CN111963618A - Inhaul cable multi-order modal vibration control method based on double dampers - Google Patents

Abstract

The invention relates to a method for controlling multi-order modal vibration of a cable based on double dampers. Based on a cable structure body, the cable structure body includes a laterally arranged load-bearing spanning member (beam) and a vertically arranged force-bearing member (tower). ), there are anchor points on the beam and the tower, there are cables between the anchor points of the beam and the tower, and there are two cable dampers on the anchor points, which are divided into a first damper and a second damper, the first damper One end of the damper is fixed on the cable, and the other end is fixed on the beam through the bracket. The setting method of the second damper includes the same-end setting and the different-end setting. When the same-end setting is used, the second damper is set in the cable sleeve of the beam. When the heresy is set, the second damper is set in the cable casing of the tower, and the first damper and the second damper comprehensively control the multi-modal vibration of the cable. Compared with the prior art, the invention has the advantages of effectively controlling the low-order vibration and high-order vortex-induced vibration of the cable, and improving the stability and service life of the cable structure.

Description

A multi-order modal vibration control method for cables based on double dampers

technical field

The invention relates to the technical field of engineering structure vibration control, in particular to a method for controlling multi-order modal vibration of a cable based on double dampers.

Background technique

Cable bearing structure is a very important civil construction structure, mainly including cable-stayed bridge, suspension bridge and mast structure. Such structures have excellent spanning and towering capabilities, and their spans or heights are still developing, and the corresponding cable lengths are increasing. The cable in this structure bears the axial tensile force, and the cross-sectional size, mass per unit length and lateral stiffness of the cable are small, and it is prone to vibration, and the vibration presents the characteristics of multi-modal and multi-mechanism, which is the bottleneck restricting the development of the cable structure. .

At present, the most commonly used control methods for cable vibration are as follows: (1) The surface of the cable sheath adopts aerodynamic measures, including winding spirals and pressing pits, etc., mainly by destroying the coupling mechanism between the cable and wind and rain. Vibration reduction; (2) A damper is added on the cable near its anchoring point to connect the cable with the structure connected to it laterally within the span to increase the energy dissipation capacity of the cable during lateral vibration, so as to achieve the effect of reducing vibration and suppressing vibration. Purpose; (3) Use auxiliary cables to connect adjacent cables to improve the overall stiffness and energy dissipation capacity of the cables.

Among the cable vibration reduction schemes, the scheme that comprehensively adopts pneumatic measures and dampers is the most widely used. The damper mainly plays the role of energy dissipation, and has damping and restraining effect on the vibration of the cable in different mechanisms and modes. In the prior art, for the low-order vibration of the cable, a damper is installed between the cable and the beam. The low-order vibration of the cable includes the first 5-order vibration of the cable or the mode with the cable vibration frequency of 0 to 3.0 Hz. , in this frequency band, the cable is prone to wind and rain vibration, and the dampers used are mainly viscous dampers, oil dampers or viscous shear dampers.

For long cables, this cable-single damper system has the potential for high-order and high-frequency vortex-induced vibration of the cables, which has been observed in practical bridges. There are two main reasons why the damper that has been installed on the cable cannot effectively control the high-order high-frequency vortex-induced vibration of the cable: (1) The high-order vortex-induced vibration mode shape of the cable is just stationary at the damper. point, that is, the cable does not vibrate at the damper position during vortex-induced vibration, and the damper cannot play a role in damping the vibration of the cable; (2) The damper generally uses a viscous damper or other liquid dampers, and the damper It has good energy dissipation effect at lower frequencies, but the vibration damping performance is insufficient under the condition of high frequency vortex vibration of the cable.

In the prior art, rubber fillers are installed at the casing openings of the cables to prevent dust, moisture and vibration; or a beam damper combined with a rubber filler at the casing openings of the towers is used, but it has the following defects: (1) The design of the rubber damper is not aimed at high-order vortex vibration, and the interaction between it and the beam damper is not quantitatively considered; (2) when the beam is installed with the damper and the casing port damper at the same time, the multi-modal vibration of the cable is not considered. control synergy. Existing research on the installation of double damper systems at different positions of the cable focuses on the comprehensive vibration reduction effect of the two dampers on the lower order and a specific order of the cable, but does not consider the reduction of the two dampers on the different modes/mechanisms of the cable. vibration effect.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a method for controlling multi-order modal vibration of a cable based on double dampers to effectively control the low-order vibration and high-order vortex-induced vibration of the cable in order to overcome the above-mentioned defects of the prior art.

