Multi-mode cooperative damping vibration attenuation method and system for large-span bridge girder

Abstract

The invention relates to a multi-mode cooperative damping vibration attenuation method for a large-span bridge girder. The multi-mode cooperative damping vibration attenuation method comprises the following steps that the type and corresponding structural characteristics of the large-span bridge girder are determined; determining a target vibration reduction design requirement according to the girder type, wherein the target vibration reduction design requirement comprises a frequency range of vortex-induced vibration under different wind attack angles, a damping ratio minimum value corresponding to each order of frequency under a vertical modal shape, and a damping ratio minimum value corresponding to each order of frequency under a torsional modal shape; and determining a cooperative control scheme of the tower beam damper and the tuned mass damper mounted on the large-span bridge on the multi-modal vibration of the main beam according to the target vibration reduction design requirement. According to the multi-mode cooperative damping vibration attenuation method for the large-span bridge main beam, the tower beam damper and the tuned mass damper are installed on the large-span bridge main beam at the same time to be used in a combined mode so as to complete cooperative vibration attenuation design, and the purposes of improving the vibration attenuation effect and achieving full coverage of multi-mode vibration frequency are achieved. The problem of vortex-induced vibration reduction of the large-span bridge girder is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of structural vibration control, and in particular to a multi-modal collaborative damping vibration reduction method and system for a main beam of a large-span bridge. Background Art

[0002] At present, cable-supported bridges (such as cable-stayed bridges, suspension bridges and cable-stayed suspension bridges) have become important structural systems for super-long span bridges, and their dynamic characteristics are low and dense vibration modes. Therefore, wind-induced vibration problems must be considered in the design, construction and operation of long-span bridges, such as taking relevant structural measures, pneumatic measures or mechanical damping measures. Commonly used mechanical damping devices include viscous fluid dampers (VFDs) and tuned mass dampers (TMDs). Both types of dampers have their own strengths and are widely used in vibration control of engineering structures.

[0003] For example, most of the bridges where vortex-induced vibrations have been observed actually use TMD dampers to suppress vortex-induced vibrations. However, the TMD dampers have an obvious control effect on a specific frequency. After the frequency shifts, the vibration reduction effect decays rapidly. Therefore, when using TMD dampers to control the multi-modal vibrations of the main beams of large-span bridges, a TMD damper of the corresponding frequency needs to be set for each mode, which can easily lead to omissions in the modal control of the entire bridge or a large number of TMD dampers installed, a large additional mass, and poor vibration reduction performance.

[0004] For another example, a tower beam damper, such as a VFD damper such as a torsional damper, is installed between the bridge main beam and the bridge pier tower. The damper installation position is limited, and when the displacement of some vibration modes of the main beam at the connection point between the main beam and the damper is very small, the control effect of the vibration mode is very poor. Summary of the invention

[0005] The technical problem to be solved by the present application is that when the related technology only uses tower-beam dampers, the installation position of the damper is limited, when only TMD dampers are used, modal control is easily missed, and the large additional mass leads to poor multi-modal vibration effect.

[0006] The present application provides a multi-modal coordinated damping vibration reduction method for a long-span bridge main beam, comprising the following steps:

[0007] Determine the main beam type and corresponding structural characteristics of long-span bridges;

[0008] Determine the target vibration reduction design requirements according to the main beam type, wherein the target vibration reduction design requirements include the frequency range of vortex-induced vibration under different wind attack angles, the minimum value of the damping ratio corresponding to each order frequency under the vertical modal vibration type, and the minimum value of the damping ratio corresponding to each order frequency under the torsional modal vibration type;

[0009] According to the target vibration reduction design requirements, a coordinated control scheme for the multi-modal vibration of the main beam by the tower-beam damper and the tuned mass damper installed on the long-span bridge is determined.

