A vibration reduction method for stay cables and main girders based on the installation position of dampers

Abstract

The present invention provides a vibration reduction method for stay cables and a main girder based on the installation position of dampers, which includes: establishing a finite element model of the main girder and each stay cable, and performing modal analysis on it to obtain the vibration modes of each stay cable and the vibration response characteristics of the main girder; for the target stay cable, determining the standard installation interval of the external damper provided between the target stay cable and the main girder; within the standard installation interval, by adjusting the position of the external damper, calculating the additional damping ratio of the main girder at different positions in combination with the change in the vibration amplitude of the main girder, and selecting the maximum value of the additional damping ratio of the main girder as the target installation position; according to the steps of determining the target installation position of the target stay cable, obtaining the target installation positions corresponding to each external damper, and setting the external dampers according to the corresponding target installation positions. The installation positions of the external dampers between each stay cable and the main girder are determined, effectively alleviating the problem of vibration of the main girder and stay cables to the greatest extent.

Description

Technical Field

[0001] This application relates to the technical field of cable-stayed bridge vibration control, and particularly to a vibration reduction method for stay cables and main girders based on the installation position of dampers. Background Art

[0002] In recent years, through the introduction of new technologies, new theories, new structures, new materials and new processes, the spanning ability of long-span cable-stayed bridges has been significantly improved. As the span of the bridge continues to increase, the main girder has become lighter, and at the same time, the mass and length of the stay cables have been continuously improved, resulting in an increase in the slenderness ratio and flexibility of the stay cables. Due to the relatively low initial damping of the stay cables themselves, under the excitation of wind, rain and other external loads, the main girder and stay cables of the cable-stayed bridge are more likely to vibrate.

[0003] In the prior art, in order to solve the vibration problems of the stay cables and the main girder, the method of installing external dampers between the stay cables and the main girder is mainly adopted. The damping parameters of the external dampers and the additional damping ratio of the main girder directly affect the vibration reduction effect of the stay cables and the main girder. The connection position of the external dampers relative to the target stay cables and the main girder will directly change the magnitude of its own damping and the additional damping ratio of the main girder, thereby affecting the vibration reduction effect of the stay cables and the main girder. Therefore, how to optimize the installation position of the external dampers between each stay cable and the main girder to most effectively reduce the vibration of the main girder and the stay cables is particularly important. Summary of the Invention

[0004] The embodiments of this application provide a vibration reduction method for stay cables and main girders based on the installation position of dampers to solve the problem in the related art of how to determine the installation position of the external dampers between each stay cable and the main girder to most effectively reduce the vibration of the main girder and the stay cables.

[0005] In a first aspect, a vibration reduction method for stay cables and main girders based on the installation position of dampers is provided, which includes: establishing a finite element model of the main girder and each stay cable, and performing modal analysis on it to obtain the vibration modes of each stay cable and the vibration response characteristics of the main girder; for a target stay cable, based on its vibration mode and the vibration response characteristics of the main girder, analyzing the vibration coupling effect between the stay cable and the main girder, and determining the standard installation interval of the external damper set between the target stay cable and the main girder; within the standard installation interval, by adjusting the position of the external damper, calculating the additional damping ratio of the main girder at different positions in combination with the change in the vibration amplitude of the main girder, and selecting the maximum value of the additional damping ratio of the main girder as the target installation position; according to the steps of determining the target installation position of the target stay cable, obtaining the target installation positions corresponding to the external dampers set between each stay cable and the main girder, and setting the external dampers between each stay cable and the main girder according to the corresponding target installation positions.

[0006] In some embodiments, the length of the stay cable is denoted as L, the connection point of the stay cable and the bridge deck is denoted as point M, and the distance from the connection point of the target damper and the target stay cable to point M is denoted as x. Then, a first threshold range is defined: A = {x|0.005L < x ≤ 0.05L}; values within the first threshold range in the standard installation range of each stay cable are obtained, and the standard installation range of the corresponding stay cable is updated.