The object of the present invention can be realized through the following technical solutions:

A method for controlling multi-order modal vibration of cables based on double dampers is based on a cable structure body. There is a cable between the anchor point of the beam and the tower, and two dampers are arranged on the side of the anchor point of the beam and the tower, which are divided into a first damper and a second damper. One end is fixed on the cable, the other end is fixed on the beam through the bracket, the setting mode of the second damper includes the same-end setting and the different-end setting, wherein the second damper is set on the casing of the beam when the same end is set , when the heresy is set, the second damper is set on the casing of the tower, the first damper and the second damper control the mode of the multi-order vibration frequency of the cable, and the steps of the control method are as follows:

Step S1: determine the installation position and damping parameters of the first damper according to the damping requirements of the low-order mode, and determine the high-order mode of the vortex-induced vibration of the cable according to the installation position and damping parameters of the first damper;

Step S2: determining the installation position and damping parameters of the second damper according to the high-order mode of the vortex-induced vibration of the cable;

Step S3: According to the influence of the second damper on the first damper, determine whether the low-order damping of the affected first damper meets the set threshold, and if so, keep the current installation of the first damper and the second damper The position and damping parameters remain unchanged, if not, adjust the installation position and damping parameters of the first damper, and go to step S1.

The distance from the first damper to the adjacent anchor point is greater than the distance from the second damper to the adjacent anchor point, and the distance from the first damper to the adjacent anchor point is 1%-3% of the length of the cable, The distance from the second damper to the adjacent anchor point is 0.5%-1.5% of the length of the cable.

Further, the distance from the first damper to the adjacent anchor point is 1-3 times the distance from the second damper to the adjacent anchor point.

The first damper controls low-order vibration modes of the cable.

Further, the vibration frequency of the low-order vibration is 0-3.0 Hz, specifically:

f _n ≤3.0Hz

Among them, f _n is the vibration frequency of the cable, n=1, 2, 3, ... is an integer representing the modal order of the cable vibration;

When the cable is long, its vibration frequency is calculated through the tension string model, as follows:

Where T is the cable force, m is the mass per unit length of the cable, and L is the total length of the cable string.

作为初值采用不动点或者牛顿法进行迭代求解，具体为：According to the sag of the cable, the dimensionless frequencies of the odd-order vibration modes of the cable are obtained by dividing the

As the initial value, fixed point or Newton's method is used for iterative solution, specifically:

为拉索在无阻尼器时振动的无量纲圆频率；in,

is the dimensionless circular frequency of the vibration of the cable when there is no damper;

The dimensionless frequencies of even-order vibration modes are:

In the calculation of the dimensionless frequency of the odd-order vibration mode, λ ² is a dimensionless parameter related to the sag of the cable. The specific calculation formula is as follows:

Among them, θ is the inclination angle of the cable, E is the elastic modulus of the cable, A is the effective cross-sectional area of the cable, g is the acceleration of gravity ( _9.81m /s ² ), and Le is the tensile force after the cable is stretched. length, as follows:

The value of the sag parameter λ ² of the cable used in the current cable-stayed bridge is between 0 and 2.5. The sag mainly affects the first-order vibration of the cable. The first-order vibration frequency in the cable plane affected by the sag is :

The second damper controls the high-order high-frequency vortex-induced vibration mode of the cable.

Further, the first damper is located at the stagnation point of the mode shape in the high-order high-frequency vortex-induced vibration mode.