[0010] In one embodiment, the method of determining the coordinated control scheme of the tower-beam damper and the tuned mass damper installed on the long-span bridge for the multi-modal vibration of the main beam according to the target vibration reduction design requirement includes:

[0011] Establishing a tower-beam damper-tuned mass damper coupling system, determining the positions of the tower-beam damper and the tuned mass damper according to the target vibration reduction design requirements, and calculating the damping ratios provided by the tower-beam damper and the tuned mass damper for different frequencies and different vibration modes;

[0012] Controlling the damping ratio of each frequency order under the vertical mode vibration mode and the torsional mode vibration mode by the tower beam damper;

[0013] When the damping ratio of some frequencies does not meet the target vibration reduction design requirement, the tuned mass damper is cross-coordinated to control the damping ratio corresponding to the some frequencies.

[0014] In one embodiment, the method of determining the coordinated control scheme of the tower-beam damper and the tuned mass damper installed on the long-span bridge for the multi-modal vibration of the main beam according to the target vibration reduction design requirement includes:

[0015] Establishing a tower-beam damper-tuned mass damper coupling system, determining the positions of the tower-beam damper and the tuned mass damper according to the target vibration reduction design requirements, and calculating the damping ratios provided by the tower-beam damper and the tuned mass damper for different frequencies and different vibration modes;

[0016] Controlling the damping ratio of the lower partial frequencies of the vertical modal vibration mode and the torsional modal vibration mode by the tower-beam damper to achieve the target vibration reduction design requirement;

[0017] The tuned mass damper is used for complementary cooperation to control the damping ratio of the residual frequency under the residual vibration mode to achieve the target vibration reduction design requirement.

[0018] In one embodiment, determining the positions of the tower-beam damper and the tuned mass damper according to the target vibration reduction design requirement includes:

[0019] According to the target vibration reduction design requirements, the tower-beam damper is installed between the bridge main beam and the bridge pier tower, one end of which is connected to the bridge pier tower, and the other end is connected to the bridge main beam through a cantilever lever structure, so that the connection point between the tower-beam damper and the bridge main beam is close to the mid-span of the bridge main beam;

[0020] According to the target vibration reduction design requirements, the tuned mass damper is installed on the bridge main beam.

[0021] In one embodiment, the calculating the damping ratio provided by the tower-beam damper and the tuned mass damper for different frequencies and different vibration modes comprises:

[0022] Establishing a characteristic equation according to the tower-beam damper-tuned mass damper coupling system;

[0023] Solving the characteristic equation to obtain the relationship between different vibration modes and damping ratios at different frequencies;

[0024] According to the parameters and installation positions of the tower-beam damper and the tuned mass damper, and the relationship, the damping ratios provided by different dampers in the tower-beam damper-tuned mass damper coupling system for different frequencies and different vibration modes are calculated.

[0025] In one embodiment, the step of determining the coordinated control scheme of the tower-beam damper and the tuned mass damper on the multi-modal vibration of the main beam according to the target vibration reduction design requirement further includes:

[0026] The parameters and installation positions of the tower-beam damper and the tuned inertial damper are adjusted, and the target control satisfaction is calculated.

[0027] In one implementation, the calculating target control satisfaction level includes:

[0028] Define the desirability function of the tower-beam damper-tuned mass damper coupled system,

[0029] The satisfaction function expression is:

[0030] In the formula, w k is the weight coefficient determined according to the damping ratio of each mode, is the logarithmic attenuation rate threshold determined according to the damping ratio of each mode, and p is the confidence index;

[0031] The satisfaction levels corresponding to different working conditions in the tower-beam damper-tuned mass damper coupling system are calculated according to the satisfaction level function.

[0032] In one embodiment, the tower beam damper includes an oil damper, a viscous damper, an eddy current damper or a cantilever lever inertial damper.

[0033] In one embodiment, the tuned mass damper is a multiple tuned mass damper, a distributed tuned mass damper or an inertial tuned damper.

[0034] The embodiment of the present application also provides a multi-modal coordinated damping vibration reduction system for a long-span bridge main beam, which includes:

[0035] A main beam determination module, which is used to determine the main beam type and corresponding structural characteristics of a long-span bridge;

[0036] A target design module, which is used to determine a target vibration reduction design requirement according to the main beam type, wherein the target vibration reduction design requirement includes a frequency range of vortex-induced vibration under different wind attack angles, a minimum value of a damping ratio corresponding to each order frequency under a vertical modal vibration type, and a minimum value of a damping ratio corresponding to each order frequency under a torsional modal vibration type;

[0037] A collaborative control module is used to determine a collaborative control scheme for the multi-modal vibration of the main beam by the tower-beam damper and the tuned mass damper installed on the long-span bridge according to the target vibration reduction design requirements.

