model system is obtained; Step 4: Use the mass correction factor to correct the mass of the segment model system, and re-perform the segment model flutter test of the suspension bridge; Step 5, repeating steps 1 to 4 until the value of the segment model system mass correction factor η no longer changes, and taking the flutter critical wind speed obtained from the current state segment model flutter test as the predicted value of the three-dimensional flutter critical wind speed of the suspension bridge.

2. The method for predicting critical wind speed of three-dimensional flutter of a suspension bridge based on segment model parameter correction according to claim 1 is characterized in that: In step 1, the fundamental vibration mode includes a fundamental symmetrical torsional mode and a two-order symmetrical vertical bending mode; For a single-span simply supported suspension bridge, its flutter vertical bending participating modes are the fundamental and second-order symmetrical vertical bending modes; for a multi-span continuously supported suspension bridge, its flutter vertical bending participating modes are the fundamental and third-order symmetrical vertical bending modes.

3. The method for predicting critical wind speed of three-dimensional flutter of a suspension bridge based on segment model parameter correction according to claim 1 is characterized in that: In step 2, the flutter derivative is obtained by interpolation calculation. The process is: Step 2.1, respectively record the vertical free vibration attenuation time history of the segment model under the condition of no wind and the condition of flutter critical wind speed, and obtain the instantaneous amplitude u0(t) of the vertical free vibration attenuation time history under the condition of no wind and the instantaneous amplitude u1(t) of the vertical free vibration attenuation time history under the condition of flutter critical wind speed; Step 2.2: Calculate the time-varying system damping ζ of the segment model under windless conditions according to the instantaneous amplitudes u0(t) and u1(t). v0 (t) and the time-varying system damping ζ of the segment model under the flutter critical wind speed condition v1 (t); Step 2.3: According to the time-varying system damping ζ of the segment model under windless conditions v0 (t) and the time-varying system damping ζ of the segment model under the flutter critical wind speed condition v1 (t), the flutter derivative is calculated 4. The method for predicting critical wind speed of three-dimensional flutter of a suspension bridge based on segment model parameter correction according to claim 3 is characterized in that: In step 2.1, the method for obtaining the instantaneous amplitudes u0(t) and u1(t) is: The vertical free vibration attenuation time history of the segment model under no wind conditions and flutter critical wind speed conditions is subjected to Hilbert transform HT to obtain the instantaneous amplitude envelope of the vertical free vibration attenuation time history. The instantaneous amplitude envelope is fitted with an exponential function to obtain the instantaneous amplitude u i The fitting expression of (t) is: In the formula, u i (t) is the instantaneous amplitude of the vertical free vibration decay history, t is the time, and u0, λ1, λ2, κ1 and κ2 are the fitting coefficients.

5. The method for predicting critical wind speed of three-dimensional flutter of a suspension bridge based on segment model parameter correction according to claim 4 is characterized in that: In step 2.2, the time-varying system damping ζ vi The calculation formula of (t) is: In the formula, ζ vi (t) is the time-varying system damping of the segment model; f vi is the vibration frequency of the vertical free vibration decay history, f v0 represents the vibration frequency of the vertical free vibration attenuation time under windless conditions, f v1 It represents the vibration frequency of the vertical free vibration attenuation time under the critical flutter wind speed condition.

6. The method for predicting critical wind speed of three-dimensional flutter of a suspension bridge based on segment model parameter correction according to claim 5 is characterized in that: In step 2.3, the flutter derivative The calculation formula is: Where ρ is the air density; B is the width of the main beam of the suspension bridge; and m is the equivalent mass of the vertical bending mode.

7. The method for predicting critical wind speed of three-dimensional flutter of a suspension bridge based on segment model parameter correction according to claim 1 is characterized in that: In step 3, the calculation formula of the segment model system quality correction factor η is: Where ρ is the air density; B is the width of the main beam of the suspension bridge; m is the equivalent mass of the vertical bending mode; ω v1 Represents the first-order natural circular frequency of the vertical bending mode, ω v2 represents the second-order natural circular frequency of the vertical bending mode; ω is the flutter circular frequency; D v1,α and D v2,α is the mode similarity factor between the vertical bending mode and the fundamental torsional mode; L g is the length of the main girder of the suspension bridge; φ vj (s g ) is the vertical bending mode shape of the main beam of the suspension bridge; φ t (s g ) is the torsional mode shape of the main beam of the suspension bridge; s g are the local coordinates of the main girder of the suspension bridge.

8. A three-dimensional flutter critical wind speed prediction system for suspension bridges based on segment model parameter correction, characterized in that: include: The flutter test module is used to perform a segment model flutter test of a suspension bridge according to the fundamental vibration mode to obtain the critical flutter wind speed and flutter frequency of the suspension bridge; A flutter derivative calculation module is used to obtain the flutter derivative by interpolation calculation according to the flutter critical wind speed. A mass correction factor calculation module is used to calculate the mass correction factor according to the flutter frequency and the flutter derivative. Based on the principle that the damping of the flutter system of the two-dimensional segment model is equal to that of the flutter system of the three-dimensional full-bridge aeroelastic model, the mass correction factor η of the segment model system is obtained; The system mass correction module is used to correct the mass of the segment model system using the mass correction factor and re-perform the segment model flutter test of the suspension bridge; The loop module is used to repeat the system mass correction and flutter test until the value of the segment model system mass correction factor η no longer changes, and the flutter critical wind speed obtained from the current state segment model flutter test is used as the predicted value of the three-dimensional flutter critical wind speed of the suspension bridge.

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