The first damper is a viscous damper or a viscoelastic damper, and the force between the two ends of the first damper and the relative displacement and velocity of the two ends satisfy the following formulas:

分别为第一阻尼器两端相对变形的位移和速度，F_I为第一阻尼器两端的力；刚度系数和阻尼系数频率和变形幅值依存性，根据试验结果确定；拉索第n阶振动时的第一阻尼器刚度系数和阻尼系数记作k_I,n和c_I,n，得到第一阻尼器对拉索偶数阶振动的阻尼值如下所示：Among them, k _I is the stiffness coefficient of the first damper, c _I is the damping coefficient of the first damper, u _I and

are the relative deformation displacement and velocity at both ends of the first damper, F _I is the force at both ends of the first damper; the dependence of the stiffness coefficient and damping coefficient on the frequency and deformation amplitude is determined according to the test results; the nth-order vibration of the cable The stiffness coefficient and damping coefficient of the first damper are denoted as k _I,n and c _I,n , and the damping value of the first damper to the even-order vibration of the cable is obtained as follows:

阻尼系数

和第一阻尼器相对安装位置

如下：Among them, the dimensionless stiffness coefficient

damping coefficient

Installation position relative to the first damper

as follows:

Wherein, l _I is the distance between the first damper and the adjacent anchor point.

The modal damping of the first damper affected by the sag on the odd order of the cable is:

具体为：where the process variable

Specifically:

The second damper is a viscoelastic damper or a high-damping rubber damper, and the mode of the vortex-induced vibration of the cable targeted by the second damper is determined according to the installation position of the first damper, and the specific mode order is:

n=int(L/l _I )

Among them, the function int() means to take the nearest integer;

The force at both ends of the second damper and the displacement and velocity of the deformation of the second damper satisfy the following formula:

为虚数单位，

为高阻尼橡胶阻尼器的损耗因子，k_II为第二阻尼器的刚度系数，u_II为第二阻尼器两端的相对变形位移，F_II为第二阻尼器的两端的力；高阻尼橡胶阻尼器对拉索各偶数阶振动的附加阻尼值均为：in,

is an imaginary unit,

is the loss factor of the high damping rubber damper, k _II is the stiffness coefficient of the second damper, u _II is the relative deformation displacement at both ends of the second damper, F _II is the force at both ends of the second damper; the high damping rubber damping The additional damping values of the damper for each even-order vibration of the cable are:

和第二阻尼器的安装位置

具体如下：Among them, the dimensionless stiffness coefficient

and the installation position of the second damper

details as follows:

Wherein, l _II is the distance between the second damper and the adjacent anchor point.

The high-damping rubber damper is mainly aimed at the high-order vibration of the cable, and the cable sag mainly affects its first-order additional damping to the cable, specifically:

具体为：where the process variable

Specifically:

When the heresy is set, the damping values of the second damper and the first damper are superimposed and calculated, specifically:

ξ _n =ξ _I,n +ξ _II,n

Among them, ξ _n is the comprehensive damping value;

When the same end is set, the comprehensive damping value of the two dampers to the even-order vibration of the cable is specifically:

Among them, the dimensionless parameters are defined as follows:

The additional damping value of the two dampers affected by the sag effect to the odd-order vibration of the cable is as follows:

The dual damper performs comprehensive damping and vibration reduction for low-order multi-mode and high-order mode. The more accurate damping value can be solved numerically according to the following equation. The specific equation is:

Θ+2Ξ _I X _I +2Ξ _II X _II +4ΛX _I X _II =0

Among them, the parameters are defined as follows:

为拉索安装阻尼器后第n阶振动的无量纲圆频率，两个阻尼器之间的距离记作

异端设置时：in,

The dimensionless circular frequency of the nth-order vibration after the damper is installed for the cable, and the distance between the two dampers is denoted as

When heresy is set:

When the same end is set:

作为初值进行迭代求解，得到复数频率

以此计算得到综合阻尼值为：Solution when installing without damper

Iterative solution as initial value to get complex frequency

Based on this calculation, the comprehensive damping value is obtained as:

Among them, imag() means to find the imaginary part of the complex number, and || means to take the modulus of the complex number.

Compared with the prior art, the present invention has the following beneficial effects:

1. The present invention controls the multi-modal vibration of the cable in combination with the first damper and the second damper, effectively controls the low-order vibration and high-order vortex-induced vibration of the cable, and eliminates the occurrence of high-order high-order vibration in the cable-single damper system. The hidden danger of frequency vortex excitation damage to the fatigue life of the cable improves the stability of the cable structure.

2. In the present invention, the second damper for controlling vortex-induced vibration is installed close to the anchoring point, which is convenient for maintenance and replacement.