[0038] The beneficial effects brought by the technical solution provided in the embodiments of the present application include:

[0039] The embodiment of the present application provides a multi-modal collaborative damping vibration reduction method for a large-span bridge main beam. In response to the multi-modal vibration control needs of large-span bridges, a tower beam damper and a tuned mass damper are installed on the main beam of the large-span bridge for combined use to complete a collaborative vibration reduction design. Through cross-coordination or complementary collaborative control of the two, the purpose of improving the vibration reduction effect and full coverage of multi-modal vibration frequencies is achieved, thereby solving the difficult problem of vortex-induced vibration reduction of the main beam of a large-span bridge. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0041] Figure 1 The figure is a flow chart of a multi-modal collaborative damping vibration reduction method for a main beam of a long-span bridge in one embodiment of the present invention.

[0042] Figure 2 The figure is a schematic diagram of the installation of a tower beam damper and a tuned mass damper on a long-span bridge in one embodiment of the present invention.

[0043] Figure 3 It is a schematic diagram of modeling of a suspension bridge-damper system in one embodiment of the present invention.

[0044] Figure 4 Schematic diagram of the analytical model of the tower-beam damper-tuned mass damper coupling system in one embodiment of the present invention.

[0045] In the figure: 1. Tower-beam damper; 12. Support bracket; 2. Tuned mass damper. DETAILED DESCRIPTION

[0046] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0047] like Figure 1 As shown, Figure 1 The figure is a flow chart of a multi-modal collaborative damping vibration reduction method for a main beam of a long-span bridge in one embodiment of the present invention.

[0048] This embodiment provides a multi-modal coordinated damping vibration reduction method for a long-span bridge main beam, comprising the following steps:

[0049] Step S1, determining the type of long-span bridge girder and the corresponding structural characteristics;

[0050] Step S2, determining the target vibration reduction design requirements according to the main beam type, the target vibration reduction design requirements including the frequency range of vortex-induced vibration under different wind attack angles, the minimum value of the damping ratio corresponding to each order frequency under the vertical modal vibration mode, and the minimum value of the damping ratio corresponding to each order frequency under the torsional modal vibration mode;

[0051] Step S3: Determine a coordinated control scheme for multi-modal vibration of the main beam by using a tower-beam damper and a tuned mass damper installed on the long-span bridge according to target vibration reduction design requirements.

[0052] The present embodiment provides a multi-modal collaborative damping vibration reduction method for a main beam of a large-span bridge. Aiming at the multi-modal vibration control requirements of a large-span bridge, a tower beam damper and a tuned mass damper are installed on the main beam of the large-span bridge for combined use to complete a collaborative vibration reduction design. Through cross-coordination or complementary collaborative control of the two, the scope of application and the vibration reduction effect are taken into account, thereby achieving the purpose of effectively improving the vibration reduction effect and fully covering the multi-modal vibration frequency, and solving the difficult problem of vortex-induced vibration reduction of the main beam of a large-span bridge.

[0053] Each step is described and explained in detail below.

[0054] Step S1, determining the type of main beam of a long-span bridge and the corresponding structural characteristics.

[0055] Specifically, it is determined whether the main girder type of the long-span bridge is a suspension bridge, a cable-stayed bridge or other type, and then the corresponding structural characteristics are determined, such as the corresponding stiffness, mass, natural frequency and vibration mode.

[0056] This application is also applicable to the vibration reduction needs of equal-length span structures during the construction of suspension bridge main beams and large cantilevers of cable-stayed bridges.

[0057] Step S2, determining the target vibration reduction design requirements according to the main beam type, the target vibration reduction design requirements including the frequency range of vortex-induced vibration under different wind attack angles, the minimum value of the damping ratio corresponding to each order frequency under the vertical modal vibration type, and the minimum value of the damping ratio corresponding to each order frequency under the torsional modal vibration type.