[0007] In some embodiments, within the standard installation range, by adjusting the position of the external damper and combining the change in the vibration amplitude of the main girder, the additional damping ratio of the main girder at different positions is calculated, which includes the following steps:

[0008] Based on the vibration response characteristics of the main girder, the peak value of the vertical vibration mode displacement of the main girder when the external damper is at the target installation position is obtained; combined with the finite element model, a vertical harmonic load is applied at the peak value of the vertical vibration mode displacement of the main girder, and then the vertical harmonic load is unloaded, and the vibration attenuation process of the main girder is analyzed to obtain displacement time history data; according to the displacement time history data, the additional damping ratio of the main girder is calculated through a second formula; the above steps are repeated to obtain the additional damping ratio of the main girder when the external damper is installed at different positions.

[0009] In some embodiments, applying a vertical harmonic load at the peak value of the vertical vibration mode displacement of the main girder includes the following steps:

[0010] Obtain the vertical natural vibration frequency of the main girder when the target damper is at the target installation position, that is, the second natural vibration frequency, denoted as ωn; denote the vertical harmonic load as P, the excitation load amplitude as F, and the loading time as t; according to , continuously apply a vertical harmonic load to the peak value of the vertical vibration mode displacement of the main girder, where , N is the number of natural vibration periods, and it is adjusted based on the vibration data of the main girder.

[0011] In some embodiments, the modal analysis includes the following content: extracting the first three vibration modes of each stay cable and the fundamental frequency vibration mode of the main girder, and quantifying the vibration amplitude distribution of the main girder under different frequency excitations through harmonic response analysis.

[0012] In some embodiments, the analysis of the vibration coupling effect is achieved through the following method: performing modal superposition on the vibration modes of the main girder and the stay cables to identify the resonance risk area; calculating the energy transfer coefficient between the main girder and the stay cables, and screening the stay cables with an energy transfer coefficient greater than the first standard value as the priority optimization targets.

[0013] In some embodiments, before implementing the vibration reduction method for the stay cables and the main girder based on the damper installation position, on-site environmental vibration tests are carried out on the cable-stayed bridge to obtain actual vibration spectrum data, and the finite element model is corrected according to the actual vibration spectrum data.

[0014] In some embodiments, the external damper is part of a stay cable damper device, which further includes a support, a connecting member, and a main lever. The connecting member is used to connect with the stay cable. One end of the main lever is fixedly connected to the connecting member, and the other end is rotatably connected to the support. The target damper is respectively connected to the upper and lower ends of the main lever.

[0015] In some embodiments, the target damper includes an in-plane damper, an in-plane lever, an out-of-plane damper, an out-of-plane lever, and an out-of-plane link rod. The support is provided with a first ear plate, a second ear plate, and a third ear plate. The in-plane damper is rotatably connected to the second ear plate. The middle part of the in-plane lever is rotatably connected to the main lever. One end of the in-plane lever is rotatably connected to the first ear plate, and the other end is connected to the in-plane damper. The out-of-plane damper is rotatably connected to the middle part of the main lever. One end of the out-of-plane link rod is rotatably connected to the bottom of the main lever. One end of the out-of-plane lever is rotatably connected to the out-of-plane link rod, and the other end is connected to the out-of-plane damper. And the middle part of the out-of-plane lever is rotatably connected to the third ear plate.

[0016] In some embodiments, the included angle between the stay cable damper device and the stay cable is 90°.

[0017] The beneficial effects brought by the technical solution provided by the embodiments of the present application include:

[0018] The embodiments of the present application provide a vibration reduction method for stay cables and main girders based on the installation position of dampers. By establishing a finite element model of the main girder and the stay cables and performing modal analysis on it, the vibration modes of each stay cable and the vibration response characteristics of the main girder are obtained, revealing the dynamic characteristics of the structure and providing data support for subsequent optimization. Combining the vibration modes of the stay cables with the vibration response characteristics of the main girder, analyzing the vibration coupling effect between the two, through modal superposition and energy transfer coefficient calculation, identifying the interaction area between the stay cables and the main girder, avoiding the problem of global resonance caused by local vibration. The standard installation interval is set based on the vibration energy concentration area, and the quantitative calculation of the additional damping ratio ensures the accuracy of position optimization. The optimal installation position is determined independently for each stay cable, and an external damper is installed uniformly. Through the finite element model and modal analysis, accurately locating the vibration-sensitive area, combined with the quantitative calculation of the additional damping ratio, avoiding the blindness of the traditional empirical method and maximizing the energy absorption efficiency of the damper. The vibration coupling effect analysis ensures that the installation of the damper not only suppresses the local vibration of the stay cable but also reduces the resonance risk between the main girder and the stay cable, improving the dynamic stability of the overall structure. Through the closed-loop process of "modeling, analysis, optimization, implementation", closely combining theoretical calculation with engineering practice, the optimization problem of the damper installation position is solved. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic flow chart for determining the damper installation position provided by the embodiments of the present application;

[0020] Figure 2 Schematic diagram for the installation and application of the stay cable damper device provided by the embodiment of the present application;

[0021] Figure 3 Schematic diagram of the specific structure of the stay cable damper device provided by the embodiment of the present application.

[0022] In the figure: 1. Stay cable damper device; 2. Stay cable; 3. Support; 31. First ear plate; 32. Second ear plate; 33. Third ear plate; 4. Connecting piece; 5. Main lever; 6. In-plane damper; 7. In-plane lever; 8. Out-of-plane damper; 9. Out-of-plane lever; 10. Out-of-plane link rod. Specific implementation manners

[0023] In order to enable those skilled in the art to better understand the solution of the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

[0024] To make the purpose, technical solution and advantages of the present application clearer, the following will further describe the embodiments of the present application in detail with reference to the drawings.

[0025] First, the embodiment of the present application provides a vibration reduction method for stay cables and main girders based on the installation position of dampers. Refer to Figure 1 , Figure 1 which is the flow chart for determining the installation position of the damper provided by the embodiment of the present application. As Figure 1 shown, the vibration reduction method for stay cables and main girders based on the installation position of dampers includes:

[0026] S1. Establish a finite element model for the main girder and each stay cable, and perform modal analysis on it to obtain the vibration modes of each stay cable and the vibration response characteristics of the main girder;

[0027] S2. For the target stay cable, based on its vibration mode and the vibration response characteristics of the main girder, analyze the vibration coupling effect between the stay cable and the main girder, and determine the standard installation range of the external damper provided between the target stay cable and the main girder;

[0028] S3. Within the standard installation range, by adjusting the position of the external damper, calculate the additional damping ratio of the main girder at different positions in combination with the change in the vibration amplitude of the main girder, and select the maximum value of the additional damping ratio of the main girder as the target installation position;

[0029] S4. According to the steps of determining the target installation positions of the target stay cables, obtain the target installation positions corresponding to the external dampers provided between each stay cable and the main girder, and install the external dampers between each stay cable and the main girder according to the corresponding target installation positions.

[0030] In this embodiment, by establishing a finite element model of the main girder and the stay cables and performing modal analysis on it, the vibration modes of each stay cable and the vibration response characteristics of the main girder are obtained, revealing the dynamic characteristics of the structure and providing data support for subsequent optimization; by combining the vibration modes of the stay cables and the vibration response characteristics of the main girder, the vibration coupling effect between the two is analyzed. Through modal superposition and calculation of the energy transfer coefficient, the interaction region between the stay cables and the main girder is identified to avoid the problem of global resonance caused by local vibration. The standard installation interval is set based on the vibration energy concentration region, and the quantitative calculation of the additional damping ratio ensures the accuracy of position optimization. The optimal installation position is determined independently for each stay cable, and the external dampers are installed uniformly; the vibration sensitive region is accurately located through the finite element model and modal analysis, combined with the quantitative calculation of the additional damping ratio, avoiding the blindness of the traditional empirical method and maximizing the energy absorption efficiency of the dampers; the analysis of the vibration coupling effect ensures that the installation of the dampers not only suppresses the local vibration of the stay cables but also reduces the resonance risk between the main girder and the stay cables, improving the dynamic stability of the overall structure. Through the closed-loop process of "modeling, analysis, optimization, implementation", the theoretical calculation is closely combined with the engineering practice, solving the optimization problem of the damper installation position and solving the problem in the related technology of how to determine the installation positions of the external dampers between each stay cable and the main girder to most effectively reduce the vibration of the main girder and the stay cables.