3. In the present invention, the second damper is installed in the cable casing. Compared with the surface winding of the cable or the addition of auxiliary cables to control the vortex vibration of the cable, it does not affect the aesthetics of the bridge and does not increase the wind load of the cable and the entire bridge. , and is also suitable for multi-modal vibration reduction of new cable structures and treatment of vortex-induced vibration of in-service cable-damper systems.

Description of drawings

Fig. 1 is a schematic structural diagram of the present invention, wherein (a) is a schematic diagram of a hetero-end arrangement, and (b) is a schematic diagram of a homo-end arrangement;

Fig. 2 is a graph showing the comparison result of the actual cable vibration monitoring of the single damper and the double damper of the present invention;

3 is a schematic diagram of the design and installation flow of the dual damper system of the present invention;

FIG. 4 is a graph showing the effect of the vortex-induced vibration damper on the damping effect of the low-order vibration damping damper according to the present invention.

Reference number:

1-first damper; 2-second damper; 3-staying cable; 4-sleeve; 5-support; 6-tower; 7-beam.

Detailed ways

The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. This embodiment is implemented on the premise of the technical solution of the present invention, and provides a detailed implementation manner and a specific operation process, but the protection scope of the present invention is not limited to the following embodiments.

As shown in Figure 1, a double damper-based multi-order modal vibration control method for cables is based on a cable structure body, which includes a horizontally arranged beam 7 and a vertically arranged tower 6. The beam 7 and There are anchor points on the tower 6, a cable 3 is provided between the anchor points of the beam 7 and the tower 6, and two dampers are provided on the anchor points of the beam 7 and the tower 6, which are divided into a first damper 1 and a second damper. For the damper 2, one end of the first damper 1 is fixed on the cable 3, and the other end is fixed on the beam 7 through the bracket 5. The setting methods of the second damper 2 include the same-end setting and the different-end setting. The second damper 2 is set on the casing 4 of the beam 7, and the second damper 2 is set on the casing 4 of the tower 6 when the heresy is set. The first damper 1 and the second damper 2 comprehensively control the multi-order mode of the cable. As shown in Figure 3, the steps of the control method are as follows:

Step S1: Determine the installation position and damping parameters of the first damper 1 according to the damping requirements of the low-order mode, and determine the high-order mode of the vortex-induced vibration of the cable according to the installation position and damping parameters of the first damper 1;

Step S2: Determine the installation position and damping parameters of the second damper 2 according to the high-order mode of the vortex-induced vibration of the cable;

Step S3: According to the influence of the second damper 2 on the first damper 1, determine whether the low-order damping of the affected first damper 1 meets the set threshold, and if so, keep the current first damper 1 and second damper 1. The installation position and damping parameters of the damper 2 remain unchanged. If they are not satisfied, adjust the installation position and damping parameters of the first damper 1, and go to step S1.

The distance from the first damper 1 to the adjacent anchor point is greater than the distance from the second damper 2 to the adjacent anchor point, and the distance from the first damper 1 to the adjacent anchor point is 1%-3% of the length of the cable. The distance between the second damper 2 and the adjacent anchor point is 0.5%-1.5% of the length of the cable.

The distance from the first damper 1 to the adjacent anchor point is 1-3 times the distance from the second damper 2 to the adjacent anchor point.

The first damper 1 controls the low-order vibration mode of the cable.

The vibration frequency of low-order vibration is 0～3.0Hz, specifically:

f _n ≤3.0Hz

Among them, f _n is the vibration frequency of the cable, and n is an integer representing the modal order of the cable vibration;

When the cable 3 is long, its vibration frequency is calculated by the tension string model, as follows:

Where T is the cable force, m is the mass per unit length of the cable, and L is the total length of the cable.

作为初值采用不动点或者牛顿法进行迭代求解，具体为：According to the sag of the cable 3, the dimensionless frequency of the vibration mode of the odd order of the cable 3 is calculated by dividing the

As the initial value, fixed point or Newton's method is used for iterative solution, specifically:

为拉索3在无阻尼器时振动的无量纲圆频率；in,

is the dimensionless circular frequency of the vibration of the cable 3 without dampers;

The dimensionless frequencies of even-order vibration modes are:

In the calculation of the dimensionless frequency of the odd-order vibration mode, λ ² is a dimensionless parameter related to the sag of the cable. The specific calculation formula is as follows:

Among them, θ is the inclination angle of the cable 3, E is the elastic modulus of the cable 3, A is the effective cross-sectional area of the cable 3, g is the acceleration of gravity (9.81m/s ² ), and L _e is the force on the cable 3 The length after elongation is as follows:

The parameter λ ² of the sag of the cable 3 is between 0 and 2.5, which affects the first-order vibration of the cable 3. The first-order vibration frequency in the plane of the cable 3 affected by the sag is:

The second damper 2 controls the high-order high-frequency vortex-induced vibration mode of the cable 3 .