[0058] Of course, in other embodiments, the target vibration reduction design requirement may also be other parameters. The target vibration reduction design requirement may be determined by conducting a wind tunnel test on a long-span bridge or according to actual engineering needs.

[0059] Step S3: Determine a coordinated control scheme for multi-modal vibration of the main beam by using a tower-beam damper and a tuned mass damper installed on the long-span bridge according to target vibration reduction design requirements.

[0060] In one embodiment, step S3, determining a coordinated control scheme for multi-modal vibration of a main beam by a tower-beam damper and a tuned mass damper installed on a long-span bridge according to a target vibration reduction design requirement, comprises:

[0061] Step S31, establishing a tower-beam damper-tuned mass damper coupling system, determining the positions of the tower-beam damper and the tuned mass damper according to the target vibration reduction design requirements, and calculating the damping ratios provided by the tower-beam damper and the tuned mass damper for different frequencies and different vibration modes;

[0062] Step S32, controlling the damping ratio of each frequency order under the vertical mode vibration mode and the torsional mode vibration mode by using the tower beam damper;

[0063] Step S33: When the damping ratio of some frequencies does not meet the target vibration reduction design requirement, the tuned mass damper is cross-coordinated to control the damping ratio corresponding to the some frequencies.

[0064] Through the above scheme, a cross-coordinated control scheme is provided. Within the frequency range that needs to be controlled, the tower-beam damper covers the entire target frequency, and the frequency portion where the damping ratio cannot reach the target vibration reduction design requirement, that is, some missed modes, are filled by the tuned mass damper.

[0065] It should be noted that the missed mode refers to the vibration mode in which the amplitude of the connection point between the damper and the main beam is very small or even the zero point of the vibration mode. The vibration energy of this vibration mode is difficult to be transmitted to the damper, so the damping and vibration reduction of this vibration mode cannot be achieved.

[0066] In one embodiment, step S3, determining a coordinated control scheme for multi-modal vibration of a main beam by a tower-beam damper and a tuned mass damper installed on a long-span bridge according to a target vibration reduction design requirement, comprises:

[0067] Step S31, establishing a tower-beam damper-tuned mass damper coupling system, determining the positions of the tower-beam damper and the tuned mass damper according to the target vibration reduction design requirements, and calculating the damping ratios provided by the tower-beam damper and the tuned mass damper for different frequencies and different vibration modes;

[0068] Step S34, controlling the damping ratio of the lower partial frequencies of the vertical mode vibration mode and the torsional mode vibration mode with the tower-beam damper to achieve the target vibration reduction design requirement;

[0069] Step S35: Using the tuned mass damper for complementary coordination, the damping ratio of the remaining frequencies under the remaining vibration modes is controlled to achieve the target vibration reduction design requirement.

[0070] Through the above scheme, a complementary cooperative control scheme is provided. Within the frequency range that needs to be controlled, most frequencies are controlled by the tower-beam damper, and the frequency parts where the tower-beam damper has poor control effect are filled by the tuned mass damper.

[0071] The cross-cooperative control scheme and the complementary cooperative control scheme can be selected based on economy and safety.

[0072] like Figure 2 As shown, Figure 2 The figure is a schematic diagram of the installation of a tower beam damper and a tuned mass damper on a long-span bridge in one embodiment of the present invention.

[0073] In one embodiment, in step S31, determining the positions of the tower beam damper and the tuned mass damper according to the target vibration reduction design requirements includes:

[0074] According to the target vibration reduction design requirements, the tower-beam damper is installed between the bridge main beam and the bridge pier tower, one end of which is connected to the bridge pier tower, and the other end is connected to the bridge main beam through an outrigger lever structure, so that the connection point between the tower-beam damper and the bridge main beam is close to the mid-span of the bridge main beam;

[0075] According to the target vibration reduction design requirements, the tuned mass damper is installed on the main beam of the bridge.