[0031] Further, in one embodiment, denote the length of the stay cable as L, denote the connection point between the stay cable and the bridge deck as point M, and denote the distance from the connection point of the target damper and the target stay cable to point M as x. Then, define the first threshold range: A = {x|0.005L < x ≤ 0.05L}; obtain the values within the first threshold range in the standard installation intervals of each stay cable, and update them as the standard installation intervals of the corresponding stay cables.

[0032] In this embodiment, the position range of the connection point between the external damper and the stay cable is defined as 0.005L to 0.05L of the total length of the stay cable, that is, 0.5% to 5%. Installing the damper in the area close to the main girder can more effectively block the transmission of the main girder vibration to the stay cable and reduce the energy input source; the setting of the first threshold range A avoids the deviation of the damper installation position from the sensitive area due to construction errors; by narrowing the candidate interval, the calculation amount of the finite element model is reduced.

[0033] Further, in one embodiment, within the standard installation range, by adjusting the position of the external damper and calculating the additional damping ratio of the main girder at different positions in combination with the change in the vibration amplitude of the main girder, the method includes the following steps: Based on the vibration response characteristics of the main girder, obtain the peak value of the vertical vibration mode displacement of the main girder when the external damper is located at the target installation position; Combine the finite element model, apply a vertical harmonic load at the peak value of the vertical vibration mode displacement of the main girder, then unload the vertical harmonic load, and analyze the vibration attenuation process of the main girder to obtain the displacement time history data; According to the displacement time history data, calculate the additional damping ratio of the main girder through the second formula; Repeat the above steps to obtain the additional damping ratio of the main girder when the external damper is installed at different positions.

[0034] In this embodiment, the displacement time history data includes all the peak values, logarithmic decrement, and attenuation coefficient during the vibration attenuation process of the main girder after unloading the vertical harmonic load; Denote the k-th peak value in the vibration attenuation section of the main girder after unloading the vertical harmonic load as and the (k + n)-th peak value as , where n is the number of wave peaks apart, denote the additional damping ratio of the main girder as , the logarithmic decrement as , and the attenuation coefficient as ; Through the second formula , obtain the additional damping ratio of the main girder.

[0035] Further, in one embodiment, applying a vertical harmonic load at the peak value of the vertical vibration mode displacement of the main girder includes the following steps: Obtain the vertical natural vibration frequency of the main girder when the target damper is located at the target installation position, that is, the second natural vibration frequency, denoted as ω n ; Denote the vertical harmonic load as P, the amplitude of the excitation load as F, and the loading time as t; According to , continuously apply a vertical harmonic load to the peak value of the vertical vibration mode displacement of the main girder, where , N is the number of natural vibration periods, and adjust based on the vibration data of the main girder.

[0036] In this embodiment, obtain the vertical natural vibration frequency of the main girder, that is, the second natural vibration frequency. The main girder follows the loading time , then let F = 0, and the stay cable 2 is in the free vibration state. Continuously apply a vertical harmonic load to the main girder bridge deck according to the set frequency, so as to analyze the subsequent entire vibration attenuation process and obtain the displacement time history data.

[0037] Further, in one embodiment, the modal analysis includes the following contents: Extract the first three vibration modes of each stay cable and the fundamental frequency vibration mode of the main girder, and quantify the vibration amplitude distribution of the main girder under different frequency excitations through harmonic response analysis.

[0038] In this embodiment, it is stipulated that the modal analysis needs to extract the first three vibration modes of the stay cables and the fundamental frequency vibration mode of the main girder, and quantify the vibration amplitude distribution of the main girder under different frequency excitations through harmonic response analysis; extracting the first three modes of the stay cables can avoid misjudgment caused by only optimizing the first-order mode, and the harmonic response analysis can quantify the vibration amplitude of the main girder at a specific frequency; based on the results of the harmonic response analysis, the frequency response characteristics of the damper can be customized; identifying the overlapping region between the high-order modes of the stay cables and the fundamental frequency of the main girder can avoid resonance risks during the optimization of the installation position.