The first damper 1 is located at the stagnation point of the mode shape in the high-order high-frequency vortex-induced vibration mode.

The first damper 1 is a viscous damper or a viscoelastic damper, and the force between the two ends of the first damper 1 and the relative displacement and velocity of the two ends satisfy the following formulas:

分别为第一阻尼器1两端相对变形的位移和速度，F_I为第一阻尼器1两端的力；刚度系数和阻尼系数频率和变形幅值依存性，根据试验方法确定；拉索3第n阶振动时的第一阻尼器1刚度系数和阻尼系数记作k_I,n和c_I,n，得到第一阻尼器1对拉索3偶数阶振动的阻尼值如下所示：Among them, k _I is the stiffness coefficient of the first damper 1, c _I is the damping coefficient of the first damper 1, u _I and

are the relative deformation displacement and velocity of the two ends of the first damper 1, respectively, F _I is the force at both ends of the first damper 1; the stiffness coefficient and damping coefficient frequency and deformation amplitude dependence are determined according to the test method; The stiffness coefficient and damping coefficient of the first damper 1 during n-order vibration are denoted as k _I,n and c _I,n , and the damping value of the first damper 1 to the even-order vibration of the cable 3 is as follows:

阻尼系数

和第一阻尼器1相对安装位置

如下：Among them, the dimensionless stiffness coefficient

damping coefficient

Installation position relative to the first damper 1

as follows:

Wherein, l _I is the distance between the first damper and the adjacent anchor point.

The modal damping of the first damper 1 affected by the sag to the odd order of the cable 3 is:

具体为：where the process variable

Specifically:

The second damper 2 is a viscoelastic damper or a high-damping rubber damper, and the mode of the vortex-induced vibration of the cable vibrated by the second damper 2 is determined according to the installation position of the first damper 1, and the specific modal order is:

n=int(L/l _I )

Among them, the function int() means to take the nearest integer;

The force at both ends of the second damper 2 and the displacement and velocity of the deformation of the second damper 2 satisfy the following formula:

为虚数单位，

为高阻尼橡胶阻尼器的损耗因子，k_II为第二阻尼器2的刚度系数，u_II为第二阻尼器2两端的相对变形位移，F_II为第二阻尼器2的两端的力；高阻尼橡胶阻尼器对拉索3各偶数阶振动的附加阻尼值均为：in,

is an imaginary unit,

is the loss factor of the high damping rubber damper, k _II is the stiffness coefficient of the second damper 2, u _II is the relative deformation displacement at both ends of the second damper 2, F _II is the force at both ends of the second damper 2; The additional damping values of the damping rubber damper for each even-order vibration of the cable 3 are:

和第二阻尼器2的安装位置

具体如下：Among them, the dimensionless stiffness coefficient

and the installation position of the second damper 2

details as follows:

Wherein, l _II is the distance between the second damper and the adjacent anchor point.

The high-damping rubber damper mainly affects the high-order vibration of the cable 3, and the cable sag mainly affects its first-order additional damping to the cable 3, specifically:

具体为：where the process variable

Specifically:

When the heresy is set, the damping values of the second damper 2 and the first damper 1 are superimposed and calculated, specifically:

ξ _n =ξ _I,n +ξ _II,n

Among them, ξ _n is the comprehensive damping value;

When set at the same end, the comprehensive damping value of the two dampers to the even-order vibration of the cable 3 is as follows:

Among them, the dimensionless parameters are defined as follows:

The additional damping value of the two dampers affected by the sag effect to the 3rd odd order vibration of the cable is as follows:

The dual dampers perform comprehensive damping and vibration reduction for low-order multi-mode and high-order modes. The more accurate damping value is obtained by numerical method based on the following equation. The specific process is as follows:

Θ+2Ξ _I X _I +2Ξ _II X _II +4ΛX _I X _II =0

Among them, each parameter satisfies:

为拉索3安装阻尼器后第n阶振动的无量纲圆频率，两个阻尼器之间的距离记作

异端设置时：in,

The dimensionless circular frequency of the nth-order vibration after the damper is installed for the cable 3, and the distance between the two dampers is denoted as

When heresy is set:

When the same end is set:

作为初值进行迭代求解，得到复数频率

以此计算得到综合阻尼值为：Solution for installation without damper

Iterative solution as initial value to get complex frequency

Based on this calculation, the comprehensive damping value is obtained as:

Among them, imag() means to find the imaginary part of the complex number, and || means to take the modulus of the complex number.

Example 1

计算得到拉索3振动的频率为：The target cable length L=546.9m, the mass per unit length m=91.3kg/m, the cable force T=6240.5kN, the diameter of the cable 3 is D=152mm, and the cable sag parameter is λ ² =1.97. Solving the frequency equation according to the sag yields

The frequency of the vibration of the cable 3 is calculated as:

The first damper 1 is a viscoelastic damper, the installation position is l _I =12.08m, as shown in Table 1, when the amplitude is 10mm and the frequency is 0.24Hz, 0.48Hz, 1.20Hz, 1.92Hz, 3.12Hz, respectively Under the periodic forced displacement, the stiffness coefficient and damping coefficient of the damper and the corresponding dimensionless coefficient are measured, and the test frequencies correspond to the 1st, 2nd, 5th, 8th and 13th order modes of the cable vibration respectively. Table 1 is as follows:

Table 1 The stiffness coefficient and damping coefficient of the damper measured

The dimensionless installation position of the first damper 1 is:

刚度k_II＝1439.62kN/m，对应的无量纲安装位置和刚度系数为：The second damper 2 is a high damping rubber damper, installed in the casing 4 at the same end of the first damper 1, the installation position l _II =4.592m, the loss factor

The stiffness k _II =1439.62kN/m, the corresponding dimensionless installation position and stiffness coefficient are:

As shown in Table 2, the damping effects of installing only damper I and installing double dampers are as follows:

Table 2 The damping effect of the first damper and the double damper on the low-order mode of the cable

After the installation of the second damper, the low-order vibration reduction effect of the first damper 1 is reduced, and the damping of the vibration modes with a cable frequency of 0-3 Hz before and after the installation of the second damper 2 meets the requirement that the Scruton number is greater than 10. The Scruton number is calculated as follows:

Among them, S _c is the Scruton number, δ is the logarithmic attenuation rate of the cable vibration, ρ=1.225kg/m ³ is the air density, if the Scruton number is greater than 10, the logarithmic attenuation rate of the cable is δ= 0.019.

For high-order vortex vibration, the solution is performed according to the mode in which the first damper 1 is located near the vibration stagnation point. The specific vibration mode is:

The damping effect of the 43rd to 47th order modal vibration of the cable is analyzed, and the corresponding frequencies are between 10 and 12 Hz, as shown in Table 3:

Table 3 Damping effect of higher-order vortex-induced vibration modes

If the effect of the first damper 1 is not considered, the modal of the cable is calculated by the logarithmic attenuation rate of 0.0045 due to the damping provided by the high-damping rubber damper, and the obtained damping value is small; as shown in Table 1, with When the vibration frequency increases, the stiffness of the viscous shear damper increases and the damping coefficient decreases. When the vibration frequency is 10 Hz, the damping effect of the first damper 1 is ignored and regarded as a spring, specifically:

Among them, the stiffness coefficient is the stiffness estimation when the frequency is 3.12Hz in Table 1; according to the spring action of the first damper 1, the second damper 2 has a great improvement in the high-order damping effect, and the logarithmic attenuation rate reaches more than 0.011 , to meet the requirement that the Scruton number is greater than 5.

As shown in Figure 2, the vibration of the cable with two dampers installed was monitored, and compared with the cable without the second damper 2, the double damper scheme suppressed the vortex-induced vibration of the cable; As shown in Figure 4, after the cable is installed with the first damper 1 or the double damper is installed, the damping of the low-order vibration of the cable is tested. The multi-order modal damping ratio of the double damper is more stable, although the first The second damper 2 reduces the 4th-order damping effect in front of the cable to a certain extent, but it still meets the requirements after the reduction, indicating that the cable with double dampers has better stability.