[0076] Specifically, the cantilever lever structure is similar to a seesaw, with one end extending under the main beam of the bridge, the middle support bracket 12 serving as the fulcrum of the seesaw, and the other end support bracket connected to the tower beam damper 1. The tower beam damper 1 can be on the same side of the fulcrum bracket or on the opposite side.

[0077] Through the above scheme, when determining the position of the tower-beam damper, under the premise of not increasing the lengthened corbel structure, the connection point between the tower-beam damper and the bridge main beam is moved close to the mid-span of the bridge main beam through the cantilever lever structure. The further it is extended towards the mid-span, the greater the vertical displacement of the main beam, the larger the installation position ratio becomes, and a higher additional damping ratio can be provided. The required damping coefficient is reduced, thereby improving the additional damping effect. When determining the tuned mass damper, it can be installed at any position on the main beam (as long as it is not at the stationary point of the target vibration mode), and there are few restrictions on the installation position. The method and position can be changed under different coordination requirements.

[0078] In one embodiment, the tower beam damper includes an oil damper, a viscous damper, an eddy current damper or an outrigger lever inertial damper. When the tower beam damper is an outrigger lever inertial damper, the additional damping ratio is increased to control the vibration of multiple vibration frequencies of the main beam, thereby achieving better broadband control effect and multi-order high-frequency vibration control.

[0079] In one embodiment, the tuned mass damper is a multiple tuned mass damper, a distributed tuned mass damper or an inertial tuned damper.

[0080] In one embodiment, in step S31, calculating the damping ratio provided by the tower-beam damper and the tuned mass damper for different frequencies and different vibration modes includes:

[0081] The characteristic equation is established based on the tower-beam damper-tuned mass damper coupling system;

[0082] Solve the characteristic equation to obtain the relationship between different vibration modes and damping ratios at different frequencies;

[0083] According to the parameters, installation positions and relationship of the tower-beam damper and tuned mass damper, the damping ratios provided by different dampers in the tower-beam damper-tuned mass damper coupling system for different frequencies and different vibration modes are calculated.

[0084] Specifically, the characteristic equation of the tower-beam damper-tuned mass damper coupling system is established based on the complex modal theory. Of course, it can also be established based on other theories. Complex modal theory is a theoretical method for analyzing vibration systems with damping characteristics. It is opposite to the real modal theory and is mainly used to deal with non-proportional damping vibration systems, in which the vibration phase difference of each point is not necessarily zero or 180 degrees, resulting in the modal coefficients becoming complex numbers. The core of complex modal theory lies in complex eigenvalues ​​and complex vibration types. Complex eigenvalues ​​contain real and imaginary parts, the real part represents damping, and the imaginary part represents circular frequency. If the real part is negative, it means that the order mode is stable; if the real part is positive, it means that the order mode is unstable. The complex vibration type is the conjugation of the complex modal parameters, which is used to derive the response calculation formula. The application of complex modal theory includes stability analysis of damped structures, random vibration analysis, etc. For example, in the field of random vibration, complex modal theory can be used to analyze stationary random responses and study the statistical characteristics of random responses through time domain analysis methods.

[0085] like Figure 3 As shown, Figure 3 It is a schematic diagram of modeling of a suspension bridge-damper system in one embodiment of the present invention.

[0086] Taking the suspension bridge-damper composite vibration reduction system as an example, the simplified model is a tensioned string subjected to two lateral forces. Among them, T, L and m represent the common tension, length and unit length mass of the suspension cable and the main beam respectively, ignoring the common sag, bending stiffness and inherent damping, the system free vibration differential equation is expressed as:

[0087]

[0088] Where: y(x,t) is the lateral displacement of the cable; δ(·) represents the Dirac function; F j Indicates that x=x j The lateral force at the location.

[0089] The free vibration differential equation of the above system should satisfy the boundary conditions, that is, y(0,t)=y(l,t)=0; the installation position of the damper should satisfy the force balance condition:

[0090]

[0091] like Figure 4 As shown, Figure 4 Schematic diagram of the analytical model of the tower-beam damper-tuned mass damper coupling system in one embodiment of the present invention.