[0039] Further, in one embodiment, the analysis of the vibration coupling effect is achieved by the following method: performing modal superposition on the vibration modes of the main girder and the stay cables to identify the resonance risk area; calculating the energy transfer coefficient between the main girder and the stay cables, and screening the stay cables with an energy transfer coefficient greater than the first standard value as the priority optimization targets.

[0040] In this embodiment, the vibration coupling effect is stipulated, and the resonance area is identified through modal superposition to avoid the limitations of single-structure optimization; by screening the energy transfer coefficient, such as > 0.5, the stay cables that contribute greatly to the overall vibration can be quickly located; reducing the transmission of the main girder vibration to the stay cables and suppressing the reverse excitation of the stay cable vibration on the main girder can achieve two-way vibration reduction; avoiding equal optimization of all stay cables can save calculation and construction costs.

[0041] Further, in one embodiment, before implementing the vibration reduction method for the stay cables and the main girder based on the damper installation position, on-site environmental vibration tests are carried out on the cable-stayed bridge to obtain actual vibration spectrum data, and the finite element model is corrected according to the actual vibration spectrum data.

[0042] In this embodiment, it is required to carry out on-site environmental vibration tests before implementing the vibration reduction method to obtain actual vibration spectrum data, and accordingly correct the boundary conditions of the finite element model; the corrected finite element model is more in line with the actual bridge characteristics, ensuring the reliability of subsequent damper position optimization; the measured spectrum data contains actual environmental excitations, enabling the model to simulate real working conditions; through regular on-site tests and model correction, the dynamic characteristic changes caused by bridge aging or damage can be tracked, and the vibration reduction scheme can be dynamically adjusted to avoid construction rework caused by model errors.

[0043] Further, in one embodiment, the external damper is a part of the stay cable damper device 1, and the stay cable damper device 1 further includes a support 3, a connecting piece 4, and a main lever 5. The connecting piece 4 is used to connect with the stay cable 2. One end of the main lever 5 is fixedly connected to the connecting piece 4, and the other end is rotatably connected to the support 3; the target damper is respectively connected to the upper and lower ends of the main lever 5.

[0044] In this embodiment, when the stay cable 2 undergoes in-plane vibration, since the stay cable 2 is connected to the connecting member 4, the in-plane vibration will be transmitted to the connecting member 4. Since one end of the main lever 5 is fixedly connected to the connecting member 4, the in-plane vibration will be transmitted from the connecting member 4 to the main lever 5. The target damper is connected to the upper end of the main lever 5. When there is in-plane vibration on the main lever 5, the target damper will absorb the in-plane vibration. In addition, when the stay cable 2 undergoes out-of-plane vibration, since the stay cable 2 is connected to the connecting member 4, the out-of-plane vibration will be transmitted to the connecting member 4. Since one end of the main lever 5 is fixedly connected to the connecting member 4, the out-of-plane vibration will be transmitted from the connecting member 4 to the main lever 5. Since the target damper is connected to the lower end of the main lever 5, when there is out-of-plane vibration on the main lever 5, the target damper will absorb the out-of-plane vibration. At the same time, by connecting the stay cable 2 through the connecting member 4, the vibration of the stay cable 2 is transmitted to the connecting member 4, and by connecting the main lever 5 through the connecting member 4, the vibration is transmitted to the main lever 5. The target damper is connected to the upper end of the main lever 5 for absorbing the in-plane vibration on the main lever 5; the target damper is connected to the lower end of the main lever 5 for absorbing the out-of-plane vibration on the main lever 5. Through this application, the in-plane vibration and the out-of-plane vibration can be absorbed.