In addition, it should be noted that the names of the specific embodiments described in this specification may be different, and the above content described in this specification is only an example to illustrate the structure of the present invention. All equivalent changes or simple changes made according to the structures, features and principles of the present invention are included in the protection scope of the present invention. Those skilled in the art to which the present invention pertains can make various modifications or additions to the specific examples described or adopt similar methods, as long as they do not deviate from the structure of the present invention or go beyond the scope defined by the claims, all It belongs to the protection scope of the present invention.

Claims (10)

1. A cable multi-order modal vibration control method based on double dampers is based on a cable structure body, the cable structure comprises a beam (7) which is transversely arranged and a tower (6) which is vertically arranged, anchoring points are arranged on the beam (7) and the tower (6), and a cable (3) is arranged between the anchoring points of the beam (7) and the tower (6), and the cable control method is characterized in that two dampers are arranged on the side edges of the anchoring points of the beam (7) and the tower (6) and are divided into a first damper (1) and a second damper (2), one end of the first damper (1) is fixed on the cable (3), the other end of the first damper is fixed on the beam (7) through a bracket (5), the setting mode of the second damper (2) comprises a same-end setting mode and a different-end setting mode, when the same-end setting mode is carried out, the second damper (2) is arranged on a sleeve (4) of the beam (7), and when the different-end setting mode is carried out, the second damper (2) is arranged on a sleeve (4) of the tower (6), the first damper (1) and the second damper (2) control the mode of the multi-step vibration frequency of the stay cable, and the control method specifically comprises the following steps:

step S1: determining the installation position and damping parameters of the first damper (1) according to the damping requirements of the low-order mode, and determining the high-order mode of the cable in vortex-induced vibration according to the installation position and the damping parameters of the first damper (1);

step S2: determining the installation position and damping parameters of a second damper (2) according to the high-order mode of the vortex-induced vibration of the stay cable;

step S3: and judging whether the low-order damping of the affected first damper (1) meets a set threshold value or not according to the influence of the second damper (2) on the first damper (1), if so, keeping the current installation positions and damping parameters of the first damper (1) and the second damper (2) unchanged, if not, adjusting the installation positions and damping parameters of the first damper (1), and turning to the step S1.

2. A guy cable multi-order modal vibration control method based on double dampers according to claim 1, wherein the distance from the first damper (1) to the adjacent anchoring point is larger than the distance from the second damper (2) to the adjacent anchoring point.

3. The method for controlling the multi-order modal vibration of the guy cable based on the double dampers as claimed in claim 2, wherein the distance from the first damper (1) to the adjacent anchoring point is 1% -3% of the length of the guy cable, and the distance from the second damper (2) to the adjacent anchoring point is 0.5% -1.5% of the length of the guy cable.

4. A guy cable multi-order modal vibration control method based on double dampers according to claim 3, wherein the distance from the first damper (1) to the adjacent anchoring point is 1-3 times the distance from the second damper (2) to the adjacent anchoring point.

5. A cable multi-order mode vibration control method based on double dampers as claimed in claim 1, characterized in that the first damper (1) controls the low-order vibration mode of the cable (3).

6. The method for controlling the multi-order modal vibration of the guy cable based on the dual dampers as claimed in claim 5, wherein the vibration frequency of the low-order vibration is 0-3.0 Hz.

7. A cable multi-order modal vibration control method based on double dampers as claimed in claim 1, wherein the second damper (2) controls a high-order high-frequency vortex-induced vibration mode of the cable (3).

8. The inhaul cable multi-order modal vibration control method based on the double dampers as claimed in claim 7, wherein the first damper (1) is located at a mode stagnation point under a high-order high-frequency vortex-induced vibration mode.

9. A cable multi-order modal vibration control method based on double dampers as claimed in claim 1, wherein the first damper (1) is a viscous damper or a viscoelastic damper.

10. A cable multi-order modal vibration control method based on dual dampers as claimed in claim 1, wherein the second damper (2) is a viscoelastic damper or a high damping rubber damper.

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