[0092] In the tower-beam damper-tuned mass damper coupled system, k ns and c nsThey represent the stiffness coefficient and damping coefficient of the tower-beam damper (specifically, viscous damper, VD damper for short). The equivalent linear tuned mass damper (TMD damper for short) is used for modeling, where m dp ,ω dp and dp denote the tuned total mass, circular frequency and modal damping ratio respectively. The lateral force amplitude of the VD damper and TMD damper can be expressed as:

[0093] F 1 =(k ns +iωc ns )U(x),F 2 =(k d +iω dp ξ dp )U(x);

[0094] Where: U(x) is the vibration mode function of the cable; F j represents the jth lateral force amplitude; n is the nth-order modal complex eigenfrequency of the coupled system. represents the normalized dynamic stiffness of the damper. Substituting the lateral force amplitude of the VD damper and the TMD damper into the above system free vibration differential equation, we get:

[0095]

[0096] Where: represents the nth-order mode complex wave number of the tower-beam damper-tuned mass damper coupled system.

[0097] The solution to the above equation can be expressed as:

[0098]

[0099] The characteristic equation of various types of tower beam damper-tuned mass damper coupling systems can be established. The tangent expression, that is, the expression of the characteristic equation, is obtained as follows:

[0100]

[0101] The Newton iteration method can be used, or the independent variable can be approximately eliminated based on the assumed conditions to simplify the solution.

[0102] Then, according to the relationship between the complex eigenvalue frequency and the modal damping ratio of the tower-beam damper-tuned mass damper coupling system, the modal damping ratio is calculated.

[0103] For example, the modal frequency ω of each order n and modal damping ratio ξ n The relationship can be expressed as:

[0104]

[0105] It can also be expressed as an expression of complex modal frequency, and can also be expressed as a relationship about complex modal wave number.

[0106] Finally, according to the parameters, installation positions and relationship of the tower-beam damper and tuned mass damper, the damping ratios provided by different dampers in the tower-beam damper-tuned mass damper coupling system for different frequencies and different vibration modes are calculated.

[0107] The vibration reduction effect of the tower-beam damper (such as the viscous damper) is not as good as that of the tuned mass damper, but it has a broad spectrum and has a vibration reduction effect in most modes. In order to achieve a better vibration reduction effect and take into account the economy, the tuned mass damper is used to optimize and enhance the parameters of the vibration reduction effect of each mode on the basis of the use of the viscous damper. The mass ratio of the tuned mass damper can take different values ​​according to the vibration reduction effect of the viscous damper. According to the actual main beam boundary conditions and the installation positions of the tower-beam damper and the tuned mass damper, the single-mode damping effect of the tower-beam damper-tuned mass damper coupling system is calculated, and then the multi-mode damping effect of the tower-beam damper-tuned mass damper coupling system is calculated according to the target vibration reduction design requirements of the structure.

[0108] In one embodiment, step S3, determining the coordinated control scheme of the tower-beam damper and the tuned mass damper for the multi-modal vibration of the main beam according to the target vibration reduction design requirements, further includes:

[0109] Step S36: adjust the parameters and installation positions of the tower-beam damper and the tuned inertial damper, and calculate the target control satisfaction.

[0110] In one embodiment, in step S36, calculating the target control satisfaction level includes:

[0111] Define the desirability function of the tower-beam damper-tuned mass damper coupled system,

[0112] The satisfaction function expression is:

[0113] In the formula, w k is the weight coefficient determined according to the damping ratio of each mode, is the logarithmic attenuation rate threshold determined according to the damping ratio of each mode, and p is the confidence index;

[0114] The satisfaction levels corresponding to different working conditions in the tower-beam damper-tuned mass damper coupling system are calculated based on the satisfaction function.

[0115] Since different frequency modes have different sensitivities to wind speed, some modes are prone to vortex-induced vibration and need to be considered. The additional damping ratio should also be increased accordingly, and different weights have different tendencies. Through the above scheme, a performance evaluation method is given to facilitate the selection of parameter combinations corresponding to each damper.