[0045] Further, in one embodiment, the target damper includes an in-plane damper 6, an in-plane lever 7, an out-of-plane damper 8, an out-of-plane lever 9, and an out-of-plane link rod 10; the support 3 is provided with a first ear plate 31, a second ear plate 32, and a third ear plate 33; the in-plane damper 6 is rotatably connected to the second ear plate 32, the middle of the in-plane lever 7 is rotatably connected to the main lever 5, one end of the in-plane lever 7 is rotatably connected to the first ear plate 31, and the other end is connected to the in-plane damper 6; the out-of-plane damper 8 is rotatably connected to the middle of the main lever 5, one end of the out-of-plane link rod 10 is rotatably connected to the bottom of the main lever 5, one end of the out-of-plane lever 9 is rotatably connected to the out-of-plane link rod 10, the other end of the out-of-plane lever 9 is connected to the out-of-plane damper 8, and the middle of the out-of-plane lever 9 is rotatably connected to the third ear plate 33.

[0046] In this embodiment, when the stay cable 2 undergoes in-plane vibration, the vibration displacement of the stay cable 2 is transmitted to the in-plane lever 7 through the connecting member 4, and then transmitted to the in-plane damper 6 to achieve vertical vibration reduction. Through the lever amplification mechanism, the relative vibration displacement transmitted to the inside of the damper is amplified, thereby improving the vertical damping vibration reduction efficiency; when the stay cable 2 undergoes out-of-plane vibration, the vibration displacement of the stay cable 2 is transmitted to the out-of-plane link 10 through the connecting member 4, and then transmitted to the out-of-plane lever 9 through the out-of-plane link 10, and then transmitted to the out-of-plane damper 8 to achieve lateral vibration reduction. Through the lever amplification mechanism, the relative vibration displacement transmitted to the inside of the damper is amplified, thereby improving the lateral damping vibration reduction efficiency; when the main girder undergoes vertical vibration, the vibration responses at various positions of the main girder will transmit the vertical vibration displacement to the in-plane damper 6 inside each stay cable damper through the base 3 to achieve vertical vibration reduction and energy dissipation of the main girder; when the main girder or the damper vibrates, due to the energy dissipation effect of the damper, the vibration responses of the stay cable 2 or the main girder can be reduced, thereby reducing the energy input at the excitation end and reducing the parametric vibration response.

[0047] Further, in one embodiment, the included angle between the stay cable damper device 1 and the stay cable 2 is 90°.

[0048] In this way, with a 90° included angle setting, the damper body 11 can effectively transmit the acting force directly to the stay cable 2 through the force transmission rod 12. This design perpendicular to the cable can maximize the ability of the damper body 11 to absorb and dissipate vibration energy; when the stay cable damper device 1 is perpendicular to the stay cable 2, it can more effectively limit the propagation of vibration during the vibration reduction process, especially for lateral vibration, and its damping effect is more significant. By adjusting the damping parameters of the damper, its response ability at a specific frequency can be further optimized.

[0049] The beneficial effects brought by the present invention include:

[0050] A vibration reduction method for stay cables and main girders based on the damper installation position is provided. By establishing the finite element models of the main girder and the stay cables and conducting modal analysis on them, the vibration modes of each stay cable and the vibration response characteristics of the main girder are obtained, revealing the dynamic characteristics of the structure and providing data support for subsequent optimization. Combining the vibration modes of the stay cables with the vibration response characteristics of the main girder, the vibration coupling effect between the two is analyzed. Through modal superposition and calculation of the energy transfer coefficient, the interaction region between the stay cables and the main girder is identified to avoid the problem of global resonance caused by local vibration. The standard installation interval is set based on the vibration energy concentration region, and the quantitative calculation of the additional damping ratio ensures the accuracy of position optimization. The optimal installation position is determined independently for each stay cable, and an external damper is installed uniformly. The vibration-sensitive region is accurately located through the finite element model and modal analysis. Combining the quantitative calculation of the additional damping ratio, the blindness of the traditional empirical method is avoided, and the energy absorption efficiency of the damper is maximized. The analysis of the vibration coupling effect ensures that the installation of the damper not only suppresses the local vibration of the stay cables but also reduces the resonance risk between the main girder and the stay cables, improving the dynamic stability of the overall structure. Through the closed-loop process of "modeling, analysis, optimization, implementation", the theoretical calculation is closely combined with engineering practice, solving the optimization problem of the damper installation position and the problem in related technologies of how to determine the installation position of the external damper between each stay cable and the main girder to most effectively reduce the vibration of the main girder and the stay cables.