[0116] The embodiment of the present application also provides a multi-modal coordinated damping vibration reduction system for a long-span bridge main beam, which includes:

[0117] A main beam determination module, which is used to determine the main beam type and corresponding structural characteristics of a long-span bridge;

[0118] The target design module is used to determine the target vibration reduction design requirements according to the main beam type. The target vibration reduction design requirements include the frequency range of vortex-induced vibration under different wind attack angles, the minimum value of the damping ratio corresponding to each order frequency under the vertical mode vibration type, and the minimum value of the damping ratio corresponding to each order frequency under the torsional mode vibration type;

[0119] The collaborative control module is used to determine the collaborative control scheme of the tower-beam damper and tuned mass damper installed on the long-span bridge for the multi-modal vibration of the main beam according to the target vibration reduction design requirements.

[0120] The functions of each module correspond to the steps in the method. The method part has been explained in detail in the previous article and will not be repeated here.

[0121] Two specific embodiments are provided below to further illustrate the cross-coordination and complementary coordination control schemes. Other contents have been simplified.

[0122] In the target control requirement of a bridge main beam, the control damping ratio of each frequency order is required to be higher than 1%, as shown in Table 1.

[0123] Table 1

[0124] Mode shape First-order vertical bending Second-order vertical bending Three-step vertical bend Fourth-order vertical bend First-order torsion Second-order torsion Frequency (Hz) 0.118 0.157 0.227 0.286 0.315 0.412

[0125] If it is a complementary cooperative control scheme, the control method is shown in Table 2.

[0126] Table 2

[0127]

[0128] If it is a cross-coordinated control scheme, the control method is shown in Table 3.

[0129] Table 3

[0130]

[0131] In the description of the present application, it should be noted that the terms "upper", "lower", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. Unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be a connection between the two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to the specific circumstances.

[0132] It should be noted that, in this application, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0133] In the description of the embodiments of the present application, unless otherwise specified, “ / ” means or, for example, A / B can mean A or B; the “and / or” in the text is merely a description of the association relationship of associated objects, indicating that three relationships may exist, for example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. In addition, in the description of the embodiments of the present application, “multiple” refers to two or more than two.

[0134] The above is only a specific implementation of the present application, so that those skilled in the art can understand or implement the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest range consistent with the principles and novel features applied for herein.

Claims

1. A multi-modal collaborative damping vibration reduction method for a long-span bridge main beam, characterized in that: The following steps are involved: Determine the main beam type and corresponding structural characteristics of long-span bridges; Determine the target vibration reduction design requirements according to the main beam type, wherein the target vibration reduction design requirements include the frequency range of vortex-induced vibration under different wind attack angles, the minimum value of the damping ratio corresponding to each order frequency under the vertical modal vibration type, and the minimum value of the damping ratio corresponding to each order frequency under the torsional modal vibration type; According to the target vibration reduction design requirements, a coordinated control scheme for the multi-modal vibration of the main beam by the tower-beam damper and the tuned mass damper installed on the long-span bridge is determined.

2. The multi-modal coordinated damping vibration reduction method for a long-span bridge main beam according to claim 1, characterized in that: The method of determining the coordinated control scheme of the tower-beam damper and the tuned mass damper installed on the long-span bridge for the multi-modal vibration of the main beam according to the target vibration reduction design requirement includes: Establishing a tower-beam damper-tuned mass damper coupling system, determining the positions of the tower-beam damper and the tuned mass damper according to the target vibration reduction design requirements, and calculating the damping ratios provided by the tower-beam damper and the tuned mass damper for different frequencies and different vibration modes; Controlling the damping ratio of each frequency order under the vertical mode vibration mode and the torsional mode vibration mode by the tower beam damper; When the damping ratio of some frequencies does not meet the target vibration reduction design requirement, the tuned mass damper is cross-coordinated to control the damping ratio corresponding to the some frequencies.