[0051] It should be noted that the serial numbers of the embodiments of the present application above are only for description and do not represent the superiority or inferiority of the embodiments.

[0052] The terms "including" and "having" and any variations thereof in the specification, claims and drawings of the present application are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device that includes a series of steps or units is not limited to the listed steps or units, but may optionally further include steps or units not listed, or may optionally further include other steps or units inherent to these processes, methods, products or devices. The descriptions with terms such as "first", "second" and "third" are used to distinguish different objects, etc., and do not represent a sequence, nor do they limit that "first", "second" and "third" are of different types.

[0053] In the description of the embodiments of the present application, terms such as "exemplary", "for example" or "for instance" are used to indicate examples, illustrations or explanations. Any embodiment or design solution described as "exemplary", "for example" or "for instance" in the embodiments of the present application should not be construed as being more preferred or having more advantages than other embodiments or design solutions. Rather, the use of terms such as "exemplary", "for example" or "for instance" is intended to present related concepts in a specific manner.

[0054] In the description of the embodiments of the present application, unless otherwise specified, " / " means "or". For example, A / B may mean A or B. The "and / or" in the text is merely a description of the association relationship between associated objects, indicating that there can be three relationships. For example, A and / or B can mean: A exists alone, A and B exist simultaneously, and B exists alone. In addition, in the description of the embodiments of the present application, "a plurality of" means two or more than two.

[0055] In some processes described in the embodiments of the present application, there are a plurality of operations or steps that appear in a specific order. However, it should be understood that these operations or steps may not be executed in the order in which they appear in the embodiments of the present application or may be executed in parallel. The serial numbers of the operations are only used to distinguish different operations, and the serial numbers themselves do not represent any execution order. In addition, these processes may include more or fewer operations, and these operations or steps may be executed in order or in parallel, and these operations or steps may be combined.

[0056] Through the description of the above embodiments, those skilled in the art can clearly understand that the above-described embodiment methods can be implemented by means of software plus a necessary general hardware platform. Of course, they can also be implemented by hardware, but in many cases, the former is a better implementation method. Based on such an understanding, the technical solution of the present application, in essence, or the part that contributes to the prior art can be embodied in the form of a software product. This computer software product is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disc) as described above and includes several instructions for causing a terminal device to execute the methods described in the various embodiments of the present application.

[0057] The above are only the preferred embodiments of the present application, and do not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made by using the content of the specification and drawings of the present application, or directly or indirectly applied in other related technical fields, shall be similarly included in the patent protection scope of the present application.

Claims

1. A vibration reduction method for stay cables and main girders based on the installation position of dampers, characterized in that It includes: Establish a finite element model of the main girder and each stay cable, and conduct modal analysis on it to obtain the vibration modes of each stay cable and the vibration response characteristics of the main girder; For the target stay cable, based on its vibration mode and the vibration response characteristics of the main girder, analyze the vibration coupling effect between the stay cable and the main girder, and determine the standard installation range of the external damper set between the target stay cable and the main girder; Within the standard installation range, by adjusting the position of the external damper, calculate the additional damping ratio of the main girder at different positions in combination with the change in the vibration amplitude of the main girder, and select the maximum value of the additional damping ratio of the main girder as the target installation position; Calculating the additional damping ratio of the main girder at different positions includes the following steps: Based on the vibration response characteristics of the main girder, obtain the peak value of the vertical vibration mode displacement of the main girder when the external damper is at the target installation position; Combine the finite element model, and apply a vertical harmonic load at the peak value of the vertical vibration mode displacement of the main girder, then unload the vertical harmonic load, and analyze the vibration attenuation process of the main girder to obtain displacement time history data; According to the displacement time history data, calculate the additional damping ratio of the main girder through the second formula; Repeat the above steps to obtain the additional damping ratio of the main girder when the external damper is installed at different positions; According to the steps of determining the target installation position of the target stay cable, obtain the target installation positions corresponding to the external dampers set between each stay cable and the main girder, and set the external dampers between each stay cable and the main girder according to the corresponding target installation positions.