3. The multi-modal coordinated damping vibration reduction method for a long-span bridge main beam according to claim 1, characterized in that: The method of determining the coordinated control scheme of the tower-beam damper and the tuned mass damper installed on the long-span bridge for the multi-modal vibration of the main beam according to the target vibration reduction design requirement includes: Establishing a tower-beam damper-tuned mass damper coupling system, determining the positions of the tower-beam damper and the tuned mass damper according to the target vibration reduction design requirements, and calculating the damping ratios provided by the tower-beam damper and the tuned mass damper for different frequencies and different vibration modes; Controlling the damping ratio of the lower partial frequencies of the vertical modal vibration mode and the torsional modal vibration mode by the tower-beam damper to achieve the target vibration reduction design requirement; The tuned mass damper is used for complementary cooperation to control the damping ratio of the residual frequency under the residual vibration mode to achieve the target vibration reduction design requirement.

4. The multi-modal coordinated damping vibration reduction method for a long-span bridge main beam according to claim 2 or 3, characterized in that: Determining the positions of the tower beam damper and the tuned mass damper according to the target vibration reduction design requirement includes: According to the target vibration reduction design requirements, the tower-beam damper is installed between the bridge main beam and the bridge pier tower, one end of which is connected to the bridge pier tower, and the other end is connected to the bridge main beam through a cantilever lever structure, so that the connection point between the tower-beam damper and the bridge main beam is close to the mid-span of the bridge main beam; According to the target vibration reduction design requirements, the tuned mass damper is installed on the bridge main beam.

5. The multi-modal coordinated damping vibration reduction method for a long-span bridge main beam according to claim 2 or 3, characterized in that: The calculating of the damping ratio provided by the tower beam damper and the tuned mass damper for different frequencies and different vibration modes comprises: Establishing a characteristic equation according to the tower-beam damper-tuned mass damper coupling system; Solving the characteristic equation to obtain the relationship between different vibration modes and damping ratios at different frequencies; According to the parameters and installation positions of the tower-beam damper and the tuned mass damper, and the relationship, the damping ratios provided by different dampers in the tower-beam damper-tuned mass damper coupling system for different frequencies and different vibration modes are calculated.

6. The multi-modal coordinated damping vibration reduction method for a long-span bridge main beam according to claim 2 or 3, characterized in that: The method of determining the coordinated control scheme of the tower-beam damper and the tuned mass damper on the multi-modal vibration of the main beam according to the target vibration reduction design requirement also includes: The parameters and installation positions of the tower-beam damper and the tuned inertial damper are adjusted, and the target control satisfaction is calculated.

7. The multi-modal coordinated damping vibration reduction method for a long-span bridge main beam according to claim 6, characterized in that: The calculation target control satisfaction includes: Define the desirability function of the tower-beam damper-tuned mass damper coupled system, The satisfaction function expression is: In the formula, w k is the weight coefficient determined according to the damping ratio of each mode, is the logarithmic attenuation rate threshold determined according to the damping ratio of each mode, and p is the confidence index; The satisfaction levels corresponding to different working conditions in the tower-beam damper-tuned mass damper coupling system are calculated according to the satisfaction level function.

8. The multi-modal coordinated damping vibration reduction method for a long-span bridge main beam according to claim 1, characterized in that: The tower beam damper includes an oil damper, a viscous damper, an eddy current damper or an outrigger lever inertial damper.

9. The multi-modal coordinated damping vibration reduction method for a main beam of a long-span bridge according to claim 1, characterized in that: The tuned mass damper is a multiple tuned mass damper, a distributed tuned mass damper or an inertial tuned damper.

10. A multi-modal cooperative damping vibration reduction system for a long-span bridge main beam, characterized in that: It includes: A main beam determination module, which is used to determine the main beam type and corresponding structural characteristics of a long-span bridge; A target design module, which is used to determine a target vibration reduction design requirement according to the main beam type, wherein the target vibration reduction design requirement includes a frequency range of vortex-induced vibration under different wind attack angles, a minimum value of a damping ratio corresponding to each order frequency under a vertical modal vibration type, and a minimum value of a damping ratio corresponding to each order frequency under a torsional modal vibration type; A collaborative control module is used to determine a collaborative control scheme for the multi-modal vibration of the main beam by the tower-beam damper and the tuned mass damper installed on the long-span bridge according to the target vibration reduction design requirements.

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