2. The vibration reduction method for stay cables and main girders based on damper installation positions as described in claim 1, characterized in that: Denote the length of the stay cable as L, denote the connection point between the stay cable and the bridge deck as point M, and denote the distance from the connection point of the target damper and the target stay cable to point M as x, then define the first threshold range: A = {x|0.005L < x ≤ 0.05L}; Obtain the values within the first threshold range in the standard installation range of each stay cable, and update them as the standard installation range of the corresponding stay cable.

3. The vibration damping method for stay cables and main girders based on the damper installation position as claimed in claim 1, characterized in that Applying a vertical harmonic load at the peak value of the vertical vibration mode displacement of the main girder includes the following steps: Obtain the vertical natural vibration frequency of the main beam where the target damper is located at the target installation position, that is, the second natural vibration frequency, denoted as ω n ; Denote the vertical harmonic load as P, the amplitude of the excitation load as F, and the loading time as t; According to , continuously apply the vertical harmonic load to the peak value of the vertical vibration mode displacement of the main beam, where , N is the number of natural vibration periods, and it is adjusted based on the vibration data of the main beam.

4. The vibration damping method for stay cables and main girders based on the damper installation position according to claim 1, characterized in that, The modal analysis includes the following contents: Extract the first three vibration modes of each stay cable and the fundamental frequency vibration mode of the main girder, and quantify the vibration amplitude distribution of the main girder under different frequency excitations through harmonic response analysis.

5. The vibration damping method for stay cables and main girders based on the damper installation position according to claim 1, characterized in that, The analysis of the vibration coupling effect is achieved through the following methods: Perform modal superposition of the vibration modes of the main girder and the stay cable to identify the resonance risk area; Calculate the energy transfer coefficient between the main girder and the stay cable, and select the stay cables with an energy transfer coefficient greater than the first standard value as the priority optimization targets.

6. The vibration damping method for stay cables and main girders based on the damper installation position according to claim 1, characterized in that, Before implementing the vibration reduction method for stay cables and main girders based on damper installation positions, conduct on-site environmental vibration tests on the cable-stayed bridge to obtain actual vibration spectrum data, and modify the finite element model according to the actual vibration spectrum data.

7. The vibration reduction method for stay cables and main girders based on damper installation positions as described in claim 1, characterized in that: The external damper is a part of the stay cable damper device (1), and the stay cable damper device (1) further includes a support (3), a connecting member (4), and a main lever (5). The connecting member (4) is used to connect with the stay cable (2). One end of the main lever (5) is fixedly connected to the connecting member (4), and the other end is rotatably connected to the support (3). The target damper is respectively connected to the upper and lower ends of the main lever (5).

8. The vibration reduction method for the stay cable and the main girder based on the damper installation position according to claim 7, wherein: The target damper includes an in-plane damper (6), an in-plane lever (7), an out-of-plane damper (8), an out-of-plane lever (9), and an out-of-plane link rod (10). The support (3) is provided with a first ear plate (31), a second ear plate (32), and a third ear plate (33). The in-plane damper (6) is rotatably connected to the second ear plate (32). The middle part of the in-plane lever (7) is rotatably connected to the main lever (5). One end of the in-plane lever (7) is rotatably connected to the first ear plate (31), and the other end is connected to the in-plane damper (6). The out-of-plane damper (8) is rotatably connected to the middle part of the main lever (5). One end of the out-of-plane link rod (10) is rotatably connected to the bottom of the main lever (5). One end of the out-of-plane lever (9) is rotatably connected to the out-of-plane link rod (10), and the other end of the out-of-plane lever (9) is rotatably connected to the out-of-plane damper (8). And the middle part of the out-of-plane lever (9) is rotatably connected to the third ear plate (33).

9. The vibration reduction method for the stay cable and the main girder based on the damper installation position according to claim 7, wherein: The included angle between the stay cable damper device (1) and the stay cable (2) is 90°